Faculty of Science

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Analysis of microbial infections in Camel (Camelus Dromedarius) milk and implications in Kenya
(Egerton University, 2007-06) Matofari, Joseph W
Raw camel milk production and marketing chain in Kenya was investigated for microbial infections and implications. Milk samples were taken using simple random sampling method in a clustered sampling plan. There were three cluster levels, the production, and processing and market levels. Analysis of samples in the laboratory for enumeration and characterization was by standard methods as described in the methodology. Data analysis was done by Pearson correlation coefficient and chi-square. At production level, 66% of the 107 samples taken had bacterial load ranging from 103-105 colony forming units per ml (cfu/ml). Over 90% of the samples from the processing and market levels ranged from 106-108 cfu/ml. The total viable counts were higher (P < 0.05) than coliform counts at production level. There were more spores at production than at market level. All the isolated organisms did not survive temperatures above 550 C. Salmonella enterica was prevalent at production and processing level. There was no S.enterica isolation at market level. Gram-negative rods (GNR) occurred at every level of the camel milk chain with an incidence of 54% of the 254 samples taken. Gram-positive cocci (42% incidence) were highest at production level. From the study, the microbial load in raw camel milk chain increased from production to the market. GNR were the majority and included the general Escherichia, Enterobacter and Pseudomonas. S.enterica contamination of raw camel milk chain exists at production and collection level and not at the market level. The S enterica serovars involved were S. enterica Typhi and S. enterica Paratyphi C. Since camels, pastoralists and camel milk handlers may act as carriers of S. enterica in the causation web, it is recommented that another study be done to determine host specificity for the serovars identified.
Relationship between realization of right to adequate food and food security: A study among pastoral and small farm holder households
(Egerton University, 2010-08) Muthoka, Stellamaris
The Universal Declaration of Human Rights and International Convention on Economic and Social Cultural Rights underpin freedom from hunger and dignified lives for all. The study aimed at developing an innovative methodology for assessment of realization of the right to adequate food at household level and its validation; investigation of realization of the right to adequate food and its influence on food security, perception of rights to adequate food among pastoral and small farm holder households and duty bearer challenges in their realization of their obligation towards attainment of realization of right to adequate food. The study developed the right to adequate food tool based on the rights obligation parameters „to respect‟, „to protect‟ and „to fulfil‟. Validation of methodology was achieved through a comparative cross-sectional survey among 249 pastoral and farming households. Data was collected using a general household questionnaire, rights to adequate food questionnaire, perception of right to adequate food questionnaire, 24 hour food recall, food frequency questionnaire, household food insecurity access scale and focus group discussions. Quantitative data was analysed using SPSS version 16 software. Qualitative data was analyzed based on thematic content analysis. A 34 item rating tool was developed, able to assess realization level of right to adequate food at household level and also articulate aspects of knowledge, entitlement, capacity, capability, empowerment and decision making. Household Right to Adequate Food Index (HRTAFI) was computed as a measure of level of realization of the right at household level. The farming community had better level of realization of both the right to adequate food and household food security compared to the pastoral community (p<0.01). The pastoral group had higher realization of the obligation parameter of fulfilment (p<0.01) compared to the farming group. Female headed households had better realization of the right to food (p<0.05) although they experience more violation with respect to the obligation parameter of protection (p<0.05).Both communities experienced violation of the right with respect to the protection parameter. Realization of the right to adequate food correlated positively with education, health and gainful occupation (p<0.01). The pastoral community however had better annual income (p<0.01) compared to the farming counterparts. Both communities had a reasonable understanding of human rights; however, the practice was contextual. Retrenchment was perceived as an opportunity to enhance livelihoods among the study group (p<0.05). Causes of violation of the right included unstable livelihoods, high food price hikes, marital conflict, civil unrest, and changing climatic conditions. Manifestation and mechanisms of redress varied among the study groups and by gender. Primary duty bearer‟s challenges included livelihood stability and changing policies. However, secondary duty bearer‟s support was crucial in fostering primary duty bearer‟s realization of the right. Single mothers had more challenges in meeting their obligations of right to adequate food for the infant. Perception of breast feeding was contextual and varied along gender lines. The pastoral community significantly breast fed the boy child longer (p<0.05). Realization of the right to adequate food increased with awareness on human rights accounting for 5% variation and varied with seasonality. It accounted for 4-14% variation in food security during wet season compared to 5-8% during the dry season. Realization of right to adequate food enhances food security. Meeting primary duty bearer needs is fundamental in capacitating them to realize their obligations in realization of the right xv to adequate food. Perceptions of human rights are not new among communities and are consistent with conventional definition of human rights, however practice is contextual. Violations of rights are based on both human and non-human factors. Realization of the right to adequate food is influenced by realization other rights such as education, health and work. The developed HRTAFI can be used as an alternative measure of food security at household level.
Occurrence, variability and management of Ralstonia solanacearum in potato production systems in Kenya.
(Egerton University, 2011-03) Nyangeri, Johnson Bwomwenga
Production of potato (Solanum tuberosum L.) in Kenya is constrained by many biotic, abiotic and socio-economic factors. Among the biotic constraints, bacterial wilt, caused by Ralstonia solanacearum (Yabuuchi et al., 1995) presents major management difficulties. Attempts to combat the disease have been difficult due to the complex heterogeneous genetic make-up of the pathogen, comprising different races and biovars, its survival mechanisms and its large number of hosts, including weeds. A study on occurrence and variability of the pathogen, alongside investigations on its interactions with various plant species was conducted to help understand the pathogen and set a basis of determining the potential hosts to avoid or crop species to include in rotational pattern programmes that would minimize effects of the disease. Population structure was determined by isolating the pathogen from collected samples. The distribution and genetic variability were determined in isolates using tobacco leaf infiltration, biochemical tests and polymerase chain reaction (PCR) with repetitive sequences, using enterobacterial repetitive intergenic concensus (ERIC), and BOX repetitive primer sets. Weeds were artificially inoculated with the pathogen to test if they were hosts. Latent infection of weeds was determined using enzyme-linked immunosorbent assay (ELISA). To determine the effect of crop rotation on potato bacterial wilt incidence and tuber yields, one and two-season rotation experiments were conducted using maize, beans, cabbage, potato and rhodes grass. Sixty eight isolates of R. solanacearum were obtained from 70 samples collected. All of the suspected potato and tomato (Lycopersicon esculentum L.) samples were found to be infected with Ralstonia solanacearum while only 33% of weed samples were infected. Ralstonia solanacearum biovar 2 and biovar 3 (race 3 and race 1, respectively) were found to be present. R. solanacearum biovar 2 was widely distributed in many areas, while biovar 3 was isolated from a restricted area (UM3 agro-ecological zone) in Murang’a. Both biovars 2 and 3 were isolated from potato and tomato samples. Some weeds were infected by both R. solanacearum biovars 2 and 3. Other weeds were exclusively infected with either biovar 2 or biovar 3. Some of the weeds were found to be latently infected. One-season rotation with maize reduced wilt incidence from 46.7% to 5%, while two-season rotation with maize, followed by beans or cabbage reduced wilt incidence from 46.7% to 1.0% and 2.0%, respectively. Planting two different crops was superior to planting the same crop in two subsequent seasons in reduction of bacterial wilt. Potato yields improved with the reduction of incidence of bacterial wilt.
Molecular characteristics and putative functions of reproduction-associated proteins of Anopheles gambiae mosquito
(Egerton University, 2013-05) Ayehngwo, Achinko Daniel
In Anopheles gambiae mosquito vector of malaria, mating is mediated by transfer of a plug (mating plug protein) from males to females. In the females, the constituents of the plug include male accessory glands (MAGs) proteins and female specific proteins that influence ovulation, oviposition, lifetime refractoriness to mating and other post-mating behaviors in the females. Manipulation of the plug can significantly affect the reproduction potential and concomitant population density of the vector. Investigations were conducted to establish in the mosquito 1) putative structural properties of MAGs proteins (transglutaminase and plugin) mediating successful interaction for mating-plug formation in the male An. gambiae 2) putative interacting proteins potentially mediating the mating-plug formation and post-mating phenotype, 3) mating responsive molecular factors in the proteins, 4) influence of the interactions among the proteins on mating responses and 5) patterns and roles of swarms in mating responses in females. Structural properties of An. gambiae MAGs (transglutaminase and plugin) proteins were identified using Protein-Predict software and type of selection pressure among related orthologs in different taxa was determined through phylogenetic analysis. Orthologs of the An. gambiae plug proteins in Drosophila melanogaster were obtained from STRING database and their interactions (protein-protein) predicted using CYTOScape software. Phylogeny among key D. melanogaster interacting protein homolog equivalents in An. gambiae (interologs) was determined by maximum likelihood phylogenetic method. Pathway analyses of the interologs in Reactome database was used to identify proteins involed in plug formation and post-mating phenotype. Expression of mRNA for genes of the proteins in males (MAGs and testes) and females (atria, ovary and spermatheca) reproductive tissues was determined by RT-qPCR, and identification of the genes verified through sequencing of the amplicons and western blot analyses. Role of the genes in mating responses in the mosquito was verified through RNAi technique. Patterns and roles of swarms in mating responses in females were determined through cage releases and observations in a semi–field setting. Plugin was predicted to be non-structural and under positive selection among the MAGs proteins, and also identified as the main protein in mating plug formation on the protein-protein interaction network. Plugin was also shown to putatively interact with TRYPSIN-LIKE SERINE PROTEASE (AGAP005195) in the female atria after mating through a putative two response regulatory pathway. Plugin (AGAP009368), TRYPSIN-LIKE SERINE PROTEASE (AGAP005195) and CATHEPSIN B (AGAP004533) appeared to interact and influence postmating effects in the females. CATHEPSIN B (AGAP004533) was co-expressed and regulated by TRYPSIN-LIKE vii SERINE PROTEASE (AGAP005195) in the female. TRYPSIN-LIKE SERINE PROTEASE (AGAP005195) specifically interacted with plugin on the mating plug and was transported to the spermatheca after mating, implicating it in postmating events within the females. Knockdown of CATHEPSIN B suggested that plugin was alternatively spliced in the male. The knockdown implicates CATHEPSIN B and TRYPSIN-LIKE SERINE PROTEASE in a common reproductive pathway in females, supported by mating propensity phenotype observed in the females. A swarming window of about 30 minutes was identified for An. gambiae mosquito where 41.3% of females were successfully inseminated. Interaction between CATHEPSIN B and plugin in the male then CATHEPSIN B and TRYPSIN-LIKE SERINE PROTEASE in the female produces successful interactions which are involved in reproductive pathways within the male and the female mosquitoes hence potentially and significantly affecting male and female reproductive processes. Detailed molecular analysis through high throughput interventions can potentially elucidate actual binding sites between CATHEPSIN B and its partner in the male (plugin) and female TRYPSIN-LIKE SERINE PROTEASE mosquitoes which can be exploited for vector control interventions.
Molecular characterisation of tsetse-endosymbiont interactions in Kenyan populations of glossina austeni and glossina pallidipes tsetse flies
(Egerton University, 2014-03) Wamwiri, Florence Njeri
Tsetse flies (Diptera: Glossinidae), which are the major vectors of human and animal trypanosomes, harbour bacterial gut symbionts Wigglesworthia glossinidia, Wolbachia pipientis and Sodalis glossinidius in close association with trypanosomes. The objective of this study was to determine the prevalence, temporal variation and strain diversity of these endosymbionts in G. austeni and G. pallidipes from the Kenyan coast. The co-relation between symbiont and trypanosomes infection was also assessed, in order to provide insight into tsetse-symbionttrypanosome interactions. Fly age was estimated using ovarian ageing and wing fray analysis. Symbiont infection was determined using symbiont-specific assays targeting wsp, 16s rRNA, GPO1 genes. Trypanosome infection was also determined by dissection and generic primers. The diversity of infecting symbiont strains was evaluated by wsp typing, multi-locus strain typing (MLST) and variable number of tandem repeats (VNTRs) methods. Trypanosomesymbiont co-infection was assessed in both natural and experimental populations and in ampicillin-treated flies. The results showed that although Wolbachia infected all G. austeni individuals sampled, no G. pallidipes sampled was Wolbachia-infected. Sodalis infection was found in 3.7% of G. austeni and in 15.9% of G. pallidipes sampled. Wolbachia strains were found to be homogenous based on wsp typing, but slight variations were detected using MLST. In addition, multiple Sodalis strain variations were detected. Age grading revealed that female flies of both species had comparable longevity; but that male G. pallidipes analysis had longer lifespan than G. austeni. Trypanosome infection rates of 12.8% and 9.6% were recorded in G. austeni and G. pallidipes respectively, of which 45.6% were T. congolense infections. In natural populations, Sodalis-trypanosome co-infection was less than 4% in both species, predominantly with T. congolense or T. simiae trypanosomes. The level of significance of the association between trypanosome and Sodalis infection was found to differ depending on fly species and trypanosome species. This study concludes that there is marked heterogeneity in gut microfauna in terms of infection incidence, strain diversity and temporal infection patterns in natural tsetse populations. Additionally, infection with a particular symbiont does not appear to influence either the presence of the other symbionts or trypanosome infection. This study highlights interspecific differences in tsetse-symbiont-trypanosomes tripartite interactions that proposed symbiont-mediated tsetse control interventions should take into account.
Effects of some abiotic and biotic factors on the zooplankton community in Lake Baringo, Kenya
(Egerton University, 2014-10) Omondi, Reuben
Lake Baringo is a turbid lake that lies in a closed drainage basin of the Kenyan East African Rift Valley. The lake’s water quality has deteriorated in the recent past mainly due to sedimentation from its catchment arising from poor agricultural practices, deforestion and overgrazing. Its fishery has also declined since the 1980s and frequent lake closures to fishing activities have not alleviated the problem. This shows that there may be other critical ecological and environmental factors affecting the ecosystem. To understand problems facing the lake, there is need for well-coordinated and comprehensive ecological investigations considering the complexity of the ecosystem. Zooplankton is important in energy transfer from primary producers and constitute a significant component of the diets of the juveniles and some adults of many fish species. The objective of the present study was to determine the effect of some physical, chemical and biological factors on the spatial and temporal distribution, abundance and biomass of zooplankton in Lake Baringo. Stratified random design was used to allow for statistical comparison between zooplankton abundance and biomass at different stations and months with environmental factors using Analysis of Variance (ANOVA). The relatively stable environmental factors across the sampling stations in the lake were attributed to its small size, shallowness and the daily mixing by wind action. A total of 39 species of zooplankton belonging to Rotifera, Cladocera and Copepoda groups were recorded. The results indicate that distribution, diversity, abundance and biomass of zooplankton were influenced by environmental factors especially depth, conductivity and turbidity. Diel vertical distribution of zooplankton was the reverse of what is reported from clear lakes with organisms congregating to the surface during the day and descending to the bottom at night. Investigations into the diet of three main fish species in the lake showed that Oreochromis niloticus baringoensis mostly depended on algae, Clarias gariepinus depended on fish while Protopterus aethiopicus thrives on molluscs as their dominant food. The growth performance of the once dominant endemic fish, O. niloticus baringoensis could be affected by the high turbidity, which reduces primary production. Moreover, reduced clarity hampers the feeding success of this visual feeding fish and has decreased macrophytes to near extinction. There is urgent need for rehabilitation of Lake Baringo and the study recommend afforestation and reduction of livestock numbers in the catchment as some of the ways of reducing soil erosion and sediment input in the lake. The results of the study may be used as an important tool for the detection of stability and trophic levels of the ecosystem and to provide data for models on maximal resource production of the lake.
Molecular characterization of Trypanosoma brucei brucei and Trypanosoma brucei rhodesiense isolates and responses of Glossina pallidipes to Trypanosoma brucei brucei challenge
(Egerton University, 2016-04) Bateta, Rosemary Wanyona
African trypanosomiases are a group of related diseases that affect humans (Human African Trypanosomiasis - HAT) and their livestock (Animal African Trypanosomiasis), with devastating medical and economic consequences for Africa. The diseases are caused by trypanosome parasites cyclically transmitted by tsetse flies. Recent reports indicate that HAT is on the decline in sub Sahara Africa. However, the disease still remains a major health problem in some parts of Africa such as South Sudan, Democratic Republic of Congo and Uganda. Reports also indicate repeated irregular T. b. rhodesiense out breaks in traditionally endemic areas in south-east Uganda, with continued spread to previously unaffected areas in central Uganda. Although the disease has been reported to spread to new areas in Uganda, observations in the field indicate that the infection rates in tsetse flies are very low. Competence of the flies to transmit the parasite is determined by host midgut responses that either leads to clearance (self-cure) or establishment of the parasite infections. Investigations were conducted to determine evolutionary dynamics behind the origin of new foci and the impact of host species on parasite genetic diversity in Uganda. Trypanosoma brucei isolates {N = 269, n= 58(for Samples isolated from cattle)} were collected from different areas in Uganda and western Kenya and genotyped at 17 genetic marker loci (microsatellite). Analysis was carried out using Bayesian clustering and Discriminant Analysis of Principal Componens. Presence of serum resistance associated (SRA) gene in the isolates was determined using PCR. Results showed that the genotyped trypansosome isolates partitioned into three distinct genetic clusters. Clusters 1 and 3 included isolates from central and southern Uganda, whereas cluster 2 was composed of mainly isolates from western Kenya. FST values between sampling sites ranged from 0 to 0.67 while between the three genetic structures it ranged from0.24 to 0.46 with most values being statistically significant P<0.01. AMOVA results at p<0.05 indicated that the genetic variation was apportioned within (71.8%) rather than among the three clusters. These analyses revealed genetic admixture among the three genetic clusters and long-range dispersal, suggesting recent and possibly on-going gene flow between them and the new foci of HAT in central Uganda is as a result of northward movement of Trypanosoma brucei rhodesiense from the traditionally endemic foci. Therefore disease control efforts need to be enhanced to prevent continued spread to new foci. To determine molecular responses in Glossina pallidipes challenged with trypanosomes, teneral female Glossina pallidipes flies were challenged with Trypanosoma brucei brucei and vii dissected at 24 or 48 hours post challenge (hpc). Tissues were collected and analysed to establish key molecular responses mediating initial phase of establishment of the parasite in the fly. Transcriptomes of midguts and respective carcasses from the challenged and unchallenged flies were sequenced on illumina RNA-Seq platform, and analyzed for differentially expressed transcripts by mapping the RNA-Seq reads on G. pallidipes gene models. The transcripts were annotated and examined for enrichment of gene categories using, heat maps, BLAST2GO and R spider network software. Results from this study indicated that most of the differentially expressed transcripts at 24 hpc were associated with lipid remodeling/lipogenesis, proteolysis, urea cycle, carnitine trafficking, collagen metabolism, apoptosis, and cell growth/differentiation. Transcripts associated with 48 hpc included those linked to embryonic growth and development, muscle/motility, suppression of tumor, serine endopeptidase and related proteosomal degradation of target protein, enhanced translation of mRNA and neuronal development. There was pronounced expression of immune responsive transcripts 48 relative to 24 hpc, indicative of gradual maturity of immune responses in the fly or institution of vector-parasite endemic stability in the guts to facilitate the establishment of infection. Overall there was a systematic suppression of immunity in the G. pallidipes midgut in the initial phase of T. b. brucei challenge, which potentially facilitated initial establishment of the infection. Gradual and sequential immunological responses subsequently emerge contingent with the durations of challenge.
Retention Efficiencies of Selected Wetland Ecosystems for Halogenated and Non-Halogenated Hydrocarbons in Lake Victoria Basin: a case study of Kigwal/Kimondi, Nyando and Nzoia Wetlands in Kenya
(Egerton University, 2016-05) Mule, Shadrack
Wetland ecosystems are noted to play a critical role in water quality improvement by retaining pollutants in river water transiting through it. This study was therefore undertaken to determine the retention efficiency of selected wetland ecosystems within Lake Victoria Basin. Samples of water, soil/sediments and selected plant materials were collected from Kigwal/Kimondi, River Nyando and River Nzoia wetland ecosystems, digested and analyzed for residual halogenated and nonhalogenated hydrocarbons using Gas Chromatography - Mass Spectrometer (GC-MS) method. Seasonal values of physical parameters such as rainfall, temperature, pH, turbidity, and flow rate were measured in situ at the inflows, midpoints and at the outflows to the wetland ecosystems using LabQuest vernier calliper instrument. All results were recorded and analyzed for measure of central tendency using SPSS statistical program. Chi square ( ) was used to reject or retain the null hypothesis. From the analysis, 15 prominent residual halogenated and non-halogenated hydrocarbons were detected and quantified by GC-MS and they included: bendiocarb, benzene hexachloride (BHC), carbaryl, cypermethrin, deltamethrin/decis, diazinon, dieldrin, DDT, DDD, DDE, malathion, propoxur, sumithion, 5-phenylrhodanine,1,3,5-trichlorobenzene, 1-(2-phenoxybenzyl)hydrazine were detected and quantified. Their levels ranged from 5 to 242 ng/mL in water samples and 6 to 423 ng/mg in sediment and plant materials. These levels are above permissible levels of residual halogenated and nonhalogenated hydrocarbons reported by U.S. EPA and WHO and thus water quality of such ecosystems is highly compromised. Calculated seasonal retention efficiencies of the selected wetland ecosystems ranged from 3% to 88% with Kimondi/Kigwal wetland ecosystem recording high retention efficiency of 88% during rain season with River Nyando and River Nzoia wetland ecosystems having low seasonal retention efficiencies. There was overall relationship between measured physical parameters, levels of detected pollutants and retention efficiencies of the wetland ecosystems. It is recommended that a study be carried out to develop environmentally friendly molecules which can be used for pest control management practices with an aim of protecting wetland ecosystems from effects of chemical pesticides and hence improve retention efficiencies of natural tropical wetland ecosystems.
Analysis of micronutrients and heavy metals of indigenous reed salts and soils from selected areas in Western Kenya
(Egerton University, 2016-11) Tsikhungu, Phanice Wangila
Most communities in Western Kenya use plant indigenous salts for cooking, medicinal and numerous uses. Typha latifolia and Cyperus rotundus reeds are widely used in Busia and Lugari regions of Western Kenya to prepare indigenous salts. The suitability of these salts and validation of micronutrients and heavy metals is unknown. The objective of this study was to assess the suitability of the indigenous reed salt used in selected parts of Western Kenya. Micronutrients and heavy metal concentrations in soil habitats, C. rotundus and T. latifolia and reed salts were determined; In addition, the effect of the various methods of processing, storage conditions and the stability of iron and iodine nutrients has been investigated. Iodometric titration (Iodine), 1, 10-phenanthroline method (Iron II), flame photometric method (Na and K) and Atomic absorption spectrophotometric method (Pb, Cd, Fe, Cr) were used for analysis. Results showed that 85% of Lugari and Busia inhabitants in Western Kenya use C. rotundus and T. latifolia reed salts. Heavy metal in the soil was of the order Fe> Cr >Pb > Cd for the dry season and Cr > Fe > Cd > Pb for the wet season both in top and sub-surface soils with higher levels in the dry season. Salt iodine was of the order Kensalt >Top-chef salt > Herbal sea salt > Sea salt > C. rotundus salt > T. latifolia and Herbal sea salt >C. rotundus salt = T. latifolia salt > Sea salt > Kensalt = Top-chef salt for Fe2+. C. rotundus and T. latifolia reed salts had higher iodine (1.1 mg/kg) than the WHO limit of 0.015 - 1.1 mg/kg , while the concentration of Fe2+ (0.9 mg/kg and 1.0 mg/kg) was below the recommended limit of 8 - 45 mg/kg. The Na: K ratio of T. latifolia salt (3.2:1) was within the recommended limit of 2.5:1 - 4:1 while that of C. rotundus salt (0.9:1) is lower. Fe, Pb and Cd levels in both C. rotundus reed and T. latifolia reed salts exceeded the WHO/FAO permissible. Effectively all iodine and Fe2+ present in the reed salts was lost within six months of storage under normal conditions of temperature and RH with more losses at elevated temperature and relative humidity. T. latifolia salt prepared using complete evaporation method and stored in LDPE container for a period not more than three months is suitable for use as table salt. C. rotundus prepared by complete evaporation method is ideal for use as a low-sodium salt.
Haematological and tissue enzyme changes in a sheep model infected with Trypanosoma brucei rhodesiense
(Egerton University, 2017-11) Mavura, Hawa
Control and management of human African trypanosomosis faces many challenges including limited available drugs that are stage specific and also toxic, treatment failures and post treatment CNS and cardiac pathology which might be fatal. Because of ethical considerations, trypanosomosis and drug trial studies are conducted using animal models which have drawbacks. It is therefore important to develop models that can address the current drawbacks and also develop enzymatic disease staging markers to detect CNS and cardiac involvement in order to institute correct choice of trypanosome drugs and/or use of adjunct to mitigated conditions. The current study evaluated a sheep model infected with Trypanosoma brucei rhodesiense as a cheap and reliable model of human trypanosomosis. In addition the model was used to asses clinical signs, haematological changes and the use of total and isoenzyme CK and LDH levels in serum and CSF as markers of cardiac and staging of CNS infection, respectively. Eight sheep were infected with 1 × 10 4 T.b rhodesiense and two were uninfected controls. Blood was collected from the ear and jugular vein for parasitemia and for haematological and biochemical changes, respectively. CSF was also collected for cells and biochemical changes while total CK and LDH plus their respective isoenzymes were done by using starch gel electrophoresis and their quantification by a UN-SCAN IT densitometry. Infected sheep developed acute infection accompanied by clinical signs and haematological changes that mimicked infections in humans, including loss of body weight and fever.The infection was also characterized by an increase in MCH and MCHC. However, there was a decline in the levels of PCV, HCT, Hb, MCV and RBC counts. All parameters however recovered to control levels after treatment.This study also showed an increase in total protein, total LDH and total CK activities in both serum and CSF of infected compared to uninfected sheep. At the same time LDH and CK total enzyme and isoenzyme changes indicated cardiac involvement suggesting the diagnostic potential of the enzymes. However the infection did not develop a chronic CNS infection since following humane treatment of the infected sheep with berenil this resulted in cure of the infection and thus did not lead to late stage CNS infection. The study indicated that the T. b.rhodesiense sheep model can be a useful animal model of human African trypanosomosis. However, the study needs to be repeated using a less virulent or low dose of trypanosome to ensure the disease develops to the chronic stage.
Effects of Structured Nutrition Education on Maternal Breastfeeding Self-Efficacy, Perceptions and Exclusive Breastfeeding Duration in Kiandutu, Thika-Kenya
(Egerton University, 2017-11) Mituki, Dorothy M.
Despite the fact that the overall benefits of exclusive breastfeeding (EBF) for the first half of infancy have well been established, especially for mother-infant pairs in low social economic status, the rates are low in Kenya. The study aimed at evaluating the effects of structured nutrition education on maternal breastfeeding self-efficacy, perceptions and EBF duration. A cluster randomized controlled intervention was carried out. The intervention included education sessions with the nutritionist at the health centre, monthly home visits by the community health workers (CHWs) plus the usual care at the Maternal Child Health (MCH) clinic. The intervention utilized the national manual on maternal infant and young child nutrition (MIYCN) and emphasized conditions infants were susceptible to with early complementary feeding, simple messages on the importance of positive attitude and making a decision to EBF, as the best choice for mothers, breastfeeding within the first hour of delivery; dietary diversity and importance of proper attachment. Monthly home visits were made by CHWs postpartum to encourage mothers to EBF and answer mothers‘ questions. Anthropometric and feeding data for the infants was collected at 6, 10, 14 and 24 weeks. Maternal anthropometric measurements (weight and height), and breastfeeding perceptions were collected at recruitment (28 weeks) at 38 weeks and 14 weeks postpartum while the feeding data was collected monthly. The primary outcome, duration of EBF for mothers in the intervention (n=256) compared to those in the comparison group (n=176) was examined. Secondary outcomes of the study (breastfeeding self-efficacy, and perceptions) were analysed in relation to involvement in the structured nutrition educational intervention or not. Analysis was done on intention to treat basis. A statistical significance difference was found between the two groups in regarding to EBF duration at 24 weeks log rank= 20.277, (1, n=314) p < 0.001. Intervention group (45.3%) compared to the comparison group (15.0%). The end line (p=0.001) maternal breastfeeding self-efficacy positively predicted EBF duration. Out of the four perceptions, only perceptions on barriers to EBF at end-line (p<0.05) positively predicted the outcome variable. Bivariate analysis yielded two socio-economic significant predictive variables of EBF duration, education level of mothers; (OR 4.75, 95% Cl 1.58-14.30, p=0.006) and household food security (OR 0.03, 95% Cl 0.01-0.09 p=0.001). Being in the intervention group, increased the likelihood of having higher BSE (Log odds 1.41, 95% Cl 0.08-2.75) and EBF duration (Log odds 10.32, 95% Cl 4.26-16.39) Structured nutrition education should be implemented to ensure mothers gain confidence and are able to deal with barriers associated with EBF for the first six months.
Antiplasmodial and toxicity activities and characterization of chemical compounds extracted from selected medicinal plants in Uganda
(Egerton University, 2018-11) Kodi, Philip
Malaria caused by Plasmodium parasite is at the moment the one of the highest killer disease in the tropics. In developing countries, where malaria is one of the most prevalent diseases, some people still rely on traditional medicine for the treatment of this disease. In the present study an ethnobotanical survey was conducted to document antimalarial medicinal plants. In vitro antiplasmodial and in vivo toxicity activities were carried out on crude root extracts and on the isolated pure compounds from Oncoba spinosa, Acacia sieberiana and Euclea latideus. Structure elucidation was also carried out on the isolated pure compounds. The ethnobotanical survey was conducted by use of semi-structured interviews and a guided questionnaire. The characterization of the isolated compounds was determined using NMR technique only. The antiplasmodial activity was performed using a fluorescence based SYBR Green 1 assay technique on 3D7 and Dd2 Plasmodium strains. Lorke’s method was used to determine the in vivo acute toxicity of the extracts on mice. Thirty three plant species from 30 genera belonging to 23 families were documented, of these ten species (30.3 %) were recorded for the first time as antimalarial plants. Acute toxicity studies showed that all crude extracts of E. latideus and A. sieberiana had LD50 > 5000 mg/kg. The LD50 for hexane and CH2Cl2 extracts of O. spinosa were > 5000 mg/kg while the EtOAc and MeOH had 547.72 mg/kg. The EtOAc extract of O. spinosa had high activity of (IC50) 3D7: 4.69 ± 0.01 μg/mL and Dd2: 3.52 ± 0.02 μg/mL. Extracts of E. latideus had high activity (IC50) 3D7: (9.75-38.21) μg/mL and Dd2: (2.78-38.93) μg/mL. A. sieberiana extracts had the highest activity of (IC50) 3D7: (4.45-27.32) μg/mL and Dd2: (3.38-21.87) μg/mL. Isolation resulted in the identification of eight known compounds which included; three triterpenoids Lupeol, betulin, 3β-(5-methoxyferuloyl)lup-20(30)-ene; two steroids β-sitosterol, stigmasitosterol; benzoic acid and an aliphatic acid chaulmoogric acid. Betulin and β-sitosterol had the highest activity (IC50) 3D7: 3.71 and 5.51 μM, respectively. Antiplasmodial activities of the extracts (IC50: 2.76- > 50) μg/mL, pure compounds (IC50: 3.71- > 120.77) μM of the three plants and the controls (IC50: 0.0056-0.0440) μg/mL showed significance among themselves at (P < 0.05). Extracts and compounds exerted a significant (P < 0.05) decrease in antiplasmodial activity compared to the standard controls. The findings show that the crude extracts and pure compounds have got high antiplasmodial activity and lack toxicity. Therefore the local communities can continue to use the three plants for the treatment of malaria and this justifies the ethanomedicinal use of the plants for the management of malaria.
Antiplasmodial and toxicity activities and characterization of chemical compounds extracted from selected medicinal plants in Uganda
(Egerton University, 2018-11) Kodi, Philip
Malaria caused by Plasmodium parasite is at the moment the one of the highest killer disease in the tropics. In developing countries, where malaria is one of the most prevalent diseases, some people still rely on traditional medicine for the treatment of this disease. In the present study an ethnobotanical survey was conducted to document antimalarial medicinal plants. In vitro antiplasmodial and in vivo toxicity activities were carried out on crude root extracts and on the isolated pure compounds from Oncoba spinosa, Acacia sieberiana and Euclea latideus. Structure elucidation was also carried out on the isolated pure compounds. The ethnobotanical survey was conducted by use of semi-structured interviews and a guided questionnaire. The characterization of the isolated compounds was determined using NMR technique only. The antiplasmodial activity was performed using a fluorescence based SYBR Green 1 assay technique on 3D7 and Dd2 Plasmodium strains. Lorke’s method was used to determine the in vivo acute toxicity of the extracts on mice. Thirty three plant species from 30 genera belonging to 23 families were documented, of these ten species (30.3 %) were recorded for the first time as antimalarial plants. Acute toxicity studies showed that all crude extracts of E. latideus and A. sieberiana had LD50 > 5000 mg/kg. The LD50 for hexane and CH2Cl2 extracts of O. spinosa were > 5000 mg/kg while the EtOAc and MeOH had 547.72 mg/kg. The EtOAc extract of O. spinosa had high activity of (IC50) 3D7: 4.69 ± 0.01 μg/mL and Dd2: 3.52 ± 0.02 μg/mL. Extracts of E. latideus had high activity (IC50) 3D7: (9.75-38.21) μg/mL and Dd2: (2.78-38.93) μg/mL. A. sieberiana extracts had the highest activity of (IC50) 3D7: (4.45-27.32) μg/mL and Dd2: (3.38-21.87) μg/mL. Isolation resulted in the identification of eight known compounds which included; three triterpenoids Lupeol, betulin, 3β-(5-methoxyferuloyl)lup-20(30)-ene; two steroids β-sitosterol, stigmasitosterol; benzoic acid and an aliphatic acid chaulmoogric acid. Betulin and β-sitosterol had the highest activity (IC50) 3D7: 3.71 and 5.51 μM, respectively. Antiplasmodial activities of the extracts (IC50: 2.76- > 50) μg/mL, pure compounds (IC50: 3.71- > 120.77) μM of the three plants and the controls (IC50: 0.0056-0.0440) μg/mL showed significance among themselves at (P < 0.05). Extracts and compounds exerted a significant (P < 0.05) decrease in antiplasmodial activity compared to the standard controls. The findings show that the crude extracts and pure compounds have got high antiplasmodial activity and lack toxicity. Therefore the local communities can continue to use the three plants for the treatment of malaria and this justifies the ethanomedicinal use of the plants for the management of malaria.
Influence of nutrition and value chain governance on enterprise performance in smallholder pig production in Kenya
(Egerton University, 2019-01) Muthui, Jonah N.
Smallholder pig production in Kenya is a popular livelihood strategy but is faced with serious challenges, key among them being high cost and poor quality of feeds and weak value chain governance which result in high enterprise costs. To minimise losses, smallholders use locally available alternative feed resources (AFR) which coud be impacting negatively on performance. This study investigated feeding decisions, bio-economic benefits of using alternative feed resources (AFR), benefits of exogenous dietary enzymes and the influence of value chain governance features on competitiveness of smallholder pig enterprises. A proportionate to size purposive sampling procedure was used to select 144 enterprises in Busia, Nakuru and Kiambu Counties using the snowballing method. Interviews were conducted using pretested structured questionnaires to collect data on enterprises. Feeding experiments were set up at Egerton University Tatton Agricultural Park. Mixed analytical methods including decriptive and inferential statistics and regression analysis were applied using SAS systems, SPSS and STATA statistical software. The study concluded that the daily allowances of dry matter, crude protein and metabolisable energy associated with AFR were significantly lower (p ≤ 0.05) than the recommended daily allowance. Sows fed on AFR had delayed puberty, lower litter sizes and longer farrowing intervals compared to sows fed on commercially compounded feeds (p ≤ 0.05). Inclusion of cold pressed canola meal and rice polishing in weaned piglet diets resulted in higher (p ≤ 0.05) metabolisable energy: average daily gain (ME: ADG) and feed cost: average daily gain (FC:ADG) ratios. Inclusion of rice bran in piglet diets did not offer any bio-economic benefits. Inclusion of a dietary multi-enzyme complex resulted in higher (p ≤ 0.05) apparent digestibility of Nitrogen, energy and feed cost efficiency. Finisher diets lower in protein (14.9 -16%) and higher in dietary fibre resulted in higher (p ≤ 0.05) killing-out percent, loin eye area and villous height. Cold pressed canola diet resulted in higher (p ≤ 0.05) back fat thickness and larger (p ≤ 0.05) crypt depth. Value chain governance features including technology adoption product quality and market access had significantly (p ≤ 0.05) positive influence on enterprise competitiveness. The quality of work in pig enterprises negatively (p ≤ 0.05) influenced competitiveness of pig enterprises. The study recommend capacity building for farmers and extension staff, animal feed testing and use of biotechnology to improve feeding decisions. Further research into waste conversion technologies, the effects of dietary components such as lipids, phenolics on carcass and digestive tract are recommended.
Screening and characterization of some anticancer compounds from Salicaceae, Myrtaceae, Euphorbiaceae and Solanaceae families
(Egerton University, 2019-10) Kipngeno, Chirchir Denis
The chemistry of natural products is very important since it has been used in the search for bioactive compounds for management of various human diseases including cancer. The increase in the incidence of cancer coupled with the undesirable side effects observed with chemotherapic agents urges the discovery of new agents from natural sources. In this study the four ethnomedicinal plants; Dovyalis abyssinica (Salicaceae), Solanum mauense (Solanaceae), Syzigium guinense (Myrtaceae) and Croton dichogamous (Euphorbiaceae) were investigated for their unvalidated anticancer activities. Crude extracts for stem bark of S. guinense, fruits of S. mauense, and roots of both D. abbysinica and roots of C. dichogamous were prepared via cold extraction method. The crude extracts were purified by repeated column chromatography and Thin Layer Chromatography. This resulted in various pure compounds which were analysed by use of 1D NMR, 2D NMR spectroscopic techniques and MS spectrometry. The NMR spectral data obtained together with MS data were interpreted, the structures of the compounds elucidated and their chemical structures proposed. A total of twelve compounds were isolated, purified, their chemical structures proposed and four of these compounds were evaluated for their anticancer activity. Two previously reported compounds; β-sitosterol (47) and betulinic acid (21), were obtained from stem bark extracts of S. guinense as well as from the fruits extracts of S. mauense. Two previously reported compounds; Tremulacin (29) and Benzoic acid (48) were isolated from the roots extract of D. abyssinica. Eight compounds were isolated from roots extract of C. dichogamous; Acetyl aleuritolic acid (49), 3β,4β:15,16-diepoxy-13(16),14-ent-clerodadiene (50), 3β, 4β:15, 16-diepoxy-13(16), 14-ent-clerodadien-17,12S-olide (51), 15,16-epoxy-5, 13(16), 14-ent-halimatriene-3-ol (52), crotodichogamoin A (53), crotohaumanoxide (54), crotodichogamoin B (55) and Cadin-1(6),2,4,7,9-penta-ene (56). Selected compounds were evaluated for their anticancer activity by use of cancer cell lines. Betulinic acid (21) was screened against 57 cell lines and only 25 gave positive results. Acetyl aleuritolic acid (49), 15,16-epoxy-5,13(16),14-ent-halimatriene- 3-ol (52) and crotodichogamoin A (53) were also evaluated for their anticancer activity and and their one dose mean value percentage growth at 15 μg/ml were 97.86, 99.39 and 100.6, respectively. The mean values of growth inhibition of the three compounds tested against one dose NCI cell line panel did not meet the standards for further testing against the five-dose NCI cell line panel. The study recommends toxicological studies be done on the medicinal plants extracts to enhance their full exploitation.
Physico-chemical qualities of selected potato (solanum tuberosum l.) cultivars and their suitability for product diversification in Rwanda
(Egerton University, 2019-11) Ndungutse, Vedaste
Potato (Solanum tuberosum L.) is bulky and perishable with up to 50% of losses in 3-5 months of storage. Losses can be reduced through processing into less bulky and more stable products. The aim of this study was to investigate morphological and biochemical factors which affect potato quality, effect of potato cultivars and fermentation on quality of French fries and crisps as well as starch characteristics. Cultivars used included vartieties like Gikungu, Kigega, Kinigi, Kirundo, Mabondo, and Sangema and clones such as CIP399075.22, CIP392617.54, CIP 393251.64 and CIP399062.115. Laboratory experiment was Completely Randomised Design (CRD) with three replications. The skin colours were red, white, yellow, pink or purple, while the flesh was yellow or white. Specific gravity was 1.075-1.099, dry matter (DM) 20.45-25.93%, starch 14.33-19.28% on Fresh Weight Basis (FWB). Reducing sugars were 0.10-0.20%, non-reducing sugars 0.16-0.35%, and total sugars 0.26-0.55% FWB. Kinigi, Kirundo, Mabondo, Sangema and CIP393251.64 were selected for processing suing discriminant analysis. Discriminant analysis did not distinguish these cultivars for crisps and French fries. Internal oil was higher than surface oil and lower for French fries than crisps. Total oil was 11.97-18.48% for French fries and 33.49-42.84% for crisps. Fermentation increased acidity 0.01-0.02%, reduced pH 7.30-4.31, acrylamide 629.6-267.73 μg/kg for French fries and 855.30-339.59 μg/kg for crisps. Potato flour had high water absorption capacity (WAC) 265.39-303.11%, oil absorption capacity (OAC) 99.21-123.14%, foaming capacity (FC) 6.27-18.05% and emulsification capacity (EC) 30.00-44.17%. Rapidly digestible starch was 0.82-2.00% for raw potatoes, 46.71-50.87% for French fries, 69.66-70.31% for crisps; slowly digestible starch was 5.89-14.40% for raw potatoes, 37.35-38.58% for French fries, and 23.50-27.21% for crisps; resistant starch was 83.61-93.30% for raw potatoes, 10.25-14.53% for French fries, 2.91-8.20% for crisps; glycemic index (GI) was 59.44-68.37% for French fries, 66.23-70.23% for crisps; glycemic load (GL) was 9.91-13.36% for French fries and 11.05-13.57% for crisps. High DM and low reducing sugars are indicators of good quality potato for fried and dehydtared products. Oil absorption reduced with increase of DM. Reduction of acrylamide increases safety of the products. High WAC of flour is an indicator for use in food as thickening agent and where bulk is needed and high OAC is good for flavour retention which inceases food palatability. GI and GL were medium for both as a crisps and French fries and they can be used for control of metabolic disorders. Therefore, potato in this study can be used
Antimicrobial activity and phytochemical studies of turraea abyssinica, meyna tetraphylla and leonotis mollissima
(Egerton University, 2019-11) Kinuthia, Esther Wanjiru
Due to the high bills involved in the importation of modern medicinal drugs, about 80% of the African population use traditional medicine from plants to treat common infectious diseases caused by microorganisms. The main objective of this research was to determine the antimicrobial activity of crude extracts and isolated compounds from Turraea abyssinica, Meyna tetraphylla (Abyssinian coral tree) and Leonotis mollissima (Lion’s ear) from Meliaceae, Rubiaceae and Lamiaceae families respectively. They were studied in this research due to their wide use by local communities of Kenya for medicinal remedies. Plant materials were sampled from Kirinyaga East, Narok North, Baringo South, Tharaka Nthi Maua, Laikipia University and Mau Narok in Kenya. They were identified and voucher specimen kept for reference. All the plants crude extracts showed significant antimicrobial activity on all the test microorganism (Bacillus cereus, Staphylococcus aureus, Escherichia coli,Salmonella typhimurium and Candida albicans) at a concentration of 1 mg/ml despite been sampled from different regions of Kenya. They had lower MIC (Minimum Inhibition Concentration) as compared to the Amoxil® and Doxycycline® antibiotics that were used as positive control for comparison. From Turraea abyssinica stem bark dichloromethane crude extract (52.42 g), three compounds 176 (Sitosterol, 4.60 mg), 177 (Scopoletin, 6.00 mg) and 178 [2-(1’,2’ Dihydroxypropyl)tetradecanoic acid, 5.65 mg] were isolated. Of the three compounds only compound 176 showed significant activity on Bacillus cereus, Staphylococcus aureus, and Candida albicans) at a concentration of 2.5 mg/mL to 4.0 mg/mL. Meyna tetraphylla leaves dichloromethane crude extract (45.24 g) gave compounds 179 (Phaeophytin, 9.40 mg), 180 (Enantiomer, 5.80 mg), 118 (α-Amyrin, 5.65 mg) and 60 (Sitigmasterol, 5.82 mg). The Structures of the compounds were elucidated using 1D-and 2D NMR. Experiments. Compound (179) showed significant activity on Escherichia coli and Salmonella typhimurium at a concentration of 4.0 mg/mL while α-Amyrin (118) had significant activity on Salmonella typhimurium at a concentration of 4.0 mg/mL. Leonotis mollissima leaves dichloromethane crude extract (79.69 g) yielded compounds 181 (Sederin, 7.70 mg), 182 (20-hydroxylucidenic acid D2, 7.10 mg) and 183 [(13R)-19α,13α-epoxylabda 6β(19).16(15)-dioldilactone, 21.20 mg]. Only compound (182) showed significant antimicrobial activity on Escherichia coli at a concentration of 0.4 mg/mL. This was a confirmation that the three plants contain compounds that can be isolated and used as drugs to treat various diseases including microbial infectious diseases.
Molecular products, thermal emissions, and radical kinetics from the thermal degradation of croton megalocarpus biodiesel and binary transport fuels
(Egerton University, 2020-06) Chelangat, Mosonik Bornes
There is an urgent interest initiated to develop clean energy resources with the aim of reducing exposure to environmental pollutants and explore model fuels that can hasten the achievement of clean energy combustion. In order to optimize the pyrolysis of binary transport fuels, diesel blends of ratios 1:1, 3:2 and 2:3 were each pyrolyzed at a contact time of 5 seconds in a quartz reactor at 1 atmosphere pressure, at a model temperature of 500 ºC. The surface morphology of the particulate emission was imaged using a field emission gun scanning electron microscope (FEG SEM) while free radical characteristics such as radical intensities and radical kinetics was investigated using an X-band electron paramagnetic resonance spectrometer (EPR). Surface bound functional groups on thermal char were studied using Fourier Transform infra-red spectrometer (FTIR). Optimized molecular structures were performed using the quantum level of theory incorporated in Gaussian ‗16 and CHEMISSIAN computational codes. The charcoal content for pure fossil diesel was compared with the binary diesel residue. Gas-phase molecular components were determined using Gas chromatography (GC) coupled to a mass selective detector (MSD). Elemental composition of thermal char was determined using Smart Elemental Analyzer. It was noted that at a ratio of 2:3 (Biodiesel: Fossil diesel), harmful molecular products reduced significantly, 76 – 99%. Elemental analysis data indicated that the carbon content from commercial diesel was very high (≈ 70.61%) as compared to approximately 53% for biodiesel-fossil diesel mixture in the same ratio 2:3. Interestingly, the free radical content was reduced by nearly 50% in favour of the biodiesel/fossil diesel mixture. Electron paramagnetic resonance (EPR) results gave a g-value of 2.0024 and a narrow ΔHp-p of 3.65 G. The radical concentration for the first EPR experiment was 9.12 × 1019 spins/g and 4.19 × 1017 spins/cm. The decay rate constant for the radicals was low ( while the half-life was ≈ 431 days. Fourier transform infrared (FTIR) results showed the presence of aromatic hydrocarbons, methyl and methylene groups on the surface of biochar while scanning electron microscopy (SEM) images indicated the existence a polymeric structure believed to be highly carbonaceous. The low g-values and low decay rate constant suggest that the free radicals in the biochar are carbon-based and stabilized by a strong π-π conjugated system. This study reports that a binary biodiesel – fossil diesel ratio of 2:3 is a future promising transport fuel because of reduced molecular emissions and decreased free radicals in
Chemical characterisation and antimicrobial activity of Compounds from some selected medicinal Kenyan ganoderma and trametes species
(Egerton University, 2020-06) Mayaka, Regina Kemunto
They are a unique group of fungi usually ignored by most fungi enthusiasts because of their typical inedibility, unfamiliar habitat and general opacity. In addition to their traditional use, contemporary research has suggested many applications for cancer treatment and boosting of the immune system. Due to increase in bacterial resistance to existing antibiotics infectious diseases have remained a major threat to human health. Hence bioactive compounds are continuously sought for disease prophylaxis and treatment. The main objective of the current work was to evaluate bioactive compounds from medicinal polypore species Ganoderma adspersum, Ganoderma applanatum, Ganoderma australe and Trametes elegans collected from Mau, Kericho area, Kabarnet and Kerio valley forests in Kenya. The dried, ground fruiting bodies of the species were extracted with methanol to give methanol crude extract, then consecutively extracted using ethyl acetate solvent to obtain an ethyl acetate extract. Fractionation and purification using column chromatography technique and further purification of some compounds was achieved on sephadex LH20. The chemical structures were determined on the basis of NMR spectroscopic data from 1H and 13C NMR, HSQC, HMBC, 1H-1H COSY and NOESY experiments, and by comparing obtained results to the values indicated in previous studies. The polypore Ganoderma adspersum yielded ergostane compounds namely ergosta-7,22-dien-3-one (54), ergosta-7,22-diene-3β -ol (55) and ergosta- 5,7,22-trien-3-ol (56). Ganoderma applanatum gave five compounds, 55, 56, 5α,8α– epidioxyergosta-6,9(11),22-trien-3β-ol (57), 5α,8α–epidioxyergosta-6,22-dien-3β-ol (58), 24- hydroxy-olean-12-en-3-one (59). The fruiting body of Ganoderma australe yielded compounds 55, 56 and 57 and Trametes elegans gave 55, 56, ergosta-7,22-dien-3,5,6-triol (60), lupeol (61) and 9,19-cycloartane-3,30-diol (62). Antimicrobial activity was assessed against important clinical bacterial and fungal strains and zones of inhibition examined using one-way ANOVA through Tukey’s PostHoc test. Most notable inhibition being against Streptococcus pyogenes 9.7 0.58 mm by compound 56, 9.0 0.58 mm by compound 55, 9.0 0.58 mm by a mixture of 57 and 58 and 8.0 0.33 mm by compound 59. It was observed that all Gram negative bacteria were insensitive to the treatment of compounds. In conclusion the study has indicated that the isolated compounds have antibacterial properties hence have demonstrated their potential as antibacterial agents. The research has also revealed that our natural indigenous forests still harbours novel natural bioactive substances and strains that needs to be investigated for novel myco-medicines in the future.
Evaluation of anti-diabetic effects of phytochemicals from urtica dioica (stinging nettle),salvia officinali(sage),Psidium(Guava) and citrus limon(lemon) using an experimental mice model
(Egerton University, 2020-08) Kanana, Faith Mbiti
Diabetes mellitus affects millions of people Worldwide. In developing countries, diabetes mellitus causes signiﬁcant morbidity and mortality to both children and adults. Although extensive research has been conducted on diabetes mellitus, effective treatment has not yet been reported. Oral anti-diabetic drugs and insulin used in clinical management are expensive, unavailable or have side effects. Therefore, there is need for safer and effective bio-active drugs from medicinal plants. The aim of this study was thus to investigate the anti- diabetic efficacy of phytochemicals from Urtica dioica, Salvia oﬂicinalis, Psidium guajava and Cirrus limon leaf extracts. Three months old fresh leaves of the plants were collected from Egeﬂon University’s Botanical Garden for extraction of phytochemicals. Methanol Was used as the primary solvent for extraction. The resultant plants extracts were partitioned with Water, ethyl acetate and hexane and concentrated using a rotary vacuum evaporator to obtain ethyl acetate, hexane, and aqueous crude extracts. Diabetes was induced in the experimental mice using a single intraperitoneal injection of alloxan monohydrate at a dose of 200 mg/kg body Weight. The crude extracts Were subjected to preliminary in vivo bio-assays for 7 days Where they Were administered orally to experimental mice. Ethyl acetate extract of S. oﬂicinalis and methanol extract of C. limon did not reveal any anti-diabetic effect while the aqueous extract of S. Qﬂicinalis showed signiﬁcant hypoglycemic effect, p< 0.05 compared to other extracts. It Was, therefore, subjected to further hypoglycemic studies Where fasting blood sugar and live Weights of various groups were monitored at intervals of 72 hours for 15 days. There was a signiﬁcant drop in blood sugar levels of the groups treated With S. ojﬁcinalis aqueous extract at 400 mg/kg and 600 mg/kg dosage levels from 452.00 zk 11.13 Mg/dl and 431.00 :1: 10.65 Mg/dl to 256.33 :1: 5.12 Mg/dl and 256.67 :1: 8.74 Mg/dl and Weight gain improvement from 28.05 i 0.39 g and 27.38 i 0.52 g to 29.32 i 0.42 g and 28.55 zt 0.38g respectively compared to controls, p< 0.05. Histopathological analysis of liver and kidney tissues obtained from euthanized mice did not reveal any significant changes compared to the controls. This indicated that the extracts did not confer adverse effects on these tissues. Phytochemical tests of the extracts revealed presence of flavonoids, sterols, saponins, tannins, alkaloids, and triterpenes. Flavonoids and triterpenes particularly have been documented to possess anti-diabetic effects on alloxan induced mice. Results from this study indicate that U. dioica, S. ojjﬁcinalis, C. limon and P. guajava extracts are potential anti-hyperglycemic and can be used in modulating blood glucose with exception of ethyl acetate extract of S. oﬂicinalis and methanol extract of C. limon.

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