Faculty of Science

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Evaluation of antimicrobial, antidermatophytic, antiproliferative and cytotoxic activity of secondary metabolites isolated from calpurnia aurea subsp. aurea (aiton) benth (l’herit) and associated fungal endophytes
(Egerton University, 2025-09) Wanga, Lucy Aketch
Antimicrobial resistance has been recognized as a significant threat to healthcare systems globally, affecting both developing and developed countries, resulting in increased rates of skin infections caused by bacterial and dermatophytic pathogens. Cancer cases have increased over the years, and existing management options often entail undesirable side effects. Medicinal plants and endophytic fungi provide alternative solutions to these challenges. This research focused on the isolation of antimicrobial, antidermatophytic, antiproliferative, and cytotoxic secondary metabolites from Calpurnia aurea subsp. aurea and its associated endophytic fungi. The leaves and stem bark of this medicinal plant were used for the isolation of endophytic fungi, while the remaining portions were used for secondary metabolite extraction using methanol. Isolated fungal endophytes were identified through molecular techniques and fermented on rice media for the extraction of secondary metabolites. All extracts from leaves, stem bark, and endophytic fungi were purified using High Performance Liquid Chromatography (HPLC) to isolate pure compounds. The structures of the isolated compounds were elucidated using 1D and 2D NMR spectroscopy, as well as Liquid Chromatography Mass Spectrometry techniques. The bioactivities (antimicrobial, antidermatophytic, antiproliferative, and cytotoxicity) of the isolated compounds were also analyzed. Nineteen endophytes were isolated, classified into the classes Eurotiomycetes, Sordariomycetes, Coleomycetes, and Agariomycetes. Together with other known compounds, five (5) previously undescribed compounds were reported, namely; quinolizidine alkaloids (46-49) and a tirucallane triterpenoid (67), additionally ten (10) phenolic compounds were reported for the first time in this study. The phenolic and quinolizidine alkaloids demonstrated antidermatophytic activity, with minimum inhibitory concentration (MIC) values ranging from 6.6 μg/mL to 300 μg/mL against Trichophyton rubrum, Trichophyton interdigitalle, Trichophyton benhamiae, Microsporum canis, and Nannizia gypsea. The cinnamic acid (65) demonstrated antimicrobial activity against Bacillus subtilis (MIC of 16.6 μg/mL), comparable to oxytetracycline (MIC 16.6 μg/mL). The phenolic compounds also exhibited antiproliferative and cytotoxic effects on KB3.1 and L929 cell lines, with compound 65 demonstrating an IC50 value of 18 μg/mL. The results of this study demonstrate the significance of C. aurea subsp. aurea and endophytic fungi as sources of antimicrobial, antidermatophytic, antiproliferative, and cytotoxic secondary metabolites, which may serve as lead compounds in drug development. Additionally, this study scientifically validates the use of C. aurea subsp. aurea in alternative medicine.
Integrating fuzzy and bipolar fuzzy metrics into digital topology for enhanced image analysis
(Egerton University, 2025) Gathigi Stephen Macharia
Digital topology provides a mathematical foundation for analysing discrete image structures. It is considered to be a very critical part of processing image data because it provides us with information about the properties of images. The approaches to digital topology have been studied to great detail by several researchers and each approach has been seen to have advantages and limitations. In general, the approaches that exist, which are the Graph theoretic and axiomatic methods, are both found to stmggle when it comes to handling the imprecision that is present in images and other digital structures. This is because such methods do not account for dual uncertainty. Consequently, this limits their effectiveness in real-world applications. While fuzzy and bipolar fuzzy set theory provide ﬂexible tools for addressing these limitations, their integration into digital topology remains underdeveloped. This study addresses this gap by developing a mathematical framework that extends traditional digital topology into fuzzy and bipolar fuzzy logic for image analysis. The research formalises fuzzy and bipolar fuzzy metric spaces on the digital plane, and attempts to integrate these bipolar fuzzy metrics into digital topology. Topological properties, including connectedness, adjacency, and surroundness, are also extended into the fuzzy and bipolar fuzzy domain. This has been done in order to ensure mathematical consistency in representing digital images. Additionally, the study proposes new similarity, distance, and entropy measures to reﬁne the important aspects of image analysis such as image segmentation. Through computational implementation, the ﬁndings contribute to a more realistic approach to image segmentation that is also mathematically sound. This research greatly improves the applicability of digital topology in image processing technique since it establishes a framework that handles uncertainty in digital images. The study’s outcomes will pave the way for deeper analysis of digital images and hence strengthen the intersection of topology, fuzzy mathematics, and artiﬁcial intelligence.
In silico drug design and characterization of selected active compounds from sapium and salvia genus as anti-cancer agents using molecular docking and molecular dynamics simulations
(Egerton University, 2025) Ouma Russell Ben Omondi
Extensive research projects have been performed to better understand the genetic landscape and tumour development of localized and metastatic breast cancer (BC) and prostate cancer (Pca). In this study, computational studies and in vitro analysis were conducted before in vivo analysis to provide predictive insights into potential mechanisms and mitigate risks and hazards associated with animal experiments. Through molecular dynamics, ligand binding within the binding pocket of a ligand-protein was investigated using parameters such as root mean square deviation (RMSD) and root mean-square ﬂuctuation (RMSF), along with molecular dynamics simulations that tracked ligand-receptor interactions over a 200-nanosecond (ns) simulation trajectory. This study presents studies of a far less explored ellagic acid (EA), [20-3H] phorbol- l2, l3-dibutyrate ([3H] PDBu), and [20-3H]-l2-deoxyphorbol-13-isobutyrate ([3H] DPB) key metabolites from the genus Sapium and compares with the widely studied salvianolic acid B (Sal B) from Salvia. The molecular interactions of these compounds with the proteins were determined using molecular docking and molecular dynamics simulation. The molecular dynamics simulations revealed that salvianolic acid B exhibited binding afﬁnities of -38.49 kJ/mol, -28.87 kJ/mol, and -33.05 kJ/mol when targeting DNA lyase, topoisomerase II alpha, and mTOR, respectively. These docking scores were comparable to those of EA, exhibiting a binding afﬁnity of-36.40 kJ/mol, -27.20 kJ/mol, and -31.80 kJ/mol when targeting DNA lyase, topoisomerase II alpha, and mTOR, respectively. Based on this, Sal B showed greater negative binding afﬁnity indicating kinetically stable ligand-protein interactions. The dominance of the ligand- protein interactions indicate the signiﬁcance of synergies such as the electrostatic interactions, Van der Waals forces and hydrogen bonds. Sal B had docking scores of - 46.86 kJ/mol and -27.24 kJ/mol respectively when docking NUDT5 and androgen receptor (AR). The ﬁndings of the molecular dynamics simulation also showed that the interaction of Sal B- protein had a stable RMSD with an average of l.5- 2.0 Angstroms (A). These in-silico results are indicative of biologic potential of Sal B as an anticancer agent. Evaluation of the RMSD values indicated that there were structural changes with time before reaching a plateau. This indicated a ﬁxed ligand binding site. The RMSF plot also provided infomiation regarding the ﬂexibility of the protein residues. In the studied ligand-receptor complexes, the RMSF values ﬂuctuation did not exceed 2 A, showing that the protein residues remained relatively rigid.
Synthesis of ruthenium(ii) and osmium(ii) complexes [ru/os(η6arene)l, l = bis(pyrazol-1-yl)methane; l = (3-chloro-6-(1h-pyrazol-1 yl)pyridazine]
(Egerton University, 2025) Kanyora Amos Kimemia
Cancer, a non-communicable disease, continues to rank among the top causes of mortality globally, with a substantial number of new diagnoses reported annually. Although platinum based drugs are involved in nearly 50% of cancer treatment regimens and are highly effective against various types of cancer, they suffer from drawbacks that limit their broader application and efficacy. As alternatives, (ε⁶-arene)ruthenium(II)/osmium(II) complexes have shown better antiproliferative properties and more favourable toxicity profiles, making them promising candidates for further exploration. This work reports the synthesis of fifteen mononuclear Ru(II) and Os(II) complexes bearing ε⁶-arene ligands in combination with either bis(pyrazol-1yl)methane or pyrazolyl-pyridazine donor systems. Comprehensive characterization was carried out using a suite of techniques, including CHN elemental analysis, FTIR, UV–Vis spectroscopy, ¹H and ¹³C NMR, mass spectrometry, and single-crystal X-ray diffraction. The electronic structures of the complexes were further examined through density functional theory (DFT) calculations. A subset of five Ru(II) pyrazolyl–pyridazine complexes was selected to probe their binding interactions with calf thymus DNA (CT-DNA) and glutathione (GSH) via UV–Vis absorption and fluorescence titration assays. The findings revealed that the Ru(II) compounds demonstrated moderate to strong affinities for CT-DNA, with binding occurring predominantly through minor groove interactions. Molecular docking studies further supported these findings, indicating stable binding conformations. The relative binding affinities were determined as follows: -5.8 kcal/mol (9) > -5.7 (4a) > -5.6 (3a) > -5.4 (3c) > -5.3 (4c) > -3.6 (cisplatin), suggesting stronger DNA binding than the standard drug cisplatin. Moderate anticancer activity was observed against the MCF-7 breast cancer cell line, with complex 9 being the most potent (IC₅₀ = 41.94 ± 2.05 μM), though none of the compounds showed efficacy against MDA-MB231. Ru(II) complexes with bis(pyrazol-1-yl)methane ligands showed low cytotoxicity across all cell lines tested. DFT results indicated that electron density on the metal centre and surrounding ligands significantly influenced reactivity. GSH studies revealed that chloro analogues were more readily deactivated than iodo analogues. Collectively, the results indicate that these complexes hold promise as foundational structures for designing more effective anticancer therapeutics.
A model for predicting undergraduate students’ adoption of e-learning in selected public universities in Kenya
(Egerton University, 2025) Getuno, Daniel Makini
The teaching and learning of science employ several approaches, each of which attempts to improve the quality of students’ leaming. One approach that is gaining prominence in higher educational institutions (HEIs) is e-learning. However, e-leaming adoption among students in Kenya’s HEIs is not succeeding the way it is expected because of both institutional and individual shortcomings. In this study, the University Students’ E-leaming Adoption Model (USeLAM) was developed with the aim of providing a basis for decision making in the adoption of e-leaming among undergraduate students in selected public universities in Kenya. The study adopted a cross-sectional survey design based on the Uniﬁed Theory of Acceptance and Use of Technology (UTAUT). The sample consisted of 388 undergraduate university students who answered 24 questions on a 7-point Likert Scale in the Students’ E-learning Adoption Questionnaire (SeLAQ). The SeLAQ was validated by six educational research experts at Egerton University and yielded Cronbach - Alpha reliability coefﬁcient of 0.78. Six hypotheses were tested above the 90% level of conﬁdence (p < .100) by applying the Partial Least Squares, Structural Equation Modelling (PLS-SEM) techniques. The results indicate that there were positive and statistically signiﬁcant relationships between Perfonnance Expectancy (PE) and Behavioral Intention to adopt e-learning (BI) ([3 = .15, t: 3.16, p = .002) and; between Effort Expectancy (EE) and BI (B = .18, t = 4.32, p < .001). However, Social Influence (SI) was not a statistically signiﬁcant predictor of BI ([3 = .00, t= 0.07, p = .945). On the other hand, BI Was found to be a positive and statistically signiﬁcant predictor of Actual Use Behaviour of e-learning (UB) (B = .08, t= 1.83, p = .067) while Facilitating Conditions (FC) was a negative but statistically signiﬁcantly predictor of UB (B I -.1 1, t: 1.79, p I .073). Further analysis of the effect of moderators on the relationship between predictors and outcomes of students’ adoption of e-learning was done using the PLS-Multi Group Analysis (MGA). The results indicate that students’ age (AGE), gender (GND) and internet experience (IXP) signiﬁcantly moderate students’ e-leaming adoption in varying degrees. In the ﬁnal analysis, the USeLAM accounted for 24% (R3 = .24) of the variance in Bl and 15 % (R2 = .15) of the variance in UB. In conclusion, therefore, the study underscores the signiﬁcant inﬂuence of PE and EE on students’ BI as well as that of BI and FC on students’ UB. The implications of this study extend to educational policy makers in general, and public university management, in particular, in improving e-leaming adoption in HEIs. Further, it lays the groundwork for future research in predicting e-learning adoption in Kenya’s HEIs and buttressing the multidisciplinary nature of the application of e-leaming in HEI’s
Synthesis of ruthenium(ii) and osmium(ii) complexes [ru/os(η6-arene)l, l = bis(pyrazol-1-yl)methane; l = (3-chloro-6-(1h-pyrazol-1-yl)pyridazine]: assessment of their dna binding and cytotoxicity activity
(Egerton University, 2025) Kanyora Amos Kimemia
Cancer, a non-communicable disease, continues to rank among the top causes of mortality globally, with a substantial number of new diagnoses reported annually. Although platinum- based drugs are involved in nearly 50% of cancer treatment regimens and are highly effective against various types of cancer, they suffer from drawbacks that limit their broader application and efﬁcacy. As altematives, (115-arene)ruthenium(II)/osmium(II) complexes have shown better antiproliferative properties and more favourable toxicity proﬁles, making them promising candidates for further exploration. This work reports the synthesis of ﬁfteen mononuclear Ru(Il) and Os(II) complexes bearing 1]“-arene ligands in combination with either bis(pyrazol-l- yl)methane or pyrazolyl-pyridazine donor systems. Comprehensive characterization was carried out using a suite of techniques, including CHN elemental analysis, FTIR, UV—Vis spectroscopy, ‘H and "C NMR, mass spectrometry, and single-crystal X-ray diffraction. The electronic structures of the complexes were further examined through density functional theory (DFT) calculations. A subset of ﬁve Ru(II) pyrazolyl—pyridazine complexes was selected to probe their binding interactions with calf thymus DNA (CT-DNA) and glutathione (GSH) via UV—Vis absorption and ﬂuorescence titration assays. The ﬁndings revealed that the Ru(II) compounds demonstrated moderate to strong afﬁnities for CT-DNA, with binding occurring predominantly through minor groove interactions. Molecular docking studies further supported these ﬁndings, indicating stable binding conformations. The relative binding afﬁnities were determined as follows: -5.8 kcal/mol (9) > -5.7 (4a) > -5.6 (3a) > -5.4 (3c) > -5.3 (4c) > -3.6 (cisplatin), suggesting stronger DNA binding than the standard drug cisplatin. Moderate anticancer activity was observed against the MCF-7 breast cancer cell line, with complex 9 being the most potent (IC50 = 41.94 i 2.05 uM), though none of the compounds showed efﬁcacy against MDA-MB- 23l. Ru(II) complexes with bis(pyrazol-l-yl)methane ligands showed low cytotoxicity across all cell lines tested. DFT results indicated that electron density on the metal centre and surrounding ligands signiﬁcantly influenced reactivity. GSH studies revealed that chloro analogues were more readily deactivated than iodo analogues. Collectively, the results indicate that these complexes hold promise as foundational structures for designing more effective anticancer therapeutics.
Differential Transcript and Protein Expression Profiles in Anopheles Gambiae Sensu Stricto Mosquito Larvae Exposed to Cadmium Heavy Metal
(Egerton University, 2021-11) Ngambi, Catherine Nyawira
Optimization of Extrusion Cooking for a Protein and dietary fibre rich Instant Flour from a Composite Blend of ...
(Egerton university, 2021-07) Wanjala, Nobert Wafula
Analysis of Extruded Ready-To-Eat Baby Foods Prepared Using Composite Flours from Orange-Fleshed Sweet Potatoes, Soybeans, and Amaranth Seeds
(Egerton University, 2023-07) Nkesiga, Jackson
There is severe food insecurity for many people who live in sub-Saharan Africa. The situation is worse for children under the age of five years who are undernourished. This is caused mainly by poverty limiting access to quality foods, as well as poor breastfeeding, and complementary feeding practices. Therefore, the purpose of this study was to develop and analyze the physicochemical properties, microbial, sensory properties, and shelf-life of extruded RTE baby foods prepared using composite flours from orange-fleshed sweet potatoes (OFSP), amaranth seeds, and soybeans. Ready-to-eat (RTE) baby foods which are conveniently distributed to the poor could be a way of mitigating this challenge. Additionally, there are advocacies for the utilization of locally available food resources for sustainable food production. Extrusion technology has been used in many parts of the world to process RTE foods. However, as with most food technologies, there are always questions regarding optimum working conditions, nutritional quality and safety, consumer outlook, and shelf stability that need to be addressed. The ingredients were optimized using the extreme vertices method of mixture design using Minitab Software. The optimum value for model verification was 57% OFSP, 24% amaranth seeds, and 19% soybeans flour, to achieve targeted values of crude protein (14%), total minerals (4.7%), and Vitamin A (813.6 Retinol Activity Equivalent μg/100g). The optimum extrusion cooking conditions were established as 90oC die temperature, 35% feed moisture content, and 400 rpm screw speed based on Box-Behnken Experimental Design of Response Surface Methodology under Design Expert Software. A completely randomized design (CRD) in a factorial experimental design was employed using statistical analysis software (SAS) for the production of extruded ready-to-eat baby foods. The results revealed that extrusion cooking and blend proportions significantly (p<0.05) affected the physicochemical properties, microbial, sensory properties, and shelf-life of extrudates. The extrusion cooking significantly (p<0.05) reduced moisture content (59.5%), protein content by 5.56%, anti-nutrient content (65.24 - 97.43%), and vitamin A content (21.33%). On the other hand, there were significant (p<0.05) increases in carbohydrate (12.31%), total minerals (10.44%), dry matter (7.06%) contents, energy value (6.38%) and energy-to-protein ratio (11.28%). Blend proportions and extrusion cooking have significant (p<0.05) positive effects on the protein quality of the extrudates in terms of in vitro protein digestibility and available lysine. The shelf-life of extrudates was found to be about 4 to 6 months. Therefore, the use of extrusion cooking techniques for OFSP, amaranth seeds, and soybeans composite flours has the potential for the production of value-added OFSP food products. These findings can be used to achieve food and nutrition security in developing countries.
Spatiotemporal Variation in Plasmodium Falciparum Transmission in Selected Sites in Western Kenya
(Egerton University, 2023) Oduma, Colins Okinyi
Asymptomatic malaria infections are a threat to elimination of this vector-borne infectious disease. In many endemic regions, malaria transmission is seasonal. However, the impact of seasonality on Plasmodium falciparum (P. falciparum) gametocyte levels in peripheral blood and their transmission to local mosquito vectors are not well understood. Data describing these parasitological indices across regions of varying transmission intensity is scanty. In addition, malaria transmission can vary significantly over small geographic scales, but the drivers of this heterogeneity are not well understood. This study evaluated the impact of seasonality on P. falciparum transmission potential, trends in parasitological indices across areas of differential malaria transmission, and factors that might correlate small scale variation in transmission. Blood samples were collected from individuals living in Homa Bay County (low transmission) and Kisumu County (moderate transmission) in the dry season (n=1116) and rainy season (n=1743). In addition, blood samples were collected from approximately 150 individuals in each of 20 clusters in Busia County (high transmission) in rainy season. Blood samples were screened for P. falciparum parasites using quantitative polymerase reaction (qPCR) and microscopy. In Homa Bay and Kisumu the presence and density of blood gametocytes was measured by reverse transcription PCR (RT-qPCR). Differences in parasite and gametocyte densities across seasons were determined by unpaired t-test. Differences in the prevalence, proportion of submicroscopic and gametocyte positive infections across study sites were determined by χ2 test. A generalized linear mixed effect model was used to determine predictors of infections. Potential mosquito larval habitats and their number within 250 m of a household were determined by ArcMap. In Homa Bay and Kisumu, mean parasite densities did not differ in dry versus rainy season (P=0.562). Gametocyte densities were 3-fold higher in the rainy than dry season (rainy: 3.46 transcripts/uL blood, dry: 1.05 transcripts/uL, P<0.001). Parasite prevalence and densities, and gametocyte prevalence and densities were highest in the high transmission region. In contrast, the proportion of asymptomatic submicroscopic infections was highest in the low transmission region. Proportion of gametocyte positive infections did not differ across transmission intensities. In Busia County, across the 20 clusters, 3-folds and 4-folds variation in parasites prevalence by qPCR and microscopy respectively was observed. Three to 34 larval habitats per cluster, and 0-15 habitats within a 250m radius around households were observed. Low altitude, kitchen located indoors, open eaves, a lower level of education of the household head, younger age, and being male were significant predictors of higher prevalence. The number of habitats and their proximity to households was not a predictor for prevalence. In conclusion, parasites increase their investment in transmission in the rainy season, reflected by higher gametocyte densities. Seasonal changes of gametocytemia among infections need to be considered when designing malaria control measures. Pronounced variation in prevalence at small scales and the determinants need to be considered for malaria surveillance and control.
The effect of Pesticide Pollutants on Transmission of Schistosomiasis in Western Kenya
(Egerton University, 2023-08) Aziz, Ganatra Akbar Abdul
Schistosomiasis is caused by trematodes that utilise planorbid snails as their intermediate hosts in Africa. The study aimed to determine the effect of pesticides on the transmission of the disease. This was done by first investigating the effect of two commonly used pesticides, imidacloprid, a neonicotinoid, and diazinon, an organophosphate, on the host snails, Biomphalaria and Bulinus, to determine their tolerance. The tolerance of the snail’s competitors and predators was also investigated. Using laboratory experiments, sensitivity distribution graphs were used to determine that the host snails were the most tolerant taxa to the pesticides chosen. Data from the field showed that the snails were present in moderately polluted sites or greater, with a distinct lack of presence in pristine waters. Binomial and mixed effects general linear models were used to determine a minimum effects model of variables that show the distribution of host snails, and were put into a principal component analysis which showed an antagonistic relationship between pesticide pollution and competitors of host snails. This led the study to conclude that pesticide pollution in the field increases the abundance of host snails by reducing the number of competitors, due to the competitor’s higher sensitivity to the pesticides. The effect of pesticides on the parasite itself were then investigated by studying the effects of the same two pesticides on the free-living life-stages of Schistosoma mansoni. The dose-response calculations revealed the tolerance to be 50-60 times the concentration of what was found in the field. Miracidia were further exposed to sub-lethal doses at 20% the EC50s, where it was shown that these concentrations could reduce the proportion of infected snails. However, these concentrations were 500-600 times greater than those in the field. Therefore, the study here shows that pesticide pollution has the potential to increase snail hosts dominance over their competitors in polluted environments, while not affecting the parasite at environmentally relevant concentrations, leading to an overall increase in risk of disease transmission. As pesticide pollution could increase the risk of schistosomiasis, it must be monitored within habitats to determine the change in risk across seasons. The study evaluated the potential of the SPEARpesticide bioindicator for use in Kenya and found it to be promising. Thus, the government of Kenya could potentially use the bioindicator to cheaply and quickly assess pesticide pollution in the rivers of Kenya and use the information to map out potential areas where the risk of schistosomiasis could increase in the coming years.
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.
Antibacterial Activity of Chrysanthemum Cinerariaefolium (Pyrethrum) Secondary Metabolites and Green Synthesized Silver Nanoparticles
(Egerton University, 2022-08) Kosgei, Caroline Jepchirchir
The development of resistance to antibacterial agents by bacteria, drive efforts in bio prospecting for new novel compounds that can be used to target these resistant microorganisms. Plants are among natural sources of novel compounds with medicinal importance due to their desirable potency. Besides, plant phytochemicals can reduce metal ions to metal nanoparticles hence play important role in the green synthesis of nanoparticles. In the current study, bioactive compounds against selected bacteria were isolated from pyrethrum plant Chrysanthemum cinerariaefolium by carrying out bioassay-guided fractionation. The isolated compounds were characterized using 1D and 2D Nuclear Magnetic Resonance (NMR). Extracts of organic solvents and aqueous of C. cinerariaefolium were also used in the green synthesis of silver nanoparticles (Ag NPs) via reduction of silver ions present in silver nitrate. Synthesis involved mixing a fixed ratio of plant crude extracts with silver ions and storing the mixture in the dark. Observation of a color change to brown signified the formation of the nanoparticles. The nanoparticles were characterized using UV-Vis, Scanning Electron Microscopy, Transmission Electron Microscopy, EDX (energy dispersive X-ray analysis), and Fourier-Transform Infrared Spectroscopy (FTIR). The compounds isolated were (Z)-2 methyl-4-oxo-3-(pent-2-en-1-yl)cyclopent-2-en-1-yl2,2-dimethyl-3-(2-methylprop-1-en-1-yl) cyclopropane-1-carboxylate (jasmolin I), 2-methyl-4-oxo-3(Z)-penta-2,4-diene-1-yl)cyclopent-2-en-1-yl3-(E)-3-methoxy-2-methyl-3-oxoprop-1-en-yl-2,2-dimethylcyclopropane-1-carboxylate (pyrethrin II), and (Z)-2-(but-2-en-1-yl)-4-hydroxy-3-methylcyclopent-2-en-1-one (cinerolone). The compounds showed more activity on the bacteria as a mixture in the ratio of 1:1:1 than individual compounds, with MIC of 25 mg/ml against Pseudomonas aeruginosa. The compounds can therefore be used as lead compounds in drug discovery against bacteria. All the nanoparticles formed were generally spherical in shape. The smallest and largest nanoparticles had sizes of 22.8± 17.5 nm and 75.3± 19.7 nm and they belonged to dichloromethane-Ag NPs and ethyl acetate-Ag NPs respectively. The particles exhibited size-dependent activity on the selected bacteria. Safety studies on the nanoparticles and pyrethrum extracts on Vero cells showed that they were not cytotoxic hence safe for utilization in drug discovery. Pyrethrum plant therefore possesses phytochemicals that can be used in green synthesis nanoparticles. Other plants should be exploited to ascertain their ability to synthesis nanoparticles.
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.
Biochemical Changes and Microbial Profiles Affecting Quality and Vase Life of Cut Gladioli (Gladiolus Grandiflorus L. ‘Fado’) Following Pulsing and Cold Wet Storage
(Egerton University, 2021-04) Chore, Judith Kavulani
Floriculture in Kenya remains among the top three foreign exchange earners. Gladiolus is one of the famous cut flowers in the world. Annual losses amounting to 30,000 metric tonnes valued at USD; 166.6 is incurred by farmers due to postharvest challenges. The aimof this study was to determine the vase life and quality parameters of cut Gladiolus grandiflorus L. cv.‘Fado’ as affected by pulsing with 600 ppm 8-hydroxyquinoline sulphate plus 5% sucrose prior to wet cold storage duration(0 – 5 days). The Gladiolus were grown in the open field from corms at the Horticulture Research and Teaching Field, in the department of Crops, Horticulture and Soils, Egerton University, Kenya, during the season of September to December 2014. A two by six factorial experiment embedded in a Completely Randomized Design with four replicates was adopted using Proc GLM model in two way ANOVA. Differences in means were determined using Tukey’s test at 5% level of significance. Pulsing treatments and interactive wet cold storage durations significantly affected cut Gladiolus quality parameters including fresh weight (P< 0.0031; 11.67% increase).,dry weight (P˂ 0.0272 ;17.62% increase)., mean water uptake (P < 0.0001; 38.14% increase)., opened florets (P˂ 0.00095; 59.8% increase) and number of unopened buds (P <0.0256 ; 61-28.88% reduction). The pulsing and cold storage treatments and their interaction significantly (P˂ 0.0001., P˂0.0003.,P˂0.0001 respectively) affected the vase life of the cut Gladiolus (11.5 ± 0.0.148 days versus 4.75 ± 0.148 days; 142% increase).The pulsing treatment coupled with wet cold storage and their interactive effects significantly (P < 0.0001) affected the concentrations of the senescence biomarkers: Total Free Amino Acids, (P<.0001; 21.97% reduction)), Total Soluble Sugars (P < 0.0001; 101.16% increase) and Total Starch(P <0.0001; 309.39 % increased) on the third day in the vase compared with the control. The levels of Total Phenols, anthocyanins and microbial proliferation were also significantly affected (P< 0.0003 (104.14% increase)., P ˂ 0.0012 (26.98% increase)., P < 0.0001 (6.032% reduction) respectively) on the third day in the vase in pulsed spikes wet cold stored for 3 days.Gladiolus cut flowers can be wet stored at 3 ± 1°C up to a maximum of 4 days without any adverse effect on their subsequent vase life and quality. Small scale farmers can adopt pulsing cutG. grandiflorus cv.Fadowith subsequent storage of upto 4 days at 3 ±1 OC to manage bulking and transportation of their produce to reduce postharvest losses. This may increase domestic livelihood withenhanced foreign exchange and consequently food and job security in Kenya.Knowledge from this study will augment existing technologies in improving quality and market value of Gladiolus cut flower.
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
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.
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.
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.
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.

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