Browsing by Author "Twinomuhwezi, Hannington"

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Antimicrobial Activity of Isolated Compounds from Zanthoxylum gilletii Stem Bark Extract
(International Research Journal of Pure and Applied Chemistry, 2026-04-20) Niringiyimana, Eric; Twinomuhwezi, Hannington; Gumula, Ivan; Odokonyero, I; Byaruhanga, Ivan; Onen, Patrick
Background: Zanthoxylum gilletii, an important African medicinal plant, is widely used in traditional medicine for treating various ailments due to its rich phytochemical composition. However, despite its extensive ethnomedicinal applications, the specific bioactive compounds responsible for its antimicrobial properties remain insufficiently characterized. Aims: The study aims to isolate and characterize bioactive compounds from Zanthoxylum gilletii stem bark and evaluate their antimicrobial activity against selected bacterial and fungal pathogens. Methodology: Zanthoxylum gilletii stem bark was collected from Mabira Forest Reserve (0°23′54″N 33°0′59″E), Buikwe District, Uganda on 17th June 2022. The experiments were performed at the Department of Chemistry, Kyambogo University, between June 2022 and July 2023. Stem barks were shade dried, powdered, and extracted using Maceration technique with a mixture of methanol and dichloromethane (ratio 1:1) solvent. The extract was subjected to open column chromatography and identified using NMR spectroscopy and compared with literature information. Antimicrobial activity of crude extract and also the isolated compounds were assessed via disk diffusion against five bacterial and two fungal strains. Results: In this study, four known compounds: lupeol (1), stigmasterol (2), α-amyrin cinnamate (3) and α-amyrin acetate (4) were isolated from stem bark extracts of Zanthoxylum gilletii. This is the first-time compound 4 is reported in Zanthoxylum genus. The compounds had antimicrobial activities against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Enterobacter cloacae, Candida albicans and Aspergillus fumigatus. The extract and the compounds displayed inhibition against the microorganisms with diameters measuring 3.0±0.0 mm to 19.0±0.0 mm. The minimal inhibitory concentrations (MICs and MFCs) for active strains ranged from 6.25 to 150 mg/mL. Conclusion: The observed activities support the traditional use of this plant in treating various ailments by Ugandan communities.
Fatty acid composition and cholesterol distribution in edible tissues of long-horned Ankole cattle
(Journal of Food Composition and Analysis, 2025-12-02) Wanyama, Joseph; Kwetegyeka, Justus; Twinomuhwezi, Hannington; Omara, Timothy; Kiganda, Ivan
Ankole cattle is a vital genetic resource and an economic asset in East and Central Africa, usually reared for their beef and milk. For the first time, the total lipid content, fatty acid composition and cholesterol concentration in beef of Ugandan long-horned Ankole cattle were determined using gas chromatography-mass spectrometry and high performance liquid chromatography. Significant variations in the total lipid content, fatty acid composition and cholesterol concentration were observed among the different samples, with the liver and kidneys possessing the highest values (P < 0.05). The fatty acid composition followed the order: monounsaturated fatty acids> saturated fatty acids > polysaturated fatty acids. Nutritional indices indicated that the kidney, liver, and heart had better fatty acid compositions. In contrast, the rib, large intestine, and chuck had higher atherogenic and thrombogenic indices, which may be associated with increased risks of cardiovascular diseases when consumed.
Mycotoxins’ toxicological mechanisms involving humans, livestock and their associated health concerns: a review
(Toxins : MDPI, 2022-02-24) Awuchi, Chinaza Godseill; Ondari, Erick Nyakundi; Nwozo, Sarah; Odongo, Grace Akinyi; Eseoghene, Ifie Josiah; Twinomuhwezi, Hannington; Ogbonna, Chukwuka U.; Upadhyay, Anjani K.; Adeleye, Ademiku O.; Okpala, Charles Odilichukwu R.
Mycotoxins are well established toxic metabolic entities produced when fungi invade agricultural/farm produce, and this happens especially when the conditions are favourable. Exposure to mycotoxins can directly take place via the consumption of infected foods and feeds; humans can also be indirectly exposed from consuming animals fed with infected feeds. Among the hundreds of mycotoxins known to humans, around a handful have drawn the most concern because of their occurrence in food and severe effects on human health. The increasing public health importance of mycotoxins across human and livestock environments mandates the continued review of the relevant literature, especially with regard to understanding their toxicological mechanisms. In particular, our analysis of recently conducted reviews showed that the toxicological mechanisms of mycotoxins deserve additional attention to help provide enhanced understanding regarding this subject matter. For this reason, this current work reviewed the mycotoxins’ toxicological mechanisms involving humans, livestock, and their associated health concerns. In particular, we have deepened our understanding about how the mycotoxins’ toxicological mechanisms impact on the human cellular genome. Along with the significance of mycotoxin toxicities and their toxicological mechanisms, there are associated health concerns arising from exposures to these toxins, including DNA damage, kidney damage, DNA/RNA mutations, growth impairment in children, gene modifications, and immune impairment. More needs to be done to enhance the understanding regards the mechanisms underscoring the environmental implications of mycotoxins, which can be actualized via risk assessment studies into the conditions/factors facilitating mycotoxins’ toxicities.