Browsing by Author "Justus, Kwetegyeka"

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Antibacterial and anticancer activities of green-synthesized silver nanoparticles using Photinia glabra fruit extract
(Nanomedicine, 2023-08) Tabbisa, Namulinda; Lei-Lei, Bao; Justus, Kwetegyeka; Ivan, Gumula; Yi-Jia, Yan; Zhi-Long, Chen
Aims: We prepared Photinia glabra (PG) aqueous fruit extract, utilized it to synthesize silver nanoparticles (PG-Ag NPs) and evaluated the antibacterial and anticancer activities of the nanoparticles (NPs). Materials & methods: Silver nitrate aqueous solution was reduced to PG-Ag NPs using aqueous PG fruit extract. NP shape, size, composition and functionalization were determined using transmission electron microscopy, x-ray photoelectron spectroscopy, Fourier transform infrared and x-ray diffraction. Results & conclusions: PG-Ag NPs were spherical, approximately 39–77 nm-sized, functionalized surfaces with notable antibacterial activity against both Escherichia coli and Staphylococcus aureus, with an MIC <30 ug/ml and cytotoxicity toward esophageal cancer cells, with IC50 values less than 20 ug/ml. PG-Ag@rt NPs have been shown to be a potent antibacterial and anticancer agent, and their enriched particle surfaces can be conjugated with other compounds for multibiomedical applications.
Concentrations and sources apportionment of polycyclic aromatic hydrocarbons in sediments from the Uganda side of Lake Victoria
(Environmental Science: Processes & Impacts, 2017) Nasifu, Kerebba; Patrick, Ssebugere; Justus, Kwetegyeka; Kenneth, Arinaitwea; John, Wasswa
This study presents the levels and possible sources of selected polycyclic aromatic hydrocarbons (PAHs) in surface sediments from the Napoleon Gulf and Murchison Bay of Lake Victoria. Sediment samples were extracted and cleaned up for PAHs using UNEP, 1992, and EPA method 3630C protocols. The analysis of sample extracts was carried out using a gas chromatograph coupled to a mass spectrometer. Fifteen congeners, mostly the high molecular weight PAHs (HPAHs) (4–6 rings) were detected. Total (∑) concentrations varied from 44.2 to 80.2 ng g−1 dry weight (d.w.) at the Napoleon Gulf, while those at the Murchison Bay ranged from 17.0 to 55.0 ng g−1 d.w. Statistical analysis showed no significant difference in the concentrations of PAHs among sites (p < 0.05, ANOVA). It was noted that the concentrations for most sampling sites were far below the lowest effect levels based on the Sediment Quality Guidelines, except for one station at the Napoleon Gulf. Principal component analysis and diagnostic ratios indicated that PAHs of combustion and petroleum origin were dominant and brought about mainly by atmospheric deposition.
Nutrient alterations in Nile perch (Lates niloticus) skins owing to various processing and cooking techniques
(International Journal of Environmental Studies, 2012-01) Margaret, Kabahenda; Jolocam, Mbabazi; Justus, Kwetegyeka; Ronald, Amega
Nile perch (Lates niloticus) skin is a major substitute for whole fish especially among low-income groups who are especially vulnerable to protein and micronutrient deficiencies. The object of this study was to determine the extent of nutrient alterations that occur in Nile perch skins when sub- jected to various processing and cooking techniques. Whereas the study showed that Nile perch skins are rich sources of zinc, iron, calcium and lipids, their content is significantly altered by the various preparative methods currently in use.
Organochlorine pesticide residues in Uganda’s honey as a bioindicator of environmental contamination and reproductive health implications to consumers
(Elsevier, 2021) Stuart Ben, Mukiibi; Steven Allan, Nyanzi; Justus, Kwetegyeka; Chijioke, Olisah; Adewale Matthew, Taiwo; Edward, Mubiru; Emmanuel, Tebandeke; Henry, Matovu; Silver, Odongo; Juma John Moses, Abayi; Emily Chelangat, Ngeno; Mika, Sillanp; Patrick, Ssebugere
Honey has multifaceted nutritional and medicinal values; however, its quality is hinged on the floral origin of the nectar. Taking advantage of the large areas that they cover; honeybees are often used as bioindicators of environmental contamination. The focus of the present paper was to examine the quality of honey from within the vicinity of an abandoned pesticide store in Masindi District in western Uganda. Surficial soils (< 20 cm depths) and honey samples were collected from within the vicinity of the abandoned pesticide store and analysed for organochlorine pesticide (OCP) residues using gas chromatograph coupled to an electron capture detector (GC-ECD). The mean level of ∑DDTs in all the soil samples was 503.6 µg/kg dry weight (d.w). ∑DDTs contributed 92.2% to the ∑OCPs contamination loads in the soil samples, and others (lindane, aldrin, dieldrin, and endosulfans) contributed only 7.8%. Ratio (p, p′-DDE + p, p′-DDD)/p, p′-DDT of 1.54 suggested historical DDT input in the area. In all the honey samples, the mean level of ∑DDTs was 20.9 µg/kg. ∑DDTs contributed 43.3% to ∑OCPs contamination loads in the honey samples, followed by lindane (29.8%), endosulfans (23.6%) and dieldrin (3.2%), with corresponding mean levels of 14.4, 11.4 and 1.55 µg/kg, respectively. Reproductive risk assessment was done based on the hazard quotient (HQ) and hazard index (HI) procedure. In our study, the calculated HIs for adults (102.38), and children (90.33) suggested high potential health risks to the honey consumers. Lindane, endosulfan and p, p′-DDD detected in the honey samples at levels exceeding the acute reference dose (ARfD) are known risk factors for spontaneous abortion, reduced implantation, menstrual cycle shortening, impaired semen quality, and prostate cancer in exposed individuals and experimental animal models.