https://ir.cut.ac.zw:8080/xmlui/handle/123456789/301 Dissertations & Theses 2026-06-06T01:36:47Z https://ir.cut.ac.zw:8080/xmlui/handle/123456789/766 An assessment of themolluscicidal potential of Cucurbita maxima seed extracts on Biomphalaria pfeifferi and Bulinus globosus snails Mtemeli, Floryn L.; Walter, Irene; Tinago, Tawanda; Shoko, Ryman Reports of snails’ resistance to niclosamide appeared recently and finding new molluscicides becomes necessary. We investigated the molluscicidal effects of Cucurbita maxima seed extracts on Biomphalaria pfeifferi, and Bulinus globosus snails under laboratory conditions. For B. pfeifferi, we tested seed extracts on juvenile and adult snails while only adult B. globosus were available for testing. Snails were exposed to water and crude ethanol extracts for 72 h and significant concentrationdependent mortality rates were observed. The number of B. pfeifferi juveniles collected was not enough for a comprehensive investigation against both solvents. We, therefore, tested them against water extracts only. A lethal concentration of 0.02 mg/mL killed 50% of the snails (LC50) for both water and ethanol extracts on adult B. pfeifferi snails. Our results suggest that pumpkin seed extracts have a significant molluscicidal effect on B. pfeifferi and B. globosus snails. The LC50 values for all the extracts in B. pfeifferi and B. globosus snails are within the threshold set for potential molluscicides by the World Health Organisation. We propose that C.maxima seed extracts be considered as potential molluscicidal agents in Schistosomiasis transmission control. 2021-03-01T00:00:00Z https://ir.cut.ac.zw:8080/xmlui/handle/123456789/736 Epidemiology of gastrointestinal nematodes of free-ranging chickens (Gallus gallus domesticus) in Africa: A systematic review and meta-analysis Walter, I.; Malatji, M. P.; Nyagura, I.; Tembe, D.; Mukaratirwa, S. A systematic review and meta-analysis were conducted, and published estimates determined the pooled prevalence of gastrointestinal nematode parasites affecting free-ranging chickens in Africa. Peer-reviewed articles published between 1993 and 2024 were systematically searched and screened. Prevalence estimates based on 76 eligible articles showed that of the 74,789 freeranging chickens screened, 13,625 were infected with gastrointestinal nematodes with an overall pooled prevalence of 15% (95% CI: 13–18%). Twenty-seven nematode species were recorded, of which Ascaridia galli and Heterakis gallinarum were the commonly reported species. Southern Africa recorded the highest pooled prevalence (22%; 95% CI: 13–33%), and western Africa had the lowest (5%; 95% CI: 0–2%) despite recording the highest nematode species diversity. Tetrameridae had the highest family-level pooled prevalence of 46% (95% CI: 28–64%), and Spiruridae had the lowest 1% (95% CI: 0–3%). Most studies were conducted between the period 2014 and 2024; however, the highest pooled prevalence was observed between 1993 and 2002 (17%; 95% CI: 11–24%). The necropsy technique recorded the highest pooled prevalence (17%; 95% CI: 14–20%) compared to coproscopy (10%; 95% CI: 7–14%). The quality effects model revealed a high heterogeneity and publication bias among studies due to the diagnostic method used (P <0.05). This systematic review provided insightful information on the occurrence and potential burden of gastrointestinal nematode species of free-ranging chickens in Africa, highlighting the need for enhanced biosecurity and further research to safeguard their health, production, and food security of rural economies. 2026-03-01T00:00:00Z https://ir.cut.ac.zw:8080/xmlui/handle/123456789/727 Phytoindication and Phytoremediation ofWater Quality Using the Local Duckweed Plant Lemna aequinoctialis Munaro, Allen Takudzwa; Tsamba, Joshua; Siziba, Nqobizitha Environmental pollution exacerbates global freshwater scarcity. In Harare, sewage pollution drives freshwater pollution, compromising its quality and security. Here, we uniquely explored the dual role of Lemna aequinoctialis as a phytoindicator and phytoremediator of freshwater quality. Using a purposive sampling strategy targeting common household freshwater abstraction sites in selected communities of Harare (Tafara and Manyame), 12 water samples and an L. aequinoctialis culture were collected from the field and incubated in the laboratory. Biochemical oxygen demand (BOD), electrical conductivity (EC), and potential hydrogen (pH)were determined by probes, while total suspended solids (TSS) and turbiditywere analyzed by UV-Vis Spectrometry. Chemical oxygen demand (COD), nitrates (NOˉ3), nitrites (NOˉ2), and orthophosphateswere analyzed by colorimetric techniques. An analytical balance measured the plant fresh weights and root lengths were measured via microscopy. Akin to +raw sewage, River B (Tafara) exhibited the highest initial pollutant load; BOD (3.8 mg/L), COD (38 mg/L), TSS (96 mg/L), NOˉ3 (0.134 mg/L), NOˉ2 (0.058 mg/L), orthophosphates (0.524 mg/L), turbidity (87 FTU), with notably reduced mean fresh biomass (2.9 g) and root length (7.3 mm) which were moderately and negatively correlated with NOˉ2 and orthophosphates, respectively. Only EC failed to improve after L. aequinoctialis incubation significantly. Despite spatial-temporal limitations, we present limited evidence suggesting a potential real-time, dual utility role that can help track, redress pollution, and suppress algal blooms enhancing public health and transcending the typical role of duckweeds. Long-term applicability of this phytotechnology requires further attention for sustainable freshwater management in resource-limited regions like Zimbabwe. 2025-01-26T00:00:00Z https://ir.cut.ac.zw:8080/xmlui/handle/123456789/710 Natural products in antimalarial drug discovery: progress, emerging technologies, and future directions Chikwaro, Ethel; Nyoni, Stephen; Ndlovu, Joice; Shoko, Ryman Malaria remains a major global health problem, caused mainly by Plasmodium falciparum and P. vivax, and is increasingly complicated by the spread of drug resistance and the limited impact of current vaccines. Natural products have played a central role in antimalarial therapy, most notably through the discovery of quinine and artemisinin, and they continue to provide an important source of bioactive chemical scaffolds. This review outlines recent progress in antimalarial drug discovery from natural products, with particular attention to advances in phytochemical isolation, structure-based drug design, and the growing use of computational methods, including molecular modelling, machine learning, and omics-based approaches. The contribution of traditional knowledge to the identification of new chemotypes and potential targets is also discussed. Key challenges, including poor bioavailability, toxicity, regulatory barriers, and pressures on biodiversity, are considered in the context of sustainability, ethical bioprospecting, and international frameworks such as the Nagoya Protocol. Finally, the review discusses practical directions for improving clinical translation, strengthening sustainable supply, and promoting equitable benefit-sharing in the continued search for new antimalarial therapies. 2026-02-14T00:00:00Z