Department of Biotechnology

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Aphrodisiac properties of some Zimbabwean medicinal plants formulations
(African Journal of Biotechnology, 2009-11-16) Gundidza, G,M; Mmbengwa, V.M; Magwa, M.L; Ramalivhana, N.J; Mukwevho, N.T; Ndaradzi, A; Samie, A
The aim of the present study was to determine the effects of formulations composed of Mondia whitei, Ekebergia capansis, aloe tincture (Aloe exelsa) and pumpkin seed (Cucurbita pepo) on sexual behaviour of inexperienced male rats. Male rats were treated orally with ethanol extracts of M. whitei and E. capensis, aloe tincture (from aloe juice) and pumpkin seed powder. The sexual behaviour of the rats treated with extracts was compared with those treated with 100 µg of testosterone as the positive control and those receiving normal rat feed as negative control. The receptivity of the females was rendered homogeneous with daily dose of estadiol benzoate. The sexual behaviour of the rats were observed over one ejaculatory phase for five consecutive days. The results showed a dose dependent increase in sexual arousability (decreased mounting latency), copulatory efficiency (decreased intercoupulatory interval) and improved sexual sensation (increased in neuromotor activity) for the rats treated with M. whitei and E. capensis, aloe and pumpkin seeds showing an increase in sexual performance in terms of intromissions and ejaculatory latency which also improved sexual sensation and coupulatory efficiency. The formulations of plants under investigation showed significant aphrodisiac properties.
The chemical composition and biological activities of essential oil from the fresh leaves of Schinus terebinthifolius from Zimbabwe
(Academic Journals, 2009-12-15) Gweru, N; Gundidza, M; Magwa, M.L; Mmbengwa, M.V; Samie, A
In the present study, the essential oil from the fresh leaves of Schinus terebinthifolius was extracted using the hydrodistillation method. The oil yield obtained was 0.65%. Gas chromatography and mass spectroscopy (GC-MS) analysis of the essential oil showed that the major constituents of the essential oil were sabinene, -pinene, -phellandrene, -pinene, terpinene-4-ol, trans--ocimene and myrcene. Using the hole-plate diffusion testing method, the essential oil exhibited potent antibacterial activity against Yersinia enterocolitica, Pseudomonas aeruginosa, Escherichia coli, Acinetobacter calcoaceticus, Bacillus subtilis, Klebsielia pneumoniae and Bacillus subtilis with at least 58% inhibition compared to the positive control. The mycelium growth inhibition method was used for anti-fungal testing. The essential oil exhibited activity against Aspergillus flavus with 58% inhibition, Candida albicans with 49.8% inhibition and Aspergillus niger with 48.7% inhibition. The -carotene, acetone and linoleic acid method was used to assess the antioxidant activity of the essential oil. The essential oil showed anti-oxidant activity of 13.1 mm mean zone of colour retention representing 72.7% activity compared to the positive control (ascorbic acid). This is the first study on S. terebinthifolius collected from sub-saharan Africa indicating the presence of trans--ocimene in the essential oil and its strong antibacterial activity against Y. enterocolitica and P. aeruginosa as well as moderate antifungal activities of the plant.
Chemical composition of volatile constituents from the leaves of Aloe ferox
(African Journal of Biotechnology, 2006-09-10) Magwa, M.L; Gundidza, M; Coopoosamy, R.M; Mayekiso, B
Volatile compounds oils play a significant role in perfumery, cosmetic, medicinal and pharmaceutical industries. In our protracted research for new useful essential oils, a volatile oil from Aloe ferox was obtained by prolonged hydrodistillation. This volatile oil was subjected to GC/MS analysis to identify the major constituents of the oil. The major constituents identified were as follows: 3, 6 octatriene (23.86%), 3-cyclohexane-1-hetanol (7.31%), Bornylene (5.24%), 1, 3-cyclopentadiene (4.07) and 5-methyl3-heptanol (3.92%). A significant number of other volatiles were also identified but in minor concentrations.
Correlates of blood pressure in an urban Zimbabwean population and comparison to other populations of African origin
(Journal of Human Hypertension, 2000-02-06) Mufunda, J; Scott, LJ; Chifamba, J; Matenga, J; Sparks, B; Cooper, R; Sparks6, H
We have evaluated the relationship between systolic blood pressure (SBP) and age, body mass index (BMI), waist circumference, sodium to potassium ratio (Na/K), and tobacco use in an urban African population. We conducted a random, population-based, cross-sectional survey of people 25 years and older in Marondera, Zimbabwe, with over-sampling in older age groups (n = 775), using a method comparable to that used in International Collaborative Study on Hypertension in Blacks (ICSHIB). The age-adjusted prevalences of hypertension in Marondera (SBP >140/DBP >90/antihypertensive medication) were 30% for women and 21% for men. The average BMI was 26.3 kg/m2 for women and 21.4 kg/m2 for men. The prevalence of hypertension had a steep association with age and in women ranged from 15% (25–34 years) to 63% (55 years and over) and in men from 9% to 47%. No tobacco use in women and greater Keywords: hypertension; obesity; Africa; black; Zimbabwe Introduction Many recent studies have reported high levels of hypertension in urban southern African populations.1–7 The prevalence of hypertension in an urban Zulu population in South Africa was 25% using World Health Organisation (WHO) criteria systolic blood pressure (SBP) >160 and/or diastolic blood pressure (DBP) >95 mm Hg for people between 30 and 65 years of age with slight increases and decreases in the criterion for younger and older people respectively.1 In an urban black population in Johannesburg, South Africa, the mean SBP in men and women aged 40–49 was 140 and 147 mm Hg, respectively, and was still higher in older age groups.2 Among women of child bearing age in a mining town in Zimbabwe, the prevalence of hypertension (SBP >160 or DBP >95 mm Hg or use of hypertensive medications) was 15%3 and the average SBP in urban Zimbabwean women, aged 40 and Correspondence: Dr Jacob Mufunda, Department of Physiology, University of Zimbabwe, P.O. Box MP167 Harare, Zimbabwe Received 30 July 1998; revised 21 April 1999; accepted 21 May 1999 Na/K ratio in spot urines in men were significantly associated with an increased SBP. In both men and women the levels of hypertension and SBP were strongly positively associated with BMI, although the relationship appeared to plateau in women with a BMI greater than >25 kg/m2 . At a given BMI, men and women had similar SBPs and prevalences of hypertension. There is a very high prevalence of hypertension among urban Zimbabweans, particularly among women. Under the assumption the studies are comparable, the prevalence of hypertension in Zimbabwean women (41%) and men (26%) after age adjustment to the ICSHIB populations, appeared higher than almost all of the ICSHIB populations, including those with higher average body mass indexes.
From Roots to Riches:
(Biotechnology Trust of Zimbabwe, 2004-01-01) Dhliwayo-Chuinzi, Patient D.
Image Interpretation and radiographer commenting 1
(HIT, 2025-11-17) HIT
Inhibitory effects of herbal medicines with claimed anticancer indications on cytochrome P450—An evaluation of drug-herb interactions risk
(Elsevier, 2023-08-03) Mudyiwa, Misheck; Sharma, Manju; Ray, Samarendra Kumar; Masimirembwa, Collen; Thelingwani, Roslyn Stella
Herbs have the potential to interact with conventional medicines or each other upon concurrent administration. This can be at the level of absorption, distribution, metabolism and excretion (ADME). With an estimation that 80% of the population in poor regions of the world utilise herbal medicines for primary healthcare, there is a likelihood that some people will take both herbal and conventional medicines. This could present a risk for herb-drug interactions (HDI) at the various levels of the ADME process. Most common HDI have been observed at metabolism level involving inhibition or induction of the major drug metabolising liver enzymes called cytochrome P450s. In this study, we investigated the inhibitory effects of Parinari curatellifolia (MC), Fluggea virosa (ST), Garcinia livingstonei (MT), Pterocarpus angolensis (M), Tapinanthus quequensis (MF) and Cussonia arborea (GM) on recombinant CYP1A2, CYP2D6, CYP2C9 and CYP2C19. Plate based fluorescent assays were used to follow enzyme activity. Inhibition was determined at 5 mg/ml and 100 mg/ ml of herbal extract, with IC50 determined for herbs that showed potent inhibition. A total of 10 out of 13 extracts showed significant inhibitory effects. Pterocarpus angolensis(bark), Fluggea virossa (leaf), Cussonia arborea(bark), Parinari curatellifollia (root) had very potent effects on CYP1A2 as indicated by an IC50 of <9.9 μg/ml. Based on the worst-case-scenario of complete absorption and exposure, these herbs are predicted to result in HDI if co-administered with medicines which depend on the affected CYPs for metabolism and elimination. Significance of the main findings: There is a potential threat of drug toxicities due to drug-herb interactions for patients undergoing chemotherapy or taking other medications where comorbidities exist during chemotherapy. Drugs that are substrates of CYP1A2 should be administered with caution for patients who are taking the herbs which have been studied in this research as risk for drug toxicities may be high. The findings act as a guide to medical doctors and patients in evaluating potential for herb-drug interactions during prescribing medications which are substrates for the studied CYPs.
TOWARDS THE DEVELOPMENT OF MIOMBO FRUIT TREES AS COMMERCIAL TREE CROPS IN SOUTHERN AFRICA
(Taylor & Francis, 2666-01-01) F. K. AKINNIFESI, F. KWESIGA , J. MHANGO , T. CHILANGA , A. MKONDA , C. A.C. KADU , .I. KADZERE, D. MITHOFER , J. D.K. SAKA, G. SILESHI, T. RAMADHANI a P. DHLlWAYO; AKINNIFESI, F.K; KWESIGA, F; MHANGO, J; CHILANGA, T; MKONDA, A; KADU, A.C; KADZERE, I; MITHOFER, D; SAKA, J.D.K; RAMADHANI, T; DHLlWAYO, P.
Many rural households rely on indigenous fruit trees as sources of cash and subsistence in the Southern Africa Development Community (SADC), but until recently there has been little effort to cultivate, improve or add value to these fruits. Since 1989 the International Centre for Research in Agroforestry (lCRAF: now the World Agroforestry Centre) initiated research-and-development work on more than 20 priority indigenous fruit trees in five SADC countries aimed at improving income in rural communities. A participatory approach was used in all stages of their domestication, product development and commercialization. Country-specific priority species were identified in five countries based on discussions with a wide range of users. These species have now become the focus of a regional tree domestication programme. An impact analysis indicates that a robust domestication programme will create incentives for farmer-led investment in the cultivation of indigenous fruit trees, as an alternative to wild fruit collection, especially where there is a decrease in fruit abundance. In Zimbabwe, the returns to family labour of collecting wild fruits are two to three times greater than other farming activities. These returns will be further increased by domestication. Progress in the domestication of four priority fruit tree species Uapaca kirkiana, Strychnos cocculoides, Parinari curatellifolia and Sclerocarya birrea from the miombo woodlands in southern Africa is reviewed. Preliminary results indicate that the long juvenile phase of Uapaca kirkiana can be shortened from 12-16 years to less than four years, using vegetative propagation methods . .r----)n-going multidisciplinary tree crop domestication research includes molecular genetic analyses, ....•••• sue culture, post-harvest storage, production economics, nutritional analyses, market and supply chain surveys, processing and feasibility assessments of pilot enterprises. Holistic plans are needed to promote cultivation and ensure product quality on farms and to maximize competitiveness at the farm gate and throughout the supply chain.