Browsing by Author "Ncube, S.F."

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    Ethnobotanical knowledge and use-value of Harpagophytum (Devil’s claw) in Matabeleland, Zimbabwe
    (Elsevier, 2021-09-17) Ncube, S.F.; Ndagurwa, H.G.; Mundy, P.J.; Sibanda, S.; Dlodlo, M.
    Quantitative ethnobotanical knowledge is important in guiding sustainable resource use, yet for many medicinal plants such as Harpagophytum (Devil's claw), this information is scanty. Thus, we documented the ethnobotanical knowledge of Devil's claw in Hwange, Gwanda, Matobo, and Tsholotsho, western Zimbabwe, in relation to a person's age, gender, level of education, and locality. Using a semi-structured questionnaire, we interviewed 205 respondents on their knowledge of the physical features, distribution, uses and use-values, part used, and the method of preparation of Devil's claw. Physical identification was assessed based on the frequency of knowledge of plant parts. Binomial General Linear Models were used to test the effect of age, education, gender, and locality on the respondent's knowledge. Relationships of age, gender, level of education, and locality to ethnoecological perceptions were assessed using Pearson's Chi-square test. Use values were assessed based on Plant Part Value (PPV), Use Value category (UVk), and Overall Use Value (OUV). Ethnobotanical knowledge varied with locality and age, with better physical description in most adults and senior respondents in Hwange and Tsholotsho. Respondent's perceptions showed that Devil's claw was more abundant in Hwange and Tsholotsho relative to Matobo and Gwanda. Tubers (53%) were most valued in all localities followed by leaves (29%), and fruits (18%). Of the five identified categories of use, medicinal (UVk of 0.38) was the most important while ethnoveterinary, rituals, personal care, and food were least important (all UVks ≤0.02). OUVs were dependent on locality, significantly higher in Hwange and Tsholotsho (0.64 and 0.58, respectively) as compared to Gwanda (0.1) and Matobo (0.28). This study provides a wealth of knowledge that contributes to the preservation of indigenous knowledge of Devil's claw, sustainable management of the plant as well as further contribute to pharmacological interventions.
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    In vitro antioxidant activity of crude extracts of Harpagophytum zeyheri and their anti-inflammatory and cytotoxicity activity compared with diclofenac
    (BMC Complementary Medicine and Therapies, 2021-09-23) Ncube, S.F.; McGaw, L.J.; Njoya, E.M.; Ndagurwa, H.G.; Mundy, P.J.; Sibanda, S.
    Background This study evaluated the in vitro antioxidant activity and comparison of anti-inflammatory and cytotoxic activity of Harpagopytum zeyheri with diclofenac. Methods In vitro assays were conducted using water, ethanol, and ethyl acetate extracts of H.zeyheri. The antioxidant activity was evaluated using the 2,2′-diphenyl-1-picrylhydrazy (DPPH) and 2,2′- azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays. The anti-inflammatory activity was determined by measuring the inhibition of nitric oxide (NO) on lipopolysaccharide (LPS)-induced RAW 264.7 mouse macrophages as well as cytokine (TNF-α and IL-10) expression on LPS-induced U937 human macrophages. For cytotoxicity, cell viability was determined using the 3-(4, 5-dimethylthiazol- 2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Results The ethyl acetate extract had the lowest IC50 values in the DPPH (5.91 μg/ml) and ABTS (20.5 μg/ml) assay compared to other extracts. Furthermore, the ethyl acetate extracts effectively inhibited NO and TNF-α and proved to be comparable to diclofenac at some concentrations. All extracts of H. zeyheri displayed dose-dependent activity and were associated with low levels of human-IL-10 expression compared to quercetin. Furthermore, all extracts displayed low toxicity relative to diclofenac. Conclusions These findings show that H. zeyheri has significant antioxidant activity. Additionally, similarities exist in the inflammatory activity of H. zeyheri to diclofenac at some concentrations as well as low toxicity in comparison to diclofenac.