Browsing by Author "Mundy, P.J."

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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.
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    Short duration overnight cattle kraaling in natural rangelands: Implications for grass composition, quality, above ground biomass, species diversity and basal cover
    (Elsevier, 2021-02-01) Huruba, R.; Mlambo, T.; Mundy, P.J.; Sebata, A.; MacFadyen, D.N.
    Short duration overnight cattle kraaling in natural rangelands is an innovative management practice aimed at improving grazing availability. We tested the ability of this practice to alter grass composition in favour of palatable species, increase aboveground grass biomass, species diversity and basal cover using a chronosequence consisting of sites kraaled 6, 12, 24 and 36 months prior to the study and compared them to the surrounding vegetation. We also determined grass quality in terms of fibre content, digestibility and nutrient content [nitrogen (N), phosphorus (P), calcium (Ca), potassium (K) and magnesium (Mg)] 12, 16 and 20 months after kraal use and in surrounding vegetation. Previously kraaled sites had higher proportions of palatable grass species, diversity, N, P, K and Mg than surrounding vegetation. Aboveground grass biomass and basal cover were lower in previously kraaled sites than surrounding vegetation, while grass fibre, digestibility and Ca content did not change with kraaling. These results demonstrate that establishing short duration overnight cattle kraals in natural rangelands improve grazing quality in terms of abundance of palatable grass species and grass nutrient content. However, improved grass quality attracted grazers such as warthogs (Phacochoerus aethiopicus), which reduced grass biomass and basal cover.