In vivo anti-malarial activity of the hydroalcoholic extract of rhizomes of Kniphofia foliosa and its constituents
Yonatan Alebachew, Daniel Bisrat, Solomon Tadesse, Kaleab Asres
Abstract
Abstract Background Kniphofia foliosa is a flamboyant robust perennial herb which has dense clumps and tick upright rhizomes with leaves at the base. In Ethiopia, it has several vernacular names including Abelbila , Ashenda , Amelmela , Yeznjero Ageda , Shemetmetie and Yezinjero Ageda . The plant is endemic to Ethiopian highlands, where its rhizomes are traditionally used for the treatment of malaria, abdominal cramps and wound healing. In the present study, the 80% methanol extract of K. foliosa rhizomes and its constituents are tested against Plasmodium berghei in mice . Methods Isolation was carried out using column and preparative thin layer chromatography (PTLC). The chemical structures of the compounds were elucidated by spectroscopic methods (ESI–MS, 1D and 2D-NMR). Peters’ 4-day suppressive test against P. berghei in mice was utilized for in vivo anti-malarial evaluation of the test substances. Results Two compounds, namely knipholone and dianellin were isolated from the 80% methanolic extract of K. foliosa rhizomes, and characterized. The hydroalcoholic extract (400 mg/kg) and knipholone (200 mg/kg) showed the highest activity with chemosuppression values of 61.52 and 60.16%, respectively. From the dose–response plot, the median effective (ED 50 ) doses of knipholone and dianellin were determined to be 81.25 and 92.31 mg/kg, respectively. Molecular docking study revealed that knipholone had a strong binding affinity to Plasmodium falciparum l-lactate dehydrogenase (pfLDH) target. Conclusion Results of the current study support the traditional use of the plant for the treatment of malaria.