Neha Sylvia Walter and Upma Bagai
Background: Investigation of traditionally used medicinal plants can provide safe and cost effective good antimalarials. The present study explores the in vitro antimalarial potential of Thalictrum foliolosum (meadow rue) leaf extract against Plasmodium falciparum. Methods: Phytochemical screening of the extract was carried out following standardized methods. WHO method based on schizont maturation inhibition was employed to assess the in vitro antiplasmodial activity of plant extract. Colorimetric MTT assay was used to evaluate the in vitro cytotoxicity of Thalictrum foliolosum. Selectivity Index was also calculated. Results: Phytochemical screening of the extract revealed presence of alkaloids, phenols, triterpenes, saponins and phytosterols. Ethanolic leaf extract of Thalictrum foliolosum (ELETF) exhibited IC50<5 μg/ml against chloroquine (CQ) resistant (RKL-9) strains of Plasmodium falciparum, whereas, it was=5.89 μg/ml against chloroquine sensitive (MRC-2) strain. The extract revealed no signs of toxicity with CC50>1000μg/ml against both HeLa cells and normal fibroblasts. Selectivity index of ELETF was calculated to be >200 and =169.7 respectively for chloroquine resistant (RKL-9) and sensitive (MRC-2) strains of the parasite. Conclusions: Based on WHO recommendations ELETF can be classified as highly active antimalarial against CQ-resistant strain and possesses promising activity against CQ-sensitive strain. The high selectivity index (SI>10) also establishes Thalictrum foliolosum as an active antimalarial against both the strains of Plasmodium falciparum.