Preliminary in vitro antiplasmodial activity of Aristolochia griffithii and Thalictrum foliolosum DC extracts against malaria parasite Plasmodium falciparum

BACKGROUND: Resistance development in human malaria parasites against commonly used antimalarial drugs has necessitated the scientific exploration of traditionally used antimalarial plants. Plant derivatives have been used for curing malaria historically. The present study involves in vitro evaluation of two medicinally important plants Aristolochia griffithii and Thalictrum foliolosum DC used in antimalarial chemotherapy by the tribes of northeast India. METHOD: Chloroform, ethyl acetate and n–butanol extracts of Aristolochia griffithii and Thalictrum foliolosum DC were evaluated in vitro against chloroquine sensitive (SS) and chloroquine resistance strains (RS) of P. falciparum. The tests were conducted following WHO standard method and the inhibition of parasite (IC(50)) was calculated. RESULTS: In A. griffithii, the IC(50) value for ethyl acetate extracts against SS was 6.2 ± 0.02 μg/ml and found to be lower than chloroform extracts, which exhibited an IC(50) value of 14.1 ± 0.1 μg/ml (t = 191.1; p < 0.0001). The IC(50) values of both chloroform and ethyl acetate extracts for RS were higher as compared to the SS (p < 0.0001). In T. foliolosum DC the IC(50) concentration of chloroform extracts for SS and RS were 0.5 ± 0.0 and 1.1 ± 0.0 μg/ml respectively (t = 54.2; p < 0.0001). CONCLUSION: The present findings, although preliminary, but scientifically demonstrate that identification and isolation of active compounds of these two plant materials and testing against different Plasmodium species could lead to the development of potential antimalarial drugs for future.