In vitro antiplasmodial effect of ethanolic extracts of traditional medicinal plant Ocimum species against Plasmodium falciparum

<正>Objective:To identify the possible antiplasmodial compounds from leaf,stem,root and flower extracts of Ocimum canum（O.canum）,Ocimum sanctum（O.sanctum） and Ocimum basilicum （O.basilicum）.Methods:The O.canum,O.sanctum and O.basilicum were collected from Ramanalhapuram District,Tamil Nadu and the extraction was carried out in ethanol.The filter sterilized extracts（100,30,23,12.5,6.23 and 3.125μg/mL） of leaf,stem,root and flower extracts of O.canum,O.sanctum and O.basilicum were tested for antiplasmodial activity against Plasmodium falciparum（P.falciparum）.The potential extracts were also tested for their phytochemical constituents.Results:The leaf extract of O.sanctum showed excellent antiplasmodial activity(IC50 3538μg/mL) followed by leaf extract of O.basilicum(IC50 4341μg/mL). The leaf extract of O.canum,root extracts of O.sanctum and O.basilicum,the stem and flower extracts of all the three tested Ocimum species showed IC50 values between 50 and 100μg/mL Statistical analysis reveals that,significant antiplasmodial activity（P<0.01） was observed between the concentrations and time of exposure.The chemical injury to erythrocytes was also carried out and it shows that,there were no morphological changes in erythrocytes by the ethanolic extract of O.canum,O.sanctum and O.basilicum.The in vitro antiplasmodial activity might be due to the presence of alkaloids,glycosides,flavonoids,phenols,saponins,triterpenoids,proteins,resins, steroids and tannins in the ethanolic extracts of tested plants.Conclusions:The ethanolic leaf extracts of O.sanctum possess lead compounds for the development of antiplasmodial drugs.