In vitro antiplasmodial activity of marine sponge Clathria indica associated bacteria against Palsmodium falciparum

ABSTRACT

Objective: To identify the possible antiplasmodial drugs from bacteria associated with marine sponge Clathria indica. Methods: Clathria indica samples were collected from Thondi coast and subjected for enumeration and isolation of associated bacteria. Filter sterilized extracts (100, 50, 25, 12.5, 6.25 and 3.125 μg.mL-1) from isolated bacterial isolates were screened for antiplasmodial activity against Palsmodium falciparum and potential extracts were also screened for biochemical constituents. Results: The count of bacterial strains were maximum in November 2007 (19×104 CFU.g-1) and the average count was maximum during the monsoon season (107×10 3 CFU.g-1). Thirty one morphologically different bacterial isolates were isolated from Clathria indica and the ethyl acetate bacterial extracts were screened for antiplasmodial activity against Palsmodiumfalciparum. The antiplasmodial activity of a isolate THB23 (IC 50 28.80 μg.mL-1) extract is highly comparable with the positive control chloroquine (IC50 19.59 μg.mL-1) and 17 bacterial extracts which showed IC50 value of more than 100 μg.mL-1. Statistical analysis reveals that, significant in vitro antiplasmodial activity (P<0.05) was observed between the concentrations and time of exposure. The chemical injury to erythrocytes showed no morphological changes in erythrocytes by the ethyl acetate extract of bacterial strains after 48 h of incubation. The in vitro antiplasmodial activity might be due to the presence of carbohydrates and alkaloids in the ethyl acetate extracts of bacterial isolates. Conclusions: The ethyl acetate extracts of THB23 possesses novel compounds for the development of antiplasmodial drugs.