Abstract

Bioactive triterpenoids; 3-acetylaleuritolic acid, stigmasterol, a mixture of triterpenoids, fatty esters and aromatic components were isolated from the aerial parts of Eclipta prostrata by column chromatography. The plant extracts were investigated for their antimicrobial activity (agar dilution method) against twenty-eight strains of gram-positive and gram-negative bacteria, including diploid fungus. In addition, antioxidant and cytotoxic activities were also evaluated.The extracts and isolated fractions exhibited antimicrobial activity against Morexella catarrhalis, Corynebacterium diphtheriae NCTC 10356 and Streptococcus pyogenes with the MIC of 64 g/mL including Saccharomyces cerevisiae ATCC 2601 (MIC 256 g/mL). The ethyl acetate extract and isolated fractions displayed antioxidant effect. In addition, the plant extracts showed cytotoxic activity (ED50 > 100 g/mL) toward HuCCA-1 and KB cells. The results demonstrate beneficial effects of E. prostrata as the antimicrobials and bioactive compounds for medicinal usages.

Key words: Eclipta prostrata, Compositae, Bioactive triterpenoids, Antimicrobials, Antioxidants, Cytotoxic activity