Antibacterial and antioxidant activities of stachytarpheta indica (L.) vahl extracts

Abstract

This project was aim on evaluation of the antibacterial and antioxidation activities of plant extracts by concerning the antibiotic resistance problem. Stachytarpheta indica(L.) Vahl is a traditional medical plant used in Malaysia as anti-inflammatory and painrelief agents. In this project, the root, stem and leave extracts from S. indica (L.) Vahl were obtained through aqueous extraction (maceration, decoction, autoclave) and organic solvent extraction (soxhlet multiply extraction using pet-ether, chloroform, and ethanol successively and exhaustively).The yield of S. indica (L.) Vahl extracts from different extraction methods was calculated and interpreted. Bacterial susceptibility test was performed using disk diffusion method on two gram-positive bacteria, Streptococcus aureus, Bacillus subtilis and one gram-negative bacteria, Salmonella typhi, but results shown that S. indica (L.) Vahl extracts do no exhibit antibacterial activity. The total phenolic content and antioxidant activity of extracts were evaluated through Folin-Ciocalteu assay and 2, 2-diphenyl-2-picryl-hydrazyl (DPPH) assay. From the results, the S. indica (L.) Vahl extracts were shown to contain satisfied phenolic content ranged from 29.195 ± 0.520 to 74.475 ± 0.900 mg GAE/g and possessed antioxidant activity ranged from 5.524% ± 1.725 to 42.639% ± 1.370 which may, in part, be associated with phenolic compounds. Phytochemical analysis of the S. indica (L.) Vahl extracts was done using preliminary phytochemical tests, the results revealed the presence of tannin, flavonoid and phenol which may have contribute to antioxidant activity.