In vitro Antibacterial Activity of Averrhoa carambola Leaf Extracts

Abstract

The aim of the present study was to determine the phytochemical constituents and antimicrobial potential of Averrhoa carambola leaf extracts against three gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus and Streptococcus mutans) and three gram-negative bacteria (Klebsiella pneumoniae, Proteus vulgaris and Pseudomonas aeruginosa) which are some of the infectious bacteria. The A.carambola leaves were extracted in three different solvents of increasing polarities (hexane, ethyl acetate, and acetone). The phytochemical analysis showed the presence of flavonoids, tannins, alkaloids, glycosides, phenols, terpenoids, saponins, emodols and coumarins. The efficacy of these extracts was tested against these bacteria through a well-diffusion method employing 50 μl leaf-extract solution per well. According to the findings of the antibacterial assay, the acetone extracts of carambola leaves showed inhibitory activity against both gram-positive bacteria and gram-negative bacteria. No activity was observed in the hexane extract towards most of the tested microorganisms. Maximum antibacterial activity was observed in the acetone extract towards P. aeruginosa, S. mutans and S. aureus, whereas least activity was observed in the hexane extract. Ethyl acetate extract showed mild activity towards most of the tested microorganisms. On the basis of the present findings, acetone leaf extract of A. carambola might be a good candidate in the search for a natural antimicrobial agent. This study provides scientific understanding to further determine the antimicrobial values and investigate other pharmacological properties. Keywords: Phytochemical, antimicrobial, ethanolic extract, well-diffusion, Averrhoa carambola Cite this Article SonaRajashree B, Sangeetha VS. In vitro antibacterial activity of Averrhoa carambola leaf extracts. Research & Reviews: A Journal of Biotechnology. 2018; 8(2): 27–32p