INHIBITORY ACTIVITY OF FRESH GREEN TEA AND BLACK TEA EXTRACTS (CAMELLIA SINENSIS) ON INTESTINAL PATHOGENS ISOLATED FROM DIARRHEAL SAMPLE

Abstract

Medicinal plants have been the major resources for therapeutic agents for remedy of many diseases. In the present investigation, antimicrobial activity of aqueous and methanol extracts of green and black tea (Camellia sinensis) against intestinal pathogens was studied by well diffusion method and minimum inhibitory concentration. About twenty six intestinal strains which include E.coli, Salmonella spp., Shigella spp. and Vibrio spp. were isolated from diarrheal samples. Results showed that methanol extracts of both green tea and black tea revealed higher inhibitory activity on intestinal bacteria than aqueous extracts. At the concentration of 12.0 mg/ml 8/12 (66%) of Salmonella spp., 06/08 (75%) of Shigella spp. and 02/04 (50%) of Vibrio spp. were sensitive to green tea aqueous extracts. All the isolates (100%) were sensitive to the green tea methanol extracts concentration of 3.0, 6.0, 12, 24 and 48 mg/ml and exhibited zone size ranging from 1.0-37 mm. The MIC of green tea for E.coli was found to be 3.0mg/ml, for Salmonella spp. was 6.0 mg/ml for aqueous and 12.0 mg/ml for methanol extract. For Shigella spp and Vibrio spp. it was 12.0 and 6.0mg/ml respectively. Our findings revealed that methanol extracts of green tea exhibited strong antibacterial activity on intestinal pathogens. Thus the extracts of tea leaves can be used as an alternative drug against intestinal pathogens without having any side effects. Green tea and black tea extracts are safe and can be a supplement for other systems of medicines for the treatment of intestinal diseases caused by bacteria.