Vol. 7, Issue 3 (2018)

Author(s):
Richa Thakur and Rajni Devi

Abstract:
Extracts of leaves from the tea plant Camellia sinensis contain polyphenolic components with activity against a wide spectrum of microbes. Studies conducted over the last 20 years have shown that the green tea polyphenolic catechins, in particular (−)-epigallocatechin gallate (EGCg) and (−)-epicatechin gallate (ECg), can inhibit the growth of a wide range of Gram-positive and Gram-negative bacterial species with moderate potency. Evidence is emerging that these molecules may be useful in the control of common oral infections, such as dental caries and periodontal disease. Though catechins have been found in other plants derivatives such as grapes, pomegranates, those found in tea have proven to be the most effective antioxidants known. The catechins epigallocatechin gallate (EGCG) is found in the greatest concentration and most studied for its health benefits. In the present study, the aqueous extracts of green tea shoots and tea powder solutions which had higher concentrations of EGCG and ECG were potent growth inhibitors of selected bacterial pathogens: L. monocytogenes (MTCC-839), P. auroginosa (MTCC-741), B. cereus (MTCC-1272), S. aureus (MTCC-96) and E. coli (MTCC-443). Teas of summer and rainy flush seasons exhibited superior biological activity compared to first and winter flush.