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Keeping in view the difference in processing techniques of different teas, the present study was
planned to evaluate phytoconstituents present and antibacterial activity of various tea (Camellia
sinensis) extracts against Staphylococcus, Streptococcus, Bacillus and multi-drug resistant E. coli.
Phytochemical screening to identify major biologically active phytoconstituents in extracts of green
tea, black tea and divya peya herbal tea showed the presence of alkaloids, flavonoids, tannins,
saponins, reducing sugars and cardiac glycosides in all the tea extracts but steroids were present in
black tea only. Ethanolic and methanolic extracts of different tea samples showed significant
antibacterial activity against Staphylococcus, Streptococcus, Bacillus and E. coli isolated from soil
samples of various locations. Results of zone of inhibition (ZOI) revealed that methanolic extract of
green tea, black tea and divya peya herbal tea had highest antibacterial activity (ZOI 19.2, 13.6,
15.8 respectively; AI-1.067±0.006, 0.756±0.005, 0.878±0.010 respectively) against Bacillus and E.
coli showed resistance to aqueous extracts of all tea samples. Results of antibacterial activity and
phytochemical screening showed that different processing techniques had no effect on the bioactive
components present in tea samples but extraction solvent played important role in extraction of these
components as evident from results of antibacterial activity. Overall study indicates that various
types of tea can be used as an alternative medicine against the bacterial infections and cariogenic
oral flora, opening a promising avenue of clinical applications in the preparation of specific and
natural antibacterial and anticariogenic remedies.
Keywords: Alkaloids, Black tea, E. coli., Herbal tea, Morphological