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highest inhibition of about 18mm which is almost same as this study. S. aureus showed

zone of inhibition of about 1.45cm and 1.3cm in green tea and black tea. This bacterium
causes skin infection, food intoxications and is found on the epidermis of skin and upper

respiratory tract. Hence tea leaves can be used for many formulations to treat skin problems,
pimples, rashes etc. Green tea and black tea also showed inhibition against shiga toxin

producing E. coli and many respiratory diseases causing K. pneumoniae. Therefore, green tea
and black tea can be used as antibacterial agent and also be used synergistically to enhance

the antibiotics.

Phytochemicals are the secondary metabolites which are produced when the plants are
in stress and they serve as a defense mechanism against different pathogenic microorganisms,

insects and other herbivores which are attacking on them. They might have numerous health

benefits. Ethanol extract of green tea and black tea revealed the presence of tannins, saponins,
flavonoids, quinone and phenols and terpenoids was only present in black tea. Polyphenols

which are the effective phytochemical found in tea is found to have antibacterial activity (M.
Radji et al., 2013). According to previous study done by A. Sharma et al., (2012),

Epigallocatechin which is proanthocyanidin and an oligomeric flavonoid present in tea
reported to interact with outer membrane of the bacteria and prevented the adhesion

to mammalian cells. It is also reported to have anticarcinogenic property,

cardioprotective activity but higher doses of it might act as mutagens, very good prooxidants
that produce free radicals and also as inhibitors of enzymes involved in different hormone

metabolism. Hence, drinking more of tea might be harmful to health. Tannins which are
found abundantly in tea and it can bind to proteins which are proline rich and interfere with

synthesis of protein. Flavonoids are the phenolic compounds which are normally synthesized
in plants in response to microbial infection. They are also having the capacity to form

complex with extracellular and soluble proteins and also with bacterial cell walls.

Therefore, it could attribute for effective in-vitro antibacterial activity against diverse
microorganisms. Saponins are also having the property of antibacterial activity for its

ability to cause leakage of proteins and certain enzymes from the cell (M.S Shihabudeen et

al., 2010).
CONCLUSIONS

This study confirms that Camellia sinensis can act as natural antimicrobial agent. The

presence of the different phytochemicals, especially tannins and flavonoids, helps in its

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