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INTRODUCTION

Since ancient times, plants have been used to cure many diseases for its therapeutic properties

present. Today, people all over the world consume tea as a recreational drink for its
stimulating effect on brain. Camellia sinensis which is commonly called as tea was

originated in north east states of India, south west of China and Tibet. The different
types of tea consumed are Green tea, Black tea, White tea, Yellow tea, Oolong tea,

Fermented tea. Tea has numerous health benefits like protection of lungs, esophagus,

pancreas, liver, boosting immune system, lowering cholesterol levels, gives mental
alertness, skin cancer etc. (A. Farjana et al., 2014). Many previous research have been done

to study the phytochemical aspects of tea plants and showed the presence of numerous
phytochemicals like alkaloids, flavonoids, tannins, caffeine, anthocyanins etc which attribute

for various other properties like antibacterial property, antifungal property and antioxidant
property.

Antibacterial activity is the process of inhibiting or killing various disease-causing bacteria.

Use of conventional antibiotics to control disease may have numerous side effects and
bacteria can become resistant to that particular antibiotic after few days (M.S Shihabudeen et

al., 2010). Hence, plant-based antibiotics might overcome those problems.

The objectives of the present study were to study the antibacterial activity of commercially

available black and green tea using ethanol as solvent against 4 different bacteria, namely
Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa,

qualitatively analyze the phytochemicals in green tea and black tea and also to evaluate the
quantity of tannins and flavonoids present in both the types of teas. From the results of our

study, it was observed that Camellia sinensis can act as natural antimicrobial agent with
additional benefits exhibited by their phytochemicals especially tannins and flavonoids. It

also has the potential to act synergistically with antibiotics to enhance its activity.

MATERIALS AND METHODS

Samples used

Tetley green tea and black tea which is available commercially was purchased.
Clinical isolates of bacteria like Escherichia coli, Staphylococcus aureus, Klebsiella

pneumoniae, Pseudomonas aeruginosa were bought from Bhagwan Mahaveer Jain Hospital.
Nutrient agar (NA), which is a general-purpose medium, was used for the growth of bacteria.

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