Zambare Vasudeo* and Bhoyte Sonika

P. G. Department of Biochemistry, New Arts, Commerce and Science College, Ahmednagar - 414 001 India.

Corresponding Author E-mail:vasuzambare@gmail.com

Abstract

Antibacterial activities of tea extracts in various solvents were tested against six organisms, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Serracia sp., and Bacillus subtilis using agar-well method. Petroleum ether and chloroform extracts of tea showed strong antibacterial activities against P. aeruginosa and B. subtilis while other extracts were less active. The minimum inhibitory concentration (MIC) of chloroform extract of tea was found to be 25µg/mL. This study may establish the need for daily use of this product for medicinal purposes.

Keywords

Tea; Camellia sinensis; antibacterial activity; extracts

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Copy the following to cite this article: Vasudeo Z, Sonika B. Antimicrobial Activity of Tea (Camellia sinensis). Biomed. Pharmacol. J.2009;2(1)

Copy the following to cite this URL: Vasudeo Z, Sonika B. Antimicrobial Activity of Tea (Camellia sinensis). Biomed. Pharmacol. J.2009;2(1). Available from: http://biomedpharmajournal.org/?p=688

Introduction

Tea is a beverage and is of infusion of variously processed leaves of one of the varieties of an evergreen shrub, Camellia sinensis L. It is the most widely drunk beverage in the world¹. It is refreshing, mildly stimulating, and produces a feeling of well-being. These properties may be due to caffeine and tannins. These compounds are known to have stimulant and anti-soporific actions that elevate mood, decrease fatigue and increase capacity for work². However, other components of tea, notably, the polyphenols, may also contribute to the effects of tea, in view of their known pharmacological properties³. The complex of oxidized polyphenols in tea is often called ‘tannin’⁴. From literature, it was observed that tea has wide range of antioxidant, anti-inflammatory, anti-carcinogenic and antibacterial activity against many pathogens^{3, 6-8}. Several reports of the antibacterial effects of tea in vitro and in vivo, mainly against intestinal pathogens were published by many researchers^9-11.

The aim of this paper describes the extraction of bioactive compounds from tea powder and antimicrobial testing against various microorganisms in vitro.

Experimental

Material and chemicals

Tea powder was purchased from local market with brand name of Red label^®. The chemicals used for extractions were procured from Qualigens Fine Chemicals (Mumbai).

Bacterial strains and culture media

Bacterial cultures used for this study are E. coli, P. aeruginosa, S. aureus, Sarracia sp. and B. subtilis. These cultures were maintained on nutrient agar slants at 4⁰C and preserved as glycerol stocks at -20⁰C. The cultivation and maintenance media were procured from Himedia Laboratories (Mumbai).

Extractions

Tea powder (10 gm) was extracted in 100mL solvents like chloroform, petroleum ether, diethyl ether and methanol. The extracts were filtered through ordinary filter paper and the filtrates were dried at room temperature. The dried extracts then weighed and calculated the total yields. These extracts were dissolved separatly in dimethy sulfoxide (DMSO) solvent and used for further studies.

Antimicrobial activity

A loopful of bacterial cultures were inoculated in nutrient broth separatly and incubated at 30⁰C for 24 hr. After full growth, 0.1 mL of cell broth was spread on nutrient agar plates. The antimicrobial activity of the extracts was done by agar well method¹². Dried extracts (20 mg/mL) were dissolved in DMSO solvent. In agar well added 0.1 mL of extract and the plates were incubated at 30⁰C for 24- 48 hr. After 48 hr, the zone of clearance around the well was observed and measured in mm.

Antibiotic effect of extract concentration on Bacillus subtilis

Chloroform extract was used to study its effective dose concentration (20-100µg/mL) against B. subtilis microorganism by agar well method. The plates were incubated at 30⁰C for 48 h and measured the zone of clearance around the well.

Minimum Inhibitory Concentration (MIC)

Minimum inhibitory concentration of the chloroform extract was measured by addition of increased concentration of extract followed by a loopful culture of B. subtilis inoculation in nutrient broth¹². These tubes were incubated at 30⁰C for 24 hrs and observed for turbidity. Tube concentrations having no turbidity were considered as MIC value of the extract for that organism.

Data Analysis

All data used for this experimentation is obtained from duplicate experiments. Standard deviation was calculated by Microsoft excel.

Results and Discussion

Tea is a plant material with numerous biological activities. Highest % yield obtained with chloroform followed by petroleum ether, methanol and diethyl ether (Table 1).

Table 1: % Yield of extracts in various solvents.

Solvents used	Yields (%dry weight)
Chloroform	3.28
Diethyl ether	1.05
Petroleum ether	2.08
Methanol	1.68

 

 

Table 2: Antimicrobial activity of different solvent extracts of tea.

Bacterial cultures	Zone of inhibition (mm) of extracts of different solvent
	Chloroform	Diethyl ether	Petroleum ether	Methanol
E. coli	14±1	10±2	14±2	12±2
P. aeruginosa	10±1	06±1	25±1	12±1
S. aureus	12±2	10±3	14±2	12±2
Serracia sp.	10±1	12±1	10±1	14±1
Bacillus subtilis	18±2	12±2	14±3	10±1

 

Inhibitory effect of chloroform extract on B. subtilis was increased linearly from 20-100 µg/mL with zone of inhibition 12±1to 22±2 mm diameter. The results are summarized in Table 3.

Table 3: Effect of chloroform extract concentration of tea on Bacillus subtilis.

Concentration (µg/ml)	Zone of inhibition (mm)
20	12±1
40	15±2
60	19±1
80	21±1
100	22±2

 

MIC value of chloroform extract with B. subtilis was found to be 25μg/mL. However, Tiwari et al.¹⁵ observed the MIC value of tea extract in range of 9.09- 94.61mg/mL for Shigella dysenteriae, Yersinia, E. coli, S. typhi, S. typhi Ty2a, S. typhimurium.

This study evident, tea extracts has promising antibacterial activity. The potential utilization of this property is especially in relieving relief from intestinal microorganisms which caused diarrhea and dysentery.

References

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