Abstract

Present study describes the antibacterial activity of green tea extracts against dental caries. Green tea samples were collected from local market of Lahore. The antibacterial activity of water and ethanol extract of Camellia sinensis (L.) Kuntze were examined againstLactobacillus acidophilus and Streptococcus mutans. Antibacterial activity was investigated by paper diffusion test and Minimum inhibitory concentration. Water extract of C. sinensisproduce zones of inhibition 6 to 18 mm and 8 to 27 mm respectively against L. acidophilusand S. mutans.  Ethanol extracts of C. sinensis produced larger zones of inhibition 15 to 33 mm and 19 to 35 mm, respectively against L. acidophilus and S. mutans. The minimum inhibitory concentration (MIC) for the green tea water extract against L. acidophilus and S. mutans extract was 0.9 and 0.8 mg/ml, respectively. Minimum inhibitory concentration (MIC) for the green tea ethanol extract against L. acidophilus and S. mutans extract was 0.7 and 0.7 mg/ml, respectively. Results showed that ethanol extracts of green tea exhibitedgreater antibacterial activities against L. acidophilus and S. mutans than water extracts. Active compounds in green tea extract were determined by high pressure liquid chromatography. Metals analyzed by Atomic abortion spectrophotometer were Ag, Pb, Na and Cr. The solubility of studied metals in tea water extracts varied widely, ranging from 0.00 to 1.477 mg/L. The concentration of  metals Ag, Na, Cr and Pb were detected in the following order 1.477>0.100>0.0096>0.00 mg/ml. Fluoride ion in green tea  was 2.8 and 2.1 ppm for water and ethanol extract of C. sinensis, respectively.

Key words: Camellia sinensis, Lactobacillus acidophilus, Streptococcus mutans.