Antibacterial activities of Camellia sinensis plant extracts against uropathogenic E. coli in vitro and in vivo

This study evaluated the in vitro and in vivo antibacterial activities of methanol and ethyl acetate extracts of Camellia sinensis (Green tea) against Escherichia coli implicated in urinary tract infections. Antibacterial activities of these plant extracts were tested against 10 multi-drug resistant E. coli isolates obtained from clinical specimens of UTI patients. Forty-five (45) Wister albino rats were used for this study and exactly 0.1 ml of standardized (0.5 McFarland’s) E. coli suspension was each inoculated into the 45 rats through intra-urethral route and observed after 48 h. This was followed by oral administration of different concentrations of methanol and ethyl acetate extracts of C. sinensis, and ciprofloxacin antibiotic for 14 days. Phytochemical screening of extracts showed the presence of bioactive components. Results revealed that methanol extract was better than ethyl acetate extract of C. sinensis in the treatment of UTI caused by E. coli. Body weight, white blood cell count, and erythrocyte sedimentation rate level returned to normal values after treatment with methanol extract of C. sinensis at 200 mg/kg body weight when compared to ethyl acetate extract of C. sinensis. This study has shown that C. sinensis possess bioactive ingredients with antimicrobial activities. Information from this study adds to the current information on the potential health benefits of green tea. Thus, further studies on other plant products should be explored so as to understand their potential health benefits and as alternative therapeutics in the treatment of bacterial infections. Key words: Antibacterial activity, E. coli, Camellia sinensis, urinary tract infections (UTIs), plant extract