In vivo, Antibacterial Effect of Green and Black Tea Extracts on Infected Liver and Kidney of Rats


The aim of this study is to investigate the antibacterial effect of hot and cold aqueous extracts of green and black tea separately against Klebsiella pneumoniae after infecting the burned rat's skin with it, also to screen the effect of both types of tea on rat's liver and kidney. Sixteen male rats divided into four Groups (4 animals each), Group 1: untreated rat (control). Group 2: burn rats infected with K. pneumoniae (1.5×108 bacteria /ml). Group 3: burn treated by Green tea aqueous extract (1000 µg/ml) for K. pneumoniae bacteria. Group 4: burn treated by black tea extract (2000 µg/ml) for K. pneumoniae bacteria. The tea extracts antimicrobial activity was analyzed by agar diffusion inhibition assay and minimum inhibitory concentration. Results exhibited that K. pneumoniae in particular, have high levels of antimicrobial resistance to widely used agents. In conclusion hot extract from both types of tea have better antibacterial effect than cold extract. Additionally, infected rats showed inflammation and sever hemorrhage in the liver and kidney of rats, but when treated with tea extracts dermally approximately restored kidney normal histological architecture of glomeruli and tubules, also liver became nearly normal in histological structure of hepatic foci and central vein. Black tea extract showed greater effectiveness in tissue recovery than green once.