Brief Article
Copyright ©2009 The WJG Press and Baishideng. All rights reserved.
World J Gastroenterol. Nov 7, 2009; 15(41): 5200-5205
Published online Nov 7, 2009. doi: 10.3748/wjg.15.5200
Antifibrotic effects of green tea on in vitro and in vivo models of liver fibrosis
Hye Kyung Kim, Taik-Hoon Yang, Hong-Yon Cho
Hye Kyung Kim, Department of Food and Biotechnology, Hanseo University, Seosan, Chungnam 356-706, South Korea
Taik-Hoon Yang, Hong-Yon Cho, Department of Food and Biotechnology, College of Science and Technology, Korea University, Jochiwon, Chungnam 339-700, South Korea
Author contributions: Kim HK and Cho HY designed the study, data analysis, interpretation and drafting of the manuscript; Yang TH performed measurements and data analysis.
Supported by A Korea University Grant
Correspondence to: Hong-Yon Cho, Professor, Department of Food and Biotechnology, College of Science and Technology, Korea University, Jochiwon, Chungnam 339-700, South Korea. hycho@korea.ac.kr
Telephone: +82-41-8601433 Fax: +82-41-8650220
Received: July 9, 2009
Revised: August 4, 2009
Accepted: August 11, 2009
Published online: November 7, 2009
Abstract

AIM: To examine the protective effect of green tea extract (GT) on hepatic fibrosis in vitro and in vivo in dimethylnitrosamine (DMN)-induced rats.

METHODS: HSC-T6, a rat hepatic stellate cell line, was used as an in vitro assay system. Cell proliferation, collagen content, and type 1 collagen expression were examined in activated HSC-T6 cells. Collagen was determined by estimating the hydroxyproline content. In rats with DMN-induced hepatic fibrosis, serum aspartate aminotransferase and alanine aminotransferase concentrations, liver hydroxyproline and lipid peroxides were determined. Pathologic changes were examined by hematoxylin & eosin staining.

RESULTS: GT administration prevented the development of hepatic fibrosis in the rat model of DMN-induced liver fibrosis. These results were confirmed both by liver histology and by quantitative measurement of hepatic hydroxyproline content, a marker of liver collagen deposition. Accordingly, inhibition of proliferation, reduced collagen deposition, and type 1 collagen expression were observed in activated HSC-T6 cells following GT treatment. These results imply that GT reduced the proliferation of activated HSC and down regulated the collagen content and expression of collagen type 1, thereby ameliorating hepatic fibrosis.

CONCLUSION: This study demonstrates that green tea administration can effectively improve liver fibrosis caused by DMN, and may be used as a therapeutic option and preventive measure against hepatic fibrosis.

Keywords: Dimethylnitrosamine; Green tea extract; HSC-T6 cell; Liver fibrosis; Rat model; Type 1 collagen