Antioxidant effect of green tea.
Article Type: Report
Subject: Antioxidants (Health aspects)
Antioxidants (Research)
Green tea (Health aspects)
Green tea (Research)
Green tea (Nutritional aspects)
Catechin (Research)
Catechin (Health aspects)
Author: Finney-Brown, Tessa
Pub Date: 03/22/2010
Publication: Name: Australian Journal of Medical Herbalism Publisher: National Herbalists Association of Australia Audience: Academic Format: Magazine/Journal Subject: Health Copyright: COPYRIGHT 2010 National Herbalists Association of Australia ISSN: 1033-8330
Issue: Date: Spring, 2010 Source Volume: 22 Source Issue: 1
Topic: Event Code: 310 Science & research
Accession Number: 223823993
Full Text: Kobayashi H, Tanaka Y, Asagiri K, Asakawa T, Tanikawa K, Kage M, Yagi M 2010. The antioxidant effect of green tea catechin ameliorates experimental liver injury. Phytomed 17;197-202.

Green tea catechins have been reported in previous studies to have antioxidative and antifibrotic effects on liver tissue. In patients with biliary atresia (BA) who undergo Kasai's hepatic portoentrerostomy, many still experience chronic hepatic inflammation with or without jaundice. Oxidative stress in these patients is considered to then be a causative factor for nonalcoholic steatohepatitis, which may worsen to fibrosis. The authors of the current study propose that the ingestion of antioxidants, such as green tea catechins, is an essential preventative measure in patients who undergo this operation.

Using a green tea catechin mixture, they conducted a murine model study evaluating the presence and degree of oxidative stress in fibrotic liver tissue, and the effects of this catechin mix upon the progression of liver damage. Twenty four male cholestatic Wistar rats were classified into three treatment groups, two of which underwent bile duct ligation (the third was a SHAM group). Of the two groups operated on, one was a no treatment group and the other was orally administered green tea catechin at 50 mg/kg/day beginning three days before the operation. On post operative day 17 all the rats were sacrificed and the levels of fibrosis and oxidative damage assessed.

The values of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), activator protein-1 m-RNA, [alpha]-smooth muscle actin, transforming growth factor-[beta], 14-hydroxynonenal and 8-oxo20deoxyguanosine, all markers of oxidative stress, liver compromise and stellate cell activation were significantly lower in the treatment group than the non treatment group. The authors conclude that green tea catechins may help to quench free radical oxidation in the liver post bile duct ligation, suppressing transcription factor expression and stellate cell activation and thus potentially reducing liver fibrosis.

Tessa Finney-Brown MNHAA

tessafinneybrown@gmail.com
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