University of Macau / Institute of Chinese Medical Sciences

Immortalized normal hepatocytes AML-12 or primary hepatocytes were cultured in control, and the methionine and choline deficient (MCD) culture medium in the presence or absence of Phyllanthus urinaria for 24 hours. Hepatocyte triglyceride contents, release of alanine aminotransferase, lipoperoxides and reactive oxygen species production were determined in the cell culture study. Age-matched wild-type C57BL/6 and diabetes db/db mice were fed control or MCD diet for 10 days with or without Phyllanthus urinaria. The levels of Hepatic steatosis, necroinflammation, triglycerides and oxidative stress were investigated. Hepatic expression of inflammatory factors and lipid regulatory mediators were assayed. The results demonstrated that Phyllanthus urinaria reduced steatosis and alanine aminotransferase (ALT) levels in culture of hepatocytes in a dose-dependent manner. Phyllanthus urinaria protected the livers against MCD-induced hepatic fat accumulation and steatohepatitis in mice. This effect was associated with repressed levels of hepatic lipid peroxides, reduced expression of cytochrome P450 (CYP) 2e1, pro-inflammatory tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), dampened activation of inflammatory C-jun N-teuninal kinase (JNK) and nuclear factor kappaB (NF-kappaB), increased expression of lipolytic Cyp4a10 and suppressed transcriptional activity of lipogenic CCAAT/enhancer binding protein beta (C/EBPbeta). Hepatic acyl co-enzyme A oxidase (ACO) that regulated hepatic beta-oxidation of fatty acid and other lipid regulators were not affected by Phyllanthus urinaria. / Non-alcoholic steatohepatitis (NASH) results from excessive accumulation of hepatic fat (steatosis) and oxidative stress. Therefore, inhibition of fatty acid cytotoxicity and liver inflammtary change is an important goal in the treatment of NASH. Phyllanthus urinaria, a herbal medicine, has been reported to have potential anti-oxidant property. We tested the effects of Phyllanthus urinaria on nutritional steatohepatitis both in vitro and in vivo, and determined the mechanism of its action. / Our study indicated that Phyllanthus urinaria effectively prevented MCD-induced steatohepatitis. This effect were probably mediated through dampening oxidative stress, ameliorating inflammation and decreasing lipid accumulation. Phyllanthus urinaria deserves further evaluation for its potential therapeutic effect on NASH in humans. / Shen, Bo. / Adviser: Henry Ly Chan. / Source: Dissertation Abstracts International, Volume: 70-09, Section: B, page: . / Thesis submitted in: November 2008. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 128-142). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.