Silymarin suppresses hepatic stellate cell activation in a dietary rat model of non-alcoholic steatohepatitis: analysis of isolated hepatic stellate cells.
Non-alcoholic steatohepatitis (NASH) is characterized by hepatocellular injury and initial fibrosis severity has been suggested as an important prognostic factor of NASH. Silymarin was reported to improve carbon tetrachloride-induced liver fibrosis and reduce the activation of hepatic stellate cells (HSC). We investigated whether silymarin could suppress the activation of HSCs in NASH induced by methionine- and choline-deficient (MCD) diet fed to insulin-resistant rats. NASH was induced by feeding MCD diet to obese diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Non-diabetic Long-Evans Tokushima Otsuka (LETO) rats were fed with standard chow and served as the control. OLETF rats were fed on either standard laboratory chow, or MCD diet or MCD diet mixed with silymarin. Histological analysis of the liver showed improved non-alcoholic fatty liver disease (NAFLD) activity score in silymarin-fed MCD-induced NASH. Silymarin reduced the activation of HSCs, evaluated by counting α-smooth muscle actin (SMA)-positive cells and measuring α-SMA mRNA expression in the liver lysates as well as in HSCs isolated from the experimental animals. Although silymarin decreased α(1)-procollagen mRNA expression in isolated HSCs, the anti-fibrogenic effect of silymarin was not prominent so as to show significant difference under histological analysis. Silymarin increased the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and decreased tumor necrosis factor (TNF)-α mRNA expression in the liver. Our study suggested that the possible protective effect of silymarin in diet induced NASH by suppressing the activation of HSCs and disturbing the role of the inflammatory cytokine TNF-α.
Department of Internal Medicine, Division of Gastroenterology,                     Inha University School of Medicine, Jung-Gu, Incheon, Republic of Korea.
Mina
M
Kim
Su-Geun
SG
Yang
Joon Mi
JM
Kim
Jin-Woo
JW
Lee
Young Soo
YS
Kim
Jung Il
JI
Lee
D000818:Animals; D001835:Body Weight; D004032:Diet; D004195:Disease Models, Animal; D018450:Disease Progression; D005234:Fatty Liver / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D055166:Hepatic Stellate Cells / Q000187:drug effects* / Q000378:metabolism*; D007333:Insulin Resistance; D008099:Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008103:Liver Cirrhosis / Q000378:metabolism / Q000473:pathology; D020935:MAP Kinase Signaling System / Q000187:drug effects; D008297:Male; D051267:NF-E2-Related Factor 2 / Q000378:metabolism; D065626:Non-alcoholic Fatty Liver Disease; D009929:Organ Size; D021381:Protein Transport; D051381:Rats; D012838:Silymarin / Q000008:administration & dosage / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism
D051267:NF-E2-Related Factor 2; D012838:Silymarin; D014409:Tumor Necrosis Factor-alpha