This study was carried out to investigate the protective effects of curcumin on acute or subacute carbon tetrachloride-induced liver damage in rats. Acute hepatotoxicity was induced by intraperitoneal injection of carbon tetrachloride after 4 consecutive days of curcumin treatment. Subacute hepatotoxicity was induced by oral administration of carbon tetrachloride twice a week during 4 weeks of curcumin treatment. In rats with acute liver injury, curcumin (100 and 200 mg kg(-1)) lowered the activity of serum alanine aminotransferase to 52-53% (P < 0.05) and aspartate aminotransferase to about 62% (P < 0.05) those of control rats. In rats with subacute liver injury, curcumin (100 mg kg(-1)) lowered the activity of serum alanine aminotransferase to 34% (P < 0.01) and alkaline phosphatase to 53% (P < 0.05) of control rats. The liver hydroxyproline content in the curcumin (100 mg kg(-1))-treated group was reduced to 48% of the carbon tetrachloride control group (P < 0.01). Malondialdehyde levels in curcumin (100 mg kg(-1)) treated rat liver was decreased to 67% of the control rat liver (P < 0.01) in subacute injury. It was concluded that curcumin improved both acute and subacute liver injury induced by carbon tetrachloride in rats.

Tetrandrine, an alkaloid isolated from the Chinese medicinal herb Stephania tetrandra, has been shown to elicit antifibrotic effects in various cell types. In the present study, the effect of tetrandrine on liver fibrosis was investigated by using bile duct ligation and scission in rats as a model of hepatic fibrosis. Treatment with tetrandrine in fibrotic rats reduced serum aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase levels to 72%, 52% and 51% that of controls at 10 mg/kg/day, respectively. Liver hydroxyproline contents in tetrandrine-treated rats with bile duct ligation and scission were also reduced to 65% of that of control rats with bile duct ligation and scission at 10 mg/kg/day. The morphological characteristics of fibrotic liver, which appeared in control bile duct ligation and scission group, were improved in tetrandrine-treated bile duct ligation and scission group. We also examined the effect of tetrandrine on cultured rat hepatic stellate cells, which plays an important role in the pathogenesis of hepatic fibrosis, activation to investigate whether it could act mainly by direct action on rat hepatic fibroblastic cells. In cultured rat hepatic stellate cells, tetrandrine reduced DNA synthesis to 57% of control hepatic stellate cells at 10 mg/ml without affecting cell viability. Smooth muscle-a-actin expression, the phenotypic marker of activated hepatic stellate cells, was also decreased. We conclude that tetrandrine has an antifibrotic effect on liver fibrosis in rats induced by bile duct ligation and scission, indicating that it might exert a direct effect on rat hepatic stellate cells.Hepatic fibrosis is a consequence of severe liver damage that occurs in many patients with chronic liver disease. Regardless of many different causes, hepatic fibrosis is characterized by increased and altered deposition of newly formed extracellular matrix components such as collagens, proteoglycans, fibronectin and hyaluronic acid (Friedman 1993), leading to the complication of portal hypertension and hepatic failure.In the injured liver, these extracellular matrix components are produced in hepatic stellate cells in the space of Disse, which function in intact liver lobules as the primary storage area for retinoids (Hendrisks et al. 1985). During the course of ongoing liver fibrogenesis, hepatic stellate cells acquire myofibroblastic features, proliferate (Friedman et al. 1989;Hautekeete & Geerts 1997), synthesize increased amounts of extracellular matrix components (Shiratori et al. 1987) and express smooth muscle-a-actin . The transformation of hepatic stellate cells into myofibroblast-like cells is recognized as a critical step in hepatic fibrosis. Therefore, this cell type is an important target for antifibrotic therapy.Tetrandrine is a bis-benzyl isoquinoline alkaloid derived from Stephania tetrandra (Moore). This compound has been characterized pharmacologically to exhibit hypotensive, immunosuppressive properties (Sutter & Wang 1993), and inhibition of lipid perox...

The antifibrotic effects of hot water extract (WEC), intracellular biopolymer (IPC) and extracellular biopolymers (EPC) from mycelial liquid culture of Cordyceps militaris on liver fibrosis were studied. Liver fibrosis was induced by a bile duct ligation and scission (BDL/S) operation, duration of 4 weeks in rats. In BDL/S rats, the levels of aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), total bilirubin in serum and hydroxyproline content in liver were dramatically increased. The WEC or IPC treatment (30 mg/kg/day for 4 weeks, p.o.) in BDL/S rats reduced the serum AST, ALT and ALP levels significantly (p<0.01). The EPC treatment (30 mg/kg/day for 4 weeks, p.o.) reduced the serum ALT, AST and ALP levels significantly (p<0.01). Malondialdehyde contents in liver treated with WEC, IPC or EPC were significantly reduced (p<0.05). But Liver hydroxyproline content was decreased only in EPC treated BDL/S rats to 55% that of BDL/S control rats (p<0.01). The morphological characteristics and expression of alpha smooth muscle like actin in fibrotic liver, which appeared in BDL/S control group were improved in EPC treated fibrotic liver. These results indicate that EPC (30 mg/kg/day for 4 weeks, p.o.) has an antifibrotic effect on fibrotic rats induced by BDL/S.

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This study was carried out to investigate the antifibrotic effects of methanol extracts from the traditional Chinese medicinal herb, the root of Scutellaria baicalensis Georgi, on liver fibrosis induced by bile duct ligation and scission (BDL) or carbon tetrachloride (CCl4) in rats. Liver fibrosis was assessed by histological observations and by measuring levels of liver hydroxyproline, lipid peroxidation based on malondialdehyde (MDA) production, and serum enzyme activities. The morphological characteristics of livertissuewere examined by Masson'strichrome staining and immunostaining against smooth muscle cell alpha-actin. In both models, the levels of hydroxyproline and MDA in liver were significantly increased. Treatment with a methanol extract of S. baicalensis significantly reduced the levels of liver hydroxyproline and MDA, with improved histological findings. In both models, the liver areas positive for smooth muscle cell alpha-actin were considerably decreased by treatment with oral methanol extract of S. baicalensis (150 mg kg(-1) daily for 28 days). A methanol extract of S. baicalensis root inhibits fibrosis and lipid peroxidation in rat liver induced by BDL or CCl4.