RESUMO
OBJECTIVE To study the anti-fibrotic effect of Cistanche phenylethanoid glycosides (CPhG) in bovine serum albumin (BSA)-induced liver fibrosis in rats and its possible mechanism METHODS Seventy-five SD rats were randomly divided into six groups:normal control(distilled water-treated),model(BSA-treated),positive drug〔BSA-treated+compound Biejiarangan tablets(BJRG) 0.6 g·kg-1〕,and BSA-treated+CPhG(0.125,0.25 and 0.5 g·kg-1)groups. There were thirteen rats in each BSA-treated+CPhG(0.125,0.25 and 0.5 g·kg-1)group and twelve rats in other groups. Subcutaneous injection and tail vein injection of BSA immunity were used to induce the rat liver fibrosis model. Meanwhile, different therapeutic drugs were ig adminstered to rats. After the experimental period,rats were fasted for 12 h prior to 10%chloral hydrate administration and immediately euthanized. The liver was weighed to calculate the liver index. Glutamic-pyruvic transaminase (GPT),glutamic-oxalactic transaminase (GOT),alkaline phosphatase(ALP),total protein(TP)and albumin(ALB)were evaluated by the Mind-Ray automatic biochemical analyzer. The density of hydroxyproline (HyP) in liver tissues was determined using a spectrophotometric method according to the kit′s instructions. Histopathological changes and expressions of typeⅠ and typeⅢcollagens in liver tissues were also determined by immunohisto?chemical staining. RESULTS Compared with the normal control group,collagen fibers of liver tissues in the model group extended their links and enveloped the entire lobule,causing lobular structural damage and the formation of pseudolobules. The liver index(P<0.05),GPT,GOT,ALP,TP and ALB serum levels(P<0.05),HyP content(P<0.01)were significantly increased,so was the expression of typeⅠcollagens and typeⅢcollagens(P<0.01)in the model group. Compared with model group,various doses (0.125,0.25 and 0.5 g · kg-1) of CPhG significantly reduced the BSA-induced elevation of the liver index;GPT,GOT,ALP,TP and ALB serum levels(P<0.05),and HyP content decreased(P<0.01);the morphology of the pathological tissue sections was close to that of the normal control group,and CPhG significantly reduced the expression of two types of collagens(P<0.01). CONCLUSION CPhG can significantly reduce the degree of BSA-induced liver fibrosis in rats. The mechanism may be associated with down-regulation of two types of collagens and suppression of the activation of hepatic stellate cells.
RESUMO
BACKGROUND: Cistanche tubulosa is a traditional Chinese herbal medicine that is widely used for regulating immunity. Phenyl ethanol glycosides (CPhGs) from this plant are the primarily efficacious materials. This aim of this study was to evaluate the preventive and therapeutic effects of CPhGs on BSA-induced hepatic fibrosis in rats and related molecular mechanisms involving hepatic stellate cells. Biejiarangan (BJRG), another traditional Chinese herbal medicine, was used as a positive control. METHODS: In in vivo experiments, 75 SD rats were randomly divided into 6 groups: normal (distilled water-treated), model (BSA-treated), positive drug (BSA-treated + BJRG 600 mg/kg/day), and BSA-treated + CPhGs (125, 250, and 500 mg/kg/day) groups. The liver and spleen indices, serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), hexadecenoic acid (HA), laminin (LN), type III procollagen (PCIII), type IV collagen (IV-C), hydroxyproline (Hyp), and transforming growth factor ß 1 (TGF-ß 1) were measured in rat livers. Histopathological grades for liver fibrosis were assessed for each group using H&E and Masson's trichrome staining. The expression of TGF-ß 1, collagen I (Col-I) and collagen III (Col-III) were determined by an immunohistochemical staining method. These effects were further evaluated in vitro by determining expression levels of NF-κB p65 and Col-I by quantitative real-time PCR analyses. Col-I protein expression was also examined by western blotting. RESULTS: All dose groups (125, 250, and 500 mg/kg/day) of CPhGs significantly reduced the liver and spleen index, decreased ALT, AST, HA, LN, PCIII, IV-C serum levels, TGF-ß 1 content (P < 0.01, P < 0.01, and P < 0.01), and Hyp content. CPhGs also markedly alleviated the swelling of liver cells and effectively prevented hepatocyte necrosis and inflammatory cell infiltration. Immunohistochemical results showed that CPhGs significantly reduced the expression of TGF-ß 1 (P < 0.01, P < 0.01, and P < 0.01), Col- I, and Col-III. The in vitro effects of CPhGs (100, 75, 50, and 25 ug/ml) on HSC-T6 showed that CPhGs significantly reduced mRNA expression of NF-κB p65 and Col-I, and CPhGs also downregulated Col-I protein expression. CONCLUSIONS: CPhGs have a significant anti-hepatic fibrosis effect, and may be used as hepatoprotective agents for treatment of hepatic fibrosis.
