The Effects Of Probucol On Experimental NASH Of Rats

Objective: In recent years, the incidence rate of non-alcoholic fatty liver disease(NAFLD) is increasing year by year, and many patients with simple fatty liver(NASH)will then suffer from non-alcoholic steatohepatitis (NASH), even hepatic fibrosis orcirrhosis. Although the decisive factors of the progression from NAFL to NASH arenot yet fully clarified, many studies have suggested that oxidative stress playes animportant role in this transition and the succedent progression. Probucol is one of themost effective anti-oxidant. This study was designed to observe the preventive effectof probucol on non-alcoholic steatohepatitis (NASH) and elucidate the mechanism,and then validate the important role of OS in the progression of NASH.Methods: Twenty four Sprague-Dawley rats weighing 210±10g were randomlydivided into three groups: 8 for normal control group(NC group) fed with regularchow,8 for model group (HF group) fed with high lipid chow and the others forprobucol- intervention group(PB group) fed with high lipid chow, too. PB group ratswere administered with PB at dose of 500mg/(kg.d) by intragastic infusion, the otherswere given considerable volume of solvent. All of the rats were killed at the end ofeighteenth week. The whole liver, bilateral perirenal fat and omental fat wereweighted to calculate the liver index (liver wet weight/body weight×100%) and fatindex (visceral fat wet weight/body weight×100%).The seral ALT, AST, TG, TC, andthe liver homogenate TG, TC,FFA were assayed. The insulin concentrations in theperipheral blood and portal blood serum were assayed with RIA, and insulinsensitivity index(ISI, ISI=ln 1/FBG×FBI) and HOMA insulin resistance index(HomalR, HomalR=ln FBG×FBI/22.5) were calculated. The lipoperoxidation makersand anti-oxidant substance in the serum and liver homogenate, such as MDA, SOD,GSH-PX and so on, were assayed. The ratio of serous SOD to MDA was calculated,too. The liver histopathologic sections of HE staining and Masson staining were observed, and the ultramicrostructure of liver cell was observed with transmissionelectron microscope,too. The statistical analysis of the data was done with thestatistical package of SPSS 13.0.Result: By the end of the eighteenth week, compared with the NC group,the liverweight, visceral fat weight, liver index and fat index of HF group and PB group weresignificantly increased (P＜0.05), as to the liver weight and the liver index,there wasno difference between HF group and PB group (P＞0.05). The serous glycosylatedserum protein(GSP) and fasting blood insulin(FBI) of HF group and PB group weresignificantly highter than that of NC group (P＜0.05). Compared to NC group,therewas upward trend of the fasting blood glucose(FBG), ISI and HomalR of the twohigh fat chow feeding groups,but no statistical difference (P＞0.05). As to thesemarkers for glucose metabolism, there was no significant difference between PBgroup and HF group(P＞0.05).However, as to the portal serous insulin concentrations,the HF group is significantly higher than that of NC group(P＜0.05),and the PB groupis significantly higher than the HF group (P＜0.05),too. Compared to NC group, theserous TC and LDL-c of the HF group are significantly increased (P＜0.05),and theHDL-c is significantly decreased (P＜0.05),but the liver homogenate FFAconcentration of this group is significantly increased (P＜0.05). The administration ofprobucol decreased the serous TC,LDL-c and the liver homogenate FFAconcentration by 33.1%,21.5%and 13.9% (P＜0.05). Surprisingly, the serous FFA ofPB group is significantly higher than that of both other groups (P＜0.05). Comparedto NC group, the MDA concentration in both serum and liver homogenate of the HFgroup are significantly increased (P＜0.05),liver homogenate SOD,GSH-PX and GSHand serous SOD/MDA are significantly decreased (P＜0.05).While, PB administrationsignificantly decreased both serum and liver homogenate MDA,and increased liverhomogenate SOD,GSH-PX and GSH and serous SOD/MDA (P＜0.05). As to the HF group, both serum ALT and AST are significantly increased, and there is severehepatic steatosis and mild to moderate inflammatory infiltration and point flake orspotty necrosis and fibrosis in the liver. TEM observation showed that part or most ofmitochondrial ridge fuse with membrane or disappeared. Probucol significantlydecreased both serous ALT and AST, and significantly improve both pathology andultrastructure of the liver.Conelusion: We successfully prepared rat model of NASH with several compositionsof metabolic syndrome, such as central obesity, dyslipidaemia, impaired glucosetolerance, hyperinsulinemia. There is both liver local and systemic oxidative injury ofthe NASH rats. And, besides oxidative injury itself, OS also trigger chronic liverinflammation and the subsequent pathological process, such as liver fibrosis and soon. Probucol preserves the antioxidant capacity of liver, prevents liver from oxidativeinjury, and thus delays non-alcoholic steatohepatitis progress. OS is an importantpathophysiologicals mechanism to promote the progress of NASH, and antioxidanttherapy is a potential treatment for NASH.