The Research On Intervention And Function Of Raspberry Ketone In Non-alcoholic Steatohepatitis (NASH)

Objective:Nonalcoholic fatty liver disease (NAFLD) is a clinicopathological term that encompasses a disease spectrum ranging from simple triglyceride accumulation in hepatocytes (hepatic steatosis) to hepatic steatosis with inflammation (nonalcoholic steatohepatitis, NASH) and cirrhosis. NASH is a very important stage. Given appropriate prevention or treatment, NASH can be recovered to steatosis, otherwise, it can evolve to fiborsis, even cirrhosis. In this paper, RK has intervention effect on NASH. Furthermore, the technology of biochemistry, enzyme histochemistry, immunohistochemistry, ELISA and other modern techniques were applied in this study. The intervention effect in nonalcoholic steatohepatitis (NASH) was tested by using high-fat diet induced NASH model, and its mechanism was explored.Method:.There were 40 Sprague Dawley (SD) rats of Specific pathogen free (SPF) grade, and the male to female ratio was 1:1, which were fed with normal diet about a week. Thus these rats were randomly divided into 5 groups:Normal Control group (NC, n=8) fed with normal diet for 8 weeks, Model Control group (MC, n=8) fed with high-fat diet (82% standard diet,8.3% yolk powder,9.0% lard,0.5% cholesterol, and 0.2% sodium taurocholate), raspberry ketone low-dose group (RKL, n=8), raspberry ketone middle-dose group (RKM, n =8), and raspberry ketone high-dose group (RKH, n=8) fed with high-fat diet for 4 weeks. After above treatment, these rats in last three groups were administered intragastrically with 0.5%,1%, and 2% of RK, respectively, the rats of other groups were administered intragastrically with salad oil at the same dose once a day, lasting for 4 weeks. After 8 weeks of experiment, all the rats were executed. The weight, appetite, behavior, state, hair and death rate of the rats were closely observed. Tissue index numbers were calculated. The blood lipid parameters (TC, TG, HDL-C, and LDL-C), the liver function parameters (ALT, AST, and ALP) of serum, and blood sugar (GLU) were tested through automatic biochemistry analyzer. Serum of insulin (INS), leptin (LEP), free fatty acid (FFA), tumor necrosis factorα(TNF-α), apoprotein A (Apo AⅠ), apoprotein B (Apo B), liver homogenate of peroxisome proliferator-activated receptor-α(PPAP-α),the low density lipoprotein receptor (LDLR), high-sensitivity C-reactive protein (hs-CRP), adiponection (APN) were tested by enzyme linked immunosorbent assay (ELISA). Insulin resistance index (IRI) and insulin sensitive index (ISI) were calculated. Liver homogenate of total glutathione (T-GSH), and superoxide dismutase (SOD), malonaldehyde (MDA) were tested by way of tissue homogenate biochemistry. The liver tissues of rats in each group were imaged by electron microsopy with hematoxylin and eosin (HE) as staining agent. Hepatic steatosis and inflammatory activity level were assessed by optical microscope. The ultrastructure of the liver tissues was observed through electron microscope.Result:In this study, we fed the rats with high-fat diet, and the results showed that the NASH of rat model had been duplicated successfully via pathological examination after 8 weeks. The results were processed by statistical analysis, and compare to NC, the levels of TG, TC, LDL-C, ALT, AST, ALP, GLU, INS, IRI, FFA, LEP, TNF-α, MDA, and hs-CRP of MC rats were significantly increased (P<0.05, P<0.01). Therefore, the levels of HDL-C, ISI, T-GSH, PPAP-a, LDLR, and APN were significantly decreased (P<0.05, P<0.01). Compared with MC, each parameter in RKL, RKM, and RKH was significantly improved (P <0.05, P<0.01).Conclusion:In this study, we successfully established the NASH model, where we employed RK to inference the steatohepatitis with high fat-diet. The results showed that the RK can reduce the lipid levels in serum and liver tissue, suppress the synthesis of FFA to protect liver cells, improve the resistance of leptin and insulin for the activation of the liver-protection function, regulation of lipid metabolism, and inhibition of inflammation. Furthermore, RK could significantly inhibit the oxidative stress and lipid peroxidation and promote the balance restoration of oxidation and antioxidant mechanisms, so as to prevent the liver from damage. In addition, RK could also reduce the damage of liver cells caused by high fat-diet, so RK could act as liver-protector. Last but not least, RK could diminish the inflammatory damages of liver cells and fatty degeneration, so that it can regenerated the structure and function of liver cells. It was believed that RK had dual effect of liver-protection and fat adjustment, and the mechanism were probably that RK alleviate fatty degeneration of liver cellsto reduce the infiltration of inflammatory cells in liver tissue, to correcte dyslipidemia, to improve of the resistance of leptin and insulin, to reduce the release of TNF-a, and to improve the antioxidant capacity.