Anti-inflammatory effects of total alkaloids from Rubus aleaefolius Poir. on non-alcoholic fatty liver disease through regulation of the NF-κB pathway

We aimed to explore the anti-inflammatory effects of total alkaloids in Rubus aleaefolius Poir. (TARAP) on nonalcoholic fatty liver disease, and to investigate the possible molecular mechanisms. A rodent non-alcoholic fatty liver disease (NAFLD) model was established by administration of a modified high-fat diet ad libitum for 8 weeks. Rats were treated with polyene phosphatidylcholine (PP), TARAP low-dose (0.72 g/kg body weight/day) and TARAP high-dose (1.44 g/kg body weight/day). The model group and the control group received distilled water. After treatment for 4 weeks, the blood samples were obtained from the abdominal aorta, and the levels of serum ALT, AST, GGT, ALP, TG, TC, HDL-C and LDL-C were measured. Changes in liver tissue morphology were evaluated by H&E staining. The expression levels of nuclear factor (NF)-kappa B, cyclooxygenase-2 (COX-2), interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha in rat livers were assayed by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry. Both TARAP and PP attenuated hepatic steatosis induced by the high-fat diet. The modified high-fat diet caused a significant increase in ALT, AST, GGT, ALP, TG, TC, LDL-C levels and a decrease in HDL-C levels. TARAP and PP treatment abrogated the increase in the levels of liver enzymes and the levels of TG, TC, LDL-C, as well as suppressed the increase in HDL-C levels. The results of RT-PCR and immunohistochemical assay showed that PP and TARAP treatment decreased the expression of NF-kappa B, COX-2, IL-6 and TNF-alpha. In conclusion, these results suggest that TARAP may protect against NAFLD through regulation of the NF-kappa B pathway.