Daming capsule, a hypolipidaemic drug, lowers blood lipids by activating the AMPK signalling pathway

[Display omitted] •In this study, for the first time, we demonstrate the potential mechanism of DMC in hyperlipidaemia.•Daming capsule exerts its strong lipid-lowering property and hepato-protective effect by activating AMPK and affecting its downstream molecules PPARα/LPL and LDLR.•This study clarifies the mechanism and provide guidelines for the clinical application of DMC. Hyperlipidaemia is a major risk factor for cardiovascular and cerebrovascular diseases. Daming capsule (DMC), a medicine for lowering blood lipids, is marketed in China; however, its mechanism is unclear. The present study aimed to investigate the mechanism by which DMC reduces blood lipids. A rat model of hyperlipidaemia was established by feeding rats a high-fat diet (HFD), and the serum lipid levels were detected with an automatic biochemical analyser. DMC (162 mg/kg) and atorvastatin calcium (10 mg/kg) were orally administered to the hyperlipidaemic rats for 4 weeks. HFD feeding markedly induced increases in the levels of total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-c); however, DMC treatment significantly decreased the levels of TC, TG, and LDL-c in rats serum. Meanwhile, the hepatic TC and TG levels, liver weight/body weight ratio, and body weight were significantly lower in the DMC-treated rats than in the HFD rats. Moreover, DMC significantly alleviated hepatomegaly, hepatic lipid deposition, and hepatic steatosis. The protein expression level of phospho-adenosine monophosphate-activated protein kinase (p-AMPK) (Thr172) in HFD rat livers was lower than that in normal rat livers, whereas it increased in the liver of the DMC-treated rats; however, the protein expression level of total-AMPK in the liver was not different among the groups. The AMPK-activating effect of DMC was blocked by Compound C (a specific AMPK inhibitor) in HepG2 cells. Additionally, DMC considerably increased peroxisome proliferator-activated receptor-alpha (PPARα) protein expression and lipoprotein lipase (LPL) transcription and concentration in the liver. This effect of DMC was also inhibited by Compound C in HepG2 cells. DMC also promoted LDL receptor (LDLR) protein expression by activating AMPK. We further found that DMC reduced the levels of TC and TG in oleic acid-treated HepG2 cells, and it restored the expression levels of p-AMPK, PPARα, LPL, and LDLR compared to the decreased levels observed in oleic acid-treated HepG2 cells. DMC lowered lipids in serum and