Abstract
Chronic mild stress (CMS) has been demonstrated to contribute to atherosclerosis. 6-gingerol (6-Gin), a phenolic component of ginger (Zingiber officinale), has been shown to exert numerous pharmacological properties, such as anti-inflammatory and cardioprotective effects. Here we investigated the role of CMS in the development of atherosclerosis in high-fat diet (HFD)-fed ApoE-/- mice and evaluated the potential therapeutic effects of 6-Gin. Mice were exposed to CMS for 20 weeks, at week 5, they were fed with a high-fat diet (HFD), then received 6-Gin (20 mg/kg/day, intragastrically) treatment. Antiatherosclerotic simvastatin (Sim) and antidepressant lorazepam (Lor) were used for positive drugs. The behavioral and atherosclerotic changes, plasma lipid profiles as well as inflammatory cytokine levels were measured. Our results showed that CMS-exposed mice exhibited reduced body weight gain, sucrose preference and locomotor activity, which are representative of some of the core symptoms of depression. Furthermore, CMS challenge aggravated atherosclerotic lesions, as indicated by increased plaque formation, elevation of plasma total cholesterol, triglyceride, low-density lipoprotein cholesterin, and proinflammatory cytokines including TNF-α, IL-1β, and IL-6. In addition, the expression levels of phosphorylated adenosine monophosphate-activated protein kinase (p-AMPK), acetyl-CoA carboxylase (ACC), hHMG-CoA reductase (HMGCR), fatty acid synthase (FAS), sterol regulatory element binding protein (SREBP)-1 and SREBP-2 in the liver tissues were altered after CMS exposure. 6-Gin not only improved the behavioral changes, but also alleviated atherosclerotic lesions, and reversed the expression levels of lipid profiles and inflammatory cytokines in stressed mice. Moreover, the antiatherosclerotic effects of 6-Gin is mediated in part by the AMPK signaling pathway, which is closely associated with cholesterol synthesis and lipid accumulation. Together, these results suggest that 6-Gin attenuates arteriosclerosis in ApoE-/- mice exposed to CMS and HFD, and it may be a potential therapeutic agent for the treatment of atherosclerosis.