Atherosclerosis is a chronic inflammatory disease in the vessel, and inflammatory cytokines play an important role in the inflammatory process of atherosclerosis. A high level of free fatty acids (FFAs) produced in lipid metabolism disorders are known to participate in the formation of atherosclerosis through multiple bioactivities. As the main saturated fatty acid in FFAs, palmitic acid stimulates the expression of inflammatory cytokines in macrophages. However, it is unclear whether palmitic acid exerts a pro-inflammatory effect on vascular smooth muscle cells (VSMCs). The purpose of the present study was to observe the effect of palmitic acid on the expression of C-reactive protein (CRP), tumor necrosis factor α (TNF-α) and inducible nitric oxide synthase (iNOS) in VSMCs. Rat VSMCs were cultured, and palmitic acid was used as a stimulant for CRP, TNF-α and iNOS expression. mRNA expression was assayed with reverse transcription-polymerase chain reaction, and protein expression was detected with western blot analysis and immunocytochemistry. The results showed that palmitic acid significantly stimulated mRNA and protein expression of CRP, TNF-α and iNOS in VSMCs in time- and concentration-dependent manners, and therefore, palmitic acid is able to exert a pro-inflammatory effect on VSMCs via stimulating CRP, TNF-α and iNOS expression. The findings provide a novel explanation for the direct pro-inflammatory and atherogenic effects of palmitic acid, and for the association with metabolic syndrome, such as type 2 diabetes mellitus, obesity and atherosclerosis. Therefore, the intervention with anti-inflammatory agents may effectively delay the formation and progression of atherosclerosis in patients with metabolic syndrome.

Previous research has shown that salvianic acid A [2-(3,4-dihydroxyphenyl)-2-hydroxy-propanoic acid, SA] extracted from Salvia miltiorrhiza BGE (Danshen) markedly inhibits lipid peroxidation of mitochondrial membrane of hepatic cells in vitro. The present study was conducted to examine protective effect of SA on liver injury induced by carbon tetrachloride (CCl4) and its possible mechanism in vivo. Male Sprague-Dowley rats weighing 180—200 g were used in the experiments. Five mmol/kg CCl4 in olive oil was given to rats i.p. Spectrophotometrical method was used to measure activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum, activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) as well as malondialdehyde (MDA) level in hepatic tissue and the rate of superoxide anion (O2·−) generation in hepatic submitochondrial particles. Hepatic histological structure was observed under light microscopy. CCl4 caused significant changes of activities of the enzymes, MDA level, and the rate of O2·− generation and histopathological changes of acute hepatic injury were noted. SA reversed the significant changes induced by CCl4. These results demonstrate that SA produces protective action on acute hepatic injury induced by CCl4 via an antioxidative mechanism.