Patchouli alcohol attenuates experimental atherosclerosis via inhibiting macrophage infiltration and its inflammatory responses.

Patchouli alcohol (PA) is a tricyclic sesquiterpene extracted from a traditional Chinese herb pogostemonis herba. Literatures have proven that PA could inhibit inflammatory responses in various inflammatory disease models. However, whether PA could protect against atherosclerosis, a chronic vascular inflammation, is unknown. In this study, we sought to explore this issue in atherosclerosis-prone apolipoprotein E knockout mice fed an atherogenic diet, with or without daily PA intragastrical administration (40mg/kg). Our results showed that PA administration did not change plasma lipids metabolism, however, it significantly attenuated atherosclerotic plaque burdens in both the aorta and the aortic root. The lesional macrophage content, shown as Mac2 positive areas, was reduced, while the lesional smooth muscle cell and collagen content, shown as α-SMA positive areas and by Sirius red staining, respectively, was not affected in PA-treated mice, compared with non-treated controls. Aortic mRNA expression of macrophage inflammatory cytokines, including MCP-1, iNOS, IL-1β, IL-6, CXCL9 and CXCL11, was also reduced in PA-treated mice. Therefore, we demonstrated that PA could attenuate atherosclerosis, possibly by inhibiting macrophage infiltration and its inflammatory responses.