Curcumin ameliorates atherosclerosis in apolipoprotein E deficient asthmatic mice by regulating the balance of Th2/Treg cells

Allergic asthma and atherosclerosis represent different directions of inflammatory responses of CD4+ T cells, and allergic asthma accelerates atherosclerosis formation. Curcumin could ameliorate the progression of both atherosclerosis and allergic asthma.We aimed to investigate the roles of curcumin in asthma-accelerated atherosclerosis plaque formation, and the change of CD4+ T-cell subsets in this process.Six to eight-week-old apolipoprotein E-/- (apoE-/-) mice were sensitized and challenged by ovalbumin (OVA) to establish an allergic asthma model, and then received curcumin or vehicle treatment for 8 weeks.The accelerated atherosclerosis was induced by allergic asthma accompanied by increased T helper cell (Th)2 and Th17 cells and decreased regulatory T cells (Tregs) in the spleen. After the 8-week treatment with curcumin, the lesion areas in the aortic root in asthmatic mice significantly improved, and the elevated Th2 and Th17 cells significantly decreased, but Tregs markedly increased. Although curcumin treatment markedly reduced the interleukin (IL)-4 and IL-13 in serum and spleen, the elevated IL-17A did not decrease. Moreover, Th1 cells showed no significant change between different groups. The mRNA expression levels of M1 macrophage-related inflammatory factors IL-6, iNOS and IL-1β were markedly elevated in the spleens of asthmatic mice, but significantly decreased after the 8-week treatment with curcumin.Curcumin ameliorated the aggravation of atherosclerotic lesions and stabilised plaque by modulating the balance of Th2/Tregs in asthmatic apoE-/- mice.