Naoxintong Protects against Atherosclerosis through Lipid-lowering and Inhibiting Maturation of Dendritic Cells in LDL Receptor Knockout Mice fed a High-fat Diet

Naoxintong (NXT), a Chinese Materia Medica standardized product, extracted from 16 various kinds of Chinese traditional herbal medicines including Salvia miltiorrhiza, Angelica sinennsis, Astragali Radix, is clinically effective in treating atherosclerosis-related diseases. Here, we tested the hypothesis that the anti-atherosclerosis effects of NXT might be mediated by suppressing maturation of dendritic cells (DCs) in a mice model of atherosclerosis. LDLR-/- mice fed a high-fat diet were treated with placebo, NXT (0.7g/kg/d, oral diet) or simvastatin (100mg/kg/d, oral diet) for 8 weeks, respectively. NXT treatment significantly reduced plasma triglyceride (112 +/- 18 mg/dl vs. 192 +/- 68 mg/dl, P<0.05) and total cholesterol (944 +/- 158 mg/dl vs. 1387 +/- 208 mg/dl, P<0.05) compared to placebo treatment. Vascular lesions were significantly smaller and macrophage content and amount of DCs in plaques were significantly less in NXT and simvastatin groups than in placebo group (all P<0.05). In addition, expressions of splenic DC membrane molecules (CD40, CD86 and CD80) and the plasma level of IL-12p70 were significantly lower in NXT and simvastatin groups than in placebo group. In conclusion, NXT protects against atherosclerosis through lipid-lowering and inhibiting DCs maturation in this mice model of atherosclerosis.