ABSTRACT
Objective To investigate the effects of Yangyin Recipe on atherosclerosis (AS) lesions, helper T cells 17 (Th17), and regulatory T cells (Treg) in apolipoprotein E knockout (ApoE-/-) mice under the heat shock protein (HSP) 65 attack, and explore the potential mechanisms. Methods ApoE-/- mice were fed with normal and high-fat diets respectively, and injected with sterile PBS or HSP65. Simvastatin was used as the positive drug to study the effects of Yangyin Recipe on blood lipids, plaques, Th17/Treg cells and related inflammation indicators in AS model mice. Drugs were all intragastric administrated with equal volume of normal saline as a control. Serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL) and high-density lipoprotein (HDL) were detected by esterase method; The area of aortic plaque was determined by oil red O staining; The amounts of IL-17A+CD4+ Th17 and Foxp3+CD25+CD4+ Treg cells in anticoagulated blood were determined by flow cytometry; Serum IL-6, IL-17, IL-2, TGF-β, and IL-10 were determined by ELISA; mRNA expression of Stat3, Stat5a, Foxp3 in spleens and Stat3, Stat5a in aortas were detected by qPCR; Protein expression of phosphorylated STAT3 (pSTAT3), phosphorylated STAT5 (pSTAT5), FOXP3 in spleen, and pSTAT3 in aortas were determined by Western blotting. Results Under the influence of Yangyin Recipe, serum TC, TG, LDL levels decreased (P < 0.01), and HDL increased (P < 0.05); Aortic plaque area decreased remarkably (P < 0.01); IL-17A+CD4+Th17 cells in peripheral blood decreased (P < 0.05), Foxp3+CD25+CD4+ Treg increased (P < 0.05), and Th17/Treg ratio decreased drastically (P < 0.01); Serum IL-6 decreased (P < 0.05), IL-2 (P < 0.01), TGF-β and IL-10 (P < 0.05) increased; Protein levels of pSTAT3 in spleens decreased (P < 0.01), but pSTAT5 (P < 0.01) and FOXP3 (P < 0.05) increased; Aortic Stat3 mRNA (P < 0.01) and pSTAT3 (P < 0.05) protein decreased. Conclusion Yangyin Recipe can improve hyperlipidemia and AS in ApoE-/- mice during HSP65 attack, and regulate the balance of Th17/Treg in peripheral blood and the secretion of inflammatory factors to improve inflammation, which may be related to attenuate IL-6/pSTAT3 and enhance IL-2/pSTAT5 signaling.