Effect of Guizhitang on Atherosclerosis by Regulating Immune and Intestinal Flora / 中国实验方剂学杂志

ABSTRACT

Objective:To observe the effect of Guizhitang （GZT） on peripheral blood monocytes， intestinal flora and AS plaque formation of ApoE^-/- mice induced by Western diet （WD）. Method:In this study， 40 12-week-old homozygous female ApoE^-/- mice were randomly divided into chow diet （CD） group （ApoE^-/-+CD）， WD group （ApoE^-/-+WD）， GZT group （ApoE^-/-+WD+GZT， 7.83 g·kg^-1） and atorvastatin （Atr） group （ApoE^-/-+WD+Atr， 3.33 mg·kg^-1）. And 10 matched C57BL/6 mice were set as wild CD control group （C57BL/6+CD）. Except the CD group， the rest groups were given WD to induce models. Treatment groups were given Guizhitang or atorvastatin orally in addition to WD， while ApoE^-/-+CD and ApoE^-/-+WD model groups were treated with the same volume of double steam water at the same time. After 4 weeks of intervention， 5 mice in each group were selected to collect the eyeball blood samples. The levels of plasma lipids were detected by automatic biochemical analyzer， and the proportion of peripheral blood mononuclear cells and its subtypes， and the expression levels of surface receptors toll like receptor 4 （TLR4） and CD36 were detected by flow cytometry， the intestinal flora of mice was detected by 16S rDNA sequencing. The remaining 5 mice in each group were intervened for 12 weeks， and the aorta was taken to detect the formation of aortic plaque by oil red O staining. Result:After intervention for 4 week， compared with C57BL/6+CD group， the levels of plasma total cholesterol （TC） and low-density lipoprotein （LDL） levels in ApoE^-/-+CD and ApoE^-/-+WD groups were increased （<italic>P</italic><0.01）. ApoE^-/-+WD group showed increase in the proportion of monocytes， their inflammatory subtypes Ly6C^__， and TLR4 expression on monocyte surface in blood （<italic>P</italic><0.05）. ApoE^-/-+WD group induced the imbalance of intestinal flora， with increase of Firmicutes and decrease of Verrucomicrobia in ileum of ApoE^-/-mice. Compared with ApoE^-/-+WD group， there was no significant change in blood lipid level and monocyte proportion in ApoE^-/-+WD+GZT group， but with decrease in the proportion of Ly6C^__， increase in the proportion of anti-inflammatory subtype Ly6C^-， and decrease in the expression of TLR4 and CD36 on monocyte surface （P<0.05）. ApoE^-/-+WD+GZT group showed decrease of Firmicutes and increase of Bacteroidetes and Verrucomicrobia in ileum of ApoE^-/-mice. After 12 weeks of intervention， ApoE^-/-+WD group showed increase in the number and area of aortic plaques in ApoE^-/-mice. ApoE^-/-+WD+GZT group showed decrease of the area of aortic AS plaques. Conclusion:GZT can reduce the immune damage and imbalance of intestinal flora caused by WD， then inhibit the formation of AS plaque.