Abstract:Aim To investigate the effects of naringenin on atherosclerotic plaque extracellular matrix remodeling and plaque stability. Methods Murine vascular smooth muscle cells were isolated and treated with various doges of naringenin. ApoE－/－ mice were fed with high-fat diet and received naringenin by lavage for 16 weeks. Intraplaque necrotic core, contents of collagen and fibrous cap thickness were measured by Sirius red-Haematoxylin staining. Elastin was detected by Van Gieson staining. Matrix metalloproteinase (MMP) activity was determined by gelatin zymography and fluorescence-gelatin staining.Results Naringenin (50 μmol/L) increased signal tansducer and activator of transciption 6 (STAT6) phosphorylation and promoted tissue inhibitor of metalloproteinase-3 (TIMP-3) expression by 3.1-fold (P＜0.001). After naringenin (80 mg/kg) treatment, compared with the control group, the area of plaque necrotic core in aortic root decreased by 53% (P＜0.01), the thickness of fibrous caps increased by nearly 50% (P＜0.05), and the degree of elastic fiber degradation decreased. At the same time, naringenin promoted the expression of TIMP-3 in plaques, and correspondingly reduced the activity of MMP in plaques. Lentivirus mediated inhibition of TIMP-3 expression in vivo could reduce the protective effect of naringenin on plaque stability. Conclusion Naringin can increase the expression of TIMP-3 in smooth muscle cells, improve the composition of extracellular matrix, and promote the stability of atherosclerotic plaque.