Efficacy and Underlying Mechanism of Berberine Against Atherosclerosis: A Meta-Analysis in Preclinical Animal Studies

Atherosclerosis is the primary cause of many cardiovascular diseases, and an increasing number of studies have shown that berberine could delay plaque formation and development. Therefore, we aimed to evaluate its effects and explore its mechanisms in this meta-analysis. We searched PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, Wanfang, and VIP databases for original preclinical studies to conduct meta-analysis. Twelve articles (16 studies; 312 ApoE(-/-) mice) were included, and all the studies scored 3-5 points according to SYRCLE's risk of bias tool. Berberine could significantly decrease plaque area and plaque macrophage content (plaque area, SMD = -2.02, 95% CI: -2.80 to -1.24, P = 0.000; plaque macrophage content, SMD = -4.28, 95% CI: -7.67 to -0.88, P = 0.013); lower the levels of TC, triglyceride, and low-density lipoprotein (TC, SMD = -1.47, 95% CI: -2.20 to -0.74, P = 0.000; triglyceride, SMD = -0.77, 95% CI: -1.21 to -0.33, P = 0.000; low-density lipoprotein, SMD = -0.61, 95% CI: -1.11 to -0.11, P = 0.000), and change the secretion of inflammatory cytokines (IL-1 beta, SMD = -2.29, 95% CI: -3.40 to -1.18, P = 0.000; interleukin-6, SMD = -1.48, 95% CI: -2.11 to -0.85, P = 0.008; tumor necrosis factor-alpha, SMD = -1.98, 95% CI: -3.01 to -0.94, P = 0.000; interleukin-10, SMD = 1.78, 95% CI: 0.76 to 2.80, P = 0.015), but there were no significant differences in high-density lipoprotein levels and plaque lipid content (high-density lipoprotein, SMD = 0.02, 95% CI: -0.35 to 0.40, P = 0.021; plaque lipid content, SMD = -6.85, 95% CI: -21.09 to 7.39, P = 0.007). The results were robust across a range of sensitivity analyses. Therefore, the results indicate that berberine is a promising drug for the treatment of atherosclerosis through regulating lipid metabolism, inflammation, and plaque composition. However, some potential mechanisms remain to be further elucidated.