Effect of Astragalus injection on inflammatory mediators in patients with viral myocarditis: A systematic review and meta-analysis

To explore the therapeutic effect and mechanism of Astragalus injection on viral myocarditis, we conducted a systematic review and meta-analysis to identify the influence of Astragalus injection on inflammatory mediators and overall efficiency in patients undergoing viral myocarditis.EMBASE, Cochrane Library, PubMed, Chinese Biomedical Literature, Chinese National Knowledge Infrastructure (CNKI), and Wanfang databases were searched to screen randomized controlled trials (RCTs) published before July 3, 2022. The quality of participating studies was assessed by the Cochrane Collaboration Risk of Bias tool. The calculation of qualitative data used a risk ratio (RR) with a 95% confidence interval (95% CI), and quantitative data had standardized mean differences (SMDs) with a 95% CI. The heterogeneity among trials was quantified with Cochran's Q test and the I2 statistic. Confounding factors were estimated by sensitivity analysis, meta-regression, and subgroup analysis. The publication bias of participating articles was evaluated by funnel plot and Egger's test. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was recommended for assessing the strength of evidence.Nineteen available studies were included in our present meta-analysis, all of which were conducted in China. The outcomes expose that Astragalus injection dramatically decreased the levels of pro-inflammatory TNF-α (SMD=-2.271, 95% CI=-2.802 to -1.739, p<0.001, I2=90.6%), IL-6 (SMD=-1.501, 95% CI=-1.872 to -1.130, p<0.001, I2=83.2%), IL-17 (SMD=-3.194, 95% CI=-4.569 to -1.818, p<0.001, I2=88.9%), 1L-8 (SMD=-6.133, 95% CI=-9.938 to -2.328, p = 0.002, I2=97%), 1L-1 (SMD=-1.814, 95% CI=-2.557 to -1.070, p<0.001, I2=92.1%), CRP (SMD=-2.020, 95% CI=-3.107 to -0.932, p<0.001, I2=92.7%), and IFN-γ (SMD=-1.512, 95% CI=-2.771 to -0.253, p = 0.019, I2=92%) and increased the total effective rate of treatment (RR=1.225, 95% CI=1.17 to 1.29, p<0.001, I2=0.0%) in patients with viral myocarditis.Astragalus injection can play a therapeutic role in patients with viral myocarditis through immunomodulatory effects. Outcomes were treated with caution due to significant heterogeneity among studies. Large-scale RCTs should be performed to support these conclusions.