Abstract
OBJECTIVE: Traditional Chinese medicine (TCM) has a long history in the treatment of Immunoglobulin A nephropathy (IgAN). A large number of animal experiments focused on the TCM treatment of IgAN are conducted every year. The evidence for these preclinical studies is not clear. This study summarized and evaluated the results of animal experiments on TCM treatment for IgAN. METHODS: We systematically searched animal studies from 6 databases from inception to August 30, 2022. We included Chinese studies from the key magazine of China technology. The quality of the included studies was evaluated with the SYRCLE animal experimental bias risk assessment tool and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE). RESULTS: Out of 832 records identified in the initial search, 30 studies were selected. The results indicated that, compared with the control group, the TCM treatment group improved 24 h urine protein (24 h-UP) level (standardized mean difference (SMD) 3.57, 95% confidence interval (CI) 4.48 to 2.66, P < 0.001), urine red blood cell (U-RBC) (SMD 13.66, 95% CI 17.99 to 9.32, P < 0.001), serum creatinine (Scr) (mean difference (MD) 10.89, 95% CI 17.00 to 4.77, P < 0.001), blood urea nitrogen (BUN) (MD 2.44, 95% CI 3.42 to 1.47, P < 0.001), tumor necrosis factor-α (TNF-α) (MD 171.28 to 95% CI 323.68 to 18.88, P=0.03), transforming growth factor-β1 (TGF-β) (SMD 4.02, 95% CI 7.26 to 0.77, P=0.02), matrix metalloproteinase-9/tissue inhibitors of metalloproteinase-1(MMP-9/TIMP-1) (MD 0.03, 95% CI 0.00 to 0.06, P=0.02), nephrin mRNA (SMD 3.39, 95% CI 2.59 to 4.18, P < 0.001). However, there is no difference in albumin level (MD 1.10, 95% CI 0.06 to 2.26, P=0.06) and interleukin-6 (IL-6) (MD 170.77, 95% CI 365.3 to 23.75, P=0.09). CONCLUSIONS: TCM can improve 24 h-UP, U-RBC, Scr, BUN, MMP-9/TIMP-1, TNF-α, TGF-β, and nephrin mRNA of IgAN animal models. Moreover, there is a need for rigorous reporting of preclinical research methodology, which is essential to support the quality of preclinical research. Registration. This review was registered with a systematic review record CRD42020171404 in the PROSPERO database.