Objective: In this Meta-analysis, we evaluated the hypoglycemic effect of 5 flavonoids found in traditional Chinese herbs (naringenin, kaempferol, puerarin, baicalein, and luteolin) on diabetic rats.
Methods: Four databases including PubMed, Web of Science, Embase, and Cochrane Library, were searched from inception to May 2020. Only studies using diabetes model rats were included in the analysis. Blood glucose data from the last measurement were collected and analyzed. Pair-wise Meta-analyses were conducted using STATA v14.0 software and a Meta-analysis was conducted using STATA v14.0, ADDIS v1.16.6, and R v3.6.1. The quality of included studies was assessed with the SYRCLE risk of bias tool for animal studies, and publication bias was evaluated with a comparisonadjusted funnel plot.
Results: A total of 33 studies were included in the analysis, in which all 5 flavonoids showed a beneficial effect on blood glucose level of diabetic rats were included in the final analysis. The standardized mean differences (95% confidence intervals) were -4.92 (-6.67, -3.17) fornaringenin, -12 (-18.74, -5.27) for kaempferol, -2.52 (-3.77, -1.26) for puerarin, -3.04 (-5.75, -0.34) for baicalein, and -1.94 (-2.95, -0.92) for luteolin. The network Meta-analysis showed no statistically significant differences between the effect sizes of the flavonoids.
Conclusion: The results of the Meta-analysis showed that naringenin, kaempferol, puerarin, baicalein, and luteolin all have clear hypoglycemic effects in rat diabetes models, highlighting their therapeutic potential for preventing and treating diabetes mellitus in clinical practice.
Keywords: Baicalein; Diabetes mellitu; Kaempferol; Luteolin; Meta-analysi; Naringenin; Puerarin.