The effects of silymarin supplementation on metabolic status and oxidative stress in patients with type 2 diabetes mellitus: A systematic review and meta-analysis of clinical trials

Objective: The effect of silymarin supplementation on metabolic status and oxidative stress of subjects with type 2 diabetes mellitus (T2DM) has not been conclusively studied. Therefore, the efficacy of silymarin supplementation in these patients was assessed through a meta-analysis. Methods: The following databases were searched up to May 15, 2018: PubMed, Scopus, Ovid (Cochrane library), Google scholar and ISI web of science. All randomized clinical trials using silymarin supplements to improve T2DM included in this meta-analysis. Mean Difference (MD) was pooled using a random-effects model. Results: Eight eligible publications from seven trials were identified for the present meta-analysis. Our results revealed that supplementation with silymarin can decrease fasting blood sugar, hemoglobin A1C, insulin, low density lipoprotein cholesterol and malondialdehyde and increase high-density lipoprotein cholesterol levels. However, silymarin did not have any significant effects on total cholesterol or triglyceride concentrations. Conclusion: Our data suggest that silymarin supplements have beneficial effects on metabolic status and oxidative stress among patients with T2DM. However, there is currently insufficient evidence to make firm conclusions about the full efficacy of supplementation.