Effects of silymarin supplementation on liver and kidney functions: A systematic review and dose–response meta‐analysis

Abstract It is suggested that supplementation with silymarin (SIL) has beneficial impacts on kidney and liver functions. This systematic review and dose–response meta‐analysis assessed the impact of SIL administration on certain hepatic, renal, and oxidative stress markers. A systematic search was conducted in various databases to identify relevant trials published until January 2023. Randomized controlled trials (RCTs) that evaluated the effects of SIL on kidney and liver markers were included. A random‐effects model was used for the analysis and 41 RCTs were included. The pooled results indicated that SIL supplementation led to a significant reduction in serum levels of alkaline phosphatase, alanine transaminase, creatinine, and aspartate aminotransferase, along with a substantial elevation in serum glutathione in the SIL‐treated group compared to their untreated counterparts. In addition, there was a nonsignificant decrease in serum levels of gamma‐glutamyl transferase, malondialdehyde (MDA), total bilirubin, albumin (Alb), total antioxidant capacity, and blood urea nitrogen. Sub‐group analyses revealed a considerable decline in MDA and Alb serum values among SIL‐treated participants with liver disease in trials with a longer duration (≥12 weeks). These findings suggest that SIL may ameliorate certain liver markers with potential hepatoprotective effects, specifically with long‐term and high‐dose supplementation. However, its nephroprotective effects and impact on oxidative stress markers were not observed. Additional high‐quality RCTs with longer durations are required to determine the clinical efficacy of SIL supplementation on renal and oxidative stress markers.