Hepatoprotective effects of Carduus marianus (Silymarin): A systematic analysis of evidence from traditional and modern medicine

Background: Liver damage, caused by factors such as viral hepatitis, alcohol use, and hepatotoxic drugs, remains a significant global health issue. Silybum marianum (milk thistle), a traditional medicinal plant, contains silymarin - a flavonolignan complex recognized for its hepatoprotective, antioxidant, and anti-inflammatory effects. This systematic review evaluates the efficacy of silymarin in preventing and treating liver damage based on preclinical and clinical evidence. Methods: A systematic search was conducted in PubMed, Scopus, ScienceDirect, and Google Scholar for studies published from January 2000 to March 2024. Search terms included “Silymarin,” “Carduus marianus,” “Liver damage,” “Hepatoprotection,” and “Treatment.” Eligible studies were screened using predefined criteria, and quality assessment was conducted using the Cochrane Risk of Bias Tool and ARRIVE guidelines. Results: A total of 45 studies were included: 22 clinical trials and 23 preclinical studies. Animal studies showed that silymarin significantly reduced liver enzymes (ALT, AST), improved histopathology, and enhanced antioxidant status. Clinical trials in conditions such as alcoholic liver disease, NAFLD, and hepatitis reported improvements in liver enzyme levels, liver ultrasound findings, and patient-reported outcomes. Most clinical studies used doses ranging from 140-600 mg/day, with favorable safety profiles. Conclusion: Silymarin demonstrates consistent hepatoprotective effects in both experimental and clinical settings. It appears effective in improving liver function and reducing oxidative stress. While promising, further well-designed randomized controlled trials are needed to confirm long-term efficacy and support clinical recommendations.