Abstract

Herbal and nutraceutical antioxidants are widely used as complementary therapies in type 2 diabetes mellitus 
(T2DM) to mitigate oxidative stress, improve glycaemic control, and prevent complications. Numerous 
plant- derived compounds-including polyphenols, flavonoids, carotenoids, and organosulfur molecules-have 
demonstrated antioxidant, anti- inflammatory, and insulin-sensitizing effects in preclinical and clinical studies. 
However, despite their perceived safety, emerging evidence highlights a “double- edged sword” nature: under 
certain conditions, these agents may exert pro- oxidant effects, interact adversely with other drugs, or induce liver 
injury. This review synthesizes the current mechanistic, toxicological, and clinical data on herbal and nutraceutical 
antioxidants in diabetes, focusing particularly on hepatotoxicity risks. We examine key antioxidants (resveratrol, 
curcumin, quercetin, α- lipoic acid, milk thistle, and anthraquinones such as chrysophanol), their beneficial 
metabolic actions, and the pathways by which they could damage the liver. We also discuss regulatory challenges, 
dose-dependent toxicity, and risk mitigation strategies. By offering a balanced and evidence-based assessment, this 
review underscores the importance of caution, quality control, and personalized use of antioxidant supplements in 
diabetic patients.