Mechanism of Gegen Qinlian Decoction in the treatment of diabetic cataract based on network pharmacology and experimental validation.

Diabetic cataract (DC) is one of the most common complications of diabetes mellitus, currently lacks effective treatments. Gegen Qinlian Decoction (GQD) is effective against diabetes and its complications, but its efficacy and mechanism against diabetic cataracts remain unclear. In this study, the effects and mechanisms of GQD in treating diabetic cataracts were evaluated in Zucker diabetic fatty (ZDF) rats. All rats were randomly divided into control, model, low/high-dose GQD and metformin groups. Each group was administered the drug or an equal volume of distilled water for 12 weeks. Fasting blood glucose and body weight were measured every two weeks. At the end of the experiment, the degree of lens opacity was examined. Pathological changes in the lenses were observed by hematoxylin-eosin staining. The contents of soluble proteins, malondialdehyde (MDA), superoxide dismutase (SOD) and sorbitol were measured in the lenses. Network pharmacology was employed to predict the signaling pathways of GQD in treating DC. Additionally, the protein expressions of p38, JNK and their phosphorylation levels were evaluated by Western blot. The results showed that GQD significantly alleviated lens opacity, reduced sorbitol accumulation and ameliorated oxidative stress in rats with DC. Network pharmacology revealed that the MAPK signaling pathway is a key regulatory pathway of GQD against DC. Western blot results further confirmed that GQD significantly downregulated the phosphorylation levels of p38 and JNK in the lenses of rats with DC.This study implicates GQD as a potential therapeutic candidate for DC.