Shenqi Dihuang Decoction Attenuates ALOX5-Mediated Ferroptosis in Diabetic Nephropathy via AMPK/mTOR and TGF-β/Smads Pathways.

To explore the underlying mechanisms about that Shenqi Dihuang decoction (SDD) attenuated diabetic nephropathy (DN), mice were fed on high-sugar and high-fat diet and treated with streptozotocin (STZ) to induce DN model, as well as HK-2 cells treated with D-glucose to establish a DN cell model. High-performance liquid chromatography (HPLC) analysis was carried out to excavate the chemical compositions existed in SDD. The network pharmacological analysis was performed to screen the key genes involved in SDD treating DN. Subsequently, the effects of SDD on ALOX5, ferroptosis- and AMPK/mTOR pathway-associated indices were examined. Finally, whether SDD attenuated ALOX5-mediated ferroptosis in DN via AMPK/mTOR and TGF-β/Smads pathways were validated using gain-of-function experiment. SDD exerted a therapeutic effect on DN mice by improving kidney function, kidney fibrosis and reducing inflammation. HPLC analysis detected two chemical compositions in SDD, containing syringic acid and gallic acid ethyl ester. Network pharmacological analysis found that SDD might inhibit DN by targeting ALOX5. In addition, SDD treatment decreased ROS, MDA, iron, ALOX5, p-mTOR/mTOR, TGF-β1, p-Smad2/3/Smad2/3 levels in DN, whereas elevated the levels of SLC7A11, GPX4 and p-AMPK/AMPK. These changes were reversed upon upregulation of ALOX5 gene expression. In conclusion, SDD inhibits ALOX5-mediated ferroptosis in DN via AMPK/mTOR and TGF-β/Smads pathways.