Puerarin Targets HIF-1α to Modulate Hypoxia-Related Sphingolipid Metabolism in Diabetic Hepatopathy via the SPTLC2/Ceramide Pathway

Background and Objectives: Diabetic hepatopathy, characterized by hepatic hypoxia and metabolic dysregulation, has a rising global incidence and prevalence, with limited effective treatments. Hepatic hypoxia activates hypoxia-inducible factor-1 alpha (HIF-1 alpha), regulating sphingolipid metabolism and elevating ceramide, a key factor in insulin resistance. Puerarin (Pue), a flavonoid derived from Pueraria lobata, exhibits therapeutic effects in diabetes, but its effects on hypoxia-related hepatic metabolism are unclear. This study investigates Pue's mechanisms in modulating hepatic metabolism, focusing on HIF-1 alpha and sphingolipid metabolism. Methods: Using bioinformatics and molecular docking, HIF-1 alpha was identified as a key target in diabetic liver disease, confirmed via drug affinity responsive target stability. In vitro experiments utilized insulin-resistant HepG2 cells to assess glucose intake and HIF-1 alpha expression. In vivo, type 2 diabetes mellitus (T2DM) was induced in mice using a high-fat diet and streptozotocin injections. Pue administration was evaluated for its effects on fasting blood glucose, oral glucose tolerance, and hepatoprotective effects. Liver metabolomics and qPCR/Western blot analyses were conducted to assess metabolic pathways. Results: Pue increased glucose uptake in HepG2 cells and bound HIF-1 alpha. Pue reduced HIF-1 alpha expression in HepG2 cells, an effect attenuated by the HIF-1 alpha stabilizer DMOG. Pue improved fasting blood glucose, oral glucose tolerance, and hepatoprotective effects in T2DM mice, which DMOG reversed. Metabolomics revealed that Pue modulates sphingolipid metabolism, decreasing ceramide content. qPCR and Western blot results confirmed that Pue dramatically decreases HIF-1 alpha and SPTLC2 expression. Conclusions: Pue improves diabetic hepatopathy by reducing ceramide expression through the HIF-1 alpha/SPTLC2 pathway, offering a novel therapeutic strategy for diabetes management.