NMR-based metabolomic analysis for the effects of Huiyang Shengji extract on rat diabetic skin ulcers.

Abstract Ethnopharmacological relevance Huiyang Shengji formula (HSF) is a compound Chinese herbal medicine prescription, and has long been used for treating chronic non-healing wounds. Aim of the study The purpose of this study was to elucidate the molecular mechanisms of HSF's healing effects. Materials and methods We established a rat diabetic skin ulcer (DSU) model, and assessed effects of four HSF treatments on DSUs by calculating wound healing rates and immunohistochemical detection of the expressions of angiogenesis-related factors in the model rats (Mod) relative to normal rats (Nor), including Huiyang extract (HE), Shengji extract (SE), Huiyang Shengji extract (HSE) and HSE associated with acupuncture (Ac-HSE). We then performed NMR-based metabolomic analyses on skin tissues of the Nor, Mod, HSE-treated, Ac-HSE-treated rats to address metabolic mechanisms underlying these effects. Results These treatments up-regulated expressions of two angiogenesis-related factors VEGF and CD31, and improved healing of DSUs, in which HSE and Ac-HSE exhibited the most significant effects. Compared with Mod, HSE and Ac-HSE groups shared four characteristic metabolites (lactate, histidine, succinate and acetate) and four significantly altered metabolic pathways with Nor. Both HSE and Ac-HSE treatments could partly reverse the metabolically disordered pathological state of DSUs to the normal state. They can enhance energy production though promoting glycolysis, improve TCA cycle through promoting BCAAs metabolism, and enhance antioxidant capacity and angiogenesis in DSUs. The Ac-HSE treatment significantly enhanced wound healing rates compared to HSE, potentially owing to significant capacities of enhancing anti-oxidation and angiogenesis and interfering three more metabolic pathways. Conclusions This work provides a mechanistic understanding of the effects of HSE and Ac-HSE treatments on DSUs, is of benefit to improvements of the HSF treatments for clinically healing chronic non-healing wounds.