Abstract:

Objective To explore the effect of Huangqi Yanghe Decoction on wound healing of diabetic foot ulcer (DFU) rats based on phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/nuclear factor-κB (NF-κB) signal pathway. Methods DFU rat model was constructed, and 48 rats successfully modeled were randomly divided into the model group, the Huangqi Yanghe Decoction low (8.5 g/kg) group, the Huangqi Yanghe Decoction high (17 g/kg) dose group and the Huangqi Yanghe Decoction high dose (17 g/kg)+LY294002 (PI3K/AKT pathway inhibitor, 0.3 mg/kg) group. There were 12 rats in each group. Another 12 rats were selected as the control group. Rats in each group were given corresponding drug intervention for 4 weeks. After the 14th and 28th day-administration, the general state and wound changes of rats were observed, and the wound healing rate was calculated. The fasting blood glucose (FBG) level of rats was measured, and the percutaneous partial pressure of oxygen (TcpO₂) of tissue around the wound was detected. Serum levels of vascular endothelial growth factor (VEGF), hypoxia inducible factor-1α (HIF-1α), C-reactive protein (CRP) and interleukin (IL)-6 were determined by enzyme linked immunosorbent assay. Histopathological changes of the wound were observed by hematoxylin-eosin staining. Immunohistochemical staining was used to measure the microvascular density of rat wound tissue. The protein expression levels of PI3K, phosphorylated PI3K (p-PI3K), AKT, phosphorylated AKT (p-AKT), NF-κB p65, phosphorylated NF-κB p65 (p-NF-κB p65) and NF-κB inhibitory protein α (IκB-α) in rat wound tissue were determined by Western blot assay. Results Rats in the control group had smooth hair color, normal diet, drinking water and excretion, more active, wound healing fast, less inflammatory reaction in wound tissue, and there were more new blood vessels. Fibroblasts and collagen matrix were abundant in granulation tissue. In the model group, the fur color of rats was dull and matte, and the activity was reduced. The symptoms of polydipsia, polyphagia and polyuria were appeared in the model group, the wound color was dark, and edema and ulcer appeared in the surrounding tissue, a large number of inflammatory cells infiltrated in the wound tissue, accompanied by tissue necrosis and exudation, fewer neovascularization and fibroblasts were observed. Wound healing rate, TcpO₂ in wound surrounding tissue, serum VEGF, HIF-1α, microvascular density, p-PI3K, p-AKT and IκB-α protein expression levels in wound tissue were decreased, and FBG, serum CRP, IL-6, p-NF-κB p65 protein expression in wound tissue were increased (P<0.05). Compared with the model group, the state of rats was gradually improved in the Huangqi Yanghe Decoction low and high dose groups, and the lesion degree of wound tissue was reduced successively, wound healing rate, TcpO₂ in wound surrounding tissue, serum VEGF, HIF-1α, microvascular density, p-PI3K, p-AKT and IκB-α protein expression levels in wound tissue were increased in turn (P<0.05). The FBG, serum CRP, IL-6 and p-NF-κB p65 protein expression in wound tissue were decreased in turn (P<0.05). LY294002 could partially reverse the therapeutic effect of high-dose Huangqi Yanghe Decoction on DFU rats (P<0.05). Conclusion Huangqi Yanghe Decoction can regulate PI3K/AKT/NF-κB pathway, inhibit inflammatory response in DFU rats, promote angiogenesis and thus promote wound healing.

Key words: Huangqi Yanghe Decoction, diabetic foot ulcer, wound healing, phosphatidylinositol 3-kinase, protein kinase B, nuclear factor-κB