RESUMO
OBJECTIVE To investigate the effects of andrographolide （Andro） on angiogenesis in rats with diabetic foot and to explore its mechanism of action based on the Hippo-Yes-associated protein （YAP） signaling pathway. METHODS The rat model of type 2 diabetes was established by using low-dose streptozotocin combined with high-fat and high-glucose diet. On the basis of successful modeling， the rat model of diabetes foot was established by scalding. Model rats were randomly divided into 5 groups with 12 rats in each group： model group， Andro low-dose， medium-dose， and high-dose groups （1， 10， and 20 mg/kg）， as well as inhibitor group （20 mg/kg Andro+100 mg/kg of verteporfin， an specific inhibitor of Hippo-YAP signaling pathway）； other 12 healthy rats were included in the Control group. Rats in each group were intragastrically and intraperitoneally injected with solvents or corresponding drugs， once a day， for 2 consecutive weeks. The wound healing， fasting blood glucose （FBG） and fasting insulin （FINS） were detected in rats after medication. HE staining was performed to observe the tissue damage and capillary number of rat trauma； the number of endothelial progenitor cells （EPCs） in peripheral blood of rats was counted by using flow cytometry； the contents of serum total cholesterol （TC）， triglyceride （TG）， high-density lipoprotein cholesterol （HDL-C） and low-density lipoprotein cholesterol （LDL-C） in rats were determined by fully automatic biochemical analyzer； the expressions of hypoxia- inducible factor 1α （HIF-1α）， vascular endothelial growth factor （VEGF） and Hippo-YAP signaling pathway-related proteins in the traumatic tissues of rats in each group were detected by Western blot. RESULTS Compared with Control group， the wound healing rate， capillary number， the proportion of EPCs， HDL-C content， as well as the protein expression levels of HIF-1α and VEGF and the phosphorylation levels of mammalian Ste20-like kinase 1， large tumor suppressor gene 1 and YAP proteins were significantly reduced in the model group， while the FBG， FINS levels and TC， TG and LDL-C contents were significantly increased （P＜0.05）. Compared with model group， the above indexes were significantly reversed in Andro low-dose， medium-dose and high-dose group， in a dose-dependent manner （P＜ 0.05）； verteporfin attenuated the above reversal effect of Andro （P＜0.05）. CONCLUSIONS Andro has the effects of lowering blood glucose and blood lipids， promoting blood vessel formation and wound healing in rats with diabetic foot， and its mechanism of action may be related to the activation of Hippo-YAP signaling pathway.