白花檵木有效部位治疗糖尿病皮肤溃疡机制研究

Mechanism of Loropetalum chinensis in treatment of diabetic skin ulcer

目的研究白花檵木醇提物(ethanol extract of Loropetalum chinensis,EELC)治疗糖尿病皮肤溃疡的分子机制。方法采用体外表皮干细胞(epidermal stem cells,ESCs)培养技术与双荧光素酶报告基因检测系统研究EELC治疗糖尿病皮肤溃疡的分子机制。结果 EELC中含有山柰酚、檞皮素、杨梅素、没食子酸。ESCs经EELC处理48 h后,Western blotting检测表明Wnt信号通路相关的Wnt、β-catenin与C-myc蛋白表达上调,且与EELC剂量呈正相关(P<0.01)。经双荧光素酶报告基因检测系统进一步验证了EELC对Wnt信号通路的靶向作用。结论 EELC激活经典Wnt信号通路,促使β-catenin关键蛋白积累,进入细胞核内与转录因子结合,激活下游特异靶基因表达,促进ESCs增殖、分化,有效地修复糖尿病溃疡皮肤创面。

Objective To study the molecule mechanism of ethanol extract of Loropetalum chinensis（EELC） in the treatment of diabetic skin ulcer. Methods In vitro epidermal stem cell（ESCs） culture technique and dual luciferase reporter gene detection system were used to study the mechanism of EELC in the treatment of diabetic skin ulcer. Results Totally 232.8 g powder was extracted from 4.5 kg Loropetalum chinensis by 75% ethanol, and the main ingredient was polyphenol. After treating for 48 h with different doses of EELC（50 and 100 μg/mL）, the expression of WNT protein, β-catenin protein and C-myc protein was all up-regulated, and was positively correlated with the dose effect（P〈0.01）. The target effect of EELC on the Wnt signaling pathway was further identified by the dual luciferase reporter gene assay system. Conclusion The results suggested that EELC could activate canonical Wnt signaling pathway, promote β-catenin protein accumulation in combination with transcription factor in the nucleus to activate the expression of specific target genes, promote ESCs proliferation and differentiation, and repair skin wounds of diabetic ulcers effectively as well.