银杏叶提取物对db/db糖尿病小鼠胰岛功能的影响

摘要

目的 探讨银杏叶提取物EGb761对胰岛分泌功能的影响及相关机制.方法 10只8周龄db/db小鼠随机分为两组,观察组(EGb761组)和糖尿病对照组(db/db组),每组各5只,分别给予EGb761 100 mg/(kg·d)和安慰剂灌胃.另选5只同周龄db/m小鼠给予安慰剂灌胃作为非糖尿病对照(db/m组).每周监测体重、血糖,8周后行腹腔葡萄糖耐量试验并取胰腺行免疫组化检测,分析胰岛内烟酰胺腺嘌呤二核苷酸磷酸(nicotinamide adenine dinucleotide phosphate,NADPH)氧化酶表达情况.结果 EGb761组血糖、胰岛素分泌功能和胰岛素敏感性、胰岛内NADPH氧化酶gp91 phox、p22phox亚基的表达水平、胰岛质量显著改善.结论 EGb761能够降低NADPH氧化酶的表达,减少氧化应激的来源,改善胰岛微环境,从而保护胰岛β细胞.%Objective To explore the effects of Ginkgo biloba extract 761 on islet function in db/db mice and relative mechanisms.Methods Ten db/db mice aged 8 weeks were randomized to EGb761 group and db/db group,fed with 100 mg/(kg · d) and placebo respectively.Five age-matched db/misty mice were concurrently treated with placebo as non-diabetic control group.Body weight and fasting blood glucose were measured every week.After 8 weeks' treatment,intraperitoneal glucose tolerance test was performed and immunohistochemical staining of NADPH oxidase subunit gp91phox and p22phox were determined.Results Eight weeks' EGb761 treatment improved glucose tolerance,insulin secretory function and insulin sensitivity.And EGb761 treatment greatly decreased staining intensity of oxidative stress sources including p22phox and gp91phox in islets,thus preserved islet mass.Conclusion EGb761 treatment remarkably decreased expression level of NADPH oxidase in β-cells,and prevented the damage from excess oxidative stress,thus protected β-cell function.