β-榄香烯对糖尿病大鼠视网膜中肿瘤坏死因子-α表达的影响

Effects of β-elemene on expression of TNF-α in retina of diabetic rats

目的探讨β-榄香烯对糖尿病大鼠视网膜肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)表达的影响。方法 10周龄SD大鼠36只,随机分为6组,除A组(每只大鼠腹腔注射等量的柠檬酸钠缓冲液)外其余组腹腔注射链脲佐菌素(streptozotocin,STZ)制成糖尿病大鼠模型,成模6周后,C组每只大鼠双眼球周给予空白乳剂5μL,D组双眼球周给予β-榄香烯5μL,E组每只大鼠同时双眼球内给予空白乳剂5μL,F组双眼球内给予β-榄香烯5μL,B组未采取局部注射作为对照。末次给药48 h后处死大鼠,取眼球固定视网膜行免疫组织化学法检测视网膜中TNF-α的表达情况;提取视网膜蛋白,采用Western Blot检测TNF-α蛋白的表达情况。结果免疫组织化学法检测结果显示:A组视网膜未见阳性染色,B组视网膜全层可见阳性表达,C组及E组阳性表达分布与B组相同,而D组及F组棕色阳性表达下降,其中F组更显著。Western Blot检测结果显示:C组及E组TNF-α蛋白的表达与A组相比差异均无统计学意义(均为P>0.05),B组较A组增高(P<0.01),而D组及F组表达与B组差异均有统计学意义(均为P<0.05)。结论β-榄香烯球周及球内注射均可降低糖尿病大鼠视网膜内TNF-α的表达,且眼内注射效果更好。

Objective To investigate the effects of β-elemene on the expression of TNF-αin the retina of diabetic rats.Methods Thirty-six 10-week-old Sprague-Dawley rats were randomly divided into control group（group A）,diabetic rats group（group B）,periocular compared group（group C）,periocular treating group（group D）,intraocular compared group（group E）,intraocular treating group（group F）.Group B,C,D,E were induced the diabetic model.Then,after 6 weeks of diabetic course,group C and D were treated with blank emulsion and β-elemene periocular injections,respectively;Meanwhile,group E and F were treated with blank emulsion and β-elemene intraocular injections,respectively.Then the retinas were fixed and immunohistochemical method was used to observe TNF-α expression in the retinas.Western Blot was used to measure the difference of TNF-α protein expression.Results Immunohistochemical results showed that no positive staining was seen in retina of group A,but seen in whole layer of group B,group C and E were same as group B,and the positive expression in group D and F decreased,especially group F.Western Blot showed that there was no statistical difference in TNF-α protein expression between group A and group C,group A and group E（all P〉0.05）,group B was higher than group A（P〈0.01）,there were statistical differences between group B and group D,group B and group F（all P〈0.05）.Conclusion β-elemene injected both periocularly and intraocularly can down-regulate the expression of TNF-α in the retina of diabetic rats,and the effect of intraocular injection is better.