番茄红素减轻糖尿病大鼠视网膜病变的作用及机制

目的 研究番茄红素(lycopene, LP)对大鼠糖尿病视网膜病变(diabetic retinopathy, DR)的作用及相关机制。方法 采用一次性腹腔注射链脲佐菌素(56 mg/kg)进行建模,并将成功建立的20只DR模型随机分为DR组和LP组,每组10只；另设10只正常大鼠为对照组(NC组)。LP组给予LP灌胃(60 mg/kg)治疗,NC组和DR组给予等量生理盐水灌胃,每日1次。干预8周后,放射免疫测定法测定各组大鼠血清中内皮素(endothelin,ET)和降钙素基因相关蛋白(calcitonin gene related protein,CGRP)的含量,免疫组化和蛋白质印迹法检测各组大鼠视网膜中血管内皮生长因子(vascular endothelial growth factor,VEGF)的表达。结果 与NC组比较,DR组的ET含量增高、CGRP含量降低、VEGF的表达增加(P<0.05)；与DR组比较,LP组的ET含量降低、CGRP含量增加、VEGF的表达降低(P<0.05)。结论 LP通过降低DR大鼠血清ET含量、提高CGRP含量、下调视网膜中VEGF的表达而减轻大鼠DR。

Protective effect of lycopene against diabetic retinopathy in rats and the related mechanism

Objective To study the protective effect of lycopene (LP) against diabetic retinopathy (DR) in rats and its related mechanism. Methods A single dose of streptozotocin (56 mg/kg) was injected intraperitoneally in SD rats to induce diabetes retinopathy (DR), and the 20 successful DR models were equally randomized into DR group and LP treatment group. Meanwhile, 10 normal rats served as normal control group (NC). LP group received LP gavage (60 mg/kg) once a day; NC and DR groups were gavaged with equivalent saline daily for 8 weeks. The serum levels of endothelin(ET) and calcitonin gene related protein(CGRP) were detected by using radioimmunoassay(RIA), and the expression of vascular endothelial growth factor (VEGF) in the retina was determined by immunohistochemistry and Western blotting analysis. Results The serum levels of ET and expression of VEGF in the retina were significantly increased in DR groups when compared with NC group (P<0.05), and the serum CGRP was significantly decreased (P<0.05); Compared with DR group, LP group had significantly lower VEGF expression and ET levels and significantly higher level of CGRP (P<0.05). Conclusion LP can protect against DR in rats by decreasing serum ET, increasing serum CGRP, and subsequent down-regulating VEGF expression.