白藜芦醇对奥沙利铂所致大鼠周围神经毒性的保护作用及机制研究

Protective Effect and Mechanism of Resveratrol on Peripheral Nerve Toxicity Induced by Oxaliplatin in Rats

目的探讨白藜芦醇对奥沙利铂所致大鼠周围神经毒性的保护作用及其分子机制。方法将雄性SD大鼠60只随机分为正常对照组,模型对照组,白藜芦醇低、中、高剂量,每组12只。除正常对照组外,其他各组均腹腔注射奥沙利铂4 mg·kg^(-1),同时分别灌胃给予溶媒或不同浓度白藜芦醇,定期检测机械和温度刺激下大鼠行为变化。规定时间处死大鼠,HE染色观察L_(4～5)背根神经节神经元形态,Western Blot检测L_(4～5)背根神经节凋亡相关蛋白Bax、Bcl-2、Cleaved-caspase-3表达水平变化。结果与正常对照组相比,模型对照组大鼠从第7天开始机械缩足反射阈值显著下降(P<0.05),从第15天开始对冷刺激的缩足反射次数显著升高(P<0.05),L_(4～5)背根神经节部分神经元核膜轮廓模糊甚至消失,核仁固缩明显,Bcl-2蛋白表达水平显著下降(P<0.01),Bax和Cleaved-caspase-3蛋白表达水平显著升高(P<0.05,P<0.01);而白藜芦醇可显著提高机械缩足反射阈值,降低冷刺激的缩足反射次数,且呈剂量依赖性;可改善奥沙利铂所致L_(4～5)背根神经节神经元形态异常,显著提高L_(4～5)背根神经节Bcl-2蛋白表达水平(P<0.05),显著降低L_(4～5)背根神经节Bax和Cleavedcaspase-3蛋白表达水平(P<0.05,P<0.01)。结论白藜芦醇能显著改善奥沙利铂所致大鼠周围神经毒性(机械刺激与冷刺激),其作用机制可能与提高Bcl-2蛋白表达水平、降低Bax和Cleaved-caspase-3蛋白表达水平有关。

Objective To explore the protective effects of resveratrol on the improvement of peripheral nerve toxicityinduced by oxaliplatin and its molecular mechanism in rats. Methods Male SD rats were randomly divided intocontrol group, model group, the low-, medium-and high-dose resveratrol groups. Except the control group,peripheral nerve toxicity rat models were established by intraperitoneal injection with oxaliplatin(4 mg · kg^-1),meanwhile, different doses of resveratrol were given by gavage. The behavior changes of rats under mechanicalstimulation and temperature were observed at different time points. At the end of the experiment, rats weresacrificed, the morphology of neurons of L4-5dorsal root ganglion were observed by HE staining, the relativeexpression levels of Bax,Bcl-2 and Cleaved-Caspase-3 in L4-5dorsal root ganglion were detected by Western Blot.Results When compared with the control group,the mechanical withdrawal threshold was significantly decreasedfrom 7th day(P < 0.05) and the counts of cold stimulation reflex were significantly increased from 15thday(P <0.05) in the model group. Furthermore,nucleus membrane of some neurons were blurred or disappeared and the pyknotic nucleolus appeared in L4-5dorsal root ganglion. In addition,the protein expression levels of Bcl-2 in L4-5dorsal root ganglion were significantly reduced(P < 0.01),while the protein expression levels of Bax and Cleaved-Caspase-3 were significantly increased(P < 0.05,P < 0.01). Conversely,resveratrol significantly elevated thethreshold of mechanical withdrawal and significantly decreased the counts of cold stimulation reflex in a dose-dependent manner. In addition,resveratrol improved the abnormal morphology of oxaliplatin-induced L4-5dorsal rootganglion, significantly increased the expression levels of Bcl-2 protein(P < 0.05), significantly decreased theexpression levels of Bax and Cleaved-Caspase-3 proteins in L4-5dorsal root ganglion(P < 0.05, P < 0.01).Conclusion Resveratrol reduces oxaliplatin-induced peripheral nerve toxicity by increasing the expression level ofBcl-2 protein and decreasing the expression levels of Bax and Cleaved-Caspase-3 proteins.