葡萄籽原花青素对急性镉染毒大鼠肾细胞DNA损伤的影响

Effect of Grape Seed Proanthocyanidins on DNA Oxidative Damage in Rat Kidney Cells Exposed to Cadmium

目的探讨葡萄籽原花青素(grape seed proanthocyanidins,GSP)对氯化镉染毒大鼠肾细胞DNA损伤的拮抗作用。方法将32只健康雄性SPF级SD大鼠按体重随机分为4组,分别为对照组(腹腔注射、灌胃生理盐水)、镉染毒组(腹腔注射1.5 mg/kg氯化镉溶液和灌胃生理盐水)和低、高剂量GSP干预组(腹腔注射1.5 mg/kg氯化镉,同时,分别灌胃20、40 mg/kg GSP溶液),每组8只。腹腔注射和灌胃染毒容量分别为3、5 ml/kg,连续染毒14 d。采用单细胞凝胶电泳技术(SCGE)检测肾细胞的DNA损伤,采用实时荧光RT-PCR技术检测c-jun N末端激酶(JNK)、p38丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)mRNA的表达。结果与对照组比较,镉染毒组大鼠肾脏细胞DNA的尾长、Olive尾矩、尾矩均显著升高,差异具有统计学意义(P<0.05)。低、高剂量GSP干预组大鼠肾脏细胞的DNA损伤均高于对照组,但差异无统计学意义。各剂量GSP干预组大鼠肾脏细胞DNA的尾长、Olive尾矩、尾矩均显著低于镉染毒组差异有统计学意义(P之0.05)。且随着GSP染毒剂量的升高,镉染毒大鼠肾脏细胞的尾长、Olive尾矩、尾矩均呈下降趋势。与镉染毒组比较,各剂量GSP干预组大鼠肾脏细胞中JNK mRNA的表达水平均显著下降,差异有统计学意义(P<0.05);而p38 MAPK mRNA的表达水平无显著变化。结论 GSP可能通过降低MAPK信号通路中JNK的表达拮抗氯化镉诱发的大鼠肾细胞DNA损伤效应。

Objective To explore the effect of grape seed proanthocyanidins （GSP） on DNA oxidative damage in kidney cells in rat exposed to CdC12. Methods Thirty-two SD rats of SPF grade were randomly divided into four groups, control group（normal saline through garage）, CdClz exposure-positive group （intraperitoneal injection of 1.5 mg/kg CdC12 and normal saline through gavage）, GSP low and high-dose intervention group （intraperitoneal injection of 1.5 mg/kg CdClz and 20 mg/kg, 40 mg/kg GSP through gavage, respectively）, eight in each group. The volume for intraperitoneal injection and gastric perfusion were 3.0 ml/kg and 5.0 ml/kg, respectively, for 14 consecutive days. DNA oxidative damage was measured by single cell gel eletrophoresis （SCGE） and real-time RT-PCR was used to detect the relative expression of JNK mRNA and p38 MAPK mRNA. Results CdC12 at a dosage of 1.5 mg/kg could induce a significant DNA oxidative damage （tail length, Olive tail moment, tail moment） and the DNA damage level in GSP intervention groups was obviously lower than CdC12 exposure-positive group. DNA damage level in GSP intervention groups was higher than that in normal control group, however, compared with CdC12 exposure-positive group, it decreased signifieantly in dose-effect manner. At the same, compared with CdCI： exposure-positive group, the relative expression of JNK mRNA in GSP intervention groups decreased remarkably, whereas expression of p38 MAPK mRNA did not change significantly. Conclusion GSP has an obvious activity of inhibiting and delaying DNA damage caused by cadmium,which may mitigate the renal further damage through down-regulating JNK mRNA expression in MAPK signal pathway.