原花青素对镉引起的鸡胚睾丸氧化损伤的缓解作用

为探索原花青素对镉引起的鸡胚睾丸氧化损伤的缓解作用,本实验设置了对照组、镉、葡萄籽提取物原花青素(grape seed proanthocyanidin extract,GSPE)和镉+GSPE组,在胚胎期第6.5天(E6.5)注射0.05 mg·kg-1镉或2.5 mg·kg-1GSPE,统计孵化率和睾丸指数,并在E17.5检测睾丸形态、氧化指标、细胞凋亡和内质网应激相关基因的表达情况。结果表明:与对照组相比,镉处理组孵化率和睾丸指数均显著降低;睾丸组织结构出现了细胞核固缩、空泡化和染色质周缘化等变化,过氧化氢和丙二醛水平升高、超氧化物歧化酶活性显著降低、谷胱甘肽含量明显减少,凋亡细胞显著增多;睾丸中抗凋亡基因Bcl-2 mRNA表达水平下降,同时促凋亡基因Caspase3和内质网应激相关基因(XBP-1和HO-1)mRNA表达水平显著上升。然而,GSPE联合处理,明显缓解了镉引起的睾丸损伤,使孵化率和睾丸指数回升,抗氧化水平和内质网应激得到改善,凋亡细胞显著减少,睾丸形态趋于正常。结果表明:GSPE可通过其抗氧化作用降低XBP-1相关的内质网应激基因的表达,从而缓解镉引起的鸡胚睾丸生殖毒性。

Ameliorative Effect of Grape Seed Proanthocyanidin Extract on Cadmium-induced Testicular Oxidative Damage in Chicken Embryos

This study was conducted to explore the ameliorative effect of grape seed proanthocyanidin extract (GSPE) on cadmium (Cd)-induced testicular oxidative damage in chicken embryos. Embryos of 6.5 days (E6.5) were injected with or without Cd (0.05 mg?kg-1) in the presence or absence of GSPE (2.5 mg?kg-1), then the hatchability and testis index were made statistically. Additionally, testicular morphology, parameters related to oxidative damage, apoptosis and the expression of endoplasmic reticulum (ER) stress related genes (XBP-1 and HO-1) mRNA were all measured at E17.5. The results showed that Cd exposure significantly reduced the hatchability and testis index, with the lesions of testis characterized by karyopyknosis, vacuolation and chromatin margination, compared with the control group. Cd exposure resulted in increased H2O2 and malondialdehyde level, reduced superoxide dismutase activity and glutathione level, enhanced apoptotic cells in the testis as well. Meanwhile, Cd exposure also down-regulated Bcl-2 mRNA level, up-regulated the expression of caspase-3, XBP-1 and HO-1 mRNA. However, GSPE supplementation attenuated the Cd-induced oxidative damage, along with the increase of hatchability and testis index, the improvement of antioxidant level and ER stress, the marked decrease of apoptotic cells, and the testicular morphology tended to be normal. In conclusion, GSPE via the antioxidative ability could ameliorate the Cd-induced testicular reproductive toxicity in chicken embryos by decreasing the expression of XBP-1 related ER stress genes mRNA.