枸杞多糖对获能新鲜和冻后猪精子抗氧化能力的影响

Effects of Lycium barbarum polysaccharide on antioxidant capacity of capacitated fresh and frozen-thawed boar sperm

为探究枸杞多糖(LBP)对猪精子获能过程中抗氧化功能的影响,用不同浓度LBP(2、4、8和16 mg/mL)处理获能过程中的猪精子,测定精子活率、线粒体活性、顶体完整率和质膜完整性,筛选出最适LBP浓度,进一步测定最适浓度下的抗氧化指标。另外,以氧化激动剂氯化镉孵育猪精子后,用RT-qPCR方法分析SOD-1和Caspase-8处理前后的相对表达量。结果表明:LBP浓度分别为2 mg/mL和8 mg/mL时,鲜精和冻精质量较空白组显著提高(P<0.05)。鲜精和冻精获能试验组总抗氧化能力和超氧化物歧化酶活性较获能空白组显著增加(P<0.05),丙二醛含量差异不显著(P>0.05)。加氯化镉诱导氧化应激后,新鲜精子和冻后精子获能试验组较获能空白组SOD-1 mRNA表达量均显著上调(P<0.05),Caspase-8 mRNA表达量显著下调(P<0.05)。结论:添加LBP能够在一定程度上提高获能新鲜和冻后猪精子抗氧化能力。

To explore the effect of Lycium barbarum polysaccharide(LBP) on the antioxidant capacity in the capacitation process of boar spermatozoa, boar spermatozoa samples in the capacitating process were treated with different concentrations(2, 4, 8, 16 mg/mL) of LBP. Then, the viability, mitochondrial activity, acrosomal integrity, and plasma membrane integrity of the spermatozoa were determined, and the optimal LBP concentration was selected to further determine the antioxidative index of the samples at the optimal concentration. In addition, the relative expression levels of SOD-1 and Caspase-8 before and after spermatozoa being treated with the oxidative agonist were analyzed by RT-qPCR. The results were that, compared with the blank control group, when the LBP concentrations were 2 mg/mL and 8 mg/mL, respectively, the quality of the fresh and frozen thawed semen were significantly improved(P<0.05);the total antioxidant capacity and superoxide dismutase activity in the test group of capacitated fresh and frozen thawed sperms were significantly increased(P<0.05), but its malondialdehyde content was not significantly different(P>0.05). After the oxidative stress induced by the addition of cadmium chloride, the expression of SOD-1 mRNA in fresh and frozen thawed sperm in the capacitated test groups was significantly increased, compared with that in the blank capacitated blank groups(P<0.05). The expression of Caspase-8 mRNA in the fresh and frozen thawed sperm capacitated test group was significantly decreased, compared with capacitated blank group(P<0. 05). In conclusion, LBP could improve the antioxidant ca-pacity of fresh and frozen thawed boar sperms.