Abstract：
This study investigated the effect of the addition of Lepidium meyenii (Maca) to the freezing extender on the post-thaw quality of dog semen. Ten canine ejaculates were frozen following a two-step protocol using a tris-glucose-citrate egg yolk extender with or without the addition of 10 µl/mL of aqueous extract of Maca (Maca and ctrl groups, respectively). Prior to (fresh semen) and after freezing (T0) sperm motility, kinetic parameters, viability and mitochondrial membrane potential (MMP), as well as the levels of malondialdehyde (MDA) were evaluated. In addition, sperm motility, kinetic parameters, viability and MMP were examined up to 2 h of incubation of 37 °C after thawing (T1 and T2) to evaluate thermo-resistance. The addition of Maca reduced MDA concentration at T0 (p < 0.05) and increased total motility, the percentage of sperm with medium velocity and WOB at T1. Progressive motility decreased (p < 0.05) at T1 in the ctrl group, whereas it was not affected in Maca group at any time point. In addition, the percentage of hyperactivated spermatozoa remained constant at T1 in the ctrl, while in the Maca group an increase (p < 0.05) of this parameter was recorded. Although no differences were found for MMP between groups at any time points, a decrease of viable sperm with low MMP was observed in ctrl group between T0 and T1 and in Maca group between T1 and T2. The addition of Maca prior freezing reduced the extent of lipid peroxidation and activated canine sperm motility and hyperactivation after thawing.
摘要：
这项研究调查了在冷冻补充剂中添加MeyeniiLepidium（Maca）对狗精液解冻后质量的影响。按照两步方案，使用tris-葡萄糖-柠檬酸盐蛋黄补充剂，在添加或不添加10μl/mL的玛卡水提取物（玛卡和ctrl组，分别)。前（新鲜精液）和冷冻后（T0）精子运动，动力学参数，活力和线粒体膜电位（MMP），以及丙二醛（MDA）的水平进行了评估。此外,精子运动性,动力学参数，在解冻后(T1和T2)37°C孵育2小时内检查活力和MMP以评估耐热性。添加Maca降低了T0时的MDA浓度（p<0.05）并增加了总运动性，T1时中等速度精子百分比和WOB。CTRL组T1时渐进性运动下降(p<0.05)，而在任何时间点，Maca组均未受到影响。此外,超激活精子的百分比在CTRL中的T1保持恒定，而在Maca组中,记录到该参数的增加(p<0.05)。尽管在任何时间点，各组之间的MMP均未发现差异，在T0和T1之间的ctrl组中，在T1和T2之间的Maca组中观察到低MMP的活精子减少。冷冻前添加Maca可降低脂质过氧化程度，并在解冻后激活犬精子活力和过度活化。
