Effects Of Gynostemma Pentaphyllum Polysaccharide On Oxidative Damage Of Mouse Oocytes Induced By H₂O₂

In order to investigate the effect of Gynostemma pentaphyllum polysaccharides（GPP）on oxidative damage in mouse oocytes induced by H₂O₂,and provide a theoretical basis for reducing damage to mouse and other mammalian oocytes from oxidative stress during in vitro maturation（IVM）,GPP was added to IVM culture medium to detect the embryonic development ability,apoptosis,apoptosis-related genes（Bcl-2,Bax,Caspase-9）,production of antioxidant enzymes,content of MDA and ROS,mitochondrial activity,mitochondrial membrane potential,ATP content,spindle morphology,and chromosomal arrangement of phase II oocytes in each group.The results found that:1.The first polar body（PB1）excretion rate of 200μMtreatment group was significantly lower than those of the control groupand 100,150μM H₂O₂group（P<0.05）,and significantly higher than 250,300,350,400μM H₂O₂group（P<0.05）;The PB1 excretion rate of mouse oocytes in the 200μM H₂O₂+200μg/m L GPP group was significantly higher than that in the H₂O₂group and other GPP groups（P<0.05）,so 200μM H₂O₂was selected establish a mouse oxidative stress model in vitroculture（P<0.05）,and the optimal concentration for GPP was 200μg/m L.2.The cleavage rate,4-cell rate,8-cell rate,16-cell rate,and blastocyst rate of mouse oocytes in the H₂O₂+GPP group after parthenogenetic activation and in vitro fertilization were significantly higher than those in the H₂O₂group（P<0.05）,but there was no significant difference compared to the control group.3.After annexin V-m Cherry labeling,there was no significant difference in the early apoptosis rate of oocytes between the H₂O₂+GPP group and the control group,but both were significantly lower than the H₂O₂group（P<0.05）;After q RT PCR and immunofluorescence labeling,the expression of Bcl-2m RNA and protein in the H₂O₂+GPP group mouse oocytes was significantly higher than that in the H₂O₂group（P<0.05）,Bax m RNA and protein expression were significantly lower than those in the H₂O₂group（P<0.05）,and Caspase-9 protein expression was significantly lower than that in the H₂O₂group（P<0.05）,with no significant difference compared to the control group.4.The levels of SOD and GSH in the H₂O₂+GPP group were significantly higher than those in the H₂O₂group（P<0.05）,while the contents of ROS and MDA were significantly lower than those in the H₂O₂group（P<0.05）,with no significant difference compared to the control group.q RT PCR detection found that the expression of SOD m RNA and GSH m RNA in the H₂O₂+GPP group and control group mouse oocytes were significantly higher than that in the H₂O₂group（P<0.05）,with no significant difference compared to the control group.5.The mitochondrial content,mitochondrial membrane potential and ATP content of mouse oocytes in the H₂O₂+GPP group were significantly higher than those in the H₂O₂group（P<0.05）,while the rates of spindle abnormality and chromosome abnormality were significantly lower than those in the H₂O₂group（P<0.05）,with no significant difference compared to the control group.In summary,200μg/m L GPP was added to the IVM medium can help improve the quality of oxidatively damaged mouse oocytes,enhance early embryonic development ability,reduce early apoptosis rate,upregulate the expression level of anti apoptotic genes,downregulate the expression level of pro apoptotic genes,enhance the antioxidant effect of mouse oocytes,increase mitochondrial content,ATP content,spindle and chromosome morphology normalization rate,and reduce mitochondrial dysfunction.