| Ovary is an important reproductive organ of female animals,and its function determines fertility.The decline of ovarian function caused by aging is an irreversible natural physiological process and is characterized mainly by the depletion of follicle reserve and low oocyte quality.Siraitia grosvenorii,mainly distributed in the subtropical regions of southern China,is a characteristic economic crop in Guangxi province and has both medicinal and edible properties.Its main active ingredient,mogroside,has anti-inflammatory,antioxidant,hypoglycemic,hypolipidemic effects,etc.Our research group recently revealed that mogroside can promote oocyte maturation and alleviate oocyte damage caused by various stresses.Given the above facts,we speculated that mogroside-rich extract(MGE)can delay the decline of ovarian function caused by aging.In this study,we took mice as the research object to explore the delaying effect of MGE on ovarian function decline in aged mice,and preliminarily explored its mechanism.The main research contents and results are as follows:1.MGE can delay the ovarian function decline in aged miceTo explore the delaying effect of MGE on ovarian function decline in aged mice,the young group(10 weeks old),the old group(normal drinking water from 10 to 44 weeks of age)and MGE treatment group(drinking water supplemented with 600 mg/kg/day MGE from 10 to 44 weeks of age)were established.The results showed that the glucose tolerance and insulin sensitivity were significantly increased in MGE treatment group compared with the old group(P < 0.05 and P < 0.01),indicating that MGE can alleviate the metabolic abnormalities caused by aging.Monitoring mouse estrous cycle changes of mice found that MGE treatment could ameliorate estrous cycle disorder in aged mice.Moreover,the ovarian follicle reserve was significantly increased(P < 0.01),the ovarian fibrosis was significantly decreased(P < 0.05),and ovarian antioxidant levels were significantly increased(P<0.05)in MGE-treated mice compared with the aged ones.We also found that the ovulation number in MGE-treated mice was significantly higher than that of aged ones(P<0.0001)with improved cell morphology.In addition,MGE can promote in vitro maturation and early embryonic development of oocytes from aged mice,principally reflected in a significant increase in the oocyte polar body excretion rate,two cell rate,blastocyst rate,and blastocyst cell number(P < 0.0001,0.05,0.05 and 0.05,respectively).The above results illustrated that MGE can alleviate ovarian function decline in aged mice.2.MGE can improve ovarian inflammatory microenvironment in aged miceTo explore the molecular mechanism of MGE delaying ovarian function decline in aged mice,transcriptome sequencing analysis was performed on the ovarian tissues of three groups.Differential expressed genes(DEGs)analysis revealed that a total of 1160 shared up-regulated DEGs and 1096 shared down-regulated DEGs were identified between the young group and MGE treatment group compared with the old group.GO analysis showed that MGE could improve gonadal development,follicle development,and steroid hormone biosynthesis;and inhibit the tumor necrosis factor production,leukocyte cell-cell adhesion,and T cell activation.KEGG analysis showed that up-regulated DEGs were enriched in the cell cycle,progesterone-mediated oocyte maturation,and TGF-βsignaling pathway.The down-regulated DEGs were enriched in phagosomes,cell adhesion molecules,antigen processing and presentation,and NF-kappa B signaling pathway.Given that down-regulated KEGG pathways were strongly related to the inflammatory response,we screened inflammation-related genes(Tnfα,Il6 ra,Il10rb,Il2,Tgfb1,and Lc3)for q RT-PCR validation,and the results unanimously confirmed that MGE significantly downregulated the expression of these genes in the ovaries of aged mice(P<0.05、0.01、0.01、0.05、0.05 and 0.001,respectively).In addition,MGE treatment can significantly reduce ovarian TNF-α levels compared with the aged model(P<0.05).The above results suggested that MGE may delay ovarian function decline in aged mice by improving the ovarian inflammatory microenvironment.In summary,this study found that MGE can delay ovarian function decline in aged mice,which may be related to the improvement of ovarian inflammatory microenvironment.The results of this study provide a reference support for anti-ovarian aging of MGE and lay a foundation for its application in reproductive medicine and animal husbandry production. |
PDF Full Text Request