Oleanolic acid promotes porcine oocyte maturation by activating the Nrf2/HO-1 signalling pathway.

This study investigated the potential role and underlying mechanisms of oleanolic acid (OA), a pentacyclic triterpene with antioxidant and anti-inflammatory properties, in porcine oocytes during in vitro maturation (IVM). The results showed that supplementation with 5 µM OA during IVM resulted in a greater percentage of mature oocytes, parthenogenetically activated embryos and somatic cell nuclear-transferred embryos. This was evidenced by significant increases in the rate of first polar body expulsion, the expansion of cumulus granulosa cells and the total cell number in blastocysts. Further analysis revealed that OA promoted fatty acid accumulation and upregulated the mRNA expression of genes involved in fatty acid ß-oxidation. OA significantly increased the intracellular mitochondrial membrane potential and ATP levels and effectively inhibited BAX/BCL2 and Cleaved Caspase3 protein expression. Notably, OA increased the protein levels of intracellular Nrf2 and HO-1, and the GSH levels and the activities of the antioxidant enzymes SOD and catalase (CAT), while reducing ROS levels. Mechanistically, OA activated the Nrf2/HO-1 signalling pathway, which is crucial for regulating the expression of antioxidant-related targets in IVM porcine oocytes. Our findings indicated that OA improved antioxidant capacity by activating the Nrf2/HO-1 signalling pathway, thereby promoting porcine oocyte maturation.

Oleanolic acid improves the in vitro developmental competence of early porcine embryos by reducing oxidative stress and ameliorating mitochondrial function.

Objective: Oleanolic acid (OA) is a pentacyclic triterpenoid with antioxidant activity that can be an effective scavenger of free radicals in cells. This study was designed to investigate the effects of OA on porcine early embryo developmental competence in vitro and its possible mechanisms of action. Methods: In the present study, parthenogenetically activated porcine embryos were used as models to assess the effect of OA on the in vitro developmental capacity of early porcine embryos in vitro. Zygotic genome activation, mitochondrial function, oxidative stress, cell proliferation and apoptosis in early porcine embryos were examined after supplementing the culture medium with 5 µM OA. Results: The results showed that 5 µM OA supplementation not only significantly increased the blastocyst diameter in early porcine embryos on day 6 but also increased the total number of blastocysts. Furthermore, OA supplementation increased the blastocyst proliferation rate and decreased blastocyst apoptosis. Moreover, OA supplementation significantly increased the proportion of embryos that developed to the 4-cell stage after 48 h of in vitro culture and upregulated the expression of genes associated with zygotic genome activation (DPPA2 and ZSCAN4). Notably, OA alleviated oxidative stress by reducing the intracellular levels of reactive oxygen species and increasing the intracellular levels of reduced glutathione at the 4-cell stage and increased the activities of superoxide dismutase and catalase. Concurrently, OA significantly increased the mitochondrial membrane potential and intracellular ATP content. Conclusion: These results suggest that OA promotes the in vitro developmental competence of parthenogenetically activated porcine embryos by reducing oxidative stress and improving mitochondrial function during in vitro culture and that OA may contribute to the efficiency of in vitro embryo production.

Chlorogenic acid improves the development of porcine parthenogenetic embryos by regulating oxidative stress and ameliorating mitochondrial function.

Chlorogenic acid (CGA) is an effective phenolic antioxidant that can scavenge hydroxyl radicals and superoxide anions. Herein, the protective effects and mechanisms leading to CGA-induced porcine parthenogenetic activation (PA) in early-stage embryos were investigated. Our results showed that 50 µM CGA treatment during the in vitro culture (IVC) period significantly increased the cleavage and blastocyst formation rates and improved the blastocyst quality of porcine early-stage embryos derived from PAs. Then, genes related to zygotic genome activation (ZGA) were identified and investigated, revealing that CGA can promote ZGA in porcine PA early-stage embryos. Further analysis revealed that CGA treatment during the IVC period decreased the abundance of reactive oxygen species (ROS), increased the abundance of glutathione and enhanced the activity of catalase and superoxide dismutase in porcine PA early-stage embryos. Mitochondrial function analysis revealed that CGA increased mitochondrial membrane potential and ATP levels and upregulated the mitochondrial homeostasis-related gene NRF-1 in porcine PA early-stage embryos. In summary, our results suggest that CGA treatment during the IVC period helps porcine PA early-stage embryos by regulating oxidative stress and improving mitochondrial function.

Maslinic Acid Supplementation during the In Vitro Culture Period Ameliorates Early Embryonic Development of Porcine Embryos by Regulating Oxidative Stress.

As a pentacyclic triterpene, MA exhibits effective free radical scavenging capabilities. The purpose of this study was to explore the effects of MA on porcine early-stage embryonic development, oxidation resistance and mitochondrial function. Our results showed that 1 µM was the optimal concentration of MA, which resulted in dramatically increased blastocyst formation rates and improvement of blastocyst quality of in vitro-derived embryos from parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT). Further analysis indicated that MA supplementation not only significantly decreased the abundance of intracellular reactive oxygen species (ROS) and dramatically increased the abundance of intracellular reductive glutathione (GSH) in porcine early-stage embryos, but also clearly attenuated mitochondrial dysfunction and inhibited apoptosis. Moreover, Western blotting showed that MA supplementation upregulated OCT4 (p < 0.01), SOD1 (p < 0.0001) and CAT (p < 0.05) protein expression in porcine early-stage embryos. Collectively, our data reveal that MA supplementation exerts helpful effects on porcine early embryo development competence via regulation of oxidative stress (OS) and amelioration of mitochondrial function and that MA may be useful for increasing the in vitro production (IVP) efficiency of porcine early-stage embryos.