Asiatic acid supplementation during the in vitro culture period improves early embryonic development of porcine embryos produced by parthenogenetic activation, somatic cell nuclear transfer and in vitro fertilization

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.

Effect of asiatic acid supplementation in tris-extender on post-thaw functional competence, antioxidant enzyme activity and in vivo fertility of bull sperm

Reactive oxygen species at supra-physiological levels trigger oxidative stress during cryopreservation, which can be neutralised by incorporating suitable antioxidants into the semen extender medium. This study was intended to explore the effect of asiatic acid (AA) as an antioxidant in semen extender on frozen-thawed sperm quality and in vivo fertility of bull sperm. Semen was collected from Holstein Friesian bulls for 10 consecutive weeks (total ejaculates = 60). Semen was cryopreserved with a Tris citric acid egg yolk-based extender supplemented with 0 (control), 20, 40, 60, and 100 μM AA. The supplementation of the extender with 40 and 60 μM AA improved (p < 0.05) post-thaw motility kinematics, plasma membrane integrity, acrosome integrity, sperm viability, and DNA integrity of bull sperm. Mitochondrial membrane potential was high (p < 0.05) with 60 μM of AA concentration in extender media. The catalase activity in seminal plasma was maintained (p < 0.05) when semen was added with 20, 40, and 60 μM of AA. The in vivo fertility was found to be significantly high with the semen extended with 60 μM AA. Conclusively, this study showed that AA supplementation in semen extender significantly improved sperm motility kinematics and cell integrity, conserved antioxidant enzyme activity, and improved in vivo fertility.

Luteolin supplementation during porcine oocyte maturation improves the developmental competence of parthenogenetic activation and cloned embryos

Luteolin (Lut), a polyphenolic compound that belongs to the flavone subclass of flavonoids, possesses anti-inflammatory, cytoprotective, and antioxidant activities. However, little is known regarding its role in mammalian oocyte maturation. This study examined the effect of Lut supplementation during in vitro maturation (IVM) on oocyte maturation and subsequent developmental competence after somatic cell nuclear transfer (SCNT) in pigs. Lut supplementation significantly increased the proportions of complete cumulus cell expansion and metaphase II (MII) oocytes, compared with control oocytes. After parthenogenetic activation or SCNT, the developmental competence of Lut-supplemented MII oocytes was significantly enhanced, as indicated by higher rates of cleavage, blastocyst formation, expanded or hatching blastocysts, and cell survival, as well as increased cell numbers. Lut-supplemented MII oocytes exhibited significantly lower levels of reactive oxygen species and higher levels of glutathione than control MII oocytes. Lut supplementation also activated lipid metabolism, assessed according to the levels of lipid droplets, fatty acids, and ATP. The active mitochondria content and mitochondrial membrane potential were significantly increased, whereas cytochrome c and cleaved caspase-3 levels were significantly decreased, by Lut supplementation. These results suggest that Lut supplementation during IVM improves porcine oocyte maturation through the reduction of oxidative stress and mitochondria-mediated apoptosis.

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.

Strategies to Improve the Efficiency of Somatic Cell Nuclear Transfer

Mammalian oocytes can reprogram differentiated somatic cells into a totipotent state through somatic cell nuclear transfer (SCNT), which is known as cloning. Although many mammalian species have been successfully cloned, the majority of cloned embryos failed to develop to term, resulting in the overall cloning efficiency being still low. There are many factors contributing to the cloning success. Aberrant epigenetic reprogramming is a major cause for the developmental failure of cloned embryos and abnormalities in the cloned offspring. Numerous research groups attempted multiple strategies to technically improve each step of the SCNT procedure and rescue abnormal epigenetic reprogramming by modulating DNA methylation and histone modifications, overexpression or repression of embryonic-related genes, etc. Here, we review the recent approaches for technical SCNT improvement and ameliorating epigenetic modifications in donor cells, oocytes, and cloned embryos in order to enhance cloning efficiency.

Antioxidant Activity and Anti-Apoptotic Effect of the Small Molecule Procyanidin B1 in Early Mouse Embryonic Development Produced by Somatic Cell Nuclear Transfer

As an antioxidant, procyanidin B1(PB1) can improve the development of somatic cell nuclear transfer (SCNT) embryos; PB1 reduces the level of oxidative stress (OS) during the in vitro development of SCNT embryos by decreasing the level of reactive oxygen species (ROS) and increasing the level of glutathione (GSH) and mitochondrial membrane potential (MMP). Metabolite hydrogen peroxide (H₂O₂) produces OS. Catalase (CAT) can degrade hydrogen peroxide so that it produces less toxic water (H₂O) and oxygen (O₂) in order to reduce the harm caused by H₂O₂. Therefore, we tested the CAT level in the in vitro development of SCNT embryos; it was found that PB1 can increase the expression of CAT, indicating that PB1 can offset the harm caused by oxidative stress by increasing the level of CAT. Moreover, if H₂O₂ accumulates excessively, it produces radical-(HO-) through Fe^2+/3+ and damage to DNA. The damage caused to the DNA is mainly repaired by the protein encoded by the DNA damage repair gene. Therefore, we tested the expression of the DNA damage repair gene, OGG1. It was found that PB1 can increase the expression of OGG1 and increase the expression of protein. Through the above test, we proved that PB1 can improve the repairability of DNA damage. DNA damage can lead to cell apoptosis; therefore, we also tested the level of apoptosis of blastocysts, and we found that PB1 reduced the level of apoptosis. In summary, our results show that PB1 reduces the accumulation of H₂O₂ by decreasing the level of OS during the in vitro development of SCNT embryos and improves the repairability of DNA damage to reduce cell apoptosis. Our results have important significance for the improvement of the development of SCNT embryos in vitro and provide important reference significance for diseases that can be treated using SCNT technology.

Tributyltin Oxide Exposure During in vitro Maturation Disrupts Oocyte Maturation and Subsequent Embryonic Developmental Competence in Pigs

Tributyltin oxide (TBTO), an organotin compound, has been demonstrated to have toxic effects on several cell types. Previous research has shown that TBTO impairs mouse denuded oocyte maturation. However, limited information is available on the effects of TBTO exposure on livestock reproductive systems, especially on porcine oocytes in the presence of dense cumulus cells. In the present research, we evaluated the effects of TBTO exposure on porcine oocyte maturation and the possible underlying mechanisms. Porcine cumulus-oocyte complexes were cultured in maturation medium with or without TBTO for 42 h. We found that TBTO exposure during oocyte maturation prevented polar body extrusion, inhibited cumulus expansion and impaired subsequent blastocyst formation after parthenogenetic activation. Further analysis revealed that TBTO exposure not only induced intracellular reactive oxygen species (ROS) accumulation but also caused a loss of mitochondrial membrane potential and reduced intracellular ATP generation. In addition, TBTO exposure impaired porcine oocyte quality by disrupting cellular iron homeostasis. Taken together, these results demonstrate that TBTO exposure impairs the porcine oocyte maturation process by inducing intracellular ROS accumulation, causing mitochondrial dysfunction, and disrupting cellular iron homeostasis, thus decreasing the quality and impairing the subsequent embryonic developmental competence of porcine oocytes.

Supplementation with asiatic acid during in vitro maturation improves porcine oocyte developmental competence by regulating oxidative stress

Asiatic acid is a natural triterpene found in Centella asiatica that acts as an effective free radical scavenger. Our previous research showed that asiatic acid delayed porcine oocyte ageing in vitro and improved preimplantation embryo development competence in vitro; however, the protective effects of asiatic acid against oxidative stress in porcine oocyte maturation are still unclear. Here, we investigated the effects of asiatic acid on porcine oocyte in vitro maturation (IVM) and subsequent embryonic development competence after parthenogenetic activation (PA) and in vitro fertilization (IVF). The results of the present research showed that 10 μM asiatic acid supplementation did not affect the expansion of cumulus cells or polar body extrusion of porcine oocytes, while asiatic acid application significantly increased the subsequent blastocyst formation rate and quality of porcine PA and IVF embryos. Hydrogen peroxide (H₂O₂) is a reactive oxygen species (ROS) that induces oxidative stress in porcine oocytes. As expected, asiatic acid supplementation not only decreased intracellular ROS levels but also attenuated H₂O₂-induced intracellular ROS generation. Further analysis revealed that asiatic acid supplementation enhanced intracellular glutathione production, mitochondrial membrane potential, and ATP generation at the end of IVM. In summary, our results reveal that asiatic acid supplementation exerts beneficial effects on porcine oocytes by regulating oxidative stress during the IVM process and could act as a potential antioxidant in porcine oocytes matured in vitro production systems.

Iron Overload-Induced Ferroptosis Impairs Porcine Oocyte Maturation and Subsequent Embryonic Developmental Competence in vitro

Accumulating evidence indicates that ferroptosis is an iron-dependent form of regulated cell death. This type of iron-dependent programmed cell death is different from traditional forms of regulated cell death, such as apoptosis and autophagy. However, the role of ferroptosis in porcine oocyte maturation and the associated mechanism remain unclear. In the present research, we investigated the effects of ferric ammonium citrate (FAC), a specific ferroptosis inducer, on porcine oocyte meiotic maturation and quality and subsequent embryonic developmental competence. FAC treatment caused obvious accumulation of intracellular ferrous ions in porcine oocytes. At the end of the in vitro maturation (IVM) period, there was a significant decrease in the polar body (PB) extrusion rate and an increase in the percentage of abnormal oocytes in the FAC treatment groups, indicating that iron overload-induced ferroptosis may suppress the meiotic process during porcine oocyte maturation. We also found that after FAC treatment, the subsequent two-cell rate, four-cell rate and blastocyst formation rate were significantly decreased in porcine parthenogenetic activation (PA) embryos, indicating that iron overload-induced ferroptosis decreased porcine oocyte quality. Further analysis revealed that FAC treatment not only enhanced intracellular reactive oxygen species (ROS) generation, decreased intracellular free thiol levels and induced mitochondrial dysfunction but also triggered autophagy in porcine oocytes. Taken together, these findings suggest that iron overload-induced ferroptosis impairs porcine oocyte meiosis and decreases porcine oocyte quality, possibly by increasing oxidative stress, inducing mitochondrial dysfunction and triggering autophagy.

Glycine alleviates fluoride-induced oxidative stress, apoptosis and senescence in a porcine testicular Sertoli cell line

Glycine is a well-known free radical scavenger in the cellular antioxidant system that prevents oxidative damage and apoptosis. Excessive fluoride exposure is associated with multiple types of cellular damage in humans and animals. The objective of the present study was to investigate the protective effects of glycine on sodium fluoride (NaF) exposure and the possible underlying mechanisms in a porcine testicular Sertoli cell line model. Cellular viability and proliferation were examined following NaF exposure and glycine supplementation, and glycine dramatically ameliorated the decreases in NaF-induced porcine testicular Sertoli cell viability and proliferation. Further investigations revealed that glycine decreased NaF-induced intracellular reactive oxygen species production, DNA fragment accumulation and the apoptosis incidence in the porcine testicular Sertoli cell line; in addition, glycine improved mitochondrial function and ATP production. Notably, results of the SPiDER-β-Gal analysis suggested that glycine alleviated NaF-induced cellular senescence and downregulated P53, P21, HMGA2 and P16INK4a gene expression in the porcine testicular Sertoli cell line. Collectively, the beneficial effects of glycine alleviate NaF-induced oxidative stress, apoptosis and senescence, and together with our previous findings, support the hypothesis that glycine plays an important role in protecting against NaF exposure-induced impairments in the porcine testicular Sertoli cell line.

Asiatic acid protects oocytes against in vitro aging-induced deterioration and improves subsequent embryonic development in pigs

As a pentacyclic triterpene in Centella asiatica, asiatic acid (AA) is a powerful antioxidant with many bioactivities. In the present research, we investigated whether AA has the potential to rescue the decrease in porcine oocyte quality that occurs during in vitro aging (IVA). Mature porcine oocytes were collected and then continuously cultured for an additional 24 h or 48 h with or without AA in maturation medium as an IVA model. The results revealed that AA supplementation reduced the percentage of abnormal aged porcine oocytes during IVA. Furthermore, AA supplementation effectively maintained aged porcine oocyte developmental competence, both parthenogenetic activation and in vitro fertilization. The number of sperm that bound to the zona pellucida on aged porcine oocytes was higher in the AA-supplemented group than in the non-supplemented group. Moreover, AA supplementation not only blocked IVA-induced oxidative stress but also maintained intracellular GSH levels and reduced the percentage of early apoptosis aged porcine oocytes. Mitochondrial functions were disordered during the IVA process. The intracellular ATP levels and mitochondrial membrane potential in aged porcine oocytes were dramatically increased by AA supplementation. Therefore, AA has beneficial effects on porcine oocyte quality and developmental potential maintenance during IVA.

Therapeutic Potential of Centella asiatica and Its Triterpenes: A Review

Centella asiatica (also known as Centella asiatica (L.) Urb. or Gotu kola) is a traditional Chinese medicine with extensive medicinal value, which is commonly used in Southeast Asian countries. This study aimed to summarize the effects of C. asiatica and its main components on neurological diseases, endocrine diseases, skin diseases, cardiovascular diseases, gastrointestinal diseases, immune diseases, and gynecological diseases, as well as potential molecular mechanisms, to study the pathological mechanism of these diseases based on the changes at the molecular level. The results showed that C. asiatica and its triterpenoids had extensive beneficial effects on neurological and skin diseases, which were confirmed through clinical studies. They exhibited anti-inflammatory, anti-oxidative stress, anti-apoptotic effects, and improvement in mitochondrial function. However, further clinical studies are urgently required due to the low level of evidence and lack of patients.

In vitro Production of Porcine Embryos: Current Status and Possibilities – A Review

This paper presents the current possibilities, state of knowledge and prospects of in vitro production (IVP) of pig embryos, which consists of in vitro oocyte maturation, in vitro fertilization and in vitro embryo culture. In pigs, oocyte maturation is one of the most important stages in the embryo IVP process. It determines the oocyte’s fertilization ability as well as its embryonic development. Through many research studies of the proper selection of oocytes and appropriate maturation medium composition (especially the addition of various supplements), the in vitro maturation of pig oocytes has been significantly improved. Recent studies have demonstrated that modifications of the diluents and in vitro fertilization media can reduce polyspermy. Furthermore, several adjustments of the porcine culture media with the addition of some supplements have enhanced the embryo quality and developmental competence. These updates show the progress of IVP in pigs that has been achieved; however, many problems remain unsolved.