Sulforaphane suppresses paraquat-induced oxidative damage in bovine in vitro-matured oocytes through Nrf2 transduction pathway

Oocyte maturation, blastocyst and embryonic development are mediated and enhanced via hormesis

The present paper provides the first integrative assessment of the capacity of dietary, endogenous and other agents to induce hormetic dose responses in oocytes, their supportive cells such as granulosa cells, blastocyst formation and early stage embryo development with the goal of improving fertility and reproductive success. The analysis showed that numerous agents enhance oocyte maturation and blastocyst/embryonic development in an hormetic fashion. These findings indicate that numerous agents improve oocyte-related biological functioning under normal conditions as well as enhancing its capacity to prevent damage from numerous chemical toxins and related stressor agents, including heat and age-related processes in pre-post conditioning and concurrent exposures. The present assessment suggests that hormetic-based lifestyles and dietary interventions may offer the potential to enhance healthy reproductive performance with applications to animal husbandry and human biology. The present findings also significantly extend the generality of the hormesis dose response concept to multiple fundamental biological processes (i.e., oocyte maturation, fertilization and blastocyst/embryo development).

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 β-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.

Protective effects of sulforaphane against toxic substances and contaminants: A systematic review

BACKGROUND

Sulforaphane (SFN) is a dietary isothiocyanate, derived from glucoraphanin, present in cruciferous vegetables belonging to the Brassica genus. It is a biologically active phytochemical that acts as a nuclear factor erythroid 2-related factor 2 (Nrf2) inducer. Thus, it has been reported to have multiple protective functions including anticancer responses and protection against a toxic agent's action.

PURPOSE

The present work systematically reviewed and synthesised the protective properties of sulforaphane against a toxic agent. This review reveals the mechanism of the action of SFN in each organ or system.

METHODS

The PRISMA guideline was followed in this sequence: researched literature, organised retrieved documents, abstracted relevant information, assessed study quality and bias, synthesised data, and prepared a comprehensive report. Searches were conducted on Science Direct and PubMed using the keywords "Sulforaphane" AND ("protective effects" OR "protection against").

RESULTS

Reports showed that liver and the nervous system are the target organs on which attention was focused, and this might be due to the key role of oxidative stress in liver and neurodegenerative diseases. However, protective activities have also been demonstrated in the lungs, heart, immune system, kidneys, and endocrine system. SFN exerts its protective effects by activating the Nrf2 pathway, which enhances antioxidant defenses and reduces oxidative stress. It also suppresses inflammation by decreasing interleukin production. Moreover, SFN inhibits apoptosis by preventing caspase 3 cleavage and increasing Bcl2 levels. Overall, SFN demonstrates multifaceted mechanisms to counteract the adverse effects of toxic agents.

CONCLUSION

SFN has potential clinical applications as a chemoprotective agent. Nevertheless, more studies are necessary to set the safe doses of SFN in humans.

Bioactive Compounds Protect Mammalian Reproductive Cells from Xenobiotics and Heat Stress-Induced Oxidative Distress via Nrf2 Signaling Activation: A Narrative Review

Oxidative stress occurs when there is an imbalance between the production of reactive oxygen species (ROS) and the body's antioxidant defenses. It poses a significant threat to the physiological function of reproductive cells. Factors such as xenobiotics and heat can worsen this stress, leading to cellular damage and apoptosis, ultimately decreasing reproductive efficiency. The nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway plays a crucial role in defending against oxidative stress and protecting reproductive cells via enhancing antioxidant responses. Dysregulation of Nrf2 signaling has been associated with infertility and suboptimal reproductive performance in mammals. Recent advancements in therapeutic interventions have underscored the critical role of Nrf2 in mitigating oxidative damage and restoring the functional integrity of reproductive cells. In this narrative review, we delineate the harmful effects of heat and xenobiotic-induced oxidative stress on reproductive cells and explain how Nrf2 signaling provides protection against these challenges. Recent studies have shown that activating the Nrf2 signaling pathway using various bioactive compounds can ameliorate heat stress and xenobiotic-induced oxidative distress and apoptosis in mammalian reproductive cells. By comprehensively analyzing the existing literature, we propose Nrf2 as a key therapeutic target for mitigating oxidative damage and apoptosis in reproductive cells caused by exposure to xenobiotic exposure and heat stress. Additionally, based on the synthesis of these findings, we discuss the potential of therapies focused on the Nrf2 signaling pathway to improve mammalian reproductive efficiency.

NRF2 attenuation aggravates detrimental consequences of metabolic stress on cultured porcine parthenote embryos

The nuclear factor erythroid 2-related factor 2 (NRF2) is a crucial transcription factor that plays a central role in regulating oxidative stress pathways by binding antioxidant response elements, but its involvement in early embryo development remains largely unexplored. In this study, we demonstrated that NRF2 mRNA is expressed in porcine embryos from day 2 to day 7 of development, showing a decrease in abundance from day 2 to day 3, followed by an increase on day 5 and day 7. Comparable levels of NRF2 mRNA were observed between early-cleaving and more developmental competent embryos and late-cleaving and less developmental competent embryos on day 4 and day 5 of culture. Attenuation of NRF2 mRNA significantly decreased development of parthenote embryos to the blastocyst stage. When NRF2-attenuated embryos were cultured in presence of 3.5 mM or 7 mM glucose, development to the blastocyst stage was dramatically decreased in comparison to the control group (15.9% vs. 27.8% for 3.5 mM glucose, and 5.4% vs. 25.3% for 7 mM glucose). Supplementation of melatonin moderately improved the development of NRF2-attenuated embryos cultured in presence of 0.6 mM glucose. These findings highlight the importance of NRF2 in early embryo development, particularly in embryos cultured under metabolically stressful conditions.

Sciadopitysin mitigates spermatological and testicular damage instigated by paraquat administration in male albino rats

Paraquat (PQ) is a herbicide that has ability to induce testicular toxicity by producing reactive oxygen species (ROS). Sciadopitysin (SPS) is a promising flavonoid that displays multiple pharmacological properties i.e., anti-inflammatory, anti-oxidant and anti-apoptotic. Therefore, the present study was designed to evaluate the mitigative role of SPS against PQ induced testicular toxicity in male rats. The experiment was performed on male albino rats (n = 48) that were divided into 4 groups. The group-1 was control group. Group-2 was administrated orally with PQ (5 mg/kg). Group-3 was administrated orally with PQ (5 mg/kg) and SPS (2 mg/kg). Group-4 was supplemented with SPS (2 mg/kg) through oral gavage. The experiment was conducted for 56 days. The exposure to PQ significantly lowered the activities of catalase (CAT), glutathione reductase (GSR), superoxide dismutase (SOD) as well as glutathione peroxidase (GPx). Whereas, a substantial increase was observed in dead sperms number, abnormalities in the tail, head as well as midpiece of sperms in PQ intoxicated rats. Moreover, a significant increase in the level of ROS and malondialdehyde (MDA) was noticed in PQ administrated group. Furthermore, steroidogenic enzymes expression was significantly decreased in PQ-intoxicated group, whereas the level of inflammatory markers was increased in PQ administrated rats. Besides, the expression of apoptotic markers was significantly escalated in PQ exposed rats, whereas the expression of anti-apoptotic markers was considerably reduced. A significant reduction in hormonal level was also noticed in the rats that were administrated with PQ. Moreover, the histopathological examination revealed that PQ significantly damaged the testicles. However, the supplementation of SPS with PQ significantly reduced the adverse effects of PQ in the testes of albino rats. Therefore, the current investigation demonstrated that SPS possesses a significant potential to avert PQ-induced testicular dysfunction due to its anti-apoptotic, androgenic, anti-oxidant and anti-inflammatory nature.

Sulforaphane alleviates the meiosis defects induced by 3-nitropropionic acid in mouse oocytes

3-Nitropropionic acid (3-NP) is a mycotoxin commonly found in plants and fungi that has been linked to mammalian intoxication. Previously, we found 3-NP treatment exhibited reproductive toxicity by inducing oxidative stress in mouse ovary; however, the toxic effects of 3-NP on mouse oocyte maturation have not been investigated. Sulforaphane (SFN) is a naturally bioactive phytocompound derived from cruciferous vegetables that has been shown to possess cytoprotective properties. The present study was designed to investigate the cytotoxicity of 3-NP during mouse oocyte maturation and the protective effects of SFN on oocytes challenged with 3-NP. The results showed 3-NP had a dose-dependent inhibitory effect on oocyte maturation, and SFN significantly alleviated the defects caused by 3-NP, including failed first polar body extrusion and abnormal spindle assembly. Furthermore, 3-NP caused abnormal mitochondrial distribution in oocytes and disrupted mitochondrial functions, including mitochondrial depolarization, decreased ATP levels, and increased mitochondrial-derived ROS. Finally, 3-NP induced oxidative stress in oocytes, leading to increased apoptosis and autophagy, while SFN supplementation had significant cytoprotective effects on these damages. Collectively, our results provide insight on the mechanism of 3-NP toxicity in mouse oocytes and suggest the application of SFN may be a viable intervention strategy to mitigate 3-NP-induced reproductive toxicity.