Protective Effect of Grape Seed Proanthocyanidins on Oxidative Damage of Chicken Follicular Granulosa Cells by Inhibiting FoxO1-Mediated Autophagy

Proanthocyanidins delaying the premature ovarian insufficiency through regulatory sirt1-p53-p21 signaling pathway in female germline stem cells

BACKGROUND

As women age, their ovarian follicle pool naturally declines. However, female germline stem cells (FGSCs) possess a unique ability to differentiate into oocytes and continuously self-renew, providing an effective means of delaying ovarian aging by replenishing the primordial follicle pool. Therefore, activating FGSCs is critical in reshaping and safeguarding ovarian function.

METHODS

In this study, we investigated the biological activity of proanthocyanidins (PACs), natural antioxidants that exhibit anti-aging and anti-inflammatory properties beneficial for both male and female reproduction. Our in vivo and in vitro experiments demonstrate that PACs promote FGSCs proliferation while delaying ovarian aging.

RESULTS

PACs increase the number of primordial follicles, primary follicles, corpus luteum while reducing cystic follicles, and elevate estradiol (E2) levels along with anti-mullerian hormone (AMH) concentration levels in mice. Additionally, PACs significantly boost FGSCs proliferation time- and dose-dependently by upregulating mRNA & protein expressions for FGSCs-specific markers such as MVH and OCT4 while downregulating p53/p21 via activation of silent information regulator 1(Sirt1) signaling pathway. The effects of PACs on FGCSs were found to be impeded by the Sirt1 inhibitor EX527.

CONCLUSION

PACS delay premature ovarian insufficiency (POI) through regulating the Sirt1-p53-p21 signaling pathway involving FGSCs.

Cross-species regulatory network analysis identifies FOXO1 as a driver of ovarian follicular recruitment

The transcriptional regulation of gene expression in the latter stages of follicular development in laying hen ovarian follicles is not well understood. Although differentially expressed genes (DEGs) have been identified in pre-recruitment and pre-ovulatory stages, the master regulators driving these DEGs remain unknown. This study addresses this knowledge gap by utilizing Master Regulator Analysis (MRA) combined with the Algorithm for the Reconstruction of Accurate Cellular Networks (ARACNe) for the first time in laying hen research to identify master regulators that are controlling DEGs in pre-recruitment and pre-ovulatory phases. The constructed ARACNe network included 10,466 nodes and 292,391 edges. The ARACNe network was then used in conjunction with the Virtual Inference of Protein-activity by Enriched Regulon (VIPER) for the MRA to identify top up- and down-regulated master regulators. VIPER analysis revealed FOXO1 as a master regulator, influencing 275 DEGs and impacting pathways related to apoptosis, proliferation, and hormonal regulation. Additionally, CLOCK, known as a crucial regulator of circadian rhythm, emerged as an upregulated master regulator in the pre-ovulatory stage. These findings provide new insights into the transcriptional landscape of laying hen ovarian follicles, offering a foundation for further exploration of follicle development and enhancing reproductive efficiency in avian species.

Pterostilbene, a Resveratrol Derivative, Improves Ovary Function by Upregulating Antioxidant Defenses in the Aging Chickens via Increased SIRT1/Nrf2 Expression

Oxidative stress is recognized as a prominent factor contributing to follicular atresia and ovarian aging, which leads to decreased laying performance in hens. Reducing oxidative stress can improve ovarian function and prolong the laying period in poultry. This study investigates the impact of Pterostilbene (PTS), a natural antioxidant, on ovarian oxidative stress in low-laying chickens. Thirty-six Hy-Line White laying chickens were evenly divided into four groups and fed diets containing varying doses of PTS for 15 consecutive days. The results showed that dietary supplementation with PTS significantly increased the laying rate, with the most effective group exhibiting a remarkable 42.7% increase. Furthermore, PTS significantly enhanced the antioxidant capacity of aging laying hens, as evidenced by increased levels of glutathione, glutathione peroxidase, superoxide dismutase, catalase, and total antioxidant capacity in the ovaries, livers, and serum. Subsequent experiments revealed decreased expressions of Bax, Caspase-3, and γ-H2AX, along with an increased expression of BCL-2 in the ovaries and livers of laying hens. PTS supplementation also positively affects fat metabolism by reducing abdominal fat accumulation and promoting fat transfer from the liver to the ovary. To elucidate the mechanism underlying the effects of PTS on ovarian function, a series of in vitro experiments were conducted. These in vitro experiments revealed that PTS pretreatment restored the antioxidant capacity of D-galactose-induced small white follicles by upregulating SIRT1/Nrf2 expression. This protective effect was inhibited by EX-527, a specific inhibitor of SIRT1. These findings suggest that the natural antioxidant PTS has the potential to regulate cell apoptosis and fat metabolism in laying chickens by ameliorating oxidative stress, thereby enhancing laying performance.

Allantoin Derived From Dioscorea opposita Thunb Ameliorates Cyclophosphamide-Induced Premature Ovarian Failure in Female Rats by Attenuating Apoptosis, Autophagy and Pyroptosis

Background and objectives Cyclophosphamide (CP) is widely used as a chemotherapy drug for the treatment of malignant tumors and autoimmune diseases, but it has strong toxic and side effects and can cause permanent damage to the ovaries, which affects women's quality of life. This study aimed to investigate the anti-premature ovarian failure protective effect of allantoin isolated from Dioscorea opposita Thunb. Methods Firstly, 75 mg/kg CP was injected into rats to establish an in vivo model of premature ovarian failure (POF). The POF rats were divided into the normal control group (NC), premature ovarian failure group (POF), and POF group treated with allantoin (ALL I 140 mg/kg and ALL II 70 mg/kg, daily 21 days). It investigated the estrous cycles, hormone levels, apoptosis rate, mitochondrial membrane potential (MMP), reactive oxygen species (ROS), mitophagy, and protein marker (Bax, Bcl2, LC3B, L-1β, caspase-1 and NLRP3). Results The results indicated that allantoin alleviated cyclophosphamide-induced premature ovarian failure in female rats, decreased the anoestrum, increased the level of estradiol (E2), and decreased the levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH), decreased apoptosis rate, MMP, mitophagy and ROS in ovarian granulosa cells of POF rats, down-regulated L-1β, caspase-1, LC3B-II/LC3B-I in ovarian tissue, and up-regulated the Bcl2 and NLRP3. Conclusions Our study revealed the ovarian-protective effect of allantoin in CP-induced premature ovarian failure for the first time, the effect was achieved through attenuation of the apoptosis, autophagy, and pyroptosis. The study underlines the potential clinical application of allantoin as a protectant agent for premature ovarian failure.

Grape Seed Proanthocyanidins Improve the Quality of Fresh and Cryopreserved Semen in Bulls

Oxidative stress leads to a decrease in semen quality during semen cryopreservation and fresh semen production. Grape seed proanthocyanidins (GSPs) are endowed with well-recognized antioxidant, anti-inflammatory, anti-cancer, and anti-aging activities. Therefore, the objective of this experiment was to explore the effects of GSPs on the quality of fresh and cryopreserved semen to provide a basis for GSPs as a new dietary additive and semen diluent additive for males' reproduction. Fresh semen from three healthy bulls aged 3 to 5 years old were gathered and mixed with semen diluents dissolved with 0 µg/mL, 30 µg/mL, 40 µg/mL, 50 µg/mL, and 60 µg/mL GSPs respectively. The motility, physiological structures (acrosome integrity, membrane integrity, mitochondrial activity), and antioxidant capacity of frozen-thawed sperm were measured after storage in liquid nitrogen for 7 days (d). Bulls were fed with 20 mg/kg body weight (BW) GSPs in their diet for 60 days; the weight of the bull is about 600 kg. Then, the reproductive performance and antioxidant indexes of bulls were measured before and after feeding. The results demonstrated that GSPs supplementation significantly increased sperm motility, physiological structures, GSH-Px, and CAT enzyme activities and significantly decreased MDA content in sperm during semen cryopreservation. The optimal concentration of GSPs was 40 µg/mL (p < 0.05). After 20 mg/kg (body weight) GSP supplementation, sperm motility was significantly heightened (p < 0.05), the sperm deformity rate was significantly reduced (p < 0.05), and antioxidant enzyme activities (such as SOD, CAT, and GSH-Px) were significantly enhanced (p < 0.05), and the production of MDA was significantly suppressed (p < 0.05) in serum compared with that before feeding. In conclusion, these results reveal that a certain concentration of GSPs has a good protective effect on sperm damage caused by semen cryopreservation and the reproductive performance reduction caused by stress in bulls, which may be attributed to the antioxidant function of GSPs. In summary, GSPs are a useful cryoprotective adjuvant and dietary additive for bull sperm quality.

Pathological Role of Oxidative Stress in Aflatoxin-Induced Toxicity in Different Experimental Models and Protective Effect of Phytochemicals: A Review

Aflatoxin B1 is a secondary metabolite with a potentially devastating effect in causing liver damage in broiler chickens, and this is mainly facilitated through the generation of oxidative stress and malonaldehyde build-up. In the past few years, significant progress has been made in controlling the invasion of aflatoxins. Phytochemicals are some of the commonly used molecules endowed with potential therapeutic effects to ameliorate aflatoxin, by inhibiting the production of reactive oxygen species and enhancing intracellular antioxidant enzymes. Experimental models involving cell cultures and broiler chickens exposed to aflatoxin or contaminated diet have been used to investigate the ameliorative effects of phytochemicals against aflatoxin toxicity. Electronic databases such as PubMed, Science Direct, and Google Scholar were used to identify relevant data sources. The retrieved information reported on the link between aflatoxin B1-included cytotoxicity and the ameliorative potential/role of phytochemicals in chickens. Importantly, retrieved data showed that phytochemicals may potentially protect against aflatoxin B1-induced cytotoxicity by ameliorating oxidative stress and enhancing intracellular antioxidants. Preclinical data indicate that activation of nuclear factor erythroid 2-related factor 2 (Nrf2), together with its downstream antioxidant genes, may be a potential therapeutic mechanism by which phytochemicals neutralize oxidative stress. This highlights the need for more research to determine whether phytochemicals can be considered a useful therapeutic intervention in controlling mycotoxins to improve broiler health and productivity.

Mechanisms of and Potential Medications for Oxidative Stress in Ovarian Granulosa Cells: A Review

Granulosa cells are essential for follicle initiation and development, and their abnormal function or apoptosis is a crucial factor leading to follicular atresia. A state of oxidative stress occurs when the balance between the production of reactive oxygen species and the regulation of the antioxidant system is disturbed. Oxidative stress is one of the most important causes of the abnormal function and apoptosis of granulosa cells. Oxidative stress in granulosa cells causes female reproductive system diseases, such as polycystic ovary syndrome and premature ovarian failure. In recent years, studies have confirmed that the mechanism of oxidative stress in granulosa cells is closely linked to the PI3K-AKT signaling pathway, MAPK signaling pathway, FOXO axis, Nrf2 pathway, NF-κB signaling pathway, and mitophagy. It has been found that drugs such as sulforaphane, Periplaneta americana peptide, and resveratrol can mitigate the functional damage caused by oxidative stress on granulosa cells. This paper reviews some of the mechanisms involved in oxidative stress in granulosa cells and describes the mechanisms underlying the pharmacological treatment of oxidative stress in granulosa cells.

Protective effect of rutin on ferroptosis-induced oxidative stress in aging laying hens through Nrf2/HO-1 signaling

Oxidative stress is a major cause of ovarian aging and follicular atresia. There is growing evidence that showed potential roles of rutin in antidiabetic, anti-inflammatory, antitumor, antibacterial and antioxidant, although it is yet unclear what the underlying mechanism is. Here, we looked into the potential effects of rutin on oxidative stress in the prehierarchical small white follicles (SWFs) from 580-day-old (D580) laying chickens. According to the findings, aging D580 layer ferroptosis was much higher than it was for laying hens during the peak period (280-day-old, D280). In both naturally aged and d-gal-induced chicken SWFs, rutin treatment concurrently boosted cell proliferation and prevented apoptosis. In addition, rutin inhibited the increased ferroptosis in aging hens. Meanwhile, rutin markedly suppressed the elevated ferroptosis and descending antioxidant capacity of D280-culture-SWFs from chicken elicited by d-gal. Rutin's activation of the Nrf2/HO-1 pathway hastened the SWFs' verbal battle with oxidative damage and reduced ferroptosis. Furthermore, activation of the ferroptosis signal increased the oxidative damage in SWFs. In conclusion, rutin alleviated oxidative stress that was induced by ferroptosis in aging chicken SWFs through Nrf2/HO-1 pathway. These findings point to a novel mechanism by which rutin protects SWFs from oxidative stress by suppressing ferroptosis, which is presumably a fresh approach to slowing ovarian aging in laying hens.

Se-Enriched Cardamine violifolia Improves Laying Performance and Regulates Ovarian Antioxidative Function in Aging Laying Hens

As a selenium-enriched plant, Cardamine violifolia (SEC) has an excellent antioxidant function. The edibility of SEC is expected to develop new sources of organic Se supplementation for human and animal nutrition. This study was conducted to investigate the effects of SEC on laying performance and ovarian antioxidant capacity in aging laying hens. A total of 450 laying hens were assigned to five treatments. Dietary treatments included the following: a basal diet (diet without Se supplementation, CON) and basal diets supplemented with 0.3 mg/kg Se from sodium selenite (SS), 0.3 mg/kg Se from Se-enriched yeast (SEY), 0.3 mg/kg Se from SEC, or 0.3 mg/kg Se from SEC and 0.3 mg/kg Se from SEY (SEC + SEY). Results showed that supplementation with SEC tended to increase the laying rate, increased the Haugh unit of eggs, and reduced the FCR. SEC promoted ovarian cell proliferation, inhibited apoptosis, and ameliorated the maintenance of follicles. SEC, SEY, or SEC + SEY increased ovarian T-AOC and decreased MDA levels. SEC increased the mRNA abundance of ovarian selenoproteins. SEC and SEC + SEY increased the mRNA abundance of Nrf2, HO-1, and NQO1, and decreased the mRNA abundance of Keap1. These results indicate that SEC could potentially to improve laying performance and egg quality via the enhancement of ovarian antioxidant capacity. SEC exerts an antioxidant function through the modulation of the Nrf2/Keap1 signaling pathway.

Protective Effect of Follicle-Stimulating Hormone on DNA Damage of Chicken Follicular Granulosa Cells by Inhibiting CHK2/p53

The increase in follicular atresia and the decrease in the fecundity of laying hens occur with the aging process. Therefore, the key measure for maintaining high laying performance is to alleviate follicular atresia in the aging poultry. Follicle-stimulating hormone (FSH), as an important pituitary hormone to promote follicle development and maturation, plays an important role in preventing reproductive aging in diverse animals. In this study, the physiological state of the prehierarchical small white follicles (SWFs) and atretic SWFs (ASWFs) were compared, followed by an exploration of the possible capacity of FSH to delay ASWFs' progression in the hens. The results showed that the DNA damage within follicles increased with aging, along with Golgi complex disintegration, cell cycle arrest, increased apoptosis and autophagy in the ASWFs. Subsequently, the ACNU-induced follicular atresia model was established to evaluate the enhancing capacity of FSH on increasing cell proliferation and attenuating apoptosis in ASWFs. FSH inhibited DNA damage and promoted DNA repair by regulating the CHK2/p53 pathway. Furthermore, FSH inhibited CHK2/p53, thus, suppressing the disintegration of the Golgi complex, cell cycle arrest, and increased autophagy in the atretic follicles. Moreover, these effects from FSH treatment in ACNU-induced granulosa cells were similar to the treatment by a DNA repair agent AV-153. These results indicate that FSH protects aging-resulted DNA damage in granulosa cells by inhibiting CHK2/p53 in chicken prehierarchical follicles.

Naringin prevents follicular atresia by inhibiting oxidative stress in the aging chicken

Oxidative stress is an essential inducement in follicle atresia and ovarian aging, resulting in decline in female fecundity. As a natural and effective antioxidant, naringin was investigated to relieve chicken follicle atresia and ovarian aging. First, the cultured small white follicles (SWFs) from D280 hens were pretreated with 0.5 mM naringin for 24 h and then treated with H₂O₂ for 72 h to establish the oxidative stress model to evaluate the putative attenuating effects of naringin on follicle atresia. Meanwhile, SWFs of D580 hens were treated with naringin for 72 h to examine the attenuating effect on the physiological aging of SWFs. Finally, each hen was fed with naringin at a dose of 50 mg/kg every day to explore the effect of naringin on follicular development and laying performance in D580 hens. Results showed that naringin could rescue the antioxidant capacity decline by increasing the antioxidant-related indexes and expression of antioxidation-associated genes. It could also maintain the homeostasis of SWFs in both the H₂O₂-induced group and natural physiological aging group. In addition, naringin increased estrogen levels, capacity of antioxidants, and the laying performance in aged laying chickens. The thickness and strength of the eggshell were increased in the naringin-treated group as well. In conclusion, this study showed that naringin is capable of relieving SWFs atresia that was induced by oxidative stress and maintaining the laying performance of aging low-yielding hens by reducing oxidative stress.