Melatonin promotes the cumulus–oocyte complexes quality of vitrified–thawed murine ovaries; with increased mean number of follicles survival and ovary size following heterotopic transplantation

Ovarian overexpression of ASMT gene increases follicle numbers in transgenic sheep: Association with lipid metabolism

Melatonin plays an important role in mammalian reproductive activities, to further understand the effects of endogenous melatonin on functions of ovary, the transgenic sheep with overexpression of melatonin synthetic enzyme gene ASMT in ovary were generated. The results showed that total melatonin content in follicular fluid of transgenic sheep was significantly greater than that in the wild type. Accordingly, the follicle numbers of transgenic sheep were also significantly greater than those in the WT. The results of follicular fluid metabolites sequencing showed that compared with WT, the differential metabolites of the transgenic sheep were significantly enriched in several signaling pathways, the largest number of metabolites was lipid metabolism pathway and the main differential metabolites were lipids and lipoid molecules. SMART-seq2 were used to analyze the oocytes and granulosa cells of transgenic sheep and WT sheep. The main differential enrichment pathway was metabolic pathway, in which lipid metabolism genes accounted for the majority. In conclusion, this is the first report to show that ovary overexpression of ASMT increased local melatonin production and follicle numbers. These results may imply that ASMT plays an important role in follicle development and formation, and melatonin intervention may be a potential method to promote this process.

Research progress on mechanism of follicle injury after frozen ovarian tissue transplantation and protective strategies

The iatrogenic ovarian dysfunction caused by cancer treatment have been increasing, along with the age at onset of malignant tumors getting younger, the survival of cancer patients being longer, as well as the delayed childbearing age for females; therefore it becomes a major clinical challenge to preserve the fertility of these patients. Ovarian tissue cryopreservation is the only solution for female cancer patients in prepubertal ages and those who cannot delay gonadotoxic therapy. However, the successful rate of cryopreservation and transplantation of ovarian tissue is still low at present due to the risk of ischemia and hypoxia of grafted tissues. Abnormal activation of primordial follicle and ischemia-reperfusion injury after blood supply recovery also cause massive loss of follicles in grafted ovarian tissues. It has been tried in various studies to reduce the damage of follicles during freezing and transplantation by adding certain drugs, and extend the duration of endocrine and reproductive function in patients with ovarian transplantation. For example, melatonin, N-acetylcysteine, erythropoietin or other antioxidants are used to reduce oxidative stress; mesenchymal stem cells derived from different tissues, basic fibroblast growth factor, vascular endothelial growth factor, angiopoietin 2 and gonadotropin are used to promote revascularization; anti-Müllerian hormone and rapamycin are used to reduce abnormal activation of primordial follicles. This article reviews the research progress on the main mechanisms of follicle loss after ovarian tissue transplantation, including hypoxia, ischemia-reperfusion injury and associated cell death, and abnormal activation of follicles; and explores the methods of reducing graft follicle loss to provide reference for improving the efficiency of ovarian tissue cryopreservation and transplantation.

Melatonin and ovarian tissue transplantation: Current frontiers in research

The progress achieved in anticancer therapy in recent years has been paralleled by an increase in the survival of women with cancer globally. Nonetheless, the gonadotoxic impact of anticancer drugs has led to ovarian failure in treated women. While there are documented cases of successful ovarian tissue transplants resulting in restored fertility and childbirth, challenges persist, including suboptimal functional recovery and limited graft lifespan. Melatonin, an inert hormone primarily secreted by the mammalian pineal gland, exhibits diverse physiological functions, including antioxidative, anti-inflammatory, anti-apoptotic, and angiogenesis-regulating properties. Consequently, researchers have explored melatonin as a modulator to enhance graft function recovery in ovarian transplantation experiments, yielding promising outcomes. This review examines the relevant literature, consolidating findings that underscore the positive effects of melatonin in safeguarding the morphology and structure of transplanted ovarian tissues, facilitating graft function recovery, and extending lifespan. The amassed evidence supports the consideration of melatonin as a prospective protective agent for human ovarian tissue transplantation in the future.

Boric Acid Improved Cryopreserved Mouse Embryo Development

Boric acid (BA) is an essential trace element that is required to support the metabolic pathways in plants, humans, and animals. The present study investigates the in vitro development and quality of single-cell mouse embryos in a BA-added culture medium after cryopreservation using the solid-surface vitrification method. For this purpose, the pronuclear-stage embryos derived from superovulated C57Bl/6j mouse strains and the one-cell embryos were then cryopreserved using the solid-surface vitrification (SSV) method. After thawing, the embryos were cultured in a BA-added medium at 37 °C in a 5% CO2 environment until the blastocyst stage. The resulting in vitro development rates of the embryos in the control group, SSV group, and SSV + 1.62 × 10-4 μM BA group were 68.11% (36/59), 40.16% (16/48), and 64.92% (28/48) respectively, indicating that the BA supported the in vitro development of the embryos cryopreserved using the SSV method. Our results suggest that the addition of boric acid to the culture media increased the development rate of the embryos that were vitrified using the SSV method.

Ovarian tissue cryopreservation and transplantation: a review on reactive oxygen species generation and antioxidant therapy

Cancer is the leading cause of death worldwide. Fortunately, the survival rate of cancer continues to rise, owing to advances in cancer treatments. However, these treatments are gonadotoxic and cause infertility. Ovarian tissue cryopreservation and transplantation (OTCT) is the most flexible option to preserve fertility in women and children with cancer. However, OTCT is associated with significant follicle loss and an accompanying short lifespan of the grafts. There has been a decade of research in cryopreservation-induced oxidative stress in single cells with significant successes in mitigating this major source of loss of viability. However, despite its success elsewhere and beyond a few promising experiments, little attention has been paid to this key aspect of OTCT-induced damage. As more and more clinical practices adopt OTCT for fertility preservation, it is a critical time to review oxidative stress as a cause of damage and to outline potential ameliorative interventions. Here we give an overview of the application of OTCT for female fertility preservation and existing challenges; clarify the potential contribution of oxidative stress in ovarian follicle loss; and highlight potential ability of antioxidant treatments to mitigate the OTCT-induced injuries that might be of interest to cryobiologists and reproductive clinicians.

Melatonin and endothelial cell-loaded alginate-fibrin hydrogel promoted angiogenesis in rat cryopreserved/thawed ovaries transplanted to the heterotopic sites

BACKGROUND

Ischemic niche can promote follicular atresia following the transplantation of cryopreserved/thawed ovaries to the heterotopic sites. Thus, the promotion of blood supply is an effective strategy to inhibit/reduce the ischemic damage to ovarian follicles. Here, the angiogenic potential of alginate (Alg) + fibrin (Fib) hydrogel enriched with melatonin (Mel) and CD144⁺ endothelial cells (ECs) was assessed on encapsulated cryopreserved/thawed ovaries following transplantation to heterotopic sites in rats.

METHODS

Alg + Fib hydrogel was fabricated by combining 2% (w/v) sodium Alg, 1% (w/v) Fib, and 5 IU thrombin at a ratio of 4: 2: 1, respectively. The mixture was solidified using 1% CaCl₂. Using FTIR, SEM, swelling rate, and biodegradation assay, the physicochemical properties of Alg + Fib hydrogel were evaluated. The EC viability was examined using an MTT assay. Thirty-six adult female rats (aged between 6 and 8 weeks) with a normal estrus cycle were ovariectomized and enrolled in this study. Cryopreserved/thawed ovaries were encapsulated in Alg + Fib hydrogel containing 100 µM Mel + CD144⁺ ECs (2 × 10⁴ cells/ml) and transplanted into the subcutaneous region. Ovaries were removed after 14 days and the expression of Ang-1, and Ang-2 was monitored using real-time PCR assay. The number of vWF⁺ and α-SMA⁺ vessels was assessed using IHC staining. Using Masson's trichrome staining, fibrotic changes were evaluated.

RESULTS

FTIR data indicated successful interaction of Alg with Fib in the presence of ionic cross-linker (1% CaCl₂). Data confirmed higher biodegradation and swelling rates in Alg + Fib hydrogel compared to the Alg group (p < 0.05). Increased viability was achieved in encapsulated CD144⁺ ECs compared to the control group (p < 0.05). IF analysis showed the biodistribution of Dil⁺ ECs within hydrogel two weeks after transplantation. The ratio of Ang-2/Ang-1 was statistically up-regulated in the rats that received Alg + Fib + Mel hydrogel compared to the control-matched groups (p < 0.05). Based on the data, the addition of Mel and CD144⁺ ECs to Alg + Fib hydrogel reduced fibrotic changes. Along with these changes, the number of vWF⁺ and α-SMA⁺ vessels was increased in the presence of Mel and CD144⁺ ECs.

CONCLUSIONS

Co-administration of Alg + Fib with Mel and CD144⁺ ECs induced angiogenesis toward encapsulated cryopreserved/thawed ovarian transplants, resulting in reduced fibrotic changes.

The effect of platelet lysate on mouse ovarian structure, function and epigenetic modifications after autotransplantation

RESEARCH QUESTION

What are the effects of platelet lysate on structure, function and epigenetic modifications of heterotopically transplanted mouse ovarian tissues?

DESIGN

Mice were divided into three groups (n = 17 per group): control (mice with no ovariectomy, grafting or treatment), autograft and autograft plus platelet lysate (3 ml/kg at the graft sites). Inflammatory markers, serum malondialdehyde (MDA) concentration and total antioxidant capacity were assessed on day 7 after transplantation. Twenty-eight days after transplantation, stereological and hormonal analyses were conducted. Chromatin immunoprecipitation and quantitative real-time polymerase chain reaction were also used to quantify the epigenetic modifications of maturation genes, parallel to their expression.

RESULTS

The total volume of the ovary, cortex and medulla, and the number of different types of follicles, the concentration of interleukin (IL)-10, progesterone and oestradiol and total antioxidant capacity significantly decreased in the autograft group compared with the control group (P < 0.001); these parameters significantly increased in the autograft plus platelet lysate group compared with the autograft group (P < 0.001). The concentrations of tumour necrosis factor alpha, IL-6 and MDA increased significantly in the autograft group compared with the control group (P < 0.001); in the autograft plus platelet lysate group, these parameters significantly decreased compared with the autograft group (P < 0.001). In the autograft plus platelet lysate group, the expression levels of Gdf-9 (P < 0.0021), Igf-1 (P < 0.0048) and Igf-2 (P < 0.0063) genes also increased along with a lower incorporation of MeCP2 in the promoter regions (P < 0.001) compared with the autograft group.

CONCLUSIONS

Platelet lysate can contribute to follicular survival by improving folliculogenesis and increasing the expression of oocyte maturation genes.

L-Carnitine improves follicular survival and function in ovarian grafts in the mouse

CONTEXT

Ovarian tissue transplantation is performed to preserve fertility in patients undergoing chemotherapy and radiotherapy. However, the ischemia-reperfusion injury which occurs after the ovarian tissue transplantation causes follicular depletion and apoptosis. l -Carnitine has antioxidant and anti-inflammation properties.

AIMS

Therefore, we aimed to investigate the beneficial effect of l -carnitine on mouse ovaries following heterotopic autotransplantation.

METHODS

Mice were randomly divided into three groups (six mice per group): control, autografted and autografted+l -carnitine (200mg/kg daily intraperitoneal injections). Seven days after ovary autografting, the serum levels of malondialdehyde (MDA), total antioxidant capacity, tumor necrosis factor alpha (TNF-α), interleukin (IL)-6 and IL-10 were measured. Ovary histology, serum concentrations of progesterone and estradiol were also measured 28days after autotransplantation. Data were analysed using one-way analysis of variance (ANOVA) and Tukey test, and the means were considered significantly different at P Key results: In the autografted+l -carnitine group, the total volume of the ovary, the volume of the cortex, the number of follicles, the serum concentrations of IL-10, estradiol and progesterone significantly increased compared to the autografted group. In the autografted+l -carnitine group, serum concentrations of IL-6, TNF-α and MDA were significantly decreased compared to the autografted group.

CONCLUSIONS

Our results indicated that l -carnitine can ameliorate the consequences of ischemia-reperfusion on the mice ovarian tissue following autotransplantation.

IMPLICATIONS

l -carnitine improves the structure and function of transplanted ovaries.

Oocyte quality and aging

It is well known that female reproduction ability decreases during the forth decade of life due to age-related changes in oocyte quality and quantity; although the number of women trying to conceive has today increased remarkably between the ages of 36 to 44. The causes of reproductive aging and physiological aspects of this phenomenon are still elusive. With increase in the women's age, during Assisted Reproductive Technologies (ART) we have perceived a significant decline in the number and quality of retrieved oocytes, as well as in ovarian follicle reserves. This is because of increased aneuploidy due to factors such as spindle apparatus disruption; oxidative stress and mitochondrial damage. The aim of this review paper is to study data on the potential role of the aging process impacting oocyte quality and female reproductive ability. We present the current evidence that show the decreased oocyte quality with age, related to reductions in female reproductive outcome. The aging process is complicated and it is caused by many factors that control cellular and organism life span. Although the factors responsible for reduced oocyte quality remain unknown, the present review focuses on the potential role of ovarian follicle environment, oocyte structure and its organelles. To find a way to optimize oocyte quality and ameliorate clinical outcomes for women with aging-related causes of infertility.

Ovarian tissue damage after grafting: systematic review of strategies to improve follicle outcomes

Frozen-thawed human ovarian tissue endures large-scale follicle loss in the early post-grafting period, characterized by hypoxia lasting around 7 days. Tissue revascularization occurs progressively through new vessel invasion from the host and neoangiogenesis from the graft. Such reoxygenation kinetics lead to further potential damage caused by oxidative stress. The aim of the present manuscript is to provide a systematic review of proangiogenic growth factors, hormones and various antioxidants administered in the event of ovarian tissue transplantation to protect the follicle pool from depletion by boosting revascularization or decreasing oxidative stress. Although almost all investigated studies revealed an advantage in terms of revascularization and reduction in oxidative stress, far fewer demonstrated a positive impact on follicle survival. As the cascade of events driven by ischaemia after transplantation is a complex process involving numerous players, it appears that acting on specific molecular mechanisms, such as concentrations of proangiogenic growth factors, is not enough to significantly mitigate tissue damage. Strategies exploiting the activated tissue response to ischaemia for tissue healing and remodelling purposes, such as the use of antiapoptotic drugs and adult stem cells, are also discussed in the present review, since they yielded promising results in terms of follicle pool protection.

N-acetylcysteine protects ovarian follicles from ischemia-reperfusion injury in xenotransplanted human ovarian tissue

STUDY QUESTION

Can antioxidant treatment with N-acetylcysteine (NAC) protect ovarian follicles from ischemia-reperfusion injury in xenotransplanted human ovarian tissue?

SUMMARY ANSWER

Daily administration of NAC for 7-12 days post-transplantation reduced ischemia-reperfusion injury and increased follicle survival in human ovarian xenografts by upregulating the antioxidant defense system and exerting anti-inflammatory and antiapoptotic effects.

WHAT IS KNOWN ALREADY

Freezing of human ovarian tissue is performed with high follicular survival rates but up to 70% of follicles appear to be lost due to hypoxia and ischemia-reperfusion injury during ovarian tissue transplantation (OTT). NAC has been demonstrated to possess antioxidant and antiapoptotic properties, and studies in rodents have shown that intraperitoneal administration of NAC reduces ischemia-reperfusion injury and increases follicle survival in autotransplanted murine ovaries.

STUDY DESIGN, SIZE, DURATION

Pieces of frozen-thawed human ovarian tissue from 28 women aged 23-36 years were transplanted to immunodeficient mice in short- and long-term xenograft studies or cultured in vitro. Three short-term xenograft studies (1-week duration) were performed, in which saline or 150 mg/kg NAC was administered for 7 days post-transplantation (n = 12 patients per group). Two long-term xenograft studies (4 weeks of duration) were performed. In one of these studies, saline or 150 mg/kg NAC was administered for 12 days (n = 12 patients per group), while in the other study 50, 150 or 300 mg/kg NAC was administered for 7 days (n = 8 patients per group). In addition, human ovarian tissue (n = 12 pieces from three patients per group) was cultured with increasing concentrations of NAC (0, 5, 25 and 75 mM) for 4 days in vitro.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Donated ovarian tissue was obtained from women who had undergone ovarian tissue cryopreservation for fertility preservation at the University Hospital of Copenhagen. Cortical tissue pieces (5 × 5 × 1 mm) were transplanted subcutaneously to immunodeficient mice and NAC or saline was injected intraperitoneally. Grafts were retrieved after 1 or 4 weeks and follicle density was assessed. Gene expression analysis of antioxidant defense markers (superoxide dismutase; Sod1/SOD1, heme oxygenase-1; Hmox1/HMOX1, catalase; Cat/CAT), proinflammatory cytokines (tumor necrosis factor-alpha; Tnf-α, interleukin-1-beta; Il1-β, interleukin 6; Il6), apoptotic factors (B-cell lymphoma 2; Bcl2/BCL2, Bcl-2-associated X protein; Bax/BAX) and angiogenic factors (vascular endothelial growth factor A; Vegfa/VEGFA, angiopoietin-like 4; Angptl4/ANGPTL4) was performed in 1-week-old human ovarian xenografts and in cultured human ovarian tissue. Grafts retrieved after 4 weeks were histologically processed and analyzed for vascularization by CD31 immunohistochemical staining, fibrosis by Masson's Trichrome staining and apoptosis by immunofluorescence using cleaved caspase-3.

MAIN RESULTS AND THE ROLE OF CHANCE

After 1-week grafting, the relative expression of Sod1, Hmox1 and Cat was significantly higher in the group receiving 150 mg/kg NAC (NAC150-treated group) compared to controls (P = 0.04, P = 0.03, and P = 0.01, respectively), whereas the expression levels of Tnf-α, Il1-β and Il6 were reduced. The Bax/Bcl2 ratio was also significantly reduced in the NAC150-treated group (P < 0.005). In vitro, the relative gene expression of SOD1, HMOX1 and CAT increased significantly in the human ovarian tissue with increasing concentrations of NAC (P < 0.001 for all genes). However, the expression of VEGFA and ANGPTL4 as well as the BAX/BCL2 ratio decreased significantly with increasing concentrations of NAC (P < 0.02, P < 0.001 and P < 0.001, respectively). After 4-week grafting, fibrosis measured by collagen content was similar in the NAC150-treated group compared to controls (control: 56.6% ± 2.2; NAC150: 57.6% ± 1.8), whereas a statistically significant reduction in the CD31-positive vessel area was found (control: 0.69% ± 0.08; NAC150: 0.51% ± 0.07; P < 0.02). Furthermore, a reduced immunoreactivity of cleaved caspase-3 was observed in follicles of the NAC150-treated xenografts compared to controls. Follicle density (follicles/mm3, mean ± SD) was higher in the NAC150-treated group compared to the control group in the 1-week xenografts (control: 19.5 ± 26.3; NAC150: 34.2 ± 53.5) and 4-week xenografts (control: 9.3 ± 11.0; NAC150: 14.4 ± 15.0). Overall, a 2-fold increase in follicle density was observed in the NAC150-group after 1-week grafting where fold changes in follicle density were calculated in relation to grafts from the same patient. Around a 5-fold increase in follicle density was observed in the NAC150 and NAC300 groups after 4-week grafting.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

Follicle density in the human ovarian cortex is highly heterogeneous and can vary 100-fold between cortex pieces from the same woman. A high variability in follicle density within and between treatment groups and patients was found in the current study. Thus, solid conclusions cannot be made. While intraperitoneal injections of NAC appeared to reduce ischemia-reperfusion injury in human ovarian xenografts, different administration routes should be investigated in order to optimize NAC for potential clinical use.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first study to demonstrate the antioxidant, anti-inflammatory and antiapoptotic properties of NAC in xenotransplanted human ovarian tissue. Therefore, NAC appears to be a promising candidate for protecting ovarian follicles from ischemia-reperfusion injury. This provides the initial steps toward clinical application of NAC, which could potentially reduce the loss of ovarian follicles following OTT.

STUDY FUNDING/COMPETING INTEREST(S)

We are grateful to the Danish Childhood Cancer Foundation, Hørslev Foundation, Aase and Einar Danielsen's Foundation (grant number: 10-001999), Dagmar Marshalls Foundation, Else and Mogens Wedell-Wedellsborgs Foundation, Knud and Edith Eriksens Mindefond, and Fabrikant Einar Willumsens Mindelegat for funding this study. None of the authors have any competing interests to declare.

Melatonin Alleviates the Suppressive Effect of Hypoxanthine on Oocyte Nuclear Maturation and Restores Meiosis via the Melatonin Receptor 1 (MT1)-Mediated Pathway

It is well known that hypoxanthine (HX) inhibits nuclear maturation of oocytes by elevating the intracellular cAMP level, while melatonin (MT) is a molecule that reduces cAMP production, which may physiologically antagonize this inhibition and restore the meiosis process. We conducted in vitro and in vivo studies to examine this hypothesis. The results showed that 10^-3 M MT potentiated the inhibitory effect of HX on mouse oocyte meiosis by lowering the rate of germinal vesicle breakdown (GVBD) and the first polar body (PB1). However, 10^-5 M and 10^-7 M MT significantly alleviated the nuclear suppression induced by HX and restored meiosis in 3- and 6-week-old mouse oocytes, respectively. We identified that the rate-limiting melatonin synthetic enzyme AANAT and melatonin membrane receptor MT1 were both expressed in oocytes and cumulus cells at the GV and MII stages. Luzindole, a non-selective melatonin membrane receptor antagonist, blocked the activity of MT on oocyte meiotic recovery (P < 0.05). This observation indicated that the activity of melatonin was mediated by the MT1 receptor. To understand the molecular mechanism further, MT1 knockout (KO) mice were constructed. In this MT1 KO animal model, the PB1 rate was significantly reduced with the excessive expression of cAPM synthases (Adcy2, Adcy6, Adcy7, and Adcy9) in the ovaries of these animals. The mRNA levels of Nppc and Npr2 were upregulated while the genes related to progesterone synthesis (Cyp11a11), cholesterol biosynthesis (Insig1), and feedback (Lhcgr, Prlr, and Atg7) were downregulated in the granulosa cells of MT1 KO mice (P < 0.05). The altered gene expression may be attributed to the suppression of oocyte maturation. In summary, melatonin protects against nuclear inhibition caused by HX and restores oocyte meiosis via MT1 by reducing the intracellular concentration of cAMP.

Single xenotransplant of rat brown adipose tissue prolonged the ovarian lifespan of aging mice by improving follicle survival

Prolonging the ovarian lifespan is attractive and challenging. An optimal clinical strategy must be safe, long-acting, simple, and economical. Allotransplantation of brown adipose tissue (BAT), which is most abundant and robust in infants, has been utilized to treat various mouse models of human disease. Could we use BAT to prolong the ovarian lifespan of aging mice? Could we try BAT xenotransplantation to alleviate the clinical need for allogeneic BAT due to the lack of voluntary infant donors? In the current study, we found that a single rat-to-mouse (RTM) BAT xenotransplantation did not cause systemic immune rejection but did significantly increase the fertility of mice and was effective for more than 5 months (equivalent to 10 years in humans). Next, we did a series of analysis including follicle counting; AMH level; estrous cycle; mTOR activity; GDF9, BMP15, LHR, Sirt1, and Cyp19a level; ROS and annexin V level; IL6 and adiponectin level; biochemical blood indices; body temperature; transcriptome; and DNA methylation studies. From these, we proposed that rat BAT xenotransplantation rescued multiple indices indicative of follicle and oocyte quality; rat BAT also improved the metabolism and general health of the aging mice; and transcriptional and epigenetic (DNA methylation) improvement in F0 mice could benefit F1 mice; and multiple KEGG pathways and GO classified biological processes the differentially expressed genes (DEGs) or differentially methylated regions (DMRs) involved were identical between F0 and F1. This study could be a helpful reference for clinical BAT xenotransplantation from close human relatives to the woman.

Melatonin Improves In Vitro Development of Vitrified-Warmed Mouse Germinal Vesicle Oocytes Potentially via Modulation of Spindle Assembly Checkpoint-Related Genes

The present study aimed to investigate the effect of melatonin (MT) supplementation on in vitro maturation of vitrified mouse germinal vesicle (GV) oocytes. The fresh oocytes were randomly divided into three groups: untreated (control), or vitrified by open-pulled straw method without (vitrification group) or with MT supplementation (vitrification + MT group). After warming, oocytes were cultured in vitro, then the reactive oxygen species (ROS) and glutathione (GSH) levels, mitochondrial membrane potential, ATP levels, spindle morphology, mRNA expression of spindle assembly checkpoint (SAC)-related genes (Mps1, BubR1, Mad1, Mad2), and their subsequent developmental potential in vitro were evaluated. The results showed that vitrification/warming procedures significantly decreased the percentage of GV oocytes developed to metaphase II (MII) stage, the mitochondrial membrane potential, ATP content, and GSH levels, remarkably increased the ROS levels, and significantly impaired the spindle morphology. The expressions of SAC-related genes were also altered in vitrified oocytes. However, when 10-7 mol/L MT was administered during the whole length of the experiment, the percentage of GV oocytes matured to MII stage was significantly increased, and the other indicators were also significantly improved and almost recovered to the normal levels relative to the control. Thus, we speculate that MT might regulate the mitochondrial membrane potential, ATP content, ROS, GSH, and expression of SAC-related genes, potentially increasing the in vitro maturation of vitrified-warmed mouse GV oocytes.

Natural antioxidants in the vitrification solution improve the ovine ovarian tissue preservation

The present study evaluated the effect of the addition of antioxidants anethole (AN) and robinin (RO) in the vitrification solution, and the in vitro incubation (IVI) medium of ovine ovarian tissue. Ovarian fragments were vitrified without antioxidant (VWA) or with different concentrations of AN (30, 300 and 2000 μg/mL) or RO (0.125, 0.25 and 0.50 mg/mL), followed by IVI (24 h). Histological analyses showed that the percentage of morphologically normal preantral follicles (MNPF) in AN 2000 did not differ from RO 0.125 or fresh ovarian tissue (CTR). Subsequently, ovarian fragments were vitrified in the presence of AN 2000 and RO 0.125 followed by IVI without or with (AN 2000+ and RO 0.125+) the same antioxidants. The follicular activation in all treatments was significantly increased as compared to the CTR. The stroma cell density (SCD) in all the vitrified fragments was significantly lower than the CTR. However, in the AN 2000 and RO 0.125 this parameter was significantly higher when compared to the VWA. The reactive oxygen species (ROS) in the ovarian cortex of the AN 2000 or AN 2000+ were significantly reduced in comparison with the CTR while the intracellular ROS levels of AN 2000 and CTR were similar. The total antioxidant capacity (TAC) in RO 0.125 was significantly higher than that of VWA, AN 2000 and AN 2000+. According to the results, the use of antioxidants (AN or RO) only in the vitrification solution of ovine ovarian tissue is recommended, due to their better preservation of the SCD. Moreover, AN 2000 best maintains the follicular morphology, while RO 0.125 has a high TAC.

Melatonin improves the structure and function of autografted mice ovaries through reducing inflammation: A stereological and biochemical analysis

Melatonin has anti-oxidant, anti-inflammatory and anti-apoptotic properties. We aimed to investigate the effect of melatonin on the structure and function of mice ovaries following autograft transplantation. NMRI mice were divided into: control, autografted + saline, autografted + melatonin (20 mg/kg/day i.p. injection for 1 day before until 7 days after transplantation). 28 days post transplantation, ovary compartments were studied stereologically. Follicle apoptosis and the level of progesterone and estradiol were also measured. The inflammation, serum MDA concentration and total antioxidant capacity were also assessed on day 7 post transplantation. The total volume of the ovary, cortex and medulla (P < 0.05) and the number of different types of follicles (P < 0.001), the concentration of IL-10, progesterone and estradiol (P < 0.001) and TAC (P < 0.01) significantly decreased in the autografted + saline group compared to the control. The levels of IL-6 (P < 0.01), TNF-α, MDA and the apoptotic rate (P < 0.001) increased significantly in the autografted + saline group compared to the control, while the total volume of the ovary, cortex and medulla (P < 0.05) and the number of different types of follicles (P < 0.001), the concentration of IL-10, progesterone and estradiol (P < 0.001) and TAC (P < 0.01) significantly increased in the autografted + melatonin group compared to the autografted + saline group. The levels of IL-6 (P < 0.01), TNF-α, MDA and the apoptotic rate (P < 0.001) decreased significantly in the autografted + melatonine group compared to the autografted + saline group. In the autografted + melatonin group, the localization of CD31-positive cells in the theca layer was similar to the control group. Melatonin can improve the structure and function of the grafted ovary.

Melatonin improves developmental competence of oocyte-granulosa cell complexes from porcine preantral follicles

Melatonin has been reported to improve the survival rate of mouse and goat preantral follicles cultured in vitro. However, the role of melatonin in the development of oocyte-granulosa cell complexes (OGCs) isolated from preantral follicles remains unclear. Cumulus-oocyte complexes were isolated from OGCs cultured in vitro for 18.5 days and were then maturated in vitro for 42 h. The matured oocytes were parthenogenetically activated and were further cultured up to the blastocyst stage. We found that the developmental capacity of oocytes from in vitro cultured OGCs was significantly inferior to that from in vivo grown counterparts. Additionally, a 10^-5 M dose of melatonin added to the medium during in vitro culture of OGCs did not improve oocyte meiotic maturation but enhanced blastocyst rate of parthenogenetically activated embryos. Besides, these beneficial effects could be reversed by luzindole treatment, a melatonin membrane receptor antagonist. mRNA sequencing analysis further revealed that melatonin caused differential expression of 76 genes of which 75 were upregulated and 1 was downregulated in OGCs. Twelve of the 76 genes were identified as potential regulators of metabolic pathways by functional analysis. Taken together, these results indicate that melatonin improves developmental competence of porcine oocyte-granulosa cell complexes.

Development of fresh and vitrified agouti ovarian tissue after xenografting to ovariectomised severe combined immunodeficiency (SCID) mice

The aim of the present study was to evaluate the development of fresh and vitrified agouti ovarian tissue after xenografting to C57Bl/6 severe combined immunodeficiency (SCID) female mice. Ovaries were obtained from five female agoutis and divided into 16 fragments. Five fragments were transplanted immediately to ovariectomised SCID mice and the others were vitrified, stored for 2 weeks and transplanted only after rewarming. Tissue fragments were transplanted under the kidney capsule in recipients. The return of ovarian activity in recipients was monitored by the observation of external signs of oestrus and vaginal cytology over a period of 40 days after transplantation, after which the grafts were removed and evaluated for morphology, cell proliferation and the occurrence of DNA fragmentation. Ovarian activity returned in four of five mice that received fresh ovarian tissue from agoutis and in one of six mice that had received vitrified tissue a mean (±s.e.m.) 20.6±8.6 days after xenotransplantation. After graft removal, a predominance of primordial and primary follicles was observed in all grafts. Vitrification reduced cell proliferation and increased the occurrence of DNA fragmentation in grafted agouti ovarian tissue. In conclusion, the present study demonstrates that xenografted agouti ovarian tissue, fresh or vitrified, is able to promote the return of ovarian activity in ovariectomised SCID C57B1/6 mice. However, improvements to vitrification protocols for agouti ovarian tissue are necessary.

The Effect of Erythropoietin in Preventing Ischemia-Reperfusion Injury in Ovarian Tissue Transplantation

Condensation Erythropoietin improved the survival of follicles in ovarian grafts most likely by reducing ischemic injury, by improving neoangiogenesis, and by its antioxidant effects.

OBJECTIVE

Ovarian tissue cryopreservation and transplantation are the only options accepted for prepubertal girls and women requiring immediate chemotherapy. Ischemia-reperfusion injury is the main obstacle for ovarian tissue transplantation. In the present study, we aimed to evaluate the effects of recombinant human erythropoietin (EPO) on tissue viability in autotransplanted rat ovaries.

STUDY DESIGN

Seventeen female rats were randomized into 3 groups as sham control group (n = 5), EPO-treated group (n = 6), and EPO-untreated group (n = 6). Both ovaries were excised and transplanted into a subcutaneous pouch formed at the anterior abdominal wall in the EPO-treated and untreated groups. In the EPO group, 5000 U/kg EPO was applied as local injection to the site that ovarian tissue was placed and the dose was repeated with the same route at the end of the fourth week. After 2 months, ovaries were removed and blood samples were obtained. Levels of estradiol (E₂), vascular endothelial growth factor (VEGF), VEGF-C, and lipid hydroperoxidase (LPO) and the activity of glutathione peroxidase (GPX), superoxide dismutase (SOD), and catalase (CAT) were measured both in blood and tissue samples. Histopathological and morphometric analyses were also performed on tissue samples.

RESULTS

Considering serum levels, mean CAT was significantly higher ( P = .003) and mean SOD ( P = .033), LPO ( P = .050), VEGF ( P = .001), and VEGF-C ( P = .024) were significantly lower in the EPO-treated group than in the untreated group. Mean serum GPX levels were similar. Significantly higher levels of E₂ were determined in the EPO group than in the untreated group. Highest serum E₂ levels were found in the sham group ( P = .001). Tissue levels of GPX (1.23) and CAT (53.17) were significantly higher in the EPO group ( P = .002 and P = .001, respectively). However, tissue levels of SOD and LPO, VEGF, and VEGF-C levels were significantly lower in the EPO group than those in the untreated group ( P = .033, P = .050, P = .002, and P = .003, respectively). In tissue examination, the highest values of x, y axis and epithelial height were in the sham group. Mean value of the EPO group was found statistically significantly higher than that of the untreated group ( P ≤ .05). In terms of antral follicle count, ordering was found as sham > EPO-treated > EPO-untreated group. Follicle counts in the EPO group were significantly higher than those in the untreated group ( P ≤ 0.05).

CONCLUSION

Erythropoietin improved the survival of follicles in ovarian grafts most likely by reducing ischemic injury, by improving neoangiogenesis, and by its antioxidant effects.

Effects of Angiopoietin-2 on Transplanted Mouse Ovarian Tissue

Transplantation of ovarian tissue (OT) is currently the only clinical option to restore fertility with cryopreserved OT. However, follicle loss caused by ischemia and slow revascularization occurs in transplanted OT. To shorten the ischemic period and promote angiogenesis, some angiogenic factors have been used. Angiopoietin-2 (Ang2) is one of the major angiogenic factors and has been reported to promote blood vessels and increase vascular permeability in ischemic and/or hypoxic environment. This study was performed to investigate the effects of Ang2 on follicle integrity and revascularization of transplanted mouse OT. Five-week-old B6D2F1 female mice were divided into a control group and two Ang2 groups, followed by ovary collection and vitrification. After warming, the ovaries were autotransplanted into kidney capsules with/without Ang2 injection (50 or 500 ng/kg), and then the mice were sacrificed at days 2, 7, 21, and 42 after transplantation. A total 2,437 follicles in OT grafts were assessed for follicular density, integrity, and classification by using hematoxylin and eosin staining. Apoptosis and revascularization were evaluated by using TUNEL assay and CD31 immunohistochemistry, respectively. Serum follicle-stimulating hormone (FSH) levels were measured by using enzyme-linked immunosorbent assay. Both Ang2 groups showed remarkable increase in morphologically intact follicle ratio across all grafting durations except D21. The numbers of CD31(+) vessels were significantly increased in both Ang2 groups compared with the control group at all durations, except in the 50 ng Ang2 group at D42. However, the mean numbers of follicles of the grafts, apoptosis ratios, and serum FSH levels showed no significant differences among the groups. Our results show that Ang2 treatment significantly increased the intact follicle ratios and the number of blood vessels of the mouse OT grafts. However, further studies performed with large animal or human OT are necessary before clinical application for fertility preservation in cancer patients, and the reliability of the systemic effects of Ang2 should be verified.

Improved development by melatonin treatment after vitrification of mouse metaphase II oocytes

The study was aimed to investigate the effect of melatonin on the development potential of mouse MII oocytes after cryopreservation. Mouse MII oocytes were subjected first to vitrification/warming and 2 h of in vitro culture (phase 1), then to parthenogenetic activation (PA) followed by in vitro culture of parthenogenetic embryos (phase 2). Different concentrations of melatonin (0, 10^-9, 10^-6 mol/L) were added to the medium during either phase 1, phase 2 or both phases. The fresh oocytes were used as control. When melatonin was used during both phases, 10^-9 mol/L melatonin-treated group showed similar rates of cleavage and 4-cell embryo development compared with control, which were significantly higher than those of melatonin-free group, while the rates in either 10^-6 mol/L melatonin-treated or melatonin-free groups were significantly lower than that in control. When 10^-9 mol/L melatonin was added during either phase 1 or phase 2, both cleavage and 4-cell embryo development rates of either group were significantly lower than those of control. After oocyte vitrification/warming and PA, the ROS levels increased significantly and maternal-to-zygotic transition (MZT) related genes (Dcp1a, Dcp2, Hspa1a, Eif1ax, Pou5f1, Sox2) expression were disorganized. However, after 10^-9 mol/L melatonin supplementation, the ROS levels decreased significantly compared with melatonin-free group, and the gene expressions were almost recovered to normal level of control group. These results demonstrated that 10^-9 mol/L melatonin supplementation could increase the developmental potential of vitrified-warmed mouse MII oocytes, which may result from ROS scavenging activities and recovery of normal levels of the expressions of MZT-related genes.

Melatonin influence in ovary transplantation: systematic review

Melatonin is an indolamine produced by the pineal gland and it can exert a potent antioxidant effect. Its free radical scavenger properties have been used to advantage in different organ transplants in animal experiments. Several concentrations and administration pathways have been tested and melatonin has shown encouraging beneficial results in many transplants of organs such as the liver, lungs, heart, pancreas, and kidneys. The objective of the present study was to review the scientific literature regarding the use of melatonin in ovary transplantation. A systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was carried out using the Cochrane and Pubmed databases and employing the terms 'melatonin' AND 'ovary' AND 'transplantation.' After analysis, 5 articles were extracted addressing melatonin use in ovary transplants and involving 503 animals. Melatonin enhanced various graft aspects like morphology, apoptosis, immunological reaction, revascularization, oxidative stress, and survival rate. Melatonin's antioxidative and antiapoptotic properties seemingly produce positive effects on ovarian graft activity. Despite the promising results, further studies in humans need to be conducted to consolidate its use, as ovary transplantation for fertility preservation is gradually being moved from the experimental stage to a clinical setting.

New Insights into the Role of Autophagy in Ovarian Cryopreservation by Vitrification

Ovarian cryopreservation by vitrification is a highly useful method for preserving female fertility during radiotherapy and chemotherapy. However, cryoinjury, osmotic stress during vitrification, and ischemia/reperfusion during transplantation lead to loss of ovarian follicles. Ovarian follicle loss may be partially reduced by several methods; however, studies regarding the mechanism of ovarian follicle loss have only investigated cell apoptosis, which consists of type I programmed cell death. Autophagy is type II programmed cell death, and cell homeostasis is maintained by autophagy during conditions of stress. The role of autophagy during cryopreservation by vitrification has rarely been reported. The potential role of autophagy during ovarian cryopreservation by vitrification is reviewed in this article.

Effect of myo-inositol and melatonin versus myo-inositol, in a randomized controlled trial, for improving in vitro fertilization of patients with polycystic ovarian syndrome

Polycystic ovarian syndrome (PCOS) induces anovulation in women of reproductive age, and is one of the pathological factors involved in the failure of in vitro fertilization (IVF). Indeed, PCOS women are characterized by poor quality oocytes. Therefore, a treatment for enhancing oocyte quality becomes crucial for these patients. Myo-Inositol and melatonin proved to be efficient predictors for positive IVF outcomes, correlating with high oocyte quality. We tested the synergistic effect of myo-inositol and melatonin in IVF protocols with PCOS patients in a randomized, controlled, double-blind trial. Five-hundred twenty-six PCOS women were divided into three groups: Controls (only folic acid: 400 mcg), Group A (Inofolic® plus, a daily dose of myo-inositol: 4000 mg, folic acid: 400 mcg, and melatonin: 3 mg), and Group B (Inofolic®, a daily dose of myo-inositol: 4000 mg, and folic acid: 400 mcg). The main outcome measures were oocyte and embryo quality, clinical pregnancy and implantation rates. The treatment lasted from the first day of the cycle until 14 days after embryo transfer. Myo-inositol and melatonin have shown to enhance, synergistically, oocyte and embryo quality. In consideration of the beneficial effect observed in our trial and on the bases of previous studies, we decided to integrate routinely MI and M supplementation in the IVF protocols. The same treatment should be taken carefully in consideration in all procedures of this kind.

Effects of three different types of antifreeze proteins on mouse ovarian tissue cryopreservation and transplantation

Background

Ovarian tissue (OT) cryopreservation is effective in preserving fertility in cancer patients who have concerns about fertility loss due to cancer treatment. However, the damage incurred at different steps during the cryopreservation procedure may cause follicular depletion; hence, preventing chilling injury would help maintain ovarian function.

Objective

This study was designed to investigate the beneficial effects of different antifreeze proteins (AFPs) on mouse ovarian tissue cryopreservation and transplantation.

Methodology

Ovaries were obtained from 5-week-old B6D2F1 mice, and each ovary was cryopreserved using two-step vitrification and four-step warming procedures. In Experiment I, ovaries were randomly allocated into fresh, vitrification control, and nine experimental groups according to the AFP type (FfIBP, LeIBP, type III) and concentration (0.1, 1, 10 mg/mL) used. After vitrification and warming, 5,790 ovarian follicles were evaluated using histology and TUNEL assays, and immunofluorescence for τH2AX and Rad51 was used to detect DNA double-strand breaks (DSBs) and repair (DDR), respectively. In Experiment II, 20 mice were randomly divided into two groups: one where the vitrification and warming media were supplemented with 10 mg/mL LeIBP, and the other where media alone were used (control). Ovaries were then autotransplanted under both kidney capsules 7 days after vitrification together with the addition of 10 mg/mL LeIBP in the vitrification-warming media. After transplantation, the ovarian follicles, the percentage of apoptotic follicles, the extent of the CD31-positive area, and the serum FSH levels of the transplanted groups were compared.

Principal Findings

In Experiment I, the percentage of total grade 1 follicles was significantly higher in the 10 mg/mL LeIBP group than in the vitrification control, while all AFP-treated groups had significantly improved grade 1 primordial follicle numbers compared with those of the vitrification control. The number of apoptotic (TUNEL-positive) follicles was significantly decreased in the groups treated with 1 and 10 mg/mL LeIBP. The proportion of τH2AX-positive follicles was significantly reduced in all AFP-treated groups, while the proportion of Rad51-positive follicles was significantly decreased in only the FfIBP- and LeIBP-treated groups. In Experiment II, after autotransplantation of OT vitrified with 10 mg/mL of LeIBP, the percentage of total grade 1 and primordial grade 1 follicles, and the extent of the CD31-positive area, were increased significantly. Moreover, the levels of serum FSH and the percentage of TUNEL-positive follicles were significantly lower in the LeIBP-treated than in the control group.

Conclusion

A supplementation with high concentrations of AFPs had protective effects on follicle preservation during OT vitrification-warming procedures. The group treated with LeIBP was protected most effectively. The beneficial effects of LeIBP were also observed after autotransplantation of vitrified-warmed OT. Further studies are necessary to determine the exact mechanism of these protective effects.

Effect of preoperative simvastatin treatment on transplantation of cryopreserved-warmed mouse ovarian tissue quality

After the ovarian tissue (OT) transplantation, the ischemia-reperfusion injury causes depletion and apoptosis of follicle. Recent reports stated that simvastatin reduces ischemic damage. Therefore, we used the mouse whole ovarian vitrification and autotransplantation models to investigate the effects of simvastatin. Five-week-old B6D2F1 mice were randomly divided into four groups. Three groups were given simvastatin orally (5 mg/kg) before ovariectomy, either 2 hours before (2H Tx) or once a day for 3 or 7 days. The control group was given saline 2 hours before ovariectomy. All ovaries were cryopreserved by vitrification, held in liquid nitrogen for 1 week before being warmed, and autotransplanted. The grafts were collected for analysis on 2, 7, or 21 days after transplantation. Ovarian follicle morphology and apoptosis were assessed by hematoxylin and eosin staining and terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Vessel integrity in ovary was evaluated by immunohistochemistry using anti-CD31 antibody. Serum FSH level was measured to estimate the transplanted ovarian reserve. The proportion of morphologically normal (G1) follicles at 7 and 21 days and the percentage of CD31 (+) tissue at 21 days was significantly higher in the 2H Tx group than that in the control group. In addition, the 2H Tx group showed a significantly increased intact primordial follicle ratio at 2 and 21 days after OT transplantation. Administration of simvastatin 2 hours before ovariectomy could improve the quality after transplantation of cryopreserved mouse OT.

Effects of erythropoietin on ischemia, follicular survival, and ovarian function in ovarian grafts

Ovarian tissue transplantation is performed to preserve fertility in patients undergoing chemotherapy and radiotherapy. However, ischemia/reperfusion (IR) injury and free radical production occurring during the revascularization of the transplanted tissue are the major limitations of this procedure. The aim of this study was to investigate the effect of erythropoietin (EPO) as an antioxidant on oxidative stress and ovary survival following transplantation. The Naval Medical Research Institute (NMRI) mice (4–5 weeks old) were divided into three groups (six mice per group): control; autograft+saline, and autograft+EPO (500 IU/kg i.p.). After 28 days, ovary compartments were estimated stereologically. DNA fragmentation and plasma malondialdehyde (MDA), progesterone, and estradiol (E2) concentrations were also evaluated. The results were analyzed using one-way ANOVA and Tukey's test, and the means were significantly different at P<0.05. The mean total volume of ovary, cortex, and medulla and the number of follicles increased significantly in the autograft+EPO group (P<0.01). Apoptosis rate in the autograft+EPO group was lower than that in the autograft+saline group. The concentration of MDA decreased significantly in the autografted EPO-treated group than in the autografted saline-treated group (P<0.01). The concentration of E2 increased significantly in the autograft+EPO group than in the autograft+saline group (P<0.01). EPO reduced IR injury, increasing follicle survival and function in grafted ovaries.

Free Persian abstract

A Persian (Farsi) translation of the abstract is freely available online at http://www.reproduction-online.org/content/147/5/733/suppl/DC1

Peripheral reproductive organ health and melatonin: ready for prime time

Melatonin has a wide variety of beneficial actions at the level of the gonads and their adnexa. Some actions are mediated via its classic membrane melatonin receptors while others seem to be receptor-independent. This review summarizes many of the published reports which confirm that melatonin, which is produced in the ovary, aids in advancing follicular maturation and preserving the integrity of the ovum prior to and at the time of ovulation. Likewise, when ova are collected for in vitro fertilization-embryo transfer, treating them with melatonin improves implantation and pregnancy rates. Melatonin synthesis as well as its receptors have also been identified in the placenta. In this organ, melatonin seems to be of particular importance for the maintenance of the optimal turnover of cells in the villous trophoblast via its ability to regulate apoptosis. For male gametes, melatonin has also proven useful in protecting them from oxidative damage and preserving their viability. Incubation of ejaculated animal sperm improves their motility and prolongs their viability. For human sperm as well, melatonin is also a valuable agent for protecting them from free radical damage. In general, the direct actions of melatonin on the gonads and adnexa of mammals indicate it is an important agent for maintaining optimal reproductive physiology.

Melatonin promotes embryonic development and reduces reactive oxygen species in vitrified mouse 2-cell embryos

Two-cell embryos of mouse were vitrified by the open-pulled straw (OPS) method. The vitrified embryos were warmed and introduced into M16 medium for culture that contains melatonin at different concentrations (10(-3), 10(-5), 10(-7), 10(-9), 10(-11) m). This process caused reactive oxygen species (ROS) formation and jeopardized the development of the embryos. Melatonin, at different concentrations, significantly suppresses ROS production and promotes embryonic development in vitrified embryos compared with untreated ones. The mechanistic studies indicated that the beneficial effects of melatonin on vitrified 2-cell embryos of mouse were melatonin receptor (MT1 and MT2) independent. The direct free radical scavenging activity, the enhancement of endogenous glutathione levels, and the anti-apoptotic capacity of melatonin may account for its protective effects on vitrified embryonic development.

Follicular dynamic and immunoreactions of the vitrified ovarian graft after host treatment with variable regimens of melatonin

PROBLEM

This study investigates dose-dependent effects of melatonin on ovarian graft.

METHOD OF STUDY

Vitrified-thawed whole ovaries of newborn mice were grafted into ovariectomized mature ones. Melatonin (20, 50, 100, and 200 mg/kg/day) was administrated to separate groups of host mice for 32 days. IgM and IgG antibodies, Th1 and Th2 cytokines, and melatonin in recipient's blood were measured. Subsequent survival of the grafted ovaries was scored. An assessment of follicular morphology was performed using TUNEL assay and hematoxylin-eosin staining.

RESULTS

The administration of melatonin did not disturb the circadian rhythm of melatonin concentration. The ovarian graft lifespan was prolonged at 200 mg/kg/day melatonin (P < 0.001). However, in doses of higher than 20 mg/kg/day melatonin, the proportion of healthy follicles and ovary size decreased. Th1 cytokines levels were reduced dose dependently. However, the effect of melatonin on Th2 cytokines was not pronounced. IgM and IgG2a decreased in recipients receiving 200 mg/kg/day melatonin in comparison with non-treated group (P < 0.001), while this variables were significantly increased at the dose of 50 mg/kg/day (P < 0.001).

CONCLUSION

Melatonin at 200 mg/kg/day has an immunosuppresent effect and produce prolongation of graft survival. However, the associated reduction in healthy follicles suggests that melatonin in doses of higher than 20 mg/kg/day has no preventative ischemic action.

Melatonin improves the oocyte and the embryo in IVF patients with sleep disturbances, but does not improve the sleeping problems

PURPOSE

We aimed to analyse the in vitro fertilization-embryo transfer (IVF-ET) outcomes of the patients with sleep disturbances who were administered melatonin.

METHODS

A total of 60 patients with sleep disturbances were divided into two groups. The study group (group A, n=30) had underwent the IVF-ET with melatonin administration and the control group (group B, n=30) without melatonin. Sleeping status after melatonin administration and the IVF outcomes were compared between the two groups.

RESULTS

Sleeping status change was not significant (p>0.05). The mean number of the retrieved oocytes, the mean MII oocyte counts, the G1 embryo ratio were significantly higher in the melatonin administered group (group A) than that the non-administered group (group B); p=0.0001; p=0.0001; p<0.05 respectively.

CONCLUSION

IVF patients with sleep disorders may benefit from melatonin administration in improving the oocyte and the embryo quality, but the sleeping problem itself may not be fixed.

Melatonin protects against clomiphene citrate-induced generation of hydrogen peroxide and morphological apoptotic changes in rat eggs

The present study was aimed to determine whether clomiphene citrate-induces generation of hydrogen peroxide in ovary, if so, whether melatonin could scavenge hydrogen peroxide and protect against clomiphene citrate-induced morphological apoptotic changes in rat eggs. For this purpose, forty five sexually immature female rats were given single intramuscular injection of 10 IU pregnant mare's serum gonadotropin for 48 h followed by single injections of 10 IU human chorionic gonadotropin and clomiphene citrate (10 mg/kg bw) with or without melatonin (20 mg/kg bw) for 16 h. The histology of ovary, ovulation rate, hydrogen peroxide concentration and catalase activity in ovary and morphological changes in ovulated eggs were analyzed. Co-administration of clomiphene citrate along with human chorionic gonadotropin significantly increased hydrogen peroxide concentration and inhibited catalase activity in ovary, inhibited ovulation rate and induced egg apoptosis. Supplementation of melatonin reduced hydrogen peroxide concentration and increased catalase activity in the ovary, delayed meiotic cell cycle progression in follicular oocytes as well as in ovulated eggs since extrusion of first polar body was still in progress even after ovulation and protected against clomiphene citrate-induced egg apoptosis. These results clearly suggest that the melatonin reduces oxidative stress by scavenging hydrogen peroxide produced in the ovary after clomiphene citrate treatment, slows down meiotic cell cycle progression in eggs and protects against clomiphene citrate-induced apoptosis in rat eggs.