Oxidative Stress in Assisted Reproductive Techniques, with a Focus on an Underestimated Risk Factor

Connecting the dots: the role of fatigue in female infertility

Fatigue, an increasingly acknowledged symptom in various chronic diseases, has garnered heightened attention, during the medical era of bio-psycho-social model. Its persistence not only significantly compromises an individual's quality of life but also correlates with chronic organ damage. Surprisingly, the intricate relationship between fatigue and female reproductive health, specifically infertility, remains largely unexplored. Our exploration into the existing body of evidence establishes a compelling link between fatigue with uterine and ovarian diseases, as well as conditions associated with infertility, such as rheumatism. This observation suggests a potentially pivotal role of fatigue in influencing overall female fertility. Furthermore, we propose a hypothetical mechanism elucidating the impact of fatigue on infertility from multiple perspectives, postulating that neuroendocrine, neurotransmitter, inflammatory immune, and mitochondrial dysfunction resulting from fatigue and its co-factors may further contribute to endocrine disorders, menstrual irregularities, and sexual dysfunction, ultimately leading to infertility. In addition to providing this comprehensive theoretical framework, we summarize anti-fatigue strategies and accentuate current knowledge gaps. By doing so, our aim is to offer novel insights, stimulate further research, and advance our understanding of the crucial interplay between fatigue and female reproductive health.

Enhancing antioxidant levels and mitochondrial function in porcine oocyte maturation and embryonic development through notoginsenoside R1 supplementation

This study examines the impact of Notoginsenoside R1 (NGR1), a compound from Panax notoginseng, on the maturation of porcine oocytes and their embryonic development, focusing on its effects on antioxidant levels and mitochondrial function. This study demonstrates that supplementing in vitro maturation (IVM) medium with NGR1 significantly enhances several biochemical parameters. These include elevated levels of glutathione (GSH), nuclear factor erythrocyte 2-related factor 2 (NRF2) and mRNA expression of catalase (CAT) and GPX. Concurrently, we observed a decrease in reactive oxygen species (ROS) levels and an increase in JC-1 immunofluorescence, mitochondrial distribution, peroxisome proliferator-activated receptor-γ coactivator-1α (PGC1α) and nuclear NRF2 mRNA levels. Additionally, there was an increase in ATP production and lipid droplets (LDs) immunofluorescence. These biochemical improvements correlate with enhanced embryonic outcomes, including a higher blastocyst rate, increased total cell count, enhanced proliferative capacity and elevated octamer-binding transcription factor 4 (Oct4) and superoxide dismutase 2 (Sod2) gene expression. Furthermore, NGR1 supplementation resulted in decreased apoptosis, reduced caspase 3 (Cas3) and BCL2-Associated X (Bax) mRNA levels and decreased glucose-regulated protein 78 kD (GRP78) immunofluorescence in porcine oocytes undergoing in vitro maturation. These findings suggest that NGR1 plays a crucial role in promoting porcine oocyte maturation and subsequent embryonic development by providing antioxidant levels and mitochondrial protection.

Correlation between seminal plasma biochemical markers and semen parameters in idiopathic oligoasthenoteratospermia: identification of biomarkers for L-carnitine therapy

Background

L-carnitine therapy for idiopathic sperm abnormalities exhibits variable effectiveness, and currently, there are no established criteria to predict patient response. This study investigated correlations between seminal plasma markers and semen parameters to identify biomarkers that can guide indications for L-carnitine therapy indications in patients with idiopathic sperm abnormalities.

Methods

A retrospective review was conducted on 223 male patients with idiopathic oligoasthenoteratospermia, who sought medical attention at our clinic between January 2020 and October 2022. These patients underwent a pretreatment seminal plasma biochemical analysis, followed by a three-month continuous L-carnitine treatment. The correlation between seminal plasma biochemical parameters and pretreatment semen parameters was analyzed. Semen quality was compared between cases with normal and abnormal seminal plasma biochemical parameters, both pretreatment and posttreatment. The correlation between the changes in semen parameters after treatment and seminal plasma biochemical parameters were investigated.

Results

Correlation analyses revealed significant associations between all pretreatment semen parameters and seminal plasma biochemical markers, except for liquefying time and the ratio of normal morphology. Subgroup analysis, stratified by seminal fructose, zinc, citric acid, and neutral glycosidase levels, demonstrated that abnormal groups exhibited significantly different levels of semen parameters compared with the normal groups. The changing difference and changing ratio in the ratio of forward motile sperm showed a negative correlation with seminal fructose levels (r=-0.165 and -0.144). The changing difference in semen volume was negatively correlated with the level of seminal neutral glycosidase (r=-0.158). The changing ratio in semen volume, sperm concentration, total sperm count, and count of forward motile sperm all exhibited negative correlations with the levels of seminal neutral glycosidase (range from -0.178 to -0.224).

Conclusion

Seminal plasma biochemical markers, particularly fructose and neutral glycosidase, may serve as valuable indicators for determining the eligibility of patients with idiopathic sperm abnormalities for L-carnitine therapy.

Nutritional supplements and IVF: an evidence-based approach

Many women undergoing IVF take supplements during treatment. The purpose of this review was to systematically review these nutritional supplements. The therapies studied are dehydroepiandrosterone (DHEA), melatonin, co-enzyme Q10 (CoQ1O), carnitine, selenium, vitamin D, myo-inositol, omega-3, Chinese herbs and dietary interventions. A literature search up to May 2023 was undertaken. The data suggest that a simple nutritional approach would be to adopt a Mediterranean diet. With regards to supplements to treat a potential poor ovarian response to ovarian stimulation, starting DHEA and COQ-10 before cycle commencement is better than control therapies. Furthermore, medication with CoQ10 may have some merit, although it is unclear whether its place is for older women, for those with a poor response to ovarian stimulation or for poor embryonic development. There appears a benefit for some IVF outcomes for the use of melatonin, although it is unclear what group of patients would derive the benefit and the appropriate dosing regimen. For women with polycystic ovary syndrome, there may be a benefit to the use of myo-inositol, although again the dosing regimen is unclear. Furthermore, the place of vitamin D supplementation has yet to be clarified, and supplementation with omega-3 free fatty acids may lead to improvements in clinical and embryological IVF outcomes.

Clinical Benefits of Decreased Photo-Oxidative Stress on Human Embryo Development

OBJECTIVE

Early embryonic development is characterized by rapid cell division and gene activation, making the embryo extremely sensitive to environmental influences. Light exposure can affect embryonic development through a direct toxic effect on the embryo via the generation of reactive oxygen species. In a previous study, we demonstrated the positive effect of improved light-protected embryo culture conditions implemented in our laboratory. This study aimed to investigate the changes in human embryo development under light protection during the conventional in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI).

MATERIALS AND METHODS

We tested the potential beneficial effect of light filters to reduce the risk of toxic effects of light. IVF outcomes were compared between two experimental conditions, light protection with red light filters versus no light protection as a control.

RESULTS

Blastocyst development rate in IVF was significantly higher in the light-protected group than in the group treated under conventional conditions (46.6 vs. 26.7%). In the case of ICSI, we obtained a similar result (44.5 vs. 31.6%). The rate of cryopreservation with at least one embryo was higher in the light-protected phase (32.8%) than in the conventionally manipulated phase (26.8%). The abortion rate was also significantly lower during the light-protected period in IVF, resulting in a higher live birth rate.

CONCLUSIONS

The implementation of light protection to reduce the embryotoxic wavelengths of light in IVF centers may improve the blastocyst development rate and embryo quality while maintaining embryo safety.

Effects of niacin supplementation during in vitro culture on the developmental competence of porcine embryos

Niacin is a water-soluble vitamin belonging to the vitamin B complex. It has been found to possess various biological activities, including antioxidant and lipid modification capacities. This study aimed to elucidate the effects of niacin treatment in porcine in vitro culture (IVC) medium on embryo developmental competence after parthenogenetic activation. IVC medium was supplemented with different concentrations of niacin (0 [control], 300, 600 and 900 μM). The results showed that embryos cultured in an IVC medium supplemented with 300 and 600 μM niacin had an increased cleavage rate (p < .05). In addition, 300 μM niacin treatment resulted in a higher blastocyst formation rate than the control and other niacin-treated groups. However, the total cell number did not differ significantly among the experimental groups. Niacin supplementation at 600 μM decreased reactive oxygen species, whereas treatment with 300, 600 and 900 μM increased glutathione levels in day two embryos. On day seven, 300 μM niacin exhibited improved fatty acid levels and fewer lipid droplets than the control group. Furthermore, gene expression at the mRNA level was performed on day two and day seven embryos, treated with or without 300 μM niacin. The expression of anti-apoptotic BCL2 and lipid metabolism PLIN2-related genes were upregulated, whereas the pro-apoptotic BAX and CASPASE3 were downregulated with niacin supplementation compared with the control group. However, SIRT1, a gene related to energy and the oxidative state, was up-regulated in niacin-treated day two embryos (p < .05). Overall, the results indicate that niacin has a beneficial effect on pre-implantation embryo development by modulating lipid metabolism and reducing oxidative stress and apoptosis. The expression patterns of PLIN2 and SIRT1 reported here suggest that these transcripts may be involved in the mechanism by which niacin affects the developmental capacity of IVC embryos.

The Effect of Holder Pasteurization and Different Variants on Breast Milk Antioxidants

BACKGROUND

After birth, breast milk (BM) is a known essential source of antioxidants for infants. We analyzed the non-enzymatic total antioxidant capacity (TAC), oxygen radical absorbance capacity (ORAC), and glutathione, calcium, transferrin, and total protein levels of human breast milk before and after Holder pasteurization (HoP).

METHODS

The collected donor BM samples were pasteurized with HoP.

RESULTS

HoP decreased TAC (-12.6%), ORAC (-12.1%), transferrin (-98.3%), and total protein (-21.4%) levels; HoP did not influence the glutathione concentration, and it increased the total calcium (+25.5%) concentration. Mothers who gave birth via Cesarean section had significantly lower TAC in their BM. TAC and glutathione levels were elevated in the BM of mothers over the age of 30. BM produced in the summer had higher glutathione and calcium levels compared to BM produced in the winter. The glutathione concentration in term milk samples was significantly higher in the first two months of lactation compared to the period between the third and sixth months. The transferrin level of BM for female infants was significantly higher than the BM for boys, and mothers with a BMI above 30 had increased transferrin in their samples.

CONCLUSIONS

Antioxidant levels in human milk are influenced by numerous factors. Environmental and maternal factors, the postpartum age at breast milk collection, and Holder pasteurization of the milk influence the antioxidant intake of the infant.

The Role of Oxidative Stress in Infertility

(1) Background: Oxidative stress markers in the follicular fluid and serum of the patient with IVF results (number of fertilized oocytes, number of embryos, cumulative pregnancy rate) are important in establishing the causes of infertility. (2) Methods: 42 patients were enrolled in the study over the duration of 24 months and were divided into two groups: the study group divided into the female etiology for infertility as a tubal factor, diminished ovarian reserve, endometriosis, and unexplained infertility, and the control group consisting of the male factor, excluding the sperm donors and with no female factor cause. On the day of ovarian puncture in IVF, follicular fluid and serum were collected from the patients. (3) Results: Malondialdehyde from the follicular fluid was higher in the control group. The total antioxidant capacity in the follicular fluid is positively correlated with the pregnancy rate. There is no statistically significant difference in the oxidative stress markers from serum in both groups. (4) Conclusions: The capacity of the follicular fluid environment to contain the reactive oxygen species (ROS) leads to a higher pregnancy rate in the control group.