Resveratrol ameliorates toxic effects of cadmium on placental development in mouse placenta and human trophoblast cells

Potential pathological mechanisms and pharmacological interventions for cadmium-induced miscarriage

The prevalence of cadmium (Cd) contamination has emerged as a significant global concern. Exposure to Cd during pregnancy is associated with adverse pregnancy outcomes, including miscarriage. However, there is currently a lack of comprehensive summaries on Cd-induced miscarriage. Therefore, it is imperative to further strengthen research into in vivo studies, clinical status, pathological mechanisms, and pharmacological interventions for Cd-induced miscarriage. This study systematically presents the current knowledge on animal models and clinical trials investigating Cd exposure-induced miscarriage. The underlying mechanisms involving oxidative stress, inflammation, endocrine disruption, and placental dysfunction caused by Cd-induced miscarriage are also extensively discussed. Additionally, potential drug interventions such as melatonin, vitamin C, and vitamin E are highlighted for their pharmacological role in mitigating adverse pregnancy outcomes induced by Cd.

Cadmium as an ovarian toxicant: A review

Cadmium (Cd) is a ubiquitous heavy metal toxicant with no biological function in the human body. Considerably, because of its long biological half-life and very low excretion rate, Cd is inclined to accumulate and cause deleterious effects on various body organs (e.g., liver, kidney, and ovary) in humans and animals. Ovaries are the most vulnerable targets of Cd toxicity. Cd has been shown to induce oxidative stress, follicular atresia, hormonal imbalance, and impairment of oocyte growth and development. Moreover, Cd toxicity has been associated with increasing incidences of menstrual disorders, pregnancy loss, preterm births, delayed puberty, and female infertility. Therefore, it is crucial to understand how Cd poisoning impacts specific ovarian processes for the development of preventive interventions to enhance female fertility. The current review attempts to collate the recent findings on Cd-induced oxidative stress, follicular apoptosis, steroid synthesis inhibition, and teratogenic toxicity, along with their possible mechanisms in the ovarian tissue of different animal species. Additionally, the review also summarizes the studies related to the use of many antioxidants, medicinal herbs, and other compounds as remedial approaches for managing Cd-induced ovarian toxicity.

Alteration of epigenetic methyl and acetyl marks by postnatal chromium(VI) exposure causes apoptotic changes in the ovary of the F1 offspring

Hexavalent chromium, Cr(VI), is a heavy metal endocrine disruptor used widely in various industries worldwide and is considered a reproductive toxicant. Our previous studies demonstrated that lactational exposure to Cr(VI) caused follicular atresia, disrupted steroid hormone biosynthesis and signaling, and delayed puberty. However, the underlying mechanism was unknown. The current study investigated the effects of Cr(VI) exposure (25 ppm) during postnatal days 1-21 via dam's milk on epigenetic alterations in the ovary of F1 offspring. Data indicated that Cr(VI) disrupted follicle development and caused apoptosis by increasing DNMT3a /3b and histone methyl marks (H3K27me3 and H3K9me3) along with decreasing histone acetylation marks (H3K9ac and H3K27ac). Our study demonstrates that exposure to Cr(VI) causes changes in the epigenetic marks, partially contributing to the transcriptional repression of genes regulating ovarian development, cell proliferation (PCNA), cell survival (BCL-XL and BCL-2), and activation of genes regulating apoptosis (AIF and cleaved caspase-3), resulting in follicular atresia. The current study suggests a role for epigenetics in Cr(VI)-induced ovotoxicity and infertility.

Stilbenes: a promising small molecule modulator for epigenetic regulation in human diseases

Stilbenes are characterized by a vinyl group connecting two benzene rings to form the basic parent nucleus. Hydrogen atoms on different positions of the benzene rings can be substituted with hydroQxyl groups. These unique structural features confer anti-inflammatory, antibacterial, antiviral, antioxidant, anticancer, cardiovascular protective, and neuroprotective pharmacological effects upon these compounds. Numerous small molecule compounds have demonstrated these pharmacological activities in recent years, including Resveratrol, and Pterostilbene, etc. Tamoxifen and Raloxifene are FDA-approved commonly prescribed synthetic stilbene derivatives. The emphasis is on the potential of these small molecules and their structural derivatives as epigenetic regulators in various diseases. Stilbenes have been shown to modulate epigenetic marks, such as DNA methylation and histone modification, which can alter gene expression patterns and contribute to disease development. This review will discuss the mechanisms by which stilbenes regulate epigenetic marks in various diseases, as well as clinical trials, with a focus on the potential of small molecule and their derivatives such as Resveratrol, Pterostilbene, and Tamoxifen.

Cadmium reduces growth of male fetuses by impairing development of the placental vasculature and reducing expression of nutrient transporters

In utero exposure to the toxic metal cadmium (Cd) alters fetoplacental growth in rodents and has been inversely associated with birth weight and infant size in some birth cohorts. Moreover, studies suggest that Cd may have differential effects on growth and development according to offspring sex. The purpose of the current study was to evaluate changes in male and female fetoplacental development following a single injection of saline (5 ml/kg ip) or cadmium chloride (CdCl2, 2.5, 5 mg/kg, ip) on gestational day (GD) 9. By GD18, no changes in fetal or placental weights were observed after treatment with 2.5 mg/kg CdCl2. By comparison, the weight and length of male fetuses and their placentas were reduced following treatment with 5 mg/kg CdCl2 whereas no change was observed in females. In addition, the area of maternal and fetal blood vessels as well as the expression of the glucose transporters, Glut1 and Glut3, and the endothelial marker, CD34, were reduced in the placentas of CdCl2-treated male offspring compared to females. Interestingly, the placentas of females accumulated 80% more Cd than males after CdCl2 (5 mg/kg) administration. Female placentas also had higher concentrations of zinc and the zinc transporter Znt1 compared to males which may explain the limited changes in fetal growth observed following CdCl2 treatment. Taken together, disruption of vasculature development and reduced expression of glucose transporters in the placenta provide potential mechanisms underlying reduced fetal growth in male offspring despite the greater accumulation of Cd in female placentas.

Cumulus Cell Transcriptome after Cumulus-Oocyte Complex Exposure to Nanomolar Cadmium in an In Vitro Animal Model of Prepubertal and Adult Age

Cadmium (Cd), a highly toxic pollutant, impairs oocyte fertilization, through oxidative damage on cumulus cells (CCs). This study analysed the transcriptomic profile of CCs of cumulus-oocyte complexes (COCs) from adult and prepubertal sheep, exposed to Cd nanomolar concentration during in vitro maturation. In both age-groups, CCs of matured oocytes underwent RNA-seq, data analysis and validation. Differentially expressed genes (DEGs) were identified in adult (n = 99 DEGs) and prepubertal (n = 18 DEGs) CCs upon Cd exposure. Transcriptomes of adult CCs clustered separately between Cd-exposed and control samples, whereas prepubertal ones did not as observed by Principal Component Analysis. The transcriptomic signature of Cd-induced CC toxicity was identified by gene annotation and literature search. Genes associated with previous studies on ovarian functions and/or Cd effects were confirmed and new genes were identified, thus implementing the knowledge on their involvement in such processes. Enrichment and validation analysis showed that, in adult CCs, Cd acted as endocrine disruptor on DEGs involved in hormone biosynthesis, cumulus expansion, regulation of cell signalling, growth and differentiation and oocyte maturation, whereas in prepubertal CCs, Cd affected DEGs involved in CC development and viability and CC-oocyte communications. In conclusion, these DEGs could be used as valuable non-invasive biomarkers for oocyte competence.

Effect of Resveratrol on Pregnancy, Prenatal Complications and Pregnancy-Associated Structure Alterations

Adverse pregnancy outcomes are considered significant health risks for pregnant women and their offspring during pregnancy and throughout their lifespan. These outcomes lead to a perturbated in-utero environment that impacts critical phases of the fetus's life and correlates to an increased risk of chronic pathological conditions, such as diabetes, obesity, and cardiovascular diseases, in both the mother's and adult offspring's life. The dietary intake of naturally occurring antioxidants promotes health benefits and disease prevention. In this regard, maternal dietary intake of polyphenolic antioxidants is linked to a reduced risk of maternal obesity and cardio-metabolic disorders, positively affecting both the fetus and offspring. In this work, we will gather and critically appraise the current literature highlighting the effect/s of the naturally occurring polyphenol antioxidant resveratrol on oxidative stress, inflammation, and other molecular and physiological phenomena associated with pregnancy and pregnancy conditions, such as gestational diabetes, preeclampsia, and preterm labor. The resveratrol impact on prenatal complications and pregnancy-associated structures, such as the fetus and placenta, will also be discussed. Finally, we will draw conclusions from the current knowledge and provide future perspectives on potentially exploiting resveratrol as a therapeutic tool in pregnancy-associated conditions.

Effect of dietary resveratrol on placental function and reproductive performance of late pregnancy sows

Placental function is vital to the fetal growth of sows, and resveratrol (RES) can protect cells against oxidative stress, which is one of the major factors impairing placental function. This study aimed to investigate the effect of dietary resveratrol (RES) on placental function and reproductive performance during late pregnancy in a sow model from the aspects of oxidative stress, insulin resistance, and gut microbiota. A total of 26 hybrid pregnant sows (Landrace × Yorkshire) with similar parity were randomly allocated into two groups (n = 13) and fed with a basal diet or a diet containing 200 mg/kg of resveratrol from day 85 of gestation until parturition. The dietary supplementation of RES increased the litter weight at parturition by 12.53% (p = 0.145), with ameliorated insulin resistance (HOMA-IR), increased triglyceride (TG) levels, and decreased interleukin (IL)-1β and IL-6 levels in serum (p < 0.05). Moreover, resveratrol increased the placental vascular density (p < 0.05) with the enhanced expression of nutrient transporter genes (SLC2A1 and SLC2A3) and antioxidant genes, such as superoxide dismutase 2 (SOD2) and heme oxygenase-1 (HO-1) but declined the expression of inflammatory genes, such as IL-1β and IL-6 (p < 0.05). The characterization of the fecal microbiota revealed that resveratrol decreased the relative abundance of the Christensensllaceae R-7 group and Ruminococcaceae UCG-008 (p < 0.05), which had a positive linear correlation with the expression of IL-1β and IL-6 (p < 0.05), but had a negative linear correlation with the expression of SOD2, HO-1, SLC2A1, and SCL2A3 genes (p < 0.05). These data demonstrated that dietary supplementation with resveratrol can improve placental function with ameliorated insulin resistance, oxidative stress, and inflammation potentially by regulating Ruminococcaceae UCG-008 and the Christensensllaceae R-7 group in sows.