Resveratrol Promotes Proliferation, Antioxidant Properties, and Progesterone Production in Yak (Bos grunniens) Granulosa Cells

Resveratrol (RES) is a class of natural polyphenolic compounds known for its strong anti-apoptotic and antioxidant properties. Granulosa cells (GCs) are one of the important components of ovarian follicles and play crucial roles in follicular development of follicles in the ovary. Here, we explored the effects of RES on the proliferation and functions of yak GCs. Firstly, we evaluated the effect of RES dose and time in culture on the viability of GCs, and then the optimum treatment protocol (10 μM RES, 36 h) was selected to analyze the effects of RES on the proliferation, cell cycle, apoptosis, malondialdehyde (MDA), glutathione (GSH), reactive oxygen species (ROS) accumulation, lipid droplet content, ATP production, and steroidogenesis of GCs, as well as the expression of related genes. The results show that RES treatment significantly (1) increased cell viability and proliferation and inhibited cell apoptosis by upregulating BCL-2 and SIRT1 genes and downregulating BAX, CASP3, P53, and KU70 genes; (2) increased the proportion of GCs in the S phase and upregulated CCND1, PCNA, CDK4, and CDK5 genes; (3) reduced ROS accumulation and MDA content and increased GSH content, as well as upregulating the relative expression levels of CAT, SOD2, and GPX1 genes; (4) decreased lipid droplet content and increased ATP production; (5) promoted progesterone (P4) secretion and the expression of P4 synthesis-related genes (StAR, HSD3B1, and CYP11A1); and (6) inhibited E2 secretion and CYP19A1 expression. These findings suggest that RES at 10 μM increases the proliferation and antioxidant properties, inhibits apoptosis, and promotes ATP production, lipid droplet consumption, and P4 secretion of yak GCs.

Steroidogenic activity of liposomal methylated resveratrol analog 3,4,5,4'-tetramethoxystilbene (DMU-212) in human luteinized granulosa cells in a primary three-dimensional in vitro model

PURPOSE

Steroid hormone secretion is one of the key functions of granulosa cells (GCs). Resveratrol is a natural polyphenol, known for its beneficial health effects, such as improving reproductive health. However, its application is limited due to poor bioavailability. The methoxy derivative of resveratrol (DMU-212) was demonstrated to be more lipophilic, and therefore of greater bioavailability. However, since the addition of methoxy groups to the stilbene scaffold was found to make the molecule insoluble in water, DMU-212 was loaded into liposomes. This study aimed to evaluate how the liposomal formulation of DMU-212 (lipDMU-212) alters estradiol and progesterone secretion of human ovarian GCs in a primary three-dimensional cell culture model.

METHODS

DMU-212-loaded liposomes were prepared by thin film hydration followed by extrusion. Cell viability was measured after exposure of GCs spheroids to the liposomal formulation of DMU-212 using CellTiter-Glo® 3D Cell Viability Assay. The secretion of estradiol and progesterone was determined using commercial ELISA kits. RT-qPCR was conducted to analyze the expression of steroidogenesis-related genes. Finally, the western blot technique was used to analyze the effect of lipDMU-212 and FSH treatments on CYP11A1 and HSD3B1 protein levels.

RESULTS

lipDMU-212 was found to significantly increase estradiol and progesterone secretion in a dose-dependent manner by enhancing the expression of CYP11A1, HSD3B1, StAR, CYP17A1, CYP19A1, and HSD17B1 genes. We have also shown that lipDMU-212, used alone and in combination with FSH, significantly increased the expression of the HSD3B1 and CYP11A1 proteins in GCs. Furthermore, our study suggests that lipDMU-212 increases FSH activity.

CONCLUSIONS

This is the first study to describe the steroidogenic activity of liposomal formulation of DMU-212, possibly through increasing the StAR and CYP19A1 expression. These findings suggest that lipDMU-212 might have a beneficial effect in the treatment of disorders related to estrogen deficiency and hyperandrogenism, such as PCOS.

The mechanisms of multidrug resistance of breast cancer and research progress on related reversal agents

Chemotherapy is the mainstay in the treatment of breast cancer. However, many drugs that are commonly used in clinical practice have a high incidence of side effects and multidrug resistance (MDR), which is mainly caused by overexpression of drug transporters and related enzymes in breast cancer cells. In recent years, researchers have been working hard to find newer and safer drugs to overcome MDR in breast cancer. In this review, we provide the molecule mechanism of MDR in breast cancer, categorize potential lead compounds that inhibit single or multiple drug transporter proteins, as well as related enzymes. Additionally, we have summarized the structure-activity relationship (SAR) based on potential breast cancer MDR modulators with lower side effects. The development of novel approaches to suppress MDR is also addressed. These lead compounds hold great promise for exploring effective chemotherapy agents to overcome MDR, providing opportunities for curing breast cancer in the future.

Identification of microRNAs implicated in modulating resveratrol-induced apoptosis in porcine granulosa cells

MicroRNAs (miRNAs) are small, noncoding RNAs that play a crucial role in the complex and dynamic network that regulates the apoptosis of porcine ovarian granulosa cells (POGCs). Resveratrol (RSV) is a nonflavonoid polyphenol compound that is involved in follicular development and ovulation. In previous study, we established a model of RSV treatment of POGCs, confirming the regulatory effect of RSV in POGCs. To investigate the miRNA-level effects of RSV on POGCs to reveal differentially expressed miRNAs, a control group (n = 3, 0 μM RSV group), a low RSV group (n = 3, 50 μM RSV group), and a high RSV group (n = 3, 100 μM RSV group) were created for small RNA-seq. In total, 113 differentially expressed miRNAs (DE-miRNAs) were identified, and a RT-qPCR analysis showed a correlation with the sequencing data. Functional annotation analysis revealed that DE-miRNAs in the LOW vs. CON group may be involved in cell development, proliferation, and apoptosis. In the HIGH vs. CON group, RSV functions were associated with metabolic processes and responses to stimuli, while the pathways were related to PI3K24, Akt, Wnt, and apoptosis. In addition, we constructed miRNA-mRNA networks related to Apoptosis and Metabolism. Then, ssc-miR-34a and ssc-miR-143-5p were selected as key miRNAs. In conclusion, this study provided an improved understanding of effects of RSV on POGCs apoptosis through the miRNA modulations. The results suggest that RSV may promote POGCs apoptosis by stimulating the miRNA expressions and provided a better understanding of the role of miRNAs combined with RSV in ovarian granulosa cell development in pigs.

Integrated analysis of lncRNA and mRNA for the apoptosis of porcine ovarian granulosa cells after polyphenol resveratrol treatment

Resveratrol (RES) is a non-flavonoid polyphenol compound that can be involved in follicular development and ovulation. However, the mechanism by which resveratrol regulates the apoptosis of porcine ovarian granulosa cells (POGCs) through long non-coding RNA (lncRNA) is poorly understood. We generated POGCs models of different doses of RES (0, 25, 50, 75, and 100 μM). It was observed that the cell viability was the highest in the 50 μM group, and the highest apoptosis rates were recorded in the 100 μM group. Therefore, a control group (n = 3, 0 μM RES group), a low RES group (n = 3, 50 μM RES group), and a high RES group (n = 3, 100 μM RES group) of POGCs were created for next RNA sequencing. Gene Ontology (GO) indicated that differentially expressed lncRNAs associated with apoptotic process were highly enriched. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of lncRNA target genes found that the Wnt signaling pathway and PI3K-Akt signaling pathway were both enriched. Furthermore, we constructed lncRNA-mRNA networks related to Metabolic and Cell Apoptosis, respectively. In the networks, five key-lncRNAs were screened, which may play a significant role in the process of POGCs metabolism and apoptosis. Furthermore, we focused on the function of a lnc-GAM (lncRNA associated with Granulosa cells Apoptosis and Metabolism) and verified that lnc-GAM could influence cell apoptosis in POGCs development by affecting the mRNA expression of apoptosis-related markers, and also affects the secretion of steroid hormones and related genes expression in POGCs cultured in vitro. Our study provides seminal data and important new insights into the regulation of reproductive mechanisms in porcine and other female mammals.

Stilbenes: Characterization, bioactivity, encapsulation and structural modifications. A review of their current limitations and promising approaches

Stilbenes are phenolic compounds naturally synthesized as secondary metabolites by the shikimate pathway in plants. Research on them has increased in recent years due to their therapeutic potential as antioxidant, antimicrobial, anti-inflammatory, anticancer, cardioprotective and anti-obesity agents. Amongst them, resveratrol has attracted the most attention, although there are other natural and synthesized stilbenes with enhanced properties. However, stilbenes have some physicochemical and pharmacokinetic problems that need to be overcome before considering their applications. Human clinical evidence of their bioactivity is still controversial due to this fact and hence, exhaustive basis science on stilbenes is needed before applied science. This review gathers the main physicochemical and biological properties of natural stilbenes, establishes structure-activity relationships among them, emphasizing the current problems that limit their applications and presenting some promising approaches to overcome these issues: the encapsulation in different agents and the structural modification to obtain novel stilbenes with better features. The bioactivity of stilbenes should move from promising to evident.

Nanoplastics impair in vitro swine granulosa cell functions

Soil, water, and air pollution by plastic represents an issue of great concern since the particles produced by degradation of plastic materials can be ingested by animals and humans, with still uncertain health consequences. As a contribution on this crucial subject, the present work reports an investigation on the in vitro effects of different concentrations of polystyrene nanoplastics (5, 25, and 75 µg/mL) on swine granulosa cells, a model of endocrine reproductive cells. In particular, cell growth (BrDU incorporation and ATP production), steroidogenesis (17-β estradiol and progesterone secretion) and redox status (superoxide and nitric oxide production, enzymatic and non-enzymatic scavenging activity) were studied. Nanoplastics, at the highest concentration, stimulated cell proliferation (P < 0.05), while cell viability resulted unaffected. Steroidogenesis was disrupted (P < 0.05). Both enzymatic and non-enzymatic scavenging activity were increased after exposure at the highest nanoplastic dose (P < 0.05, P < 0.001). Nitric oxide secretion was increased by 25 and 75 µg/mL (P < 0.05) while superoxide generation was stimulated (P < 0.001) only by the highest concentration tested. Taken together, main features of cultured swine granulosa cells resulted affected by exposure to nanoplastics. These results raise concerns since environment nanoplastic contamination can represents a serious threat to animal and human health.

Effects of resveratrol on female reproduction: A review

The present review summarizes the current knowledge concerning physiological effects of resveratrol (RSV) with emphasis on the RSV action on female reproductive processes. The review outlines provenance, properties, mechanisms of action, physiological and therapeutic actions of RSV on female reproduction and other physiological processes, as well as areas of possible application of R. This review is based on the search for the related full papers indexed in Medline/Pubmed, Web of Science and SCOPUS databases between the year 2000 and 2021 according to the criteria of preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews and other related guidelines. The analysis of the available information suggests that RSV has a number of properties which enable its influence on various physiological processes including female reproduction at various regulatory levels via various extra- and intracellular signalling pathways. Despite some contradictions and limitations in the available data, they indicate applicability of both stimulatory and inhibitory effects of RSV for control and influence of various reproductive and non-reproductive processes and treatment of their disorders in phytotherapy, animal production, medicine, biotechnology and assisted reproduction. To establish the clinical efficacy of RSV, further high quality studies are needed.

Low Doses of Resveratrol Protect Human Granulosa Cells from Induced-Oxidative Stress

Resveratrol is a phytoalexin present in plant-derived foods, including grape’s skin, cocoa, and peanuts. Evidence suggests that it has beneficial effects on human health because of its antioxidant properties. However, there is limited knowledge about the part played by resveratrol in ovarian function. In this paper, the influence of resveratrol on granulosa cells (GC) was evaluated. In addition to being the main estradiol producers, GC are in direct contact with the oocyte, playing a fundamental role in its growth and development. The cell line COV434 and human granulosa cells (hGC), obtained from women undergoing assisted reproductive technology (ART), were used. GC were treated with resveratrol (0.001–20 μM) at different times (24–72 h). Low concentrations of this compound suggest a protective role, as they tend to reduce ROS/RNS formation after inducement of stress. On the contrary, high concentrations of resveratrol affect GC viability and steroidogenic function. As it may act as a direct modulator of GC oxidative balance, this work may help to clarify the impact of resveratrol on GC and the usefulness of this antioxidant as adjunct to infertility treatments.

Orexin B inhibits viability and differentiation of stromal cells from swine adipose tissue

Adipose tissue is recognized as a fundamental endocrine organ. Nowadays, we are also aware that it contains the highest number of stromal cells (ASCs) per unit of volume. These cells can differentiate between different phenotypes among which the adipocytes. The aim of this work was to verify whether orexin B, crucial mediator of the energy balance, modifies the differentiation of cultured ASCs. We used the pig as a model. Our data demonstrate that swine ASCs express prepro-orexin. Orexin B treatment inhibits ASCs proliferation (P < 0.05) and adipogenic differentiation (P < 0.05). Data collected could be interesting both in animal production field because consumers require lean meat, and in human medicine study about obesity because pig can be considered a valuable animal model for translational studies.

The Stemness of Human Ovarian Granulosa Cells and the Role of Resveratrol in the Differentiation of MSCs-A Review Based on Cellular and Molecular Knowledge

Ovarian Granulosa Cells (GCs) are known to proliferate in the developing follicle and undergo several biochemical processes during folliculogenesis. They represent a multipotent cell population that has been differentiated to neuronal cells, chondrocytes, and osteoblasts in vitro. However, progression and maturation of GCs are accompanied by a reduction in their stemness. In the developing follicle, GCs communicate with the oocyte bidirectionally via gap junctions. Together with neighboring theca cells, they play a crucial role in steroidogenesis, particularly the production of estradiol, as well as progesterone following luteinization. Many signaling pathways are known to be important throughout the follicle development, leading either towards luteinization and release of the oocyte, or follicular atresia and apoptosis. These signaling pathways include cAMP, PI3K, SMAD, Hedgehog (HH), Hippo and Notch, which act together in a complex manner to control the maturation of GCs through regulation of key genes, from the primordial follicle to the luteal phase. Small molecules such as resveratrol, a phytoalexin found in grapes, peanuts and other dietary constituents, may be able to activate/inhibit these signaling pathways and thereby control physiological properties of GCs. This article reviews the current knowledge about granulosa stem cells, the signaling pathways driving their development and maturation, as well as biological activities of resveratrol and its properties as a pro-differentiation agent.

Expression and function of the stromal cell-derived factor-1 (SDF-1) and CXC chemokine receptor 4 (CXCR4) in the swine ovarian follicle

The most characterized stromal cell-derived factor-1 (SDF-1) variants are the isoform α, which is the predominant one but undergoes rapid proteolysis, and the β isoform, which is more resistant. Through the interaction with a specific chemokine receptor called CXCR4, SDF-1 is able to regulate different physiological processes. The aim of this study was to verify the expression and potential functional role of SDF-1 and CXCR4 in the porcine ovary. Firstly, the expression of SDF-1 and its receptor in different ovarian districts was verified for the first time. Thereafter, the effect of SDF-1 β isoform (51-72) fragment on functional parameters, such as proliferation, metabolic activity, redox status, nitric oxide production, and steroidogenic activity, was assessed on granulosa cells collected from follicles. In addition, the potential effect of this protein in vascular events was verified through investigations on porcine aortic (AOC) endothelial cells, such as the production of nitric oxide and viability tests. The proliferation and metabolic activity were not affected by treatment with the cytokine. As regard to steroidogenesis, the peptide stimulated both estrogen (P = 0.049) and progesterone production (P = 0.039). Redox status was affected by the examined substance since superoxide anion was inhibited (P = 0.001), while antioxidant power (P = 0.034), as well as nitric oxide generation, were stimulated (P = 0.034). Tests performed on AOCs showed significant stimulation of nitric oxide production (P = 0.004) by the examined peptide, while cell viability was unaffected. Therefore, the potential role of cytokine in the mechanisms involved in the regulation of follicular function can be hypothesized.

Bisphenol S, a Bisphenol A alternative, impairs swine ovarian and adipose cell functions

The high-volume-produced plastic monomer Bisphenol A (BPA) has been in the spotlight in the last years because of its endocrine disruptor (ED) behavior, leading to disclosure of the association between the widespread human and wildlife exposure to BPA and reproductive, metabolic, and developmental disorders and hormone-dependent cancer onset. These evidences caused restrictions and prohibitions of BPA industrial uses and prompted investigation of harmless alternative compounds. Above all, several countries have substituted the parental analogue with Bisphenol S (BPS) in baby care product manufacturing, even if its structural homology to BPA suggests similar ED properties not yet completely ruled out. In light of this consideration, the aim of this in vitro study was to investigate the effect of BPS exposure (0.1, 1, and 10 μM for 48 h) on granulosa cells that are considered the prime ovarian targets of BPA as a "reproductive toxicant". Our data document that BPS inhibited E2 production, cell proliferation, and scavenging nonenzymatic activity (P < 0.05) while it significantly (P < 0.05) stimulated cell viability, superoxide (O₂^-) and nitric oxide (NO) production in cultured swine granulosa cells, a previously validated endocrine cell model for BPA. Evidence also exists that BPA and its analogues, as environmental lipophilic pollutants, are involved in the disruption of adipose tissue (AT) endocrine function, resulting in metabolic effects and thus in potential reproductive disorders. On this basis, our second purpose was the assessment of BPS effects on mesenchymal stromal cells (MSCs) isolated from porcine AT, taking into account MSCs viability and adipogenic differentiation, a process actually demonstrated to be largely affected by EDs. Our results show that BPS decreased (P < 0.001) cell viability of proliferating adipose stromal cells. Taken as a whole, our data demonstrate an effective BPS ED activity at μM concentrations, suggesting that further studies are needed before considering its use in industrial application as an alternative to BPA.

Anticancer Activity of Stilbene-Based Derivatives

Stilbene is an abundant structural scaffold in nature, and stilbene-based compounds have been widely reported for their biological activity. Notably, (E)-resveratrol and its natural stilbene-containing derivatives have been extensively investigated as cardioprotective, potent antioxidant, anti-inflammatory, and anticancer agents. Starting from its potent chemotherapeutic activity against a wide variety of cancers, the stilbene scaffold has been subject to synthetic manipulations with the aim of obtaining new analogues with improved anticancer activity and better bioavailability. Within the last decade, the majority of new synthetic stilbene derivatives have demonstrated significant anticancer activity against a large number of cancer cell lines, depending on the type and position of substituents on the stilbene skeleton. This review focuses on the structure-activity relationship of the key compounds containing a stilbene scaffold and describes how the structural modifications affect their anticancer activity.

Ovarian actions of resveratrol

Resveratrol, a natural polyphenol found in grapes, berries, and medicinal plants, exhibits antioxidant and anti-inflammatory activities and has been proposed to be a longevity-prolonging agent. There is also growing evidence that resveratrol has cardioprotective properties and beneficial effects on both glucose and lipid metabolism. Recently, several studies have examined the use of resveratrol as a therapeutic agent to treat numerous pathological and metabolic disorders. Herein, we present insights into the mechanisms of action, biological effects, and current evidence of actions of resveratrol on the ovary. In vitro, resveratrol inhibits proliferation and androgen production by theca-interstitial cells. Resveratrol also exerts a cytostatic, but not cytotoxic, effect on granulosa cells, while decreasing aromatization and vascular endothelial growth factor expression. In vivo, resveratrol treatment reduced the size of adipocytes and improved estrus cyclicity in the previously acyclic rat model of polycystic ovary syndrome (PCOS). In addition, resveratrol increased the ovarian follicular reserve and prolonged the ovarian life span in rats. Taken together, resveratrol emerges as a potential therapeutic agent to treat conditions associated with androgen excess, such as PCOS. The efficacy of resveratrol in the treatment of gynecological conditions requires further investigation.

Resveratrol-Related Polymethoxystilbene Glycosides: Synthesis, Antiproliferative Activity, and Glycosidase Inhibition

A small library of polymethoxystilbene glycosides (20-25) related to the natural polyphenol resveratrol have been synthesized and subjected, together with their aglycones 17-19, to an antiproliferative activity bioassay toward Caco-2 and SH-SY5Y cancer cells. Six of the compounds exhibit antiproliferative activity against at least one cell line. In particular, compounds 17 and 18 proved highly active on at least one of the two cell cultures. Compound 18 showed a GI50 value of 3 μM against Caco-2 cells, a value comparable to that of the anticancer drug 5-fluorouracil. The closely related compound 19 proved inactive, and its conjugates 22 and 25 showed weak cell growth inhibition. The results indicate that minimal differences in the structure of both polymethoxystilbenes and their glycosides can substantially affect the antiproliferative activity. The possible hydrolytic release of the aglycones 17-19 by β-glucosidase or β-galactosidase was also evaluated. Compounds 20-25 were also tested as potential β-glucosidase, β-galactosidase, and α-glucosidase inhibitors. A promising inhibitory activity toward α-glucosidase was observed for 21 (IC50 = 78 μM) and 25 (IC50 = 70 μM), which might be indicative of their potential as lead compounds for development of antidiabetic or antiobesity agents.

3,4',5-trans-Trimethoxystilbene; a natural analogue of resveratrol with enhanced anticancer potency

Resveratrol is a phytoalexin produced by many plant species as a defence mechanism. Over the last decade, this polyphenol has been reported to be active against multiple targets associated with chronic disorders. However, its poor pharmacokinetic profile, as well as multiple discrepancies related to its in vitro and in vivo profile, has resulted not only on the study of suitable delivery systems, but the use of resveratrol derivatives. In this regard, the 3,4',5-trans-trimethoxystilbene (TMS), a natural analogue of resveratrol, has emerged as a strong candidate. TMS has an enhanced anticancer profile compared to resveratrol, exhibiting higher potency than resveratrol, as shown by multiple reports describing an improved cancer cell proliferation inhibition, induction of cell cycle arrest, decreased metastasis, reduced angiogenesis, and increased apoptosis. In this review, we provide a concise summary of results reported in the literature, related to the similarities and differences between resveratrol and TMS, and we submit to the scientific community that TMS is a promising and (still) understudied natural agent candidate, with potential applications in cancer research. Nevertheless, based on the available evidence, we also submit to the scientific community that TMS may also find a niche in any other research area in which resveratrol has been used.

Effects of a Ferulate-Derived Dihydrobenzofuran Neolignan on Angiogenesis, Steroidogenesis, and Redox Status in a Swine Cell Model

In the ongoing search for new therapeutic compounds, lignans and neolignans, which are widely distributed in plants, deserve special attention because of their interactions with several biological targets. Searching for potential antiangiogenic agents related to natural lignans/neolignans, we were attracted by a previously studied synthetic dihydrobenzofuran neolignan. We synthesized the compound by means of an eco-friendly, enzyme-mediated biomimetic coupling of the methyl ester of ferulic acid, and the present study was aimed to deeply investigate its effect in angiogenesis bioassays validated in our laboratory. In addition, a previously well-defined granulosa cell model was employed to evaluate the effect of dihydrobenzofuran neolignan on cell viability, steroidogenesis, and redox status. Present data support the antiangiogenic effect of this neolignan. Moreover, we demonstrate that, at least at the highest concentrations tested, dihydrobenzofuran neolignan affects granulosa cell viability and steroidogenesis. In addition, the compound inhibits generation of free radicals and stimulates scavenger enzyme activities. The present data, which are a further deepening of the evaluation of the biological activities of the dihydrobenzofuran lignan in well-defined cell models, are of interest and worthy of special attention.

Inhibition of CYP17A1 activity by resveratrol, piceatannol, and synthetic resveratrol analogs

BACKGROUND

Resveratrol (RSV) and resveratrol analogs have a potential use in prostate cancer chemoprevention due to effects on for example, cell growth, apoptosis, angiogenesis, and metastasis. However, inhibition of CYP17A1, a key enzyme in the androgen biosynthesis and a target for prostate cancer therapy, has not been explored as a possible mechanism behind the effects on prostate cancer.

METHODS

Human adrenocortical carcinoma cells, H295R, were treated with RSV, piceatannol (PIC), 3,5,4'-triacetylresveratrol (RSVTA), 3,5-diacetylresveratrol (RSVDA), and 3,5,4'-trimethylresveratrol (RSVTM) for 24 hr at concentrations of 1, 5, 10, 25, and 50 µM. Steroid secretion, enzyme activities, and gene expression of key steps in steroidogenesis were investigated.

RESULTS

Secretion of dihydroepiandrosterone (DHEA), testosterone, and cortisol were drastically decreased by all test compounds at concentrations that did not affect cell viability. Progesterone and aldosterone secretion were increased. This steroid secretion pattern can be explained by the demonstrated inhibition of CYP17A1 enzyme activity. The most efficient CYP17A1 inhibitors were the synthetic analogs RSVTA, RSVDA, and RSVTM. Inhibition by RSVTM was more selective on the 17,20-lyase activity than hydroxylase activity of CYP17A1. Treatment of cells with all compounds, except RSVTM, caused increased estradiol levels, which could be explained by the demonstrated inhibition of estrogen sulfate conjugation, catalyzed by SULT1E1.

CONCLUSIONS

Our results on CYP17A1 inhibition of RSV and RSV analogs suggest a novel mechanism for chemoprevention of prostate cancer by resveratrol and the analogs. Especially RSVTM, which has a preferential inhibition on the 17,20-lyase activity of CYP17A1, may be a promising candidate for prostate cancer chemoprevention.

Atrazine disrupts steroidogenesis, VEGF and NO production in swine granulosa cells

Atrazine is one of the most widely employed herbicides. Due to its environmental persistence, it can be detected in ground and water thus becoming the subject of a serious concern because of its potential endocrine disrupting activity. In particular, several in vitro and in vivo studies point out adverse effects on reproduction. However, these data were mainly collected in the male, while studies on females are lacking. Present work was therefore set up on swine ovarian granulosa cells to investigate the effect of atrazine on steroidogenesis and proliferation. Moreover, since vessel growth is fundamental for reproductive function, we evaluated the herbicide's effect on two of the main angiogenesis signaling molecules, VEGF and NO. Our data show that atrazine markedly interferes with steroidogenesis while it does not modify cell proliferation; in addition, the herbicide has also been found to affect the production of the examined angiogenesis molecules. Collectively, these results indicate for the first time a potential negative effect of atrazine on ovarian functions in the swine species.

Effects of resveratrol on growth and function of rat ovarian granulosa cells

OBJECTIVE

To evaluate the effects of resveratrol on growth and function of granulosa cells. Previously, we demonstrated that resveratrol exerts profound proapoptotic effects on theca-interstitial cells.

DESIGN

In vitro study.

SETTING

Research laboratory.

ANIMAL(S)

Immature Sprague-Dawley female rats.

INTERVENTION(S)

Granulosa cells were cultured in the absence or presence of resveratrol.

MAIN OUTCOME MEASURE(S)

DNA synthesis was determined by thymidine incorporation assay, apoptosis by activity of caspases 3/7, cell morphology by immunocytochemistry, steroidogenesis by mass spectrometry, antimüllerian hormone (AMH), and vascular endothelial growth factor (VEGF) expression by polymerase chain reaction and Western blot.

RESULT(S)

Resveratrol induced a biphasic effect on DNA synthesis, whereby a lower concentration stimulated thymidine incorporation and higher concentrations inhibited it. Additionally, resveratrol slightly increased the cell number and modestly decreased the activity of caspases 3/7 with no effect on cell morphology or progesterone production. However, resveratrol decreased aromatization and VEGF expression, whereas AMH expression remained unaltered.

CONCLUSION(S)

Resveratrol, by exerting cytostatic but not cytotoxic effects, together with antiangiogenic actions mediated by decreased VEGF in granulosa cells, may alter the ratio of theca-to-granulosa cells and decrease vascular permeability, and therefore may be of potential therapeutic use in conditions associated with highly vascularized theca-interstitial hyperplasia and abnormal angiogenesis, such as those seen in women with polycystic ovary syndrome.

Resveratrol reduces steroidogenesis in rat ovarian theca-interstitial cells: the role of inhibition of Akt/PKB signaling pathway

Polycystic ovary syndrome is characterized by theca-interstitial hyperplasia and increased expression of steroidogenic genes, leading to excessive androgen production. Resveratrol, a natural polyphenol, promotes apoptosis and reduces rat theca-interstitial cell growth, in part by inhibiting the mevalonate pathway and decreasing the availability of substrates of isoprenylation [farnesyl-pyrophosphate (FPP) and geranylgeranyl-pyrophosphate (GGPP)]. This study evaluated the effect of resveratrol on rat theca-interstitial cell steroidogenesis. Because resveratrol may activate sirtuins, this study also investigated whether steroidogenesis was affected by sirtuin inhibitors (nicotinamide, sirtinol). Theca-interstitial cells were cultured with or without resveratrol (1-10 μm), GGPP (30 μm), FPP (30 μm), nicotinamide (1 mm), and/or sirtinol (10 μm). Resveratrol did not affect progesterone levels but reduced androgen production in a concentration-dependent fashion (androstenedione by up to 78% and androsterone by up to 76%). This inhibitory effect correlated with a decrease in mRNA expression of genes regulating androgen production, especially Cyp17a1 (by up to 73%). GGPP and FPP had no effect on androgen levels and Cyp17a1 mRNA levels and did not alter the effects induced by resveratrol. Similarly, sirtuin inhibitors did not reverse resveratrol-induced inhibition of steroidogenesis. However, resveratrol decreased activity of serine-threonine kinase/protein kinase B pathway, a cell-signaling pathway involved in ovarian steroidogenesis. The present findings indicate that resveratrol reduces androgen production primarily by inhibiting Cyp17a1 mRNA expression, and this inhibition may be mediated, in part, by blocking the activity of the serine-threonine kinase/protein kinase B pathway. These findings may be of clinical relevance to conditions associated with excessive production of androgens by theca cells, such as polycystic ovary syndrome.

Resveratrol promotes expression of SIRT1 and StAR in rat ovarian granulosa cells: an implicative role of SIRT1 in the ovary

BACKGROUND

Resveratrol is a natural polyphenolic compound known for its beneficial effects on energy homeostasis, and it also has multiple properties, including anti-oxidant, anti-inflammatory, and anti-tumor activities. Recently, silent information regulator genes (Sirtuins) have been identified as targets of resveratrol. Sirtuin 1 (SIRT1), originally found as an NAD+-dependent histone deacetylase, is a principal modulator of pathways downstream of calorie restriction, and the activation of SIRT1 ameliorates glucose homeostasis and insulin sensitivity. To date, the presence and physiological role of SIRT1 in the ovary are not known. Here we found that SIRT1 was localized in granulosa cells of the human ovary.

METHODS

The physiological roles of resveratrol and SIRT1 in the ovary were analyzed. Immunohistochemistry was performed to localize the SIRT1 expression. SIRT1 protein expression of cultured cells and luteinized human granulosa cells was investigated by Western blot. Rat granulosa cells were obtained from diethylstilbestrol treated rats. The cells were treated with increasing doses of resveratrol, and subsequently harvested to determine mRNA levels and protein levels. Cell viability was tested by MTS assay. Cellular apoptosis was analyzed by caspase 3/7 activity test and Hoechst 33342 staining.

RESULTS

SIRT1 protein was expressed in the human ovarian tissues and human luteinized granulosa cells. We demonstrated that resveratrol exhibited a potent concentration-dependent inhibition of rat granulosa cells viability. However, resveratrol-induced inhibition of rat granulosa cells viability is independent of apoptosis signal. Resveratrol increased mRNA levels of SIRT1, LH receptor, StAR, and P450 aromatase, while mRNA levels of FSH receptor remained unchanged. Western blot analysis was consistent with the results of quantitative real-time RT-PCR assay. In addition, progesterone secretion was induced by the treatment of resveratrol.

CONCLUSIONS

These results suggest a novel mechanism that resveratrol could enhance progesterone secretion and expression of luteinization-related genes in the ovary, and thus provide important implications to understand the mechanism of luteal phase deficiency.

CdTe/CdSe quantum dots improve the binding affinities between α-amylase and polyphenols

People exposed to engineered nanomaterials have potential health risks associated. Human α-amylase is one of the key enzymes in the digestive system. There are few reports about the influence of quantum dots (QDs) on the digestive enzymes and their inhibition system. This work focused on the toxic effect of CdTe/CdSe QDs on the interactions between α-amylase and its natural inhibitors. Thirty-six dietary polyphenols, natural α-amylase inhibitors from food, were studied for their affinities for α-amylase in the absence and presence of CdTe/CdSe QDs by a fluorescence quenching method. The magnitudes of apparent binding constants of polyphenols for α-amylase were almost in the range of 10(5)-10(7) L mol(-1) in the presence of CdTe/CdSe QDs, which were higher than the magnitudes of apparent binding constants in the absence of CdTe/CdSe QDs (10(4)-10(6) L mol(-1)). CdTe/CdSe QDs obviously improved the affinities of dietary polyphenols for α-amylase up to 389.04 times. It is possible that the binding interaction between polyphenols and α-amylase in the presence of CdTe/CdSe QDs was mainly caused by electrostatic interactions. QDs significantly influence the digestive enzymes and their inhibition system.

Chemical composition and biological activities of Arachis species

Arachis hypogaea , known as the peanut, is native to South America. Peanut contains several active components including flavonoids, phenolic acids, phytosterols, alkaloids, and stilbenes. Some therapeutic effects have been reported for peanut seed extracts, such as antioxidative, antibacterial, antifungal, and anti-inflammatory activities. This paper aims to give an overview of the chemical composition, focusing on secondary metabolites, and of the biological activity of A. hypogaea, to stimulate new studies about species of the Arachis genus.

Structure-activity relationship of resveratrol and its analogue, 4,4'-dihydroxy-trans-stilbene, toward the endothelin axis in human endothelial cells

Resveratrol inhibits endothelin-1, a vascular tension regulator. We synthesized the resveratrol analogue 4,4'-dihydroxy-trans-stilbene with 2 hydroxyl groups in the 4 and 4' position to obtain a molecule more active than resveratrol (3,4',5-trihydroxy-trans-stilbene). The results demonstrate that 4,4'-dihydroxy-trans-stilbene led to a significant decrease in total endothelin-1 secretion and in endothelin-1 messenger RNA (mRNA) levels in human endothelial cells. In addition, resveratrol and its analogue decreased endothelin-converting enzyme-1 mRNA levels and further reduced the activity of the enzyme. 4,4'-dihydroxy-trans-stilbene was more active than resveratrol because the new molecule exerted greater activity at the level of endothelin synthesis and conversion, even at a lower concentration. Although 4,4'-dihydroxy-trans-stilbene and resveratrol inhibited formation of reactive oxygen species and lipid peroxidation, the treatment of cells with different oxidant agents did not modify the endothelin-1 release. This finding suggests that the inhibition of endothelin-1 secretion is independent of the antioxidant properties of the 2 compounds. On the basis of these results, the resveratrol analogue 4,4'-dihydroxy-trans-stilbene could be a promising chemopreventive agent against cardiovascular diseases.

Preclinical pharmacokinetic evaluation of resveratrol trimethyl ether in sprague-dawley rats: the impacts of aqueous solubility, dose escalation, food and repeated dosing on oral bioavailability

Resveratrol trimethyl ether (trans-3,5,4'-trimethoxystilbene, RTE) is a naturally occurring and pharmacologically active resveratrol derivative. To evaluate its suitability as a drug candidate, a pharmacokinetic study was carried out in Sprague-Dawley rats with the emphasis to identify the impact of aqueous solubility, dose escalation, food, and repeated dosing on its oral bioavailability. Upon single intravenous administration (5 mg/kg), RTE displayed moderate clearance (35.5 ± 5.3 mL/min/kg) and a fairly long terminal elimination half-life (511 ± 136 min); dose escalation (5-20 mg/kg) did not cause nonlinear pharmacokinetics. When given orally in suspension (60 mg/kg), RTE was poorly absorbed with negligible bioavailability (< 1.5%), fasting further decreased its bioavailability (<1%). However, when administered in a solution formulated with randomly methylated-β-cyclodextrin (15 mg/kg), RTE was rapidly absorbed with good bioavailability (46.5 ± 4.8%). Dose escalation resulted in increased bioavailability (64.6 ± 8.0%) at the dose of 60 mg/kg. Repeated RTE dosing (7 daily oral doses) did not alter the clearance, terminal elimination half-life and bioavailability. In summary, the aqueous solubility of RTE was a barrier to oral absorption; repeated RTE administrations did not alter its pharmacokinetic profiles; as RTE possessed appropriate pharmacokinetic profiles, further investigation on RTE as a drug candidate is warranted.

Stanniocalcin 1 affects redox status of swine granulosa cells

Stanniocalcin 1 (STC1) is a glycoprotein hormone expressed in different mammalian tissues. In previous studies, we showed STC1 expression in swine ovarian follicles and we demonstrated that STC1 may be a physiological regulator of follicular function. Since reactive oxygen species (ROS) are important signal transducers in the ovary, the present study was undertaken to investigate STC1 action on ROS generation and on the activity of the major enzymatic and non-enzymatic scavengers in swine granulosa cells. O(2)- generation, catalase activity and FRAP levels were increased by STC1, whereas H(2)O(2) generation and peroxidase activity were decreased by STC1. Taken together, our data show that STC1 modulates redox status in swine granulosa cells.