Effect of resveratrol on proliferation and differentiation of embryonic cardiomyoblasts

E-Stilbenes: General Chemical and Biological Aspects, Potential Pharmacological Activity Based on the Nrf2 Pathway

Stilbenes are phytoalexins, and their biosynthesis can occur through a natural route (shikimate precursor) or an alternative route (in microorganism cultures). The latter is a metabolic engineering strategy to enhance production due to stilbenes recognized pharmacological and medicinal potential. It is believed that in the human body, these potential activities can be modulated by the regulation of the nuclear factor erythroid derived 2 (Nrf2), which increases the expression of antioxidant enzymes. Given this, our review aims to critically analyze evidence regarding E-stilbenes in human metabolism and the Nrf2 activation pathway, with an emphasis on inflammatory and oxidative stress aspects related to the pathophysiology of chronic and metabolic diseases. In this comprehensive literature review, it can be observed that despite the broad number of stilbenes, those most frequently explored in clinical trials and preclinical studies (in vitro and in vivo) were resveratrol, piceatannol, pterostilbene, polydatin, stilbestrol, and pinosylvin. In some cases, depending on the dose/concentration and chemical nature of the stilbene, it was possible to identify activation of the Nrf2 pathway. Furthermore, the use of some experimental models presented a challenge in comparing results. In view of the above, it can be suggested that E-stilbenes have a relationship with the Nrf2 pathway, whether directly or indirectly, through different biological pathways, and in different diseases or conditions that are mainly related to inflammation and oxidative stress.

Integrated Analysis of mRNA and MicroRNA Co-expressed Network for the Differentiation of Bovine Skeletal Muscle Cells After Polyphenol Resveratrol Treatment

Resveratrol (RSV) has been confirmed to benefit human health. Resveratrol supplemented in the feeds of animals improved pork, chicken, and duck meat qualities. In this study, we identified differentially expressed (DE) messenger RNAs (mRNAs) (n = 3,856) and microRNAs (miRNAs) (n = 93) for the weighted gene co-expression network analysis (WGCNA) to investigate the co-expressed DE mRNAs and DE miRNAs in the primary bovine myoblasts after RSV treatment. The mRNA results indicated that RSV treatments had high correlations with turquoise module (0.91, P-value = 0.01) and blue module (0.93, P-value < 0.01), while only the turquoise module (0.96, P-value < 0.01) was highly correlated with the treatment status using miRNA data. After biological enrichment analysis, the 2,579 DE genes in the turquoise module were significantly enriched in the Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The top two GO terms were actin filament-based process (GO:0030029) and actin cytoskeleton organization (GO:0030036). The top two KEGG pathways were regulation of actin cytoskeleton (bta04810) and tight junction (bta04530). Then, we constructed the DE mRNA co-expression and DE miRNA co-expression networks in the turquoise module and the mRNA–miRNA targeting networks based on their co-expressions in the key module. In summary, the RSV-induced miRNAs participated in the co-expression networks that could affect mRNA expressions to regulate the primary myoblast differentiation. Our study provided a better understanding of the roles of RSV in inducing miRNA and of the characteristics of DE miRNAs in the key co-expressed module in regulation of mRNAs and revealed new candidate regulatory miRNAs and genes for the beef quality traits.

Effects of resveratrol on the proliferation and osteogenic differentiation of deciduous dental pulp stem cells from neurofibromatosis type 1 patient

PURPOSE

We aimed at verifying whether resveratrol can decrease cell proliferation and change osteogenic differentiation of cells obtained from patients with type 1 neurofibromatosis (NF1).

METHODS

Deciduous dental pulp derived stem cells were isolated from NF1 patient and healthy volunteer. These cells were subjected to increasing concentrations of resveratrol and evaluated for proliferation and mineralization of osteogenic differentiation.

RESULTS

The results showed that resveratrol reduced the difference in proliferation between CNT and NF1 cells in a dose-dependent manner and this property was more prominent in affected cells than in healthy cells. Resveratrol showed no statistically significant changes in mineralization in osteogenic differentiation of NF1 cells, at low doses tested.

CONCLUSIONS

In conclusion, in a dose-dependent manner, resveratrol displays interesting properties that could be applied in a possible treatment aimed at decreasing cellular proliferation in neurofibromatosis. Furthermore, it is selective concerning healthy cells and not affecting cell differentiation. Further research to cell selectivity, differentiation to other tissue types, and cell cytotoxicity are needed.

Bioapplications of Bacterial Cellulose Polymers Conjugated with Resveratrol for Epithelial Defect Regeneration

Excellent wound dressing is essential for effective wound repair and regeneration. However, natural polymeric skin substitutes often lack mechanical strength and hydrophilicity. One way to overcome this limitation is to use biodegradable polymers with high mechanical strength and low skin-irritation induction in wet environments. Bacterial cellulose (BC) is an attractive polymer for medical applications; unlike synthetic polymers, it is biodegradable and renewable and has a strong affinity for materials containing hydroxyl groups. Therefore, we conjugated it with resveratrol (RSV), which has a 4'-hydroxyl group and exhibits good biocompatibility and no cytotoxicity. We synthesized BC scaffolds with immobilized RSV and characterized the resulting BC/RSV scaffold with scanning electron microscopy and Fourier-transform infrared spectroscopy. We found that RSV was released from the BC in vitro after ~10 min, and immunofluorescence staining showed that BC was highly biocompatible and regenerated epithelia. Additionally, Masson's trichrome staining showed that the scaffolds preserved the normal collagen-bundling pattern and induced re-epithelialization in defective rat epidermis. These results indicated that RSV-conjugated BC created a biocompatible environment for stem cell attachment and growth and promoted epithelial regeneration during wound healing.

Resveratrol as a Therapy to Restore Neurogliogenesis of Neural Progenitor Cells Infected by Toxoplasma gondii

The intracellular protozoan Toxoplasma gondii may cause congenital toxoplasmosis and serious brain damage in fetus. However, the underlying mechanism of neuropathogenesis in brain toxoplasmosis remains unclear. For this study, neural progenitor cells (NPCs) were obtained from embryo telencephalons (embryonic day 13) and induced to proliferation in the presence of growth factors (GFs). For gathering insights into the biological effects of resveratrol (RSV) on neurogenesis, this study aimed to investigate effects of RSV concentrations (0.1 to 100 μM) on proliferation, migration and differentiation of NPCs infected by T. gondii. T. gondii infection increased the presence of cells in Sub G1 phase, reducing the global frequency of undifferentiated cells in S and G2/M phases of cell cycle and reduced cell viability/mithochondrial activity of infected NPCs. Moreover T. gondii stimulated neural migration and gliogenesis during neutral differentation. However, the treatment with RSV stimulated cell proliferation, restored cellular viability of infected NPCs and exerted an inhibitory effect on gliogenesis of infected NPCs favorecing neuronal maturation during toxoplasmosis infection. Thus, we have successfully to demonstrated that RSV is promising as therapeutic for congenital toxoplasmosis.

Resveratrol pretreatment attenuates injury and promotes proliferation of neural stem cells following oxygen-glucose deprivation/reoxygenation by upregulating the expression of Nrf2, HO-1 and NQO1 in vitro

There is considerable interest in the use of drugs and other methods for protecting implanted neural stem cells (NSCs) from the adverse environment of injured tissue for successful cell therapy. Resveratrol can modify cardiac stem cells to enhance their survival and differentiation, however, its effect and the mechanism underlying its neuroprotective effect on NSCs following stroke remain to be fully elucidated. Nuclear factor erythroid 2-related factor 2 (Nrf-2) signaling is important in antioxidative stress, and the role of Nrf-2 signaling in the enhanced neuroprotection of NSCs by resveratrol following stroke also remains to be elucidated. In the present study, NSCs were pretreated with resveratrol prior to oxygen-glucose deprivation/reoxygenation (OGD/R) in vitro. The survival, apoptosis and proliferation of the NSCs were assessed using an MTT assay, Hoechst 33258 staining of nuclei and flow cytometry, respectively. In addition, the activity of superoxide dismutase (SOD), level of malondiadehyde (MDA) and content of glutathione (GSH) were determined. The protein expressions levels of Nrf-2, NAD(P)H:quinone oxidoreductase 1 (NQO-1), and heme oxygenase 1 (HO-1) were detected using western blot analysis. It was found that resveratrol markedly enhanced NSC survival and proliferation, decreased apoptosis and the levels of MDA, and increased the activity of SOD and content of GSH in a concentration-dependent manner following OGD/R injury in vitro. In addition, the protein expression levels of Nrf2, HO-1 and NQO1 were significantly upregulated. These findings suggested that resveratrol attenuated injury and promoted proliferation of the NSCs, at least in part, by upregulating the expression of Nrf2, HO-1 and NQO1 following OGD/R injury in vitro.

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.

The impact of resveratrol and hydrogen peroxide on muscle cell plasticity shows a dose-dependent interaction

While reactive oxygen species (ROS) play a role in muscle repair, excessive amounts of ROS for extended periods may lead to oxidative stress. Antioxidants, as resveratrol (RS), may reduce oxidative stress, restore mitochondrial function and promote myogenesis and hypertrophy. However, RS dose-effectiveness for muscle plasticity is unclear. Therefore, we investigated RS dose-response on C2C12 myoblast and myotube plasticity 1. in the presence and 2. absence of different degrees of oxidative stress. Low RS concentration (10 μM) stimulated myoblast cell cycle arrest, migration and sprouting, which were inhibited by higher doses (40–60 μM). RS did not increase oxidative capacity. In contrast, RS induced mitochondria loss, reduced cell viability and ROS production, and activated stress response pathways [Hsp70 and pSer36-p66(ShcA) proteins]. However, the deleterious effects of H₂O₂ (1000 µM) on cell migration were alleviated after preconditioning with 10 µM-RS. This dose also enhanced cell motility mediated by 100 µM-H₂O₂, while higher RS-doses augmented the H₂O₂-induced impaired myoblast regeneration and mitochondrial dehydrogenase activity. In conclusion, low resveratrol doses promoted in vitro muscle regeneration and attenuated the impact of ROS, while high doses augmented the reduced plasticity and metabolism induced by oxidative stress. Thus, the effects of resveratrol depend on its dose and degree of oxidative stress.

Assessment of reference genes for real-time quantitative PCR gene expression normalization during C2C12 and H9c2 skeletal muscle differentiation

Skeletal muscle differentiation occurs during muscle development and regeneration. To initiate and maintain the differentiated state, a multitude of gene expression changes occur. Accurate assessment of these differentiation-related gene expression changes requires good quality template, but more specifically, appropriate internal controls for normalization. Two cell line-based models used for in vitro analyses of muscle differentiation incorporate mouse C2C12 and rat H9c2 cells. In this study, we set out to identify the most appropriate controls for mRNA expression normalization during C2C12 and H9c2 differentiation. We assessed the expression profiles of Actb, Gapdh, Hprt, Rps12 and Tbp during C2C12 differentiation and of Gapdh and Rps12 during H9c2 differentiation. Using NormFinder, we validated the stability of the genes individually and of the geometric mean generated from different gene combinations. We verified our results using Myogenin. Our study demonstrates that using the geometric mean of a combination of specific reference genes for normalization provides a platform for more precise test gene expression assessment during myoblast differentiation than using the absolute expression value of an individual gene and reinforces the necessity of reference gene validation.

Resveratrol and cardiovascular health--promising therapeutic or hopeless illusion?

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a natural polyphenolic compound that exists in Polygonum cuspidatum, grapes, peanuts and berries, as well as their manufactured products, especially red wine. Resveratrol is a pharmacologically active compound that interacts with multiple targets in a variety of cardiovascular disease models to exert protective effects or induce a reduction in cardiovascular risks parameters. This review attempts to primarily serve to summarize the current research findings regarding the putative cardioprotective effects of resveratrol and the molecular pathways underlying these effects. One intent is to hopefully provide a relatively comprehensive resource for clues that may prompt ideas for additional mechanistic studies which might further elucidate and strengthen the role of the stilbene family of compounds in cardiovascular disease and cardioprotection. Model systems that incorporate a significant functional association with tissues outside of the cardiovascular system proper, such as adipose (cell culture, obesity models) and pancreatic (diabetes) tissues, were reviewed, and the molecular pathways and/or targets related to these models and influenced by resveratrol are discussed. Because the body of work encompassing the stilbenes and other phytochemicals in the context of longevity and the ability to presumably mitigate a plethora of afflictions is replete with conflicting information and controversy, especially so with respect to the human response, we tried to remain as neutral as possible in compiling and presenting the more current data with minimal commentary, permitting the reader free reign to extract the knowledge most helpful to their own investigations.

Resveratrol inhibits the phosphatidylinositide 3-kinase/protein kinase B/mammalian target of rapamycin signaling pathway in the human chronic myeloid leukemia K562 cell line

Resveratrol inhibits the initiation, promotion and progression of tumors, however, the mechanism by which resveratrol inhibits the proliferation of the human chronic myeloid leukemia K562 cell line remains unclear. The present study was conducted to investigate the effect of resveratrol on the activation of the phosphatidylinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling cascade in K562 cells. Resveratrol showed significant cytotoxic effects and induced apoptosis in K562 cells in a dose- and time-dependent manner. In addition, resveratrol attenuated the phosphorylation of PI3K, Akt and mTOR in the K562 cells. Furthermore, the selected inhibitors of PI3K (LY294002), Akt (SH-6) and mTOR (rapamycin) enhanced the effects of resveratrol in K562 cells. In addition, cyclin D1 levels were found to decrease and the activation of caspase-3 was observed. Resveratrol was also found to significantly attenuate the phosphorylation of the downstream molecules, p70S6K and 4EBP1. These results suggested that the downregulation of the PI3K/Akt/mTOR signaling cascades may be a crucial mediator in the inhibition of proliferation and induction of apoptosis by resveratrol in K562 cells.

Resveratrol: from basic studies to bedside

Plants produce a remarkable amount of low molecular mass natural products endowed with a large array of pivotal biological activities. Among these molecules, resveratrol (3,5,4'-trihydroxystilbene) has been identified as an important modulator of cell phenotype with a complex and pleiotropic mode of action. Extensive literature regarding its activity, mainly employing cellular models, suggests that this polyphenol controls cell proliferation, induces differentiation, and activates apoptosis and autophagy. The compound also modulates angiogenesis and inflammation. Similarly, studies on implanted cancers and chemical-induced tumors confirm the potential chemotherapeutical interest of the compound. Likewise, several reports clearly demonstrated, in animal models, that the compound might positively affect the development and evolution of chronic diseases including type 2 diabetes, obesity, coronary heart disease, metabolic syndrome, and neurogenerative pathologies. Finally, a number of investigations stated that the toxicity of the molecule is scarce. Despite these promising observations, few clinical trials have yet been performed to evaluate the effectiveness of the molecule both in prevention and treatment of human chronic disease. Preliminary findings therefore suggest the need for more extensive clinical investigations.

Influence of resveratrol on rheumatoid fibroblast-like synoviocytes analysed with gene chip transcription

Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease that primarily attacks joints and is therefore a common cause of chronic disability and articular destruction. The hyperplastic growth of RA-fibroblast-like synoviocytes (FLSs) and their resistance against apoptosis are considered pathological hallmarks of RA. The natural antioxidant resveratrol is known for its antiproliferative and pro-apoptotic properties. This study investigated the effect of resveratrol on RA-FLS. RA-FLS were isolated from the synovium of 10 RA patients undergoing synovectomy or joint replacement surgery. RA-FLS were first stressed by pre-incubation with interleukin 1beta (IL-1β) and then treated with 100 μM resveratrol for 24h. In order to evaluate the influence of resveratrol on the transcription of genes, a Gene Chip Human Gene 1.0 ST Array was applied. In addition, the effect of dexamethasone on proliferation and apoptosis of RA-FLS was compared with that of resveratrol. Gene array analysis showed highly significant effects of resveratrol on the expression of genes involved in mitosis, cell cycle, chromosome segregation and apoptosis. qRT-PCR, caspase-3/7 and proliferation assays confirmed the results of gene array analysis. In comparison, dexamethasone showed little to no effect on reducing cell proliferation and apoptosis. Our in vitro findings point towards resveratrol as a promising new therapeutic approach for local intra-articular application against RA, and further clinical studies will be necessary.

Resveratrol inhibits the proliferation of neural progenitor cells and hippocampal neurogenesis

Resveratrol is a phytoalexin and natural phenol that is present at relatively high concentrations in peanuts and red grapes and wine. Based upon studies of yeast and invertebrate models, it has been proposed that ingestion of resveratrol may also have anti-aging actions in mammals including humans. It has been suggested that resveratrol exerts its beneficial effects on health by activating the same cellular signaling pathways that are activated by dietary energy restriction (DR). Some studies have reported therapeutic actions of resveratrol in animal models of metabolic and neurodegenerative disorders. However, the effects of resveratrol on cell, tissue and organ function in healthy subjects are largely unknown. In the present study, we evaluated the potential effects of resveratrol on the proliferation and survival of neural progenitor cells (NPCs) in culture, and in the hippocampus of healthy young adult mice. Resveratrol reduced the proliferation of cultured mouse multi-potent NPCs, and activated AMP-activated protein kinase (AMPK), in a concentration-dependent manner. Administration of resveratrol to mice (1-10 mg/kg) resulted in activation of AMPK, and reduced the proliferation and survival of NPCs in the dentate gyrus of the hippocampus. Resveratrol down-regulated the levels of the phosphorylated form of cyclic AMP response element-binding protein (pCREB) and brain-derived neurotrophic factor (BDNF) in the hippocampus. Finally, resveratrol-treated mice exhibited deficits in hippocampus-dependent spatial learning and memory. Our findings suggest that resveratrol, unlike DR, adversely affects hippocampal neurogenesis and cognitive function by a mechanism involving activation of AMPK and suppression of CREB and BDNF signaling.

Sirtuin 1 regulates skeletal myoblast survival and enhances differentiation in the presence of resveratrol

Sirtuin 1 also known as NAD-dependent deacetylase sirtuin 1, is a protein that in humans is encoded by the Sirt1 gene. Sirt1 is an enzyme that deacetylates proteins that contribute to cellular regulation and is a key regulator of cell defenses and survival in response to stress. Deletion of Sirt1 abolishes the increase in lifespan induced by calorie restriction or sublethal cytokine stress, indicating that Sirt1 promotes longevity and survival. We have demonstrated that administration of a sublethal dose of tumour necrosis factor-α (TNF-α; 1.25 ng ml(-1)) inhibits myotube formation, and co-incubation with insulin-like growth factor I (IGF-I; 1.5 ng ml(-1)) facilitates C2 myoblast death rather than rescuing differentiation. A higher dose of TNF-α (10 ng ml(-1)) resulted in significant apoptosis, which was rescued by IGF-I (1.5 ng ml(-1); 50% rescue; P < 0.05). We aimed to investigate the role of Sirt1 in the conflicting roles of IGF-I. Quantitative real-time PCR revealed that Sirt1 expression was elevated in myoblasts following incubation of 10 ng ml(-1) TNF-α or 1.25 ng ml(-1) TNF-α plus IGF-I (fivefold and 7.2-fold increases versus control, respectively; P < 0.05). A dose of 10 ng ml(-1) TNF-α induced ∼21 ± 0.7% apoptosis, which was reduced (∼50%; P < 0.05) when administered with IGF-I. Likewise, Sirt1 expression was elevated following 10 ng ml(-1) TNF-α administration, but was reduced (∼30%; P < 0.05) in the presence of IGF-I. C2C12 myoblasts, a subclone of the C2 cell line produced for their differentiation potential and used to examine intrinsic ageing, unlike C2 cells, do not die in the presence of TNF-α and do not upregulate Sirt1. As conditions that induced the greatest myoblast stress/damage resulted in elevated Sirt1 expression, we investigated the effects of Sirt1 gene silencing. Treatment with 10 ng ml(-1) TNF-α or co-incubation with 1.25 ng ml(-1) TNF-α and 1.5 ng ml(-1) IGF-I resulted in apoptosis (20.33 ± 2.08 and 19 ± 2.65%, respectively), which was increased when myoblasts were pretreated with Sirt1 small interfering RNA (31 ± 2.65 and 27.33 ± 2.52%, respectively; P < 0.05) and was reduced (14.33 ± 3.05%, P < 0.05 and 12.78 ± 4.52%, P = 0.054) by resveratrol, which also significantly rescued the block on differentiation. In conclusion, Sirt1 expression increases in conditons of stress, potentially serving to reduce or dampen myoblast death.

Resveratrol derivative, trans-3,5,4'-trimethoxystilbene, exerts antiangiogenic and vascular-disrupting effects in zebrafish through the downregulation of VEGFR2 and cell-cycle modulation

Angiogenesis plays an important role in the development of neoplastic diseases such as cancer. Resveratrol and its derivatives exert antiangiogenic effects, but the mechanisms of their actions remain unclear. The aim of this study was to evaluate the antiangiogenic activity of resveratrol and its derivative trans-3,5,4'-trimethoxystilbene in vitro using human umbilical vein endothelial cells (HUVECs) and in vivo using transgenic zebrafish, and to clarify their mechanisms of action in zebrafish by gene expression analysis of the vascular endothelial growth factor (VEGF) receptor (VEGFR2/KDR) and cell-cycle analysis. trans-3,5,4'-Trimethoxystilbene showed significantly more potent antiangiogenic activity than that of resveratrol in both assays. In zebrafish, trans-3,5,4'-trimethoxystilbene caused intersegmental vessel regression and downregulated VEGFR2 mRNA expression. Trans-3,5,4'-trimethoxystilbene also induced G2/M cell-cycle arrest, most specifically in endothelial cells of zebrafish embryos. We propose that the antiangiogenic and vascular-targeting activities of trans-3,5,4'-trimethoxystilbene result from the downregulation of VEGFR2 expression and cell-cycle arrest at G2/M phase.

Ascorbic acid improves embryonic cardiomyoblast cell survival and promotes vascularization in potential myocardial grafts in vivo

Organ restoration via cell therapy and tissue transplantation is limited by impaired graft survival. We tested the hypothesis that ascorbic acid (AA) reduces cell death in myocardial grafts both in vitro and in vivo and introduced a new model of autologous graft vascularization for later transplantation. Luciferase (Fluc)- and green fluorescent protein (GFP)-expressing H9C2 cardiomyoblasts were seeded in gelatin scaffolds to form myocardial artificial grafts (MAGs). MAGs were supplemented with AA (5 or 50 mumol/L) or plain growth medium. Bioluminescence imaging showed increased cell photon emission from day 1 to 5 in grafts supplemented with 5 mumol/L (p < 0.001) and 50 mumol/L (p < 0.01) AA. The amount of apoptotic cells in plain MAGs was significantly higher than in AA-enriched grafts. In our in vitro model, AA also enhanced H9C2 cell myogenic differentiation. For in vivo studies, MAGs containing H9C2-GFP-Fluc cells and enriched with AA (n = 10) or phosphate-buffered saline (n = 10) were implanted in the renal pouch of Wistar rats. At day 6, postimplantation bioluminescence signals decreased by 74% of baseline in plain MAGs versus 36% in AA-enriched MAGs (p < 0.0001). AA grafts contained significantly higher amounts of blood vessels, GFP(+) donor cells, and endothelial cells. In this study, we identified AA as a potent supplement that improves cardiomyoblast survival and promotes neovascularization in bioartificial grafts.