Resveratrol as anti-aging therapy for age-related bone loss

Therapeutic effects of resveratrol on epigenetic mechanisms in age-related diseases: A comprehensive review

Recently, various studies have shown that epigenetic changes are associated with aging and age-related diseases. Both animal and human models have revealed that epigenetic processes are involved in aging mechanisms. These processes happen at multiple levels and include histone modification, DNA methylation, and changes in noncoding RNA expression. Consequently, changes in the organization of chromatin and DNA accessibility lead to the regulation of gene expression. With increasing awareness of the pivotal function of epigenetics in the aging process, researchers' attention has been drawn to how these epigenetic changes can be modified to prevent, stop, or reverse aging, senescence, and age-related diseases. Among various agents that can affect epigenetic, polyphenols are well-known phytochemicals found in fruits, vegetables, and plants. Polyphenols are found to modify epigenetic-related mechanisms in various diseases and conditions, such as metabolic disorders, obesity, neurodegenerative diseases, cancer, and cardiovascular diseases. Resveratrol (RSV) is a member of the stilbene subgroup of polyphenols which is derived from various plants, such as grapes, apples, and blueberries. Therefore, herein, we aim to summarize how RSV affects different epigenetic processes to change aging-related mechanisms. Furthermore, we discuss its roles in age-related diseases, such as Alzheimer's, Parkinson's, osteoporosis, and cardiovascular diseases.

Resveratrol Improves Cognitive Function in Post-stroke Depression Rats by Repressing Inflammatory Reactions and Oxidative Stress via the Nrf2/HO-1 Pathway

Post-stroke depression (PSD) is a prevalent mental health issue, and resveratrol (RES) has been implicated in its management. This study aimed to elucidate the impact of RES on PSD. A PSD rat model was established through middle cerebral artery occlusion and chronic unpredictable mild stress. Rats received RES via gavage, and depressive behaviors were evaluated through various measures. Cerebral infarction areas and brain tissue pathology were assessed using TTC and H&E staining. Levels of inflammatory factors (TNF-α/IL-1β/IL-6/IL-10), neurotransmitters (ACH/DA/5-HT/BDNF), and oxidative stress-related indicators (SOD/GSH-Px/MDA), along with the total Nrf2/C-Nrf2/N-Nrf2/HO-1 proteins, were analyzed. The role of the Nrf2/HO-1 pathway was investigated by co-treating rats with RES and either an Nrf2 pathway specific inhibitor (ML385) or activator (dimethyl fumarate). PSD rats exhibited depressive behaviors, disrupted neurotransmitter levels, and oxidative stress markers. RES treatment effectively alleviated these symptoms and activated the Nrf2/HO-1 pathway in PSD rat brain tissues. Co-administration of ML385 attenuated the beneficial effects of RES in PSD rats. Altogether, RES mitigates depressive behaviors, improves cognitive dysfunction, and reduces oxidative stress and inflammatory response in PSD rats. These effects are mediated through the activation of the Nrf2/HO-1 pathway, suggesting RES as a potential therapeutic agent for PSD-related cognitive impairment.

Exploring epigenetic strategies for the treatment of osteoporosis

The worldwide trend toward an aging population has resulted in a higher incidence of chronic conditions, such as osteoporosis. Osteoporosis, a prevalent skeletal disorder characterized by decreased bone mass and increased fracture risk, encompasses primary and secondary forms, each with distinct etiologies. Mechanistically, osteoporosis involves an imbalance between bone resorption by osteoclasts and bone formation by osteoblasts. Current pharmacological interventions for osteoporosis, such as bisphosphonates, denosumab, and teriparatide, aim to modulate bone turnover and preserve bone density. Hormone replacement therapy and lifestyle modifications are also recommended to manage the condition. While current medications offer therapeutic options, they are not devoid of limitations. Recent studies have highlighted the importance of epigenetic mechanisms, including DNA methylation and histone modifications, in regulating gene expression during bone remodeling. The use of epigenetic drugs, or epidrugs, to target these mechanisms offers a promising avenue for therapeutic intervention in osteoporosis. In this review, we comprehensively examine the recent advancements in the application of epidrugs for treating osteoporosis.

The effects of resveratrol in animal models of primary osteoporosis: a systematic review and meta-analysis

BACKGROUND

There is still a lack of sufficient evidence-based medical data on the effect of resveratrol (Res) on primary osteoporosis (OP). This meta-analysis aimed to comprehensively evaluate the role of Res in animal models of primary OP.

METHODS

The PubMed, Cochrane Library, Web of Science and Embase databases were searched up to August 2023. The risk of bias was assessed by the SYRCLE RoB tool. Random- or fixed-effects models were used to determine the 90% confidence interval (CI) or standardized mean difference (SMD). Statistical analysis was performed with RevMan 5.4 and Stata 14.0.

RESULTS

A total of 24 studies containing 714 individuals were included. Compared with those in the control group, the bone mineral density (BMD) (P < 0.00001), bone volume/total volume (BV/TV) (P < 0.001), trabecular thickness (Tb.Th) (P < 0.00001), and trabecular number (Tb.N) (P < 0.00001) were markedly greater, and the trabecular separation (Tb.Sp) (P < 0.00001) was significantly greater. Compared with the control group, the Res group also exhibited marked decreases in alkaline phosphatase (ALP) (P < 0.05), tartrate-resistant acid phosphatase 5b (TRAP5b) (P < 0.01), and type I collagen strong carboxyl peptide (CTX-1) (P < 0.00001) and a marked increase in osteoprotegerin (OPG) (P < 0.00001).

CONCLUSION

In summary, we concluded that Res can markedly increase BMD, improve morphometric indices of trabecular microstructure and serum bone turnover markers (BTMs), and exert a protective effect in animal models of primary osteoporosis. This study can supply experimental reference for Res in primary osteoporosis treatment.

Morphological and biomechanical characterization of long bones and peri-implant bone repair in type 2 diabetic rats treated with resveratrol

Type 2 diabetes interferes with bone remodeling mechanisms, requiring studies to reverse this damage, and resveratrol is a polyphenol with rich properties. This study aimed to characterize the long bone morphology and peri-implant biomechanics of normoglycemic and type 2 diabetic animals treated with resveratrol. Thirty-two male Wistar rats were used and divided into normoglycemic and diabetic with or without treatment. They had the installation of implants in the tibia and treatment with oral resveratrol within 45 days. Resveratrol was responsible for weight homeostasis and decreased glycemic levels in rats with type 2 diabetes. The three-point bending testing, resveratrol showed positive effects on the biomechanics of long bones, corroborating a more resistant bone in comparison to untreated diabetics. Micro-ct revealed how bone metabolism is affected by systemic disease, decreasing bone quality. The counter-torque of normoglycemic animals showed superior osseointegration to diabetes, with no differences in the administration of the polyphenol, showing the sovereignty of the deleterious effects of the disease when there is a tissue lesion and an inflammatory picture installed. Overall, resveratrol acted positively in the etiopathogenesis of type 2 diabetes and revealed positive effects on the strength of long bones.

Revisiting Resveratrol as an Osteoprotective Agent: Molecular Evidence from In Vivo and In Vitro Studies

Resveratrol (RSV) (3,5,4'-trihydroxystilbene) is a stilbene found in abundance in berry fruits, peanuts, and some medicinal plants. It has a diverse range of pharmacological activities, underlining the significance of illness prevention and health promotion. The purpose of this review was to delve deeper into RSV's bone-protective properties as well as its molecular mechanisms. Several in vivo studies have found the bone-protective effects of RSV in postmenopausal, senile, and disuse osteoporosis rat models. RSV has been shown to inhibit NF-κB and RANKL-mediated osteoclastogenesis, oxidative stress, and inflammation while increasing osteogenesis and boosting differentiation of mesenchymal stem cells to osteoblasts. Wnt/β-catenin, MAPKs/JNK/ERK, PI3K/AKT, FoxOs, microRNAs, and BMP2 are among the possible kinases and proteins involved in the underlying mechanisms. RSV has also been shown to be the most potent SIRT1 activator to cause stimulatory effects on osteoblasts and inhibitory effects on osteoclasts. RSV may, thus, represent a novel therapeutic strategy for increasing bone growth and reducing bone loss in the elderly and postmenopausal population.

Gold Nanoparticles Encapsulated Resveratrol as an Anti-Aging Agent to Delay Cataract Development

Nanoparticle-based drug delivery systems, which can overcome the challenges associated with poor aqueous solubility and other harmful side effects of drugs, display potent applications in cataract treatment. Herein, we designed a nanosystem of gold nanoparticles containing resveratrol (RGNPs) as an anti-aging agent to delay cataracts. The spherical RGNPs had a superior ability to inhibit hydrogen peroxide-mediated oxidative stress damage, including reactive oxygen species (ROS) production, malondialdehyde (MDA) generation, and glutathione (GSH) consumption in the lens epithelial cells. Additionally, the present data showed that RGNPs could delay cellular senescence induced by oxidative stress by decreasing the protein levels of p16 and p21, reducing the ratio of BAX/BCL-2 and the senescence-associated secretory phenotype (SASP) in vitro. Moreover, the RGNPs could also clearly relieve sodium selenite-induced lens opacity in a rat cataract model. Our data indicated that cell senescence was reduced and cataracts were delayed upon treatment with RGNPs through activating the Sirt1/Nrf2 signaling pathway. Our findings suggested that RGNPs could serve as an anti-aging ingredient, highlighting their potential to delay cataract development.

Mechanism of Resveratrol-Induced Programmed Cell Death and New Drug Discovery against Cancer: A Review

Resveratrol (3,5,4'-trihydroxy-trans-stilbene), a polyphenol found in grapes, red wine, peanuts, and apples, has been reported to exhibit a wide range of biological and pharmacological properties. In addition, resveratrol has been reported to intervene in multiple stages of carcinogenesis. It has also been known to kill several human cancer cells through programmed cell death (PCD) mechanisms such as apoptosis, autophagy, and necroptosis. However, resveratrol has limitations in its use as an anticancer agent because it is susceptible to photoisomerization owing to its unstable double bond, short half-life, and is rapidly metabolized and eliminated. Trans-(E)-resveratrol is nontoxic, and has several biological and pharmacological activities. However, little is known about the pharmacological properties of the photoisomerized cis-(Z)-resveratrol. Therefore, many studies on resveratrol derivatives and analogues that can overcome the shortcomings of resveratrol and increase its anticancer activity are underway. This review comprehensively summarizes the literature related to resveratrol-induced PCD, such as apoptosis, autophagy, necroptosis, and the development status of synthetic resveratrol derivatives and analogues as novel anticancer drugs.

Nutritional Status and Habits among People on Vegan, Lacto/Ovo-Vegetarian, Pescatarian and Traditional Diets

Background: This study assessed the possible dependencies between nutritional habits and body composition among subjects with different dietary habits. Materials: A total of 196 healthy (aged 18−50 yrs) participants were enrolled in the study and divided into 4 groups according to their diet: vegans-VEGAN (n = 53), lacto/ovo-vegetarians—VEGE (n = 52), pescatarians-PESCA (n = 28), and omnivores-OMN (n = 43). Methods: The Food Frequency Questionnaire (FFQ) was used, and body composition was assessed on the In-Body120 analyzer. Results: Our result revealed in OMN + PESCA groups a higher average consumption frequency of sweets (p = 0.024), cheese/plant cheese (p < 0.001), eggs and egg dishes/egg substitutes (p < 0.001), butter, margarine/plant margarine (p < 0.001), cream /plant cream (p = 0.018), wine and cocktails (p = 0.028), vodka (p = 0.039) and lower of natural cottage cheese/tofu/tempeh (p < 0.001), vegetable oils (p = 0.036), legumes (p < 0.001) and nuts and seeds(p < 0.001) compared to the VEGAN + VEGE groups. The body composition analysis showed significant differences in skeletal muscle mass (SMM) (p = 0.019) and the content of minerals (p = 0.048) between groups. VEGAN disclosed the lowest average values of body fat mass (BFM), percentage body fat (PBF), and visceral adipose tissue (VAT) than other studied groups. Conclusions: The body composition analysis showed mean values within normal ranges in all of the groups, but some average results of OMN, PESCA, and VEGE compared to VEGAN were not highly satisfactory (in addition to eating behavior outcomes).

Effects and Mechanisms of Resveratrol on Aging and Age-Related Diseases

The aging of population has become an issue of great concern because of its rapid increase. Aging is an important risk factor of many chronic diseases. Resveratrol could be found in many foods, such as grapes, red wine, peanuts, and blueberries. Many studies reported that resveratrol possessed various bioactivities, such as antioxidant, anti-inflammatory, cardiovascular protection, anticancer, antidiabetes mellitus, antiobesity, neuroprotection, and antiaging effects. The antiaging mechanisms of resveratrol were mainly ameliorating oxidative stress, relieving inflammatory reaction, improving mitochondrial function, and regulating apoptosis. Resveratrol could be an effective and safe compound for the prevention and treatment of aging and age-related diseases. In this review, we summarize the effects of resveratrol on aging, life extension, and several age-related diseases, with special attention paid to the mechanisms of antiaging action.

Sirt1 activation negatively regulates overt apoptosis in Mtb-infected macrophage through Bax

Apoptotic pathways play an important role in Mycobacterium tuberculosis-infected macrophages. Sirt1 is a member of the deacetylase family that is known to promote apoptosis resistance in many mammalian cells. However, the apoptotic role of Sirt1 in the process of M. tuberculosis infection remains unclear. With the help of mouse macrophage samples, 129/Sv background mice, and PBMCs-derived macrophages from healthy controls and patients with tuberculosis, we have shown that M. tuberculosis infection reduced Sirt1 mRNA and protein expression, however, increased Bax mRNA and protein expression. Further, we found that resveratrol, a Sirt1 activator, inhibited M. tuberculosis-induced Bax expression. Thus, it seems that Sirt1 acts as a novel regulator of apoptosis signaling in M. tuberculosis infection via its effects on Bax. Sirt1 activation may therefore be a new candidate for the prevention and treatment of tuberculosis.

Regular Supplementation With Resveratrol Improves Bone Mineral Density in Postmenopausal Women: A Randomized, Placebo-Controlled Trial

Resveratrol, a naturally occurring polyphenol in red grapes and berries, can act as a phytoestrogen. It has been shown to improve both systemic and cerebral circulatory functions, possibly through activation of endothelial estrogen receptors. in vitro and in vivo studies in rodent models also indicate a bone-protective role for resveratrol, particularly in ovariectomized rat models that mimic postmenopausal osteoporosis caused by estrogen deficiency. Hypothesizing a circulatory benefit of resveratrol in bone tissue, we investigated whether resveratrol supplementation could improve bone health in postmenopausal women. The Resveratrol for Healthy Aging in Women (RESHAW) trial was a 24-month randomized, double-blind, placebo-controlled, two-period crossover intervention conducted to evaluate the effects of resveratrol (75 mg twice daily) on cognition, cerebrovascular function, bone health, cardiometabolic markers, and well-being in postmenopausal women. After 12 months of supplementation with resveratrol versus placebo, there were positive effects on bone density in the lumbar spine (+0.016 ± 0.003 g/cm² ) and neck of femur (+0.005 ± 0.002 g/cm² ), which were accompanied by a 7.24% reduction in C-terminal telopeptide type-1 collagen levels, a bone resorption marker, compared with placebo. The increase in bone mineral density in the femoral neck resulted in an improvement in T-score (+0.070 ± 0.018) and a reduction in the 10-year probability of major and hip fracture risk. The magnitude of improvement was higher in women with poor bone health biomarker status. Importantly, the improvement in femoral neck T-score with resveratrol correlated with improvement in perfusion. Our subanalysis also revealed that the bone-protective benefit of resveratrol was greater in participants who supplemented with vitamin D plus calcium. Regular supplementation with 75 mg of resveratrol twice daily has the potential to slow bone loss in the lumbar spine and femoral neck, common fracture sites in postmenopausal women without overt osteoporosis. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.

Resveratrol treatment promotes titanium implant osseointegration in diabetes mellitus rats

Type II diabetes mellitus (T2DM) is the most common metabolic disorder; it is characterized by hyperglycemia and causes implant failure by influencing implant osseointegration. Resveratrol promotes bone formation, but it is unclear if resveratrol improves implant osseointegration. Thirty 12-week-old Sprague-Dawley rats were divided into control (CTL), diabetes mellitus (DM), and resveratrol treatment (DM + Res) groups. In the DM and DM + Res groups (n = 10 each), T2DM was induced via streptozotocin injections; the remaining 10 rats were considered the CTL group. Eight weeks after the insertion of a rod-like Ti implant with a 12-mm length and 1-mm diameter in the left leg, the rats were euthanized. We analyzed implant osseointegration using microcomputed tomography (micro-CT), histological analyses, and biomechanical tests. The parameters showed that T2DM negatively influenced implant osseointegration in the tibia. Compared to that in the DM group, the bone loss of peri-implant bone mass in the DM + Res group was decreased significantly. However, resveratrol still did not induce the same level of implant osseointegration as that observed in the CTL group according to the histological and micro-CT analyses. These results indicated that resveratrol reduced the influence of DM in implant osseointegration, resulting in increased peri-implant bone density, improved trabecular architecture, and enhanced biomechanical fixation.

Activation of FoxO1/SIRT1/RANKL/OPG pathway may underlie the therapeutic effects of resveratrol on aging-dependent male osteoporosis

Background

Age-dependent male osteoporosis remains a poorly studied medical problem despite its significance. It is estimated that at least 1 of 5 men will suffer from osteoporotic consequences. Given that multiple mechanisms are involved in the process of senescence, much attention has been given to compounds with polymodal actions. To challenge such a health problem, we tested here the therapeutic potential of resveratrol in male osteoporosis. We also studied the possible molecular mechanisms that may underlie resveratrol effects.

Methods

Thirty male Wistar albino rats were used in the present study. Rats were divided (10/group) into: control (3–4 months old weighing 150–200 g receiving vehicle), aged (18–20 months old, weighing 350–400 g and receiving vehicle), and resveratrol treated aged (18–20 months old, weighing 350–400 g and receiving resveratrol 20 mg/kg/day for 6 weeks) groups. Assessment of serum calcium, phosphate, bone specific alkaline phosphatase, inflammatory cytokines, oxidative stress markers, and rat femur gene expression of FoxO1, SIRT1, RANKL and OPG proteins was carried out. Histopathological assessment of different levels of rat femur was also performed.

Results

Age-dependent osteoporosis resulted in significant increase in serum levels of phosphate, bone specific alkaline phosphatase, hsCRP, IL-1β, IL-6, TNF-α, MDA, NO, and RANKL gene expression. However, there was significant decrease in serum level of GSH, and gene expression of FoxO1, SIRT1 and OPG. Osteoporotic changes were seen in femur epiphysis, metaphysis and diaphysis. Resveratrol restored significantly age-dependent osteoporotic changes.

Conclusion

We concluded that resveratrol can play an important role in the prevention of male osteoporosis. Resveratrol can counter the molecular changes in male osteoporosis via anti-inflammatory, anti-oxidant and gene modifying effects.

Sirt1 Promotes Osteogenic Differentiation and Increases Alveolar Bone Mass via Bmi1 Activation in Mice

Sirtuin 1 (Sirt1), a protein deacetylase, is a novel target for bone metabolism. To investigate whether overexpression of Sirt1 in mandibular mesenchymal stem cells (M-MSCs) increased alveolar bone mass in vivo, we generated Sirt1 transgenic mice (Sirt1^TG ), with Sirt1 gene expression driven by the Prx1 gene, which represents the mesenchymal lineage. Our results demonstrated that overexpression of Sirt1 in M-MSCs increased the alveolar bone volume in 1-month-old, 9-month-old, and 18-month-old Sirt1^TG mice compared with age-matched wild-type (WT) mice, and in ovariectomized Sirt1^TG mice compared with ovariectomized WT mice by stimulating M-MSC differentiation into osteoblasts. Treatment with resveratrol, a Sirt1 activator, increased Sirt1 binding with Bmi1 and reduced Bmi1 acetylation in a dose-dependent manner demonstrated in M-MSC cultures. Both treatment with resveratrol in M-MSC cultures and overexpressed Sirt1 in M-MSCs ex vivo cultures increased nuclear translocation of Bmi1. Furthermore, we demonstrated that deletion of Bmi1 blocked the increased alveolar bone volume in Sirt1^TG mice. The Sirt1 activator resveratrol inhibited human MSC senescence and promoted their differentiation into osteoblasts, which were associated with upregulating the expression levels of Sirt1 and nuclear translocation of Bmi1. The present results suggested that Sirt1 promotes MSC proliferation and osteogenic differentiation, inhibits MSC senescence to increase alveolar bone volume by promoting the deacetylation and nuclear translocation of Bmi1. Thus, our study elucidated the mechanism by which Sirt1 increases alveolar bone mass, and these findings are important for the clinical application of the Sirt1 activator resveratrol for the promotion of alveolar bone formation and prevention of alveolar bone loss. © 2019 American Society for Bone and Mineral Research.

Mitochondrial Regulation of Stem Cells in Bone Homeostasis

Mitochondria have emerged as key contributors to the organismal homeostasis, in which mitochondrial regulation of stem cells is becoming increasingly important. Originated from mesenchymal stem cell (MSC) and hematopoietic stem cell (HSC) lineage commitments and interactions, bone is a representative organ where the mitochondrial essentiality to stem cell function has most recently been discovered, underlying skeletal health, aging, and diseases. Furthermore, mitochondrial medications based on modulating stem cell specification are emerging to provide promising therapies to counteract bone aging and pathologies. Here we review the cutting-edge knowledge regarding mitochondrial regulation of stem cells in bone homeostasis, highlighting mechanistic insights as well as mitochondrial strategies for augmented bone healing and tissue regeneration.

Advance on Resveratrol Application in Bone Regeneration: Progress and Perspectives for Use in Oral and Maxillofacial Surgery

The natural polyphenol Resveratrol (RSV) claims numerous positive effects on health due to the well documented biological effects demonstrating its potential as a disease-preventing agent and as adjuvant for treatment of a wide variety of chronic diseases. Since several studies, both in vitro and in vivo, have highlighted the protective bone aptitude of RSV both as promoter of osteoblasts' proliferation and antagonist of osteoclasts' differentiation, they could be interesting in view of applications in the field of dentistry and maxillofacial surgery. This review has brought together experimental findings on the use of RSV in the regeneration of bone tissue comprising also its application associated with scaffolds and non-transfusional hemocomponents.

Therapeutic effect of resveratrol on mice with depression

The effect and mechanism of resveratrol on depression-like behavior in mice with depression were investigated. A mouse model of depression was established by social isolation combined with chronic unpredictable stress. The mice were randomly divided into the control group, the model group, the low dose group, the medium dose group and the high dose group. The rats in the low, medium and high dose groups were intraperitoneally injected with resveratrol 10, 20 and 30 mg/kg, respectively. The control and model groups were intraperitoneally injected with an equal volume of normal saline. After 21 days of continuous treatment, the neurobehavioral changes of each group were analyzed by forced swimming test, tail suspension experiment and sucrose consumption experiment. Dopamine (DA) and serotoni (5-HT) and the level of brain-derived nerve growth factor (BDNF) in the prefrontal cortex of each group were analyzed by ELISA. The level of neuropeptide (NPY) expression was analyzed by western blot analysis. Compared with the model group, the immobility time of the tail suspension experiment and forced swimming experiment in the low, medium and high dose groups was significantly prolonged (P<0.05), while the 24 h sucrose consumption was significantly increased (P<0.05), showing a dose-dependent manner. Compared with the model group, the levels of DA and 5-HT in the prefrontal cortex of the low, medium and high dose groups were significantly increased, and showed a dose-dependent effect (P<0.05). Compared with the model group, the expression levels of NPY protein in the low, medium and high dose groups were significantly increased, and gradually increased with the increase of the dose, the difference was statistically significant (P<0.05). Resveratrol can significantly increase the levels of neurotransmitters DA and 5-HT in the prefrontal cortex and increase the expression of NPY in the brain, which can play an antagonistic role in depression.

Resveratrol restores the level of key inflammatory cytokines and RANKL/OPG ratio in the femur of rat osteoporosis model

Resveratrol's effect on bone mineral density (BMD) and expression of cytokines in ovariectomized rats (postmenopausal osteoporosis model) was studied. The study was conducted on 3-month-old Sprague-Dawley rats that were (a) sham-operated, (b) ovariectomized, (c) ovariectomized and treated with β-estradiol (487.5 µg/kg weight/day), and (d) ovariectomized and treated with resveratrol (625 µg/Kg body weight/day). The treatment was for 4 weeks. After sacrifice BMD and gene expression (RANKL, OPG, IL-23, and IL-17A, IL-1β, and TNFα) were measured in tibia and femur respectively. Resveratrol could restore RANKL/OPG ratio, slightly increase BMD, and moderately but significantly reduce IL-23, IL-17A, IL-1β, and TNF-α cytokine expression levels.

Effects of resveratrol on bone health in type 2 diabetic patients. A double-blind randomized-controlled trial

Objectives

Patients with type 2 diabetes (T2DM) are at increased fracture risk. Resveratrol has shown beneficial effects on bone health in few studies. The aim of this trial was to investigate the effects of resveratrol on bone mineral density (BMD) and on calcium metabolism biomarkers in T2DM patients.

Methods

In this double-blind randomized placebo-controlled trial 192 T2DM outpatients were randomized to receive resveratrol 500 mg/day (Resv500 arm), resveratrol 40 mg/day (Resv40 arm) or placebo for 6 months. BMD, bone mineral content (BMC), serum calcium, phosphorus, alkaline phosphatase, and 25-hydroxy vitamin D were measured at baseline and after 6 months.

Results

At follow-up, calcium concentrations increased in all patients, while within-group variations in alkaline phosphatase were higher in both resveratrol arms, and 25-hydroxy vitamin D increased in the Resv500 arm only, without between-group differences. Whole-body BMD significantly decreased in the placebo group, while whole-body BMC decreased in both the placebo and Resv40 arms. No significant changes in BMD and BMC values occurred in the Resv500 arm. The adjusted mean differences of change from baseline were significantly different in the Resv500 arm vs placebo for whole-body BMD (0.01 vs −0.03 g/cm², p = 0.001), whole-body BMC (4.04 vs −58.8 g, p < 0.001), whole-body T-score (0.15 vs −0.26), and serum phosphorus (0.07 vs −0.01 µmol/L, p = 0.002). In subgroup analyses, in Resv500 treated-patients BMD values increased to higher levels in those with lower calcium and 25-hydroxy vitamin D values, and in alcohol drinkers.

Conclusions

Supplementation with 500 mg resveratrol prevented bone density loss in patients with T2DM, in particular, in those with unfavorable conditions at baseline.

Resveratrol and Related Stilbenoids, Nutraceutical/Dietary Complements with Health-Promoting Actions: Industrial Production, Safety, and the Search for Mode of Action

This paper reviews the potential of stilbenoids as nutraceuticals. Stilbenoid compounds in wine are considered key factors in health-promoting benefits. Resveratrol and resveratrol-related compounds are found in a large diversity of vegetal products. The stilbene composition varies from wine to wine and from one season to another. Therefore, the article also reviews how food science and technology and wine industry may help in providing wines and/or food supplements with efficacious concentrations of stilbenes. The review also presents results from clinical trials and those derived from genomic/transcriptomic studies. The most studied stilbenoid, resveratrol, is a very safe compound. On the other hand, the potential benefits of stilbene intake are multiple and are apparently due to downregulation more than upregulation of gene expression. The field may take advantage from identifying the mechanism of action(s) and from providing useful data to show evidence for specific health benefits in a given tissue or for combating a given disease.

Didox and resveratrol sensitize colorectal cancer cells to doxorubicin via activating apoptosis and ameliorating P-glycoprotein activity

Doxorubicin (DOX) has limited efficacy in colorectal cancer due to multi-drug resistance. Resveratrol (RES) and didox (DID) are polyhydroxyphenols with potential chemosensitizing effects. Herein, we assessed the chemomodulatory effects of RES and DID to DOX in colorectal cancer cells. Equitoxic combination of DOX with RES and DID in HCT 116 reduced the IC₅₀ of DOX from 0.96 ± 0.02 μM to 0.52 ± 0.05 μM and 0.4 ± 0.06 μM, respectively. Similarly, combination of DOX with RES and DID in HT-29 decreased the IC₅₀’s of DOX from 0.88 ± 0.03 μM to 0.47 ± 0.02 μM and 0.29 ± 0.04 μM, respectively. The expressions of p53 and Bax genes were markedly elevated in HCT 116 cells after exposure to DOX/DID. In HT-29 cells, the expression of Bcl-XL gene was significantly decreased after exposure to DOX/DID. In addition, combination of DOX with RES significantly increased the expression of Bax gene in HCT 116 cells. RES treatment induced significant S-phase arrest in DOX-treated HCT 116 cells, while DID induced G₂/M- and S-phase arrest in HCT 116 and HT-29, respectively. Both RES and DID significantly enhanced the intracellular entrapment of DOX due to blocking the efflux activity of p-glycoprotein pump. In conclusion, RES and DID sensitize colorectal cancer cells to DOX via facilitating apoptosis and enhancing intracellular entrapment of DOX.

(Z)-3,5,4'-Trimethoxystilbene Limits Hepatitis C and Cancer Pathophysiology by Blocking Microtubule Dynamics and Cell-Cycle Progression

Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related deaths worldwide. Chronic hepatitis C virus (HCV) infection causes induction of several tumors/cancer stem cell (CSC) markers and is known to be a major risk factor for development of HCC. Therefore, drugs that simultaneously target viral replication and CSC properties are needed for a risk-free treatment of advanced stage liver diseases, including HCC. Here, we demonstrated that (Z)-3,5,4'-trimethoxystilbene (Z-TMS) exhibits potent antitumor and anti-HCV activities without exhibiting cytotoxicity to human hepatocytes in vitro or in mice livers. Diethylnitrosamine (DEN)/carbon tetrachloride (CCl4) extensively induced expression of DCLK1 (a CSC marker) in the livers of C57BL/6 mice following hepatic injury. Z-TMS exhibited hepatoprotective effects against DEN/CCl4-induced injury by reducing DCLK1 expression and improving histologic outcomes. The drug caused bundling of DCLK1 with microtubules and blocked cell-cycle progression at G2-M phase in hepatoma cells via downregulation of CDK1, induction of p21(cip1/waf1) expression, and inhibition of Akt (Ser(473)) phosphorylation. Z-TMS also inhibited proliferation of erlotinib-resistant lung adenocarcinoma cells (H1975) bearing the T790M EGFR mutation, most likely by promoting autophagy and nuclear fragmentation. In conclusion, Z-TMS appears to be a unique therapeutic agent targeting HCV and concurrently eliminating cells with neoplastic potential during chronic liver diseases, including HCC. It may also be a valuable drug for targeting drug-resistant carcinomas and cancers of the lungs, pancreas, colon, and intestine, in which DCLK1 is involved in tumorigenesis. Cancer Res; 76(16); 4887-96. ©2016 AACR.

Novel chemical library screen identifies naturally occurring plant products that specifically disrupt glioblastoma-endothelial cell interactions

Tumor growth is not solely a consequence of autonomous tumor cell properties. Rather, tumor cells act upon and are acted upon by their microenvironment. It is tumor tissue biology that ultimately determines tumor growth. Thus, we developed a compound library screen for agents that could block essential tumor-promoting effects of the glioblastoma (GBM) perivascular stem cell niche (PVN). We modeled the PVN with three-dimensional primary cultures of human brain microvascular endothelial cells in Matrigel. We previously demonstrated stimulated growth of GBM cells in this PVN model and used this to assay PVN function. We screened the Microsource Spectrum Collection library for drugs that specifically blocked PVN function, without any direct effect on GBM cells themselves. Three candidate PVN-disrupting agents, Iridin, Tigogenin and Triacetylresveratrol (TAR), were identified and evaluated in secondary in vitro screens against a panel of primary GBM isolates as well as in two different in vivo intracranial models. Iridin and TAR significantly inhibited intracranial tumor growth and prolonged survival in these mouse models. Together these data identify Iridin and TAR as drugs with novel GBM tissue disrupting effects and validate the importance of preclinical screens designed to address tumor tissue function rather than the mechanisms of autonomous tumor cell growth.

Natural Products from Chinese Medicines with Potential Benefits to Bone Health

Osteoporosis is a progressive, systemic bone disorder characterized by loss of bone mass and microstructure, leading to reduced bone strength and increased risk of fracture. It is often associated with reduced quality of life and other medical complications. The disease is common in the aging population, particularly among postmenopausal women and patients who receive long-term steroidal therapy. Given the rapid growth of the aging population, increasing life expectancy, the prevalence of bone loss, and financial burden to the healthcare system and individuals, demand for new therapeutic agents and nutritional supplements for the management and promotion of bone health is pressing. With the advent of global interest in complementary and alternative medicine and natural products, Chinese medicine serves as a viable source to offer benefits for the improvement and maintenance of bone health. This review summarizes the scientific information obtained from recent literatures on the chemical ingredients of Chinese medicinal plants that have been reported to possess osteoprotective and related properties in cell-based and/or animal models. Some of these natural products (or their derivatives) may become promising leads for development into dietary supplements or therapeutic drugs.

Resveratrol provides neuroprotection by inhibiting phosphodiesterases and regulating the cAMP/AMPK/SIRT1 pathway after stroke in rats

Dysfunction of energy metabolism can be a significant and fundamental pathophysiological basis for strokes. In studies of both humans and rodents, resveratrol, a natural polyphenol, has been reported to provide protection from cerebral ischemic injury by regulating expression of silent mating type information regulation 2 homolog 1 (SIRT1). However, direct evidence demonstrating that resveratrol exerts neuroprotection from cerebral ischemia injury by decreasing energy consumption is still lacking. Therefore, the aim of this study was to elucidate the mechanisms and signaling pathways through which resveratrol regulates energy metabolism in the ischemic brain, and to identify potential targets of resveratrol. ATP levels in brain tissues were detected by high performance liquid chromatography. SIRT1 and the phosphorylation of adenosine-monophosphate-activated protein kinase (P-AMPK) expressiones were evaluated by western blot. Levels of phosphodiesterase (PDEs) and cAMP were quantitated by real-time PCR and ELISA, respectively. Results showed that resveratrol significantly reduced the harmful effects of cerebral ischemic injury in vivo. Moreover, levels of ATP, p-AMPK, SIRT1, and cAMP were increased by resveratrol and PDE inhibitors. In conclusion, our findings indicate that resveratrol provides neuroprotection by inhibiting PDEs and regulating the cAMP/AMPK/SIRT1 pathway, which reduces ATP energy consumption during ischemia.

Evaluating resveratrol as a therapeutic bone agent: preclinical evidence from rat models of osteoporosis

Resveratrol (RSV) is a naturally occurring plant polyphenol that has potential to attenuate osteoporosis with distinct pathologies. This review evaluates preclinical evidence regarding the efficacy and safety of RSV as a therapeutic bone agent using different rat models. Limitations of these animal models are discussed, and suggestions for strengthening the experimental design of future studies are provided. The ovariectomized rat model of postmenopausal osteoporosis reported that RSV supplementation attenuated estrogen deficiency-induced bone loss and trabecular structural deterioration. RSV safety was indicated by the absence of stimulation of estrogen-sensitive tissue. Providing RSV to rats aged >6 months attenuated age-related bone mass loss and structural deterioration but produced inconsistent effects on bones in rats aged <6 months. The hindlimb-suspension rat model of disuse osteoporosis reported that RSV attenuated bone loss in old rats, but higher doses and longer duration supplementation before mechanical loading were required for younger rats. Limitations common to studies using rat models of osteoporosis include requirements to include animals that are skeletally mature, longer study durations, and to adjust for potential confounding effects due to altered body weight and endocrine function. Strengthening experimental design can contribute to translation of animal results to clinically relevant recommendations for humans.

Effects of resveratrol supplementation on bone growth in young rats and microarchitecture and remodeling in ageing rats

Osteoporosis is a highly prevalent skeletal disorder in the elderly that causes serious bone fractures. Peak bone mass achieved at adolescence has been shown to predict bone mass and osteoporosis related risk fracture later in life. Resveratrol, a natural polyphenol compound, may have the potential to promote bone formation and reduce bone resorption. However, it is unclear whether it can aid bone growth and bone mass accumulation during rapid growth and modulate bone metabolism during ageing. Using rat models, the current study investigated the potential effects of resveratrol supplementation during the rapid postnatal growth period and in late adulthood (early ageing) on bone microarchitecture and metabolism. In the growth trial, 4-week-old male hooded Wistar rats on a normal chow diet were given resveratrol (2.5 mg/kg/day) or vehicle control for 5 weeks. In the ageing trial, 6-month-old male hooded Wistar rats were treated with resveratrol (20 mg/kg/day) or vehicle for 3 months. Treatment effects in the tibia were examined by μ-computer tomography (μ-CT) analysis, bone histomorphometric measurements and reverse transcription-polymerase chain reaction (RT-PCR) gene expression analysis. Resveratrol treatment did not affect trabecular bone volume and bone remodeling indices in the youth animal model. Resveratrol supplementation in the early ageing rats tended to decrease trabecular bone volume, Sirt1 gene expression and increased expression of adipogenesis-related genes in bone, all of which were statistically insignificant. However, it decreased osteocalcin expression (p = 0.03). Furthermore, serum levels of bone resorption marker C-terminal telopeptides type I collagen (CTX-1) were significantly elevated in the resveratrol supplementation group (p = 0.02) with no changes observed in serum levels of bone formation marker alkaline phosphatase (ALP). These results in rat models suggest that resveratrol supplementation does not significantly affect bone volume during the rapid growth phase but may potentially have negative effects on male skeleton during early ageing.

Resveratrol supplementation affects bone acquisition and osteoporosis: Pre-clinical evidence toward translational diet therapy

Osteoporosis is a major public health issue that is expected to rise as the global population ages. Resveratrol (RES) is a plant polyphenol with various anti-aging properties. RES treatment of bone cells results in protective effects, but dose translation from in vitro studies to clinically relevant doses is limited since bioavailability is not taken into account. The aims of this review is to evaluate in vivo evidence for a role of RES supplementation in promoting bone health to reduced osteoporosis risk and potential mechanisms of action. Due to multiple actions on both osteoblasts and osteoclasts, RES has potential to attenuate bone loss resulting from different etiologies and pathologies. Several animal models have investigated the bone protective effects of RES supplementation. Ovariectomized rodent models of rapid bone loss due to estrogen-deficiency reported that RES supplementation improved bone mass and trabecular bone without stimulating other estrogen-sensitive tissues. RES supplementation prior to age-related bone loss was beneficial. The hindlimb unloaded rat model used to investigate bone loss due to mechanical unloading showed RES supplementation attenuated bone loss in old rats, but had inconsistent bone effects in mature rats. In growing rodents, RES increased longitudinal bone growth, but had no other effects on bone. In the absence of human clinical trials, evidence for a role of RES on bone heath relies on evidence generated by animal studies. A better understanding of efficacy, safety, and molecular mechanisms of RES on bone will contribute to the determination of dietary recommendations and therapies to reduce osteoporosis. This article is part of a Special Issue entitled: Resveratol: Challenges in translating pre-clinical findings to improved patient outcomes.