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

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.

Resveratrol as sensitizer in colorectal cancer plasticity

Despite tremendous medical treatment successes, colorectal cancer (CRC) remains a leading cause of cancer deaths worldwide. Chemotherapy as monotherapy can lead to significant side effects and chemoresistance that can be linked to several resistance-activating biological processes, including an increase in inflammation, cellular plasticity, multidrug resistance (MDR), inhibition of the sentinel gene p53, and apoptosis. As a consequence, tumor cells can escape the effectiveness of chemotherapeutic agents. This underscores the need for cross-target therapeutic approaches that are not only pharmacologically safe but also modulate multiple potent signaling pathways and sensitize cancer cells to overcome resistance to standard drugs. In recent years, scientists have been searching for natural compounds that can be used as chemosensitizers in addition to conventional medications for the synergistic treatment of CRC. Resveratrol, a natural polyphenolic phytoalexin found in various fruits and vegetables such as peanuts, berries, and red grapes, is one of the most effective natural chemopreventive agents. Abundant in vitro and in vivo studies have shown that resveratrol, in interaction with standard drugs, is an effective chemosensitizer for CRC cells to chemotherapeutic agents and thus prevents drug resistance by modulating multiple pathways, including transcription factors, epithelial-to-mesenchymal transition-plasticity, proliferation, metastasis, angiogenesis, cell cycle, and apoptosis. The ability of resveratrol to modify multiple subcellular pathways that may suppress cancer cell plasticity and reversal of chemoresistance are critical parameters for understanding its anti-cancer effects. In this review, we focus on the chemosensitizing properties of resveratrol in CRC and, thus, its potential importance as an additive to ongoing treatments.

Prevention and Co-Management of Breast Cancer-Related Osteoporosis Using Resveratrol

Breast cancer (BC) is currently one of the most common cancers in women worldwide with a rising tendency. Epigenetics, generally inherited variations in gene expression that occur independently of changes in DNA sequence, and their disruption could be one of the main causes of BC due to inflammatory processes often associated with different lifestyle habits. In particular, hormone therapies are often indicated for hormone-positive BC, which accounts for more than 50-80% of all BC subtypes. Although the cure rate in the early stage is more than 70%, serious negative side effects such as secondary osteoporosis (OP) due to induced estrogen deficiency and chemotherapy are increasingly reported. Approaches to the management of secondary OP in BC patients comprise adjunctive therapy with bisphosphonates, non-steroidal anti-inflammatory drugs (NSAIDs), and cortisone, which partially reduce bone resorption and musculoskeletal pain but which are not capable of stimulating the necessary intrinsic bone regeneration. Therefore, there is a great therapeutic need for novel multitarget treatment strategies for BC which hold back the risk of secondary OP. In this review, resveratrol, a multitargeting polyphenol that has been discussed as a phytoestrogen with anti-inflammatory and anti-tumor effects at the epigenetic level, is presented as a potential adjunct to both support BC therapy and prevent osteoporotic risks by positively promoting intrinsic regeneration. In this context, resveratrol is also known for its unique role as an epigenetic modifier in the regulation of essential signaling processes-both due to its catabolic effect on BC and its anabolic effect on bone tissue.

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.

Protective effect and possible mechanisms of resveratrol in animal models of osteoporosis: A preclinical systematic review and meta-analysis

Resveratrol (RES) has extensively been utilized to treat osteoporosis (OP) in animal models. However, the anti-OP effects of RES have not been tested during clinical application due to the lack of evidence and poor knowledge of the underlying mechanisms. Moreover, there is little preclinical evidence to support the use of RES in the management of OP. In the present paper, we conducted a preclinical systematic review and meta-analysis to assess the efficacy of RES in animal OP models. The potential mechanisms underlying the efficacy of RES against OP were summarized. The online databases PubMed, CNKI, EMBASE, Wanfang, Web of Science, Chinese Biomedical Literature, Cochrane Library, and Chinese VIP were retrieved from inception to December 2021. The CAMARADES 10-item quality checklist was utilized to assess the risk of bias of the included studies. STATA 12.0 software was employed to analyze the data. The quality of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. Thirteen studies containing 248 animals were included yielding a mean risk of bias score of 5.54 (range 4-7). The pooled estimates showed that the administration of RES could significantly elevate the bone mineral density (BMD) both at femur (SMD = 2.536; 95% CI = 1.950-3.122; p < 0.001) and lumbar spine (SMD = 1.363; 95% CI = 0894-1.832; p < 0.001), bone volume over total volume (BV/TV) (SMD = 2.543; 95% CI = 2.023-3.062; p < 0.001), trabecular linear density (Tb.N) (SMD = 2.724; 95% CI = 2.186-3.262; p < 0.001) and trabecular thickness (Tb.Th) (SMD = 1.745; 95% CI = 1.294-2.196; p < 0.001), while serum phosphorus (S-P) (SMD = -2.168; 95% CI = -2.753 to -1.583; p < 0.001) and trabecular separation (Tb.Sp) (SMD = -2.856; 95% CI = -4.218 to -1.494; p < 0.001) were significantly reduced in animal OP models. No significant change in serum calcium (S-Ca) (SMD = -2.448; 95% CI = -5.255-0.360; p = 0.087) was observed after RES treatment. Furthermore, RES could significantly improve the bone biomechanical indexes: bone maximum load (BML) (SMD = 2.563; 95% CI = 1.827-3.299; p < 0.001) and connectivity density (Conn.D) (SMD = 1.512; 95% CI = 0.909-2.116; p < 0.001) and decrease the structural model index (SMI) (SMD = -2.522; 95% CI = -3.243 to -1.801; p < 0.001). Overall, the present study revealed that RES has huge prospects as a medicine or dietary supplement for the clinical treatment of OP. High-quality studies with stringent designs and larger sample sizes are warranted to substantiate our conclusion.

Effects of resveratrol in an animal model of osteoporosis: a meta-analysis of preclinical evidence

Background

Resveratrol is a natural polyphenol compound that is widely present in herbal medicines such as Reynoutria japonica Houtt., Veratrum nigrum L., and Catsiatora Linn and is used in traditional Chinese medicine to treat metabolic bone deseases. Animal experiments have shown that resveratrol may have a strong treatment effect against osteoporosis (OP). The purpose of this study was to explore the efficacy of resveratrol in treating OP animal models based on preclinical research data.

Methods

This study was completed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We searched the PubMed, Embase, Cochrane Library, and China National Knowledge Infrastructure (CNKI) databases from inception to May 8, 2023, to identify animal experiments on the treatment of OP with resveratrol. The effect sizes of bone mineral density (BMD), parameters of micro-CT, serum calcium, phosphorus, alkaline phosphatase (ALP) and osteocalcin were expressed as the mean differences (MDs) and 95% confidence intervals (CIs). RevMan 5.4 software was used for data analysis.

Results

This meta-analysis included a total of 15 animal experiments, including 438 OP rats. The meta-analysis results showed that compared with the control group, resveratrol (<10, 10-25, 40-50, ≥ 60 mg/kg/day) significantly increased femoral and lumbar bone mineral density (BMD) in OP rats (p < 0.05). Resveratrol (<10 mg/kg/day) significantly increased the BMD of the total body (MD = 0.01, 95% CI: 0.01 to 0.01, p < 0.001). In terms of improving the parameters related to micro-CT, resveratrol (40-50 mg/kg/day) can increase trabecular thickness and trabecular number and reduce trabecular spacing (p < 0.05). Compared with the control group, resveratrol can reduce the concentration of calcium and phosphorus in serum but has no significant effect on serum ALP and osteocalcin (p > 0.05). The results of subgroup analysis showed that resveratrol increased the whole-body BMD of SD rats (p = 0.002) but did not improve the whole-body BMD of 3-month-old rats (p = 0.17).

Conclusion

Resveratrol can increase BMD in OP rat models, and its mechanism of action may be related to improving bone microstructure and regulating calcium and phosphorus metabolism. The clinical efficacy of resveratrol in the treatment of OP deserves further research.

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.

Resveratrol prevents ovariectomy-induced bone quality deterioration by improving the microarchitectural and biophysicochemical properties of bone

INTRODUCTION

Osteoporosis is a major health problem that is very common worldwide and is characterized by both low bone density and deterioration in bone quality. New treatment options without side effects have become an active area of research in recent years. This study was designed to investigate the preventive effects of resveratrol on bone quality deterioration caused by ovariectomy.

MATERIALS AND METHODS

Sixty rats were randomly divided into five groups (12 animals per group): Control, Sham-operated (SHAM), ovariectomized (OVX), OVX + Resveratrol-40 mg/kg/day (OVX + Res40), OVX + Resveratrol-80 mg/kg/day (OVX + Res80). Resveratrol was administered by oral gavage (40 and 80 mg/kg/day) for ten weeks. Micro-CT measurements, biomechanical testing, Raman spectroscopy analysis, and RT-PCR analysis were performed. ALP, OCN, TAS, and TOS levels were also measured from blood serum.

RESULTS

Bone strength, bone volume/total volume, trabecular volume, and trabecular thickness were higher in the OVX + RES-80 group than in the OVX group. Resveratrol increased osteogenic differentiation, as the expression of osteogenic markers ALP, Col1A1, Runx2, OPG, OCN increased in both OVX + RES-80 and OVX + RES-40 groups compared to the OVX group. 80 mg/kg/day resveratrol administration decreased the levels of ALP, OCN and TOS in ovariectomized rats. Raman spectroscopy findings showed a preventive effect of resveratrol administration against ovariectomy-induced deterioration in biophysiochemical properties of bone tissue.

CONCLUSION

This study revealed that administration of different doses of 80 mg/kg/day and 40 mg/kg/day of resveratrol had protective effects on bone quality deterioration caused by ovariectomy.

Does resveratrol favor peri-implant bone repair in rats with ovariectomy-induced osteoporosis? Gene expression, counter-torque and micro-CT analysis

This study investigated the influence of resveratrol on peri-implant repair and its effects on bone-related markers in ovariectomy-induced osteoporosis in rats. Animals were divided into: OVX+PLAC (n = 10): ovariectomized animals treated with placebo; OVX+RESV (n = 10): OVX treated with resveratrol; OVX+PLAC+ZOL (n = 10): OVX treated with PLAC and zoledronate; OVX+RESV+ZOL (n = 10): OVX treated with RESV and ZOL; and SHOVX+PLAC (n = 10): sham ovariectomy treated with PLAC. RESV and PLAC were administrated after ovariectomy and ZOL after six weeks after OVX, until the end of experiment. One implant was inserted in each tibiae of animals 18 weeks after ovariectomy. After 4 weeks, one implant was removed for counter-torque, and peri-implant tissue was collected for mRNA quantification of several osteogenic markers by PCR. The other tibia was submitted to micro-computed tomography analysis. Reduced counter-torque values, bone-implant contact (BIC) and bone volume fraction (BV/TV), and higher bone porosity (BP) were detected in OVX+PLAC group when compared to SHOVX+PLAC (p < 0.05). OVX+RESV rats presented lower BIC, BV/TV, and trabecular number (Tb.N), and augmented BP and trabecular spacing (Tb.Sp) when compared to SHOVX+PLAC (p < 0.05). Higher Tb.N and connectivity density (Conn.Dn) and reduced Tb.Sp were observed in OVX rats treated with ZOL, independently of RESV, when compared to OVX+PLAC and OVX+RESV groups (p < 0.05), whereas the combination ZOL+RESV promoted lower BP when compared to OVT+PLAC and OVX+RESV (p < 0.05). Gene expression was not influenced by RESV (p > 0.05), whereas ZOL promoted up-regulation of BMP-2 (p<0.05). RESV did not improve peri-implant bone repair in rats with ovariectomy-induced osteoporosis.

Metabolomic analysis to elucidate the change of the n-3 polyunsaturated fatty acids in senescent osteoblasts

Senile osteoporosis is a major public health concern, and yet, effective treatment methods do not exist. Herein, we used metabolomics to analyze the change of n-3 polyunsaturated fatty acids (PUFA) in senescent osteoblasts. We found that with an increase in the number of passages, the osteoblasts proliferative ability, alkaline phosphatase activity, and expression levels of bone metabolism genes decreased, the expression levels of aging-related genes increased, the damage caused by oxidative stress became more severe. Furthermore, levels of n-3 PUFA family members were downregulated in passage 10 than in passage 3 osteoblasts. These findings indicated that multiple passages led to more severe oxidative stress damage in senescent osteoblasts, which could be related to a decrease in n-3 PUFA levels. We believe that unsaturated fatty acid metabolism is a key factor involved in osteoblast senescence and that a proper dietary intake of n-3 PUFA may delay the occurrence senile osteoporosis.

Protective effect of resveratrol on estrogen deficiency-induced osteoporosis though attenuating NADPH oxidase 4/nuclear factor kappa B pathway by increasing miR-92b-3p expression

Introduction:

Resveratrol (RES) exhibits estrogen-like effects and has potential applications to treatment of osteoporosis caused by estrogen deficiency; however, the specific mechanism of action of RES remains unclear. Here, we examined the therapeutic effects of RES on ovariectomized (OVX) rats with osteoporosis and determined the underlying mechanism.

Methods:

We established an OVX rat model to study osteoporosis caused by estrogen deficiency. The treatment groups were given orally with RES (50, 100, and 200 mg/day), the estrogen group received 0.8 mg/kg E2 daily via oral route, and the sham-operated and control groups received an equivalent dose of sodium carboxymethylcellulose orally. After 12 weeks of treatment, we used real-time quantitative polymerase chain reaction (PCR) and Western blot analysis to measure the gene and protein expression of miR-92b-3p, Nox4, NF-κBp65, IκB, BMP2, Smad7, and RUNX-2 in bone tissues. Right femur structural parameters were evaluated by micro-CT. Dual-energy X-ray 4500 W was used to determine systemic bone mineral density (BMD). Enzyme-linked immunosorbent assay (ELISA) kits were used to determine the serum levels of bone alkaline phosphatase (BALP), osteoprotegerin (OPG), anti-tartrate acid phosphatase-5b (PTRA5b), and carboxylated terminal peptide (CTX-I). The rat femoral bone specimens were stained using hematoxylin and eosin for pathological examination

Results:

We observed increased levels of serum estrogen in both ovaries, elevated miR-92b-3p levels in bone tissues, reduced levels of Nox4, NF-κBp65, p-IκB-a, and cathepsin K, and elevated gene and protein expression of BMP2, Smad7, and RUNX-2 in the OVX rat model of osteoporosis after treatment with RES. Elevated levels of BALP, OPG, ALP, and BMD along with reduced levels of TRAP-5b and CTX-I were also observed. The structural model index (SMI) and the trabecular space (Tb. Sp) decreased, while the trabecular thickness (Tb. Th), bone volume fraction (BV/TV), trabecular number (Tb.N), and tissue bone density (Conn.D) increased, thereby improving osteoporosis induced by estrogen deficiency in both ovaries.

Conclusion:

Cathepsin K expression and Nox4/NF-κB signaling pathway were suppressed by the elevated expression of miR-92b-3p. This inhibition was pivotal in the protective effect of RES against osteoporosis induced by estrogen deficiency in both ovaries. Thus, RES efficiently alleviated osteoporosis induced by estrogen deficiency in rats.

Resveratrol attenuates inflammation environment-induced nucleus pulposus cell senescence in vitro

Intervertebral disc degeneration is a disease identified as an inflammation response-participated pathological process. As a classical cellular feature, disc cell senescence is reported to be closely related with disc cell senescence. Resveratrol has a protective role against inflammation in some cells. However, its biological effects on disc cells remain largely unclear. The present study was aimed to study the effects of resveratrol on disc nucleus pulposus (NP) cell senescence in an inflammation environment. Isolated NP cells were cultured in cultured medium with (control group) or without (inflammation group) inflammatory cytokine TNF-α and IL-1β for 14 days. Resveratrol was added along with the NP cells treated with inflammatory cytokines to investigate its effects. NP cell senescence was analyzed by senescence-associated β-Galactosidase (SA-β-Gal) staining, cell proliferation, G0/1 cell cycle arrest, telomerase activity, gene/protein expression of senescence markers (p16 and p53) and NP matrix biosynthesis. In addition, the intracellular reactive oxygen species (ROS) was also analyzed. Compared with the control group, inflammation group significantly increased SA-β-Gal activity and ROS content, decreased cell proliferation and telomerase activity, promoted G0/1 cell cycle arrest, up-regulated gene/protein expression of senescence markers (p16 and p53) and matrix catabolism enzymes (MMP-3, MMP-13 and ADAMTS-4), and down-regulated gene/protein expression of NP matrix macromolecules (aggrecan and collagen II). However, resveratrol partly reversed the effects of inflammatory cytokine on these cell senescence-associated parameters. Together, resveratrol was effective to suppress cell senescence in an inflammatory environment. The present study shows new knowledge on how to retard inflammation response-initiated disc degeneration.

The Role of Macrophage in the Pathogenesis of Osteoporosis

Osteoporosis is a systemic disease with progressive bone loss. The bone loss is associated with an imbalance between bone resorption via osteoclasts and bone formation via osteoblasts. Other cells including T cells, B cells, macrophages, and osteocytes are also involved in the pathogenesis of osteoporosis. Different cytokines from activated macrophages can regulate or stimulate the development of osteoclastogenesis-associated bone loss. The fusion of macrophages can form multinucleated osteoclasts and, thus, cause bone resorption via the expression of IL-4 and IL-13. Different cytokines, endocrines, and chemokines are also expressed that may affect the presentation of macrophages in osteoporosis. Macrophages have an effect on bone formation during fracture-associated bone repair. However, activated macrophages may secrete proinflammatory cytokines that induce bone loss by osteoclastogenesis, and are associated with the activation of bone resorption. Targeting activated macrophages at an appropriate stage may help inhibit or slow the progression of bone loss in patients with osteoporosis.