Caspase-8 has an essential role in resveratrol-induced apoptosis of rheumatoid fibroblast-like synoviocytes

Research progress of SIRTs activator resveratrol and its derivatives in autoimmune diseases

Autoimmune diseases (AID) have emerged as prominent contributors to disability and mortality worldwide, characterized by intricate pathogenic mechanisms involving genetic, environmental, and autoimmune factors. In response to this challenge, a growing body of research in recent years has delved into genetic modifications, yielding valuable insights into AID prevention and treatment. Sirtuins (SIRTs) constitute a class of NAD-dependent histone deacetylases that orchestrate deacetylation processes, wielding significant regulatory influence over cellular metabolism, oxidative stress, immune response, apoptosis, and aging through epigenetic modifications. Resveratrol, the pioneering activator of the SIRTs family, and its derivatives have captured global scholarly interest. In the context of AID, these compounds hold promise for therapeutic intervention by modulating the SIRTs pathway, impacting immune cell functionality, suppressing the release of inflammatory mediators, and mitigating tissue damage. This review endeavors to explore the potential of resveratrol and its derivatives in AID treatment, elucidating their mechanisms of action and providing a comprehensive analysis of current research advancements and obstacles. Through a thorough examination of existing literature, our objective is to advocate for the utilization of resveratrol and its derivatives in AID treatment while offering crucial insights for the formulation of innovative therapeutic approaches.

Mini-encyclopedia of mitochondria-relevant nutraceuticals protecting health in primary and secondary care-clinically relevant 3PM innovation

Despite their subordination in humans, to a great extent, mitochondria maintain their independent status but tightly cooperate with the "host" on protecting the joint life quality and minimizing health risks. Under oxidative stress conditions, healthy mitochondria promptly increase mitophagy level to remove damaged "fellows" rejuvenating the mitochondrial population and sending fragments of mtDNA as SOS signals to all systems in the human body. As long as metabolic pathways are under systemic control and well-concerted together, adaptive mechanisms become triggered increasing systemic protection, activating antioxidant defense and repair machinery. Contextually, all attributes of mitochondrial patho-/physiology are instrumental for predictive medical approach and cost-effective treatments tailored to individualized patient profiles in primary (to protect vulnerable individuals again the health-to-disease transition) and secondary (to protect affected individuals again disease progression) care. Nutraceuticals are naturally occurring bioactive compounds demonstrating health-promoting, illness-preventing, and other health-related benefits. Keeping in mind health-promoting properties of nutraceuticals along with their great therapeutic potential and safety profile, there is a permanently growing demand on the application of mitochondria-relevant nutraceuticals. Application of nutraceuticals is beneficial only if meeting needs at individual level. Therefore, health risk assessment and creation of individualized patient profiles are of pivotal importance followed by adapted nutraceutical sets meeting individual needs. Based on the scientific evidence available for mitochondria-relevant nutraceuticals, this article presents examples of frequent medical conditions, which require protective measures targeted on mitochondria as a holistic approach following advanced concepts of predictive, preventive, and personalized medicine (PPPM/3PM) in primary and secondary care.

The Role of Aryl Hydrocarbon Receptor in Bone Biology

Aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor, is crucial in maintaining the skeletal system. Our study focuses on encapsulating the role of AhR in bone biology and identifying novel signaling pathways in musculoskeletal pathologies using the GEO dataset. The GEO2R analysis identified 8 genes (CYP1C1, SULT6B1, CYB5A, EDN1, CXCR4B, CTGFA, TIPARP, and CXXC5A) involved in the AhR pathway, which play a pivotal role in bone remodeling. The AhR knockout in hematopoietic stem cells showed alteration in several novel bone-related transcriptomes (eg, Defb14, ZNF 51, and Chrm5). Gene Ontology Enrichment Analysis demonstrated 54 different biological processes associated with bone homeostasis. Mainly, these processes include bone morphogenesis, bone development, bone trabeculae formation, bone resorption, bone maturation, bone mineralization, and bone marrow development. Employing Functional Annotation and Clustering through DAVID, we further uncovered the involvement of the xenobiotic metabolic process, p450 pathway, oxidation-reduction, and nitric oxide biosynthesis process in the AhR signaling pathway. The conflicting evidence of current research of AhR signaling on bone (positive and negative effects) homeostasis may be due to variations in ligand binding affinity, binding sites, half-life, chemical structure, and other unknown factors. In summary, our study provides a comprehensive understanding of the underlying mechanisms of the AhR pathway in bone biology.

Targeting glycolytic pathway in fibroblast-like synoviocytes for rheumatoid arthritis therapy: challenges and opportunities

INTRODUCTION

Rheumatoid arthritis (RA) is a chronic autoimmune disorder characterized by hyperplastic synovium, pannus formation, immune cell infiltration, and potential articular cartilage damage. Notably, fibroblast-like synoviocytes (FLS), especially rheumatoid arthritis fibroblast-like synoviocytes (RAFLS), exhibit specific overexpression of glycolytic enzymes, resulting in heightened glycolysis. This elevated glycolysis serves to generate ATP and plays a pivotal role in immune regulation, angiogenesis, and adaptation to hypoxia. Key glycolytic enzymes, such as hexokinase 2 (HK2), phosphofructose-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3), and pyruvate kinase M2 (PKM2), significantly contribute to the pathogenic behavior of RAFLS. This increased glycolysis activity is regulated by various signaling pathways.

MATERIALS AND METHODS

A comprehensive literature search was conducted to retrieve relevant studies published from January 1, 2010, to the present, focusing on RAFLS glycolysis, RA pathogenesis, glycolytic regulation pathways, and small-molecule drugs targeting glycolysis.

CONCLUSION

This review provides a thorough exploration of the pathological and physiological characteristics of three crucial glycolytic enzymes in RA. It delves into their putative regulatory mechanisms, shedding light on their significance in RAFLS. Furthermore, the review offers an up-to-date overview of emerging small-molecule candidate drugs designed to target these glycolytic enzymes and the upstream signaling pathways that regulate them. By enhancing our understanding of the pathogenic mechanisms of RA and highlighting the pivotal role of glycolytic enzymes, this study contributes to the development of innovative anti-rheumatic therapies.

The role of resveratrol on rheumatoid arthritis: From bench to bedside

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by symmetrical polyarthritis as its main clinical manifestation. Uncontrolled RA eventually leads to joint deformities and loss of function. Currently, the pathogenesis of RA remains under discussion, and RA treatment is still at the bottleneck stage. Resveratrol has long been regarded as a potential antioxidant drug for RA treatment. Currently, resveratrol is considered to exert therapeutic effects on RA by activating silent information regulator 1 (SIRT1) and its downstream pathways. There is notable crosstalk between the SIRT1 and NF-κB pathways, and these pathways, which play an essential role in the development of RA, are unexpectedly linked to the influence of resveratrol. Based on recent studies of almost all the pathways that resveratrol can affect, this review summarizes a regulatory chain of core components that cover multiple tracks. We also list the effects of resveratrol on immune cells and other subtle controls, which can help clinicians understand the known mechanism of resveratrol and better treat patients with RA.

A comprehensive insight into effects of resveratrol on molecular mechanism in rheumatoid arthritis: A literature systematic review

AIM

Rheumatoid arthritis (RA) is an inflammatory autoimmune disease, which is characterized by massive pain and destruction of synovial joints, leads to bone erosion, damage to cartilage, and disability. Several studies suggested that resveratrol supplementation may be effective in the prevention and management of RA. Therefore, a systematic review was conducted to summarize published studies that assess the effect of resveratrol supplementation on the complications of RA.

METHODS

A comprehensive search to identify in vitro, animal, and human studies investigating the impact of resveratrol on the complications of RA was performed up to February 2022. Two independent reviewers evaluated studies based on inclusion/exclusion criteria and performed data extraction.

RESULTS

All studies examining the effects of resveratrol supplementation on the complications of RA were included. From a total of 571 retrieved articles, 32 studies were eligible for the current systematic review. The evidence reviewed here indicates that resveratrol supplementation may exert beneficial effects on the complications of RA by attenuating inflammation and oxidative stress, modulating the immune response, and down-regulating the messenger RNA expression of genes related to inflammatory pathways.

CONCLUSION

Due to the promising therapeutic effects of resveratrol on RA complications and limited number of human studies in this subject, further clinical trials are suggested.

Signalling and putative therapeutic molecules on the regulation of synoviocyte signalling in rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease characterized by symmetrical and chronic polyarthritis. Fibroblast-like synoviocytes are mainly involved in joint inflammation and cartilage and bone destruction by inflammatory cytokines and matrix-degrading enzymes in RA. Approaches that induce various cellular growth alterations of synoviocytes are considered as potential strategies for treating RA. However, since synoviocytes play a critical role in RA, the mechanism and hyperplastic modulation of synoviocytes and their motility need to be addressed. In this review, we focus on the alteration of synoviocyte signalling and cell fate provided by signalling proteins, various antioxidant molecules, enzymes, compounds, clinical candidates, to understand the pathology of the synoviocytes, and finally to achieve developed therapeutic strategies of RA.

Cite this article: Bone Joint Res 2021;10(4):285–297.

Autophagy Activation by Resveratrol Reduces Severity of Experimental Rheumatoid Arthritis

SCOPE

Previous work reported that dietary supplementation with resveratrol lowers synovial hyperplasia, inflammatory and oxidative damage in an antigen-induced arthritis (AIA) model. Here, it is investigated whether resveratrol can regulate the abnormal synovial proliferation by inducing autophagy and controlling the associated inflammatory response.

METHODS AND RESULTS

Animals treated with resveratrol 8 weeks before AIA induction show the highest significant signal for microtubule-associated protein 1 light chain 3 by confocal microscopy. Besides, resveratrol significantly reduces p62 expression, but it does not increase the signal of beclin-1. Also, active caspase-3 expression, as well as poly(ADP-ribose) polymerase, is upregulated in the AIA group, and is significantly reduced in resveratrol-treated AIA group. Resveratrol also mitigates angiopoietin-1 and vascular endothelial growth factor signals. Finally, resveratrol significantly reduces the serum levels of IL-1β, C reactive protein, and prostaglandin E2, as well as nuclear factor κB synovial tissue expression, which shows a significant correlation with p62 expression.

CONCLUSION

Dietary supplementation with resveratrol induces the noncanonical autophagy pathway and limits the cross-talk with inflammation, which in consequence modulates the synovial hyperplasia. Preventive strategies that incorporate dietary intervention with resveratrol may offer a potential therapeutic alternative to drugs to influence the risk of rheumatoid arthritis and influence its course.

Daphnetin induces apoptosis in fibroblast-like synoviocytes from collagen-induced arthritic rats mainly via the mitochondrial pathway

Rheumatoid arthritis (RA) is a chronic, symmetric, systemic autoimmune disease. Because insufficient apoptosis of fibroblast-like synoviocytes (FLS) is an important characteristic of RA, promoting apoptosis is considered a potential therapeutic tool for treating RA. We have previously found that daphnetin (7,8-dihydroxycoumarin, DAP) has a pro-apoptotic effect on fibroblast-like synoviocytes from collagen-induced arthritis (CIA) rats. In the present study, we further investigated the mechanisms of DAP-induced apoptosis in CIA-FLS. CIA-FLS were incubated with DAP for 48 h in the presence or absence of caspase inhibitors, including inhibitors of caspase-3, caspase-8, or caspase-9 or a pan-caspase inhibitor; then, a series of experiments were performed to evaluate the mechanisms of DAP-induced apoptosis. Our results showed that DAP markedly decreased cell viability and induced the apoptosis of CIA-FLS along with typical morphological and ultrastructural changes; moreover, DAP increased FasL, cytochrome c (Cyt-c), Bax, caspase-3, caspase-8, and caspase-9 mRNA expression and Bax, caspase-3, caspase-8, and caspase-9 protein expression. In contrast, DAP decreased Bcl-2 mRNA and protein expression and promoted the release of Cyt-c from the mitochondria into the cytosol; these effects were attenuated to varying degrees by pre-treatment with caspase inhibitors, especially with caspase-3 or caspase-9 inhibitors or a pan-caspase inhibitor. In conclusion, the current findings demonstrate that the DAP-induced apoptosis of CIA-FLS occurred mainly via a caspase-dependent pathway, in particular the mitochondrial pathway, and that the Bax/Bcl-2 ratio was involved in this process. Thus, DAP may be a potential therapeutic agent for RA.

Epigenetically regulated co-expression network of genes significant for rheumatoid arthritis

Aim: To identify epigenetically regulated network of genes in peripheral blood mononuclear cells significant for rheumatoid arthritis (RA). Methods: Differentially expressed genes (DEGs) and their associated differentially expressed miRNAs and differentially methylated positions (DMPs) were identified. Causal inference test (CIT) identified the causal regulation chains. The analyses, for example, weighted gene co-expression network (WGCNA), protein-protein interaction and functional enrichment, evaluated interaction patterns among the DEGs and the associated epigenetic factors. Results: A total of 181 DEGs were identified. The DEGs were significantly regulated by DMPs and/or differentially expressed miRNAs. Causal inference test analyses identified 18 causal chains of DMP-DEG-RA and 16 intermediate DEGs enriched in 'protein kinase inhibitor activity'. BTN2A1 was co-expressed with other 9 intermediate genes and 11 known RA-associated genes and played a pivotal role in the co-expression network. Conclusion: Epigenetically regulated network of genes in peripheral blood mononuclear cells (PBMC) contributed to RA. The causal DMPs and key intermediate genes may serve as potential biomarkers for RA.

Higher incidence of sperm granuloma in the epididymis of C57BL/6N mice

C57BL/6N mice are inbred strains widely used in biomedical research. Hence, a large amount of basic data has been accumulated. However, in the field of histopathology, spontaneous data for relatively younger mice that are used more frequently are not yet abundant, in contrast to data for older mice and their neoplastic lesions. To acquire the essential background data required by various research and toxicological assessments, 120 mice of the C57BL/6N strain (10 and 13 weeks of age) were collected from two institutions (From Korea and Japan) and subjected to histopathological analyses of the major organs (liver, spleen, kidney, thymus, heart, testis, epididymis). The results showed significantly higher incidence of sperm granulomas in the epididymides (10-56%) of these mice, compared with that in other strains or species of lab animals. Upon closer inspection, oligospermia/clear cell hyperplasia, cellular debris, and tubular vacuolation were also observed in the epididymides with sperm granulomas. Moreover, diseased organs were significantly heavier than healthy ones. Immunohistochemical staining showed a significant increase in the chromatic figures of cysteine-dependent aspartate-directed proteases-3 (caspase-3) and cleaved-poly(ADP-ribose) polymerase (c-PARP), and damages to the tubule due to spontaneous apoptosis, which may have led to the sperms leaking out of the tubule, causing the granuloma. To conclude, spontaneous sperm granuloma can occur in 10- and 13-week-old C57BL/6N mice and may thus affect the results of various studies using these mice. Therefore, sperm granuloma in epididymis needs to be carefully considered as an important factor when design the study using C57BL/6N.

Resveratrol as an effective adjuvant therapy in the management of rheumatoid arthritis: a clinical study

Resveratrol (RSV), a naturally occurring polyphenol, has been found to have potent antioxidant, anti-inflammatory, and anticancer effects. Recently, RSV was reported as a new potential agent to suppress inflammation of collagen-induced arthritis in a mouse model. Nevertheless, the clinical benefits of RSV in the management of rheumatoid arthritis (RA) were not studied. This randomized controlled clinical trial aims to shed some light on the therapeutic benefits of RSV in the treatment of RA in patients with different stages of the disease activity. In this randomized controlled clinical trial, 100 RA patients (68 female, 32 male) were enrolled randomly and divided into two groups, each of 50 patients: an RSV-treated group that received a daily RSV capsule of 1 g with the conventional treatment for 3 months and a control group that just received the regular treatment. The clinical and biochemical markers of RA in both groups were assessed. It was found that the clinical markers (i.e., the 28-joint count for swelling and tenderness) and the disease activity score assessment for 28 joints were significantly lowered in the RSV-treated group. Moreover, serum levels of certain biochemical markers (i.e., C-reactive protein, erythrocyte sedimentation rate, undercarboxylated osteocalcin, matrix metalloproteinase-3, tumor necrosis factor alpha, and interleukin-6) were also significantly decreased in RSV-treated patients. The current study suggests the addition of RSV as an adjuvant to the conventional antirheumatic drugs.

Apoptotic effects of ε-viniferin in combination with cis-platin in C6 cells

Glioblastoma (GBM) is one of the most common and lethal forms of primary brain tumors in human adults. Treatment options are limited, and in most cases ineffective. Natural products are sources of novel compounds endowed with therapeutic properties in many human diseases like cancer. ε-viniferin is a resveratrol dimer and well known for having antiproliferative and apoptotic effects on cancer cells. Cisplatin is a platinum containing anti-cancer drug. In this study, we aimed to investigate antiproliferative and apoptotic effects of using cis-platin and ε-viniferin alone or in combined treatment of C6 cells. Cell proliferation was detected by WST-1. Mitochondrial membrane potential changes in the cells (ΔΨm) were evaluated using cationic dye JC1. Apoptotic index which is a hallmark of late apoptosis was detected by using Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method and apoptotic alterations were observed by transmission electron microscope (TEM). Activation of caspase-8, -9, -3 in C6 cells at various incubation periods was measured by flow cytometer. Apoptotic index increased at highest level in only combined treatment cells (91.6%) after 48 h incubation. These results were supported by TEM images. Caspase-8 activation in C6 cells increased to a maximum (12.5%) after 6 h by using combined cis-platin/ε-viniferin treatment (13.25/95 μM). Caspase-9 was activated at 44.5% after combined treatment for 24 h. This rate is higher than using cis-platin (14.2%) or ε-viniferin (43.3%) alone. The combined 13.25 μM/cisplatin and 95 μM ε-viniferin treatment caused maximum caspase-3 activation in C6 cells (15.5%) at the end of the 72 h incubation. In conclusion, it was observed that caspase-8, -9, -3 activation which was determined in vitro, trigerred apoptotic mechanism in C6 cells by using low concentrations of combined cis-platin and ε-viniferin.

Association of SIRT-1 Gene Polymorphism and Vitamin D Level in Egyptian Patients With Rheumatoid Arthritis

Background

We investigated SIRT-1 genetic variant and its association with vitamin D level in Egyptian patients with rheumatoid arthritis (RA).

Methods

Seventy Egyptian subjects were enrolled in our study and divided into two groups: RA group (n = 50 patients) and healthy control group (n = 20 subjects). Five milliliter blood sample was withdrawn from each subject followed by laboratory investigation and DNA extraction for SIRT-1 gene polymorphism assessment (rs7895833 A>G, rs7069102 C>G and rs2273773 C>T) and vitamin D level expression.

Results

There was statistically significant difference between rheumatoid cases and controls with regard to vitamin D level with 88% of cases showing insufficient vitamin D versus all controls showing sufficient level. SIRT-1 different SNPs rs2273773, rs7895833and rs7069102 genotype frequencies were statistically significant in RA compared to control group (P = 0.001). There was no statistically significant difference between different genotypes of rs2273773, rs7895833 and rs7069102 with regard to vitamin D level.

Conclusion

We concluded that there is a strong association between SIRT-1 polymorphism genotyping and RA. Vitamin D level was insufficient in Egyptian patients with RA.

Resveratrol induces mitochondria-mediated, caspase-independent apoptosis in murine prostate cancer cells

Found in the skins of red fruits, including grapes, resveratrol (RES) is a polyphenolic compound with cancer chemopreventive activity. Because of this activity, it has gained interest for scientific investigations. RES inhibits tumor growth and progression by targeting mitochondria-dependent or -independent pathways. However, further investigations are needed to explore the underlying mechanisms.

The present study is focused on examining the role of RES-induced, mitochondria-mediated, caspase-independent apoptosis of prostate cancer cells, namely transgenic adenocarcinoma of mouse prostate (TRAMP) cells. These cells were exposed to RES for various times, and cell killing, cell morphology, mitochondrial membrane potential (Δψm), expression of Bax and Bcl2 proteins, the role of caspase-3, and DNA fragmentation were analyzed.

TRAMP cells exposed to RES showed decreased cell viability, altered cell morphology, and disrupted Δψm, which led to aberrant expression of Bax and Bcl2 proteins. Furthermore, since the caspase-3 inhibitor, z-VAD-fmk (benzyloxycarbonyl-valine-alanine-aspartic acid-fluoromethyl ketone), had no appreciable impact on RES-induced cell killing, the killing was evidently caspase-independent. In addition, RES treatment of TRAMP-C1, TRAMP-C2, and TRAMP-C3 cells caused an appreciable breakage of genomic DNA into low-molecular-weight fragments.

These findings show that, in inhibition of proliferation of TRAMP cells, RES induces mitochondria-mediated, caspase-independent apoptosis. Therefore, RES may be utilized as a therapeutic agent to control the proliferation and growth of cancer cells.

Evolution of pain at 3 months by oral resveratrol in knee osteoarthritis (ARTHROL): protocol for a multicentre randomised double-blind placebo-controlled trial

INTRODUCTION

Osteoarthritis (OA) pathophysiology is driven in part by joint inflammation. Resveratrol has in vitro anti-inflammatory properties. We aim to assess the efficacy of oral resveratrol for knee pain at 3 months in people with knee OA.

METHODS AND ANALYSIS

We will conduct a randomised double-blind placebo-controlled trial. Overall, 164 individuals with knee OA fulfilling 1986 American College of Rheumatology criteria will be recruited in three tertiary care centres in France and randomised to receive oral resveratrol, 40 mg (two caplets) two times per day for 1 week, then 20 mg (one caplet) two times per day or a matching placebo for a total of 6 months. Randomisation will be centralised and stratified by centre. The allocation ratio of assignments will be 1:1. The primary outcome will be the mean change from baseline in knee pain on a self-administered 11-point pain Numeric Rating Scale at 3 months. Secondary outcomes will be the mean change in knee pain at 6 months, the function subscore of the Western Ontario and McMaster Universities Arthritis Index score, patient global assessment, proportion of responders according to the Osteoarthritis Research Society International-Outcome Measures in Rheumatology criteria at 3 and 6 months, and self-reported number of intra-articular injections of corticosteroids or hyaluronic acid and consumption of analgesics and non-steroidal anti-inflammatory drugs since the last contact. Other interventions will be allowed and self-reported. Adherence will be monitored by capsule counts and a booklet and adverse events recorded at 3 and 6 months. Statisticians, treating physicians and participants will be blinded to the allocated treatment.

ETHICS AND DISSEMINATION

The oral resveratrol in knee osteoarthritis (ARTHROL) trial has been authorised by the AgenceNationale de Sécurité du Médicament et des Produits de Santé and ethics were approved by the Comité deProtection des Personnes Île-de-France III. The findings of the study will be published in a peer-reviewed journal and disseminated at conferences. The design of ARTHROL will warrant the translation of its findings into clinical practice.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier: NCT02905799. Pre-results. First received: 14 September 2016. Last updated: 16 September 2016. Status: not yet recruiting.

Tamaractam, a New Bioactive Lactam from Tamarix ramosissima, Induces Apoptosis in Rheumatoid Arthritis Fibroblast-Like Synoviocytes

Chemical investigation of Tamarix ramosissima Ledeb, a traditional herbal medicine used for rheumatoid arthritis (RA) treatment in northwest China, led to the discovery of a new phenolic aromatic rings substituted lactam, tamaractam (1), together with the previously reported compounds cis-N-feruloyl-3-O-methyldopamine (2) and trans-N-feruloyl-3-O-methyldopamine (3). The structures of the compounds were determined by high resolution electrospray ionization mass spectroscopy (HRESIMS) and 1D and 2D-NMR experiments, as well as comparison with the literature data. The effects of the three compounds on the viability of RA fibroblast-like synoviocytes (RA-FLS) were assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Pro-apoptosis effect of compound 1 in RA-FLS was further investigated by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay, activated caspase-3/7 level assessment using luminescence assay, and sub-G₁ fraction measurement using flow cytometry. It was found that these three compounds displayed variable proliferation inhibitory activity in RA-FLS, and compound 1 exhibited the strongest effect. Compound 1 could remarkably induce cellular apoptosis of RA-FLS, increase activated caspase-3/7 levels, and significantly increase sub-G₁ fraction in the cell cycle. The results suggested that compound 1 may inhibit the proliferation of RA-FLS through apoptosis-inducing effect, and these compounds may contribute to the anti-RA effect of T. ramosissima.

Resveratrol, Potential Therapeutic Interest in Joint Disorders: A Critical Narrative Review

Trans-resveratrol (t-Res) is a natural compound of a family of hydroxystilbenes found in a variety of spermatophyte plants. Because of its effects on lipids and arachidonic acid metabolisms, and its antioxidant activity, t-Res is considered as the major cardioprotective component of red wine, leading to the “French Paradox” health concept. In the past decade, research on the effects of resveratrol on human health has developed considerably in diverse fields such as cancer, neurodegenerative and cardiovascular diseases, and metabolic disorders. In the field of rheumatic disorders, in vitro evidence suggest anti-inflammatory, anti-catabolic, anti-apoptotic and anti-oxidative properties of t-Res in various articular cell types, including chondrocytes and synoviocytes, along with immunomodulation properties on T and B lymphocytes. In preclinical models of osteoarthritis and rheumatoid arthritis, resveratrol has shown joint protective effects, mainly mediated by decreased production of pro-inflammatory and pro-degradative soluble factors, and modulation of cellular and humoral responses. Herein, we comprehensively reviewed evidence supporting a potential therapeutic interest of t-Res in treating symptoms related to rheumatic disorders.

Autophagy and mitochondrial dysfunction in adjuvant-arthritis rats treatment with resveratrol

Resveratrol is a polyphenol derivatives which exhibits a pro-apoptotic effect in a variety of human cancers by triggering mitochondria apoptosis pathway and autophagy. However, there are scarcely reports on its apoptosis-promoting effect in abnormal proliferation fibroblast-like synoviocytes (FLSs). In this study, we investigated the underlying mechanism and apoptosis-inducing effects of resveratrol on the abnormal proliferation of FLSs in adjuvant-arthritis (AA) rats. Since using resveratrol for 12 days resulted in a significant decreasing the swelling degree of the paw, reducing malondialdehyde (MDA) content and enhancing superoxide dismutase (SOD) activity, antioxidant capacity, glutathione peroxidase and glutathione reductase ratio in AA rats. Moreover, we found that 5 μMH₂O₂ could increase cells viability, Beclin1, LC3A/B, MnSOD, SIRT3 protein expression in FLSs. But, resveratrol could reverse these effects by changing mitochondrial membrane potential (Δψm) to promote mitochondrial reactive oxygen species (mtROS) generation in 5 μMH₂O₂-treatment FLSs. These results suggest that oxidative stress existed in AA rats. Resveratrol could suppress oxidative stress in AA rats and increase mtROS production by reducing autophagy protein Beclin1, LC3A/B and oxidative stress protein MnSOD to promoted the apoptosis of FLSs. Thus, targeting of mtROS may be a crucial mechanism of resveratrol confers patients with rheumatoid arthritis.

Fas/FasL, Bcl2 and Caspase-8 gene polymorphisms in Chinese patients with rheumatoid arthritis

Apoptosis signals are necessary for maintaining homeostasis and an adequate immune response. Dysregulation of apoptosis-related genes in the immune system has an important impact on autoimmune diseases such as rheumatoid arthritis (RA). Thus, we investigated the association between Fas rs2234767 G/A, FasL rs763110 C/T, Bcl2 rs12454712 T/C, Bcl2 rs17757541 C/G, and Caspase-8 rs1035142 G/T polymorphisms and RA susceptibility in a Chinese population. These five single-nucleotide polymorphisms (SNPs) were studied in a Chinese population consisting of 615 patients with RA and 839 controls. Genotyping was performed using a custom-by-design 48-Plex SNP scan TM kit. Furthermore, we undertook a meta-analysis between FasL rs763110 C/T and RA. This study indicated that Fas rs2234767 and Bcl2 rs17757541 polymorphisms were risk factors for RA. No association was observed between FasL rs763110 C/T, Bcl2 rs12454712 T/C, and Caspase-8 rs1035142 G/T polymorphisms and RA in this study. The results of this meta-analysis suggested no significant association between FasL rs763110 C/T and RA. However, stratification analysis of this meta-analysis indicated that FasL rs763110 C/T increased the risk of Caucasian RA patients. In conclusion, this study demonstrated that Fas rs2234767 G/A and Bcl2 rs17757541 T/C polymorphisms might be associated with an increased risk of RA. This meta-analysis revealed that FasL rs763110 C/T was associated with an increased risk of Caucasian RA patients.

An update on dietary phenolic compounds in the prevention and management of rheumatoid arthritis

Certain nutritional components influence the cellular metabolism and interfere in the pathological inflammatory process, so that they may act as a coadjuvant in the treatment of many chronic inflammatory diseases, including rheumatoid arthritis (RA).

Aryl hydrocarbon receptor antagonism and its role in rheumatoid arthritis

Although rheumatoid arthritis (RA) is the most common autoimmune disease, affecting approximately 1% of the population worldwide, its pathogenic mechanisms are poorly understood. Tobacco smoke, an environmental risk factor for RA, contains several ligands of aryl hydrocarbon receptor (Ahr), also known as dioxin receptor. Ahr plays critical roles in the immune system. We previously demonstrated that Ahr in helper T-cells contributes to development of collagen-induced arthritis, a mouse model of RA. Other studies have shown that cigarette smoke condensate and pure Ahr ligands exacerbate RA by altering bone metabolism and inducing proinflammatory responses in fibroblast-like synoviocytes. Consistent with these findings, several Ahr antagonists such as α-naphthoflavone, resveratrol, and GNF351 reverse the effect of Ahr ligands in RA pathogenesis. In this review, we summarize the current knowledge of Ahr function in the immune system and the potential clinical benefits of Ahr antagonism in treating RA.

Cell death pathway induced by resveratrol-bovine serum albumin nanoparticles in a human ovarian cell line

Resveratrol-bovine serum albumin nanoparticles (RES-BSANP) exhibit chemotherapeutic properties, which trigger apoptosis. The aim of the present study was to investigate the caspase-independent cell death pathway induced by RES-BSANP in human ovarian cancer SKOV3 cells and to analyze its mechanism. Morphological changes were observed by apoptotic body/cell nucleus DNA staining using inverted and fluorescence microscopy. The cell death pathway was determined by phosphatidylserine translocation. Western blot analysis was conducted to detect the activation of apoptosis-inducing factor (AIF), cytochrome c (Cyto c) and B-cell lymphoma 2-associated X protein (Bax). Apoptotic body and nuclear condensation and fragmentation were observed simultaneously following treatment with RES-BSANP. RES-BSANP induced apoptosis in a dose-dependent manner in the human ovarian cancer SKOV3 cells. The translocation of AIF from the mitochondria to the cytoplasm occurred earlier than that of Cyto c. In addition, Bax binding to the mitochondria was required for the release of AIF and Cyto c from the mitochondria. The AIF apoptosis pathway may present an alternative caspase-dependent apoptosis pathway in human ovarian cell death induced by RES-BSANP. Elucidation of this pathway may be critical for the treatment of cancer using high doses of RES-BSANP.

Pifithrin-α ameliorates resveratrol-induced two-cell block in mouse preimplantation embryos in vitro

Treatment with resveratrol at concentrations greater than 0.5 μmol/L resulted in the arrest of mouse embryo development at the two-cell stage. Resveratrol-induced cytotoxicity was investigated in embryos by evaluating morphologic features by using the bromodeoxyuridine assay and acridine orange and ethidium bromide double staining. Resveratrol was found to significantly increase the expressions of p53, p21, Atf3, smac/Diablo, Bax, Bak1, Bok, and Noxa mRNA in the embryos, whereas Cullin 3 and Cdk1 expressions were decreased. Furthermore, active p53 positive signal in embryos arrested at the two-cell stage was localized in the nucleus, whereas no active p53 signal was observed in control embryos. Pretreatment with pifithrin-α, a p53 inhibitor, downregulated active p53 in two-cell embryo nuclei and ameliorated approximately 50% of the embryonic developmental defect caused by resveratrol. The findings of the present study, therefore, suggest that pifithrin-α could be used as an effective cytoprotective agent against a reproductive toxin such as resveratrol.

Bufalin exerts inhibitory effects on IL-1β-mediated proliferation and induces apoptosis in human rheumatoid arthritis fibroblast-like synoviocytes

Rheumatoid arthritis fibroblast-like synoviocytes (RAFLSs) proliferate abnormally and resist apoptosis. Bufalin inhibits cell proliferation and induces apoptosis in human cancer cells. In this study, we explored the effects of bufalin on interleukin-1beta (IL-1β)-induced proliferation and apoptosis of RAFLSs. The cell proliferation and apoptosis were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide assay and annexin V/propidium iodide staining, respectively. Bufalin dose-dependently inhibited IL-1β-induced RAFLS proliferation. Mechanistically, bufalin decreased the activation of mitogen-activated protein kinases (MAPKs) and nuclear factor-kappa B (NF-κB), both of which are involved in IL-1β-mediated RAFLS proliferation. Moreover, bufalin induced apoptosis and mitochondrial damage of RAFLSs, which was associated with Bcl-2 downregulation, Bax upregulation, mitochondrial cytochrome c release, and enhanced cleavages of caspase-3 and poly-(ADP-ribose) polymerase. Collectively, our results reveal that bufalin suppresses IL-1β-induced proliferation of RAFLSs through MAPK and NF-κB signaling pathways and induces RAFLS apoptosis via the mitochondria-dependent pathway.

Korean red ginseng saponin fraction rich in ginsenoside-Rb1, Rc and Rb2 attenuates the severity of mouse collagen-induced arthritis

Despite a multitude of reports on anti-inflammatory properties of ginseng extracts or individual ginsenosides, data on antiarthritic effect of ginseng saponin preparation with mixed ginsenosides is limited. On the other hand, a combined therapy of safe and inexpensive plant-derived natural products such as ginsenosides can be considered as an alternative to treat arthritis. Our previous in vitro data displayed a strong anti-inflammatory action of red ginseng saponin fraction-A (RGSF-A). We, herein, report a marked antiarthritic property of RGSF-A rich in ginsenoside Rb1, Rc, and Rb2. Collagen-induced arthritic (CIA) mice were treated with RGSF-A or methotrexate (MTX) for 5 weeks. Joint pathology, serum antibody production and leukocye activation, cytokine production in the circulation, lymph nodes, and joints were examined. RGSF-A markedly reduced severity of arthritis, cellular infiltration, and cartilage damage. It suppressed CD3(+)/CD69(+), CD4(+)/CD25(+), CD8(+) T-cell, CD19(+), B220/CD23(+) B-cell, MHCII(+)/CD11c(+), and Gr-1(+)/CD11b(+) cell activations. It further suppressed anti-CII- or anti-RF-IgG/IgM, TNF-α, IL-1β, IL-17, and IL-6 secretions but stimulated IL-10 levels in the serum, joint, or splenocyte. RGSF-A attenuated arthritis severity, modified leukocyte activations, and restored cytokine imbalances, suggesting that it can be considered as an antiarthritic agent with the capacity to ameliorate the immune and inflammatory responses in CIA mice.

Epigenetic-based immune intervention for rheumatic diseases

Rheumatic disease is a large spectrum of heterogeneous conditions affecting the loco-motor system including joints, muscles, connective tissues, and soft tissues around the joints and bones. Many rheumatic diseases have an element of autoimmunity including systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Aberrant epigenetic regulation of gene expression is emerging as a major factor within rheumatic disease, and indicates potential new therapeutic avenues of approach to these debilitating conditions. Understanding the precise role of epigenetics in the development and treatment of rheumatic diseases particularly those which have an associated autoimmune element may be important for the long-term management of such conditions.

The class III histone deacetylase sirtuin 1 in immune suppression and its therapeutic potential in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic debilitating disease of the joints. Both the innate and adaptive immune responses participate in the development and progression of RA. While several therapeutic reagents, such as TNF-α agonists, have been successfully developed for the clinical use in the treatment of RA, more than half of the patients do not respond to anti-TNF therapy. Therefore, new therapeutic reagents are needed. Recent studies have shown that sirtuin 1 (Sirt1), a nicotinamide adenine dinucleotide (NAD)-dependent histone deacetylase, is a critical negative regulator of both the innate and adaptive immune response in mice, and its altered functions are likely to be involved in autoimmune diseases. Small molecules that modulate Sirt1 functions are potential therapeutic reagents for autoimmune inflammatory diseases. This review highlights the role of Sirt1 in immune regulation and RA.

Torilin ameliorates type II collagen-induced arthritis in mouse model of rheumatoid arthritis

Advancements in rheumatoid-arthritis-(RA) therapies have shown considerable progresses in the comprehension of disease. However, the development of new potential agents with relative safety and efficacy continues and natural compounds have been considered as alternatives to identify new entities. Since previous in-vivo data and our in-vitro findings showed that torilin has a strong anti-inflammatory property, we further investigated its effect against collagen-induced-arthritis-(CIA) in mice. CIA-induced DBA/1J mice were treated with torilin or methotrexate (MTX) for 5-weeks. Arthritis severity was evaluated by arthritic score and joint histopathology. Draining lymph node (dLN), joint and peripheral-blood mononuclear-cell (PBMC) counts, and activation/localization of T-/B-lymphocytes, dendritic cells (DCs) and neutrophils were examined by FACS analysis. Serum anti-type-II-collagen-(CII) antibody levels and cultured-splenocyte and serum cytokines were also evaluated. Torilin markedly reduced CIA-induced arthritic score, histopathology and leukocyte counts. Besides, torilin suppressed CIA-activated T-cells including CD3+, CD3+/CD69+, CD8+, CD4+ and CD4+/CD25+ in dLNs or joints. It also modified CD19+ or CD20+/CD23+ (B-cells), MHCII+/CD11c+ (DCs) and Gr-1+/CD11b+ (neutrophil) subpopulations. It further depressed total anti-CII-IgG, anti-CII-IgG1 and anti-CII-IgG2a antibody productions. Moreover, while IFN-γ and IL-10 were not affected, torilin suppressed CIA-induced serum TNF-α, IL-1β and IL-6 levels. Interestingly, torilin also blocked IFN-γ, IL-17 and IL-6 cytokines while it did not affect IL-10 but enhanced IL-4 in splenocytes. These results show that torilin attenuated arthritis severity, modified leukocyte activations in dLNs or joints, and restored serum and splenocyte cytokine imbalances. Torilin may have immunomodulatory and anti-inflammatory properties with the capacity to ameliorate the inflammatory response in CIA-mice.

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 TNF-α-induced IL-1β, MMP-3 production in human rheumatoid arthritis fibroblast-like synoviocytes via modulation of PI3kinase/Akt pathway

Resveratrol (trans-3,4'-trihydroxystilbene), a natural phytoalexin, possesses anti-inflammatory, anti-proliferative, and immunomodulatory properties and has the potential for treating inflammatory disorders. The present study was designed to investigate the effects of resveratrol on TNF-α-induced inflammatory cytokines production of IL-1β and MMP3 in Rheumatoid arthritis (RA) Fibroblast-like synoviocytes (FLS) and further to explore the role of PI3K/Akt signaling pathway by which resveratrol modulates those cytokines production. The levels of IL-1β, MMP-3 in cultural supernatants among groups were measured by enzyme-linked immunosorbent assay. Messenger RNA expression of IL-1β and MMP-3 in RA FLS was analyzed using a reverse transcription-polymerase chain reaction. Western blot analysis was used to detect proteins expression in RA FLS intervened by resveratrol. Resveratrol inhibited both mRNA and proteins expressions of IL-1β and MMP-3 on RA FLS in a dose-dependent manner. Resveratrol also decreased significantly the expression of phosphorylated Akt dose dependently. Activation of PI3K/Akt signaling pathway exists in TNF-α-induced production of IL-1β and MMP3 on RA FLS, which is hampered by PI3K inhibitor LY294002. Immunofluorescence staining showed that TNF-α alone increased the production of P-Akt, whereas LY294002 and 50 μM resveratrol suppressed the TNF-α-stimulated expression of P-Akt. Resveratrol attenuates TNF-α-induced production of IL-1β and MMP-3 via inhibition of PI3K-Akt signaling pathway in RA FLS, suggesting that resveratrol plays an anti-inflammatory role and might have beneficial effects in preventing and treating RA.

Resveratrol induces apoptosis via a Bak-mediated intrinsic pathway in human lung adenocarcinoma cells

Our recent study have shown that resveratrol (RV), a natural plant polyphenol found in red grape skins as well as other food product, induced apoptosis via the downstream factors, caspase-independent AIF and to lesser extent caspase-9, of intrinsic apoptosis pathway in human lung adenocarcinoma (ASTC-a-1) cells. This report is designed to explore the roles of the upstream mediators of the intrinsic pathway, such as Bak/Bax, Bim, Puma and Noxa, during RV-induced apoptosis in human lung adenocarcinoma (ASTC-a-1 and A549) cell lines. RV treatment remarkably induced the activation of Bak but not Bax, and silencing Bak but not Bax by shRNA almost completely prevented RV-induced cell death, mitochondrial dysfunction and also largely prevented RV-induced AIF release, demonstrating the preferential engagement of Bak but not Bax during RV-induced apoptosis. In addition, although RV treatment induced a significant degradation of Mcl-1, knockdown of Mcl-1 by shRNA only modestly increased RV-induced Bak activation. Interestingly, silencing Bim but not Puma and Noxa remarkably attenuated RV-induced cell death, loss of mitochondrial membrane potential, and Bak activation, suggesting the important roles of Bim. Collectively, our findings for the first time demonstrate that RV induces apoptosis dominantly via a Bak- but not Bax-mediated AIF-dependent mitochondrial apoptotic signaling pathway in which Bim but not Puma and Noxa may supply the force to trigger Bak activation and subsequent apoptosis in both ASTC-a-1 and A549 cell lines.

Effects of flavonoids and other polyphenols on inflammation

Flavonoids are a family of polyphenolic compounds which are widespread in nature (vegetables) and are consumed as part of the human diet in significant amounts. There are other types of polyphenols, including, for example, tannins and resveratrol. Flavonoids and related polyphenolic compounds have significant antiinflammatory activity, among others. This short review summarizes the current knowledge on the effects of flavonoids and related polyphenolic compounds on inflammation, with a focus on structural requirements, the mechanisms involved, and pharmacokinetic considerations. Different molecular (cyclooxygenase, lipoxygenase) and cellular targets (macrophages, lymphocytes, epithelial cells, endothelium) have been identified. In addition, many flavonoids display significant antioxidant/radical scavenging properties. There is substantial structural variation in these compounds, which is bound to have an impact on their biological profile, and specifically on their effects on inflammatory conditions. However, in general terms there is substantial consistency in the effects of these compounds despite considerable structural variations. The mechanisms have been studied mainly in myeloid cells, where the predominant effect is an inhibition of NF-κB signaling and the downregulation of the expression of proinflammatory markers. At present there is a gap in knowledge of in vitro and in vivo effects, although the pharmacokinetics of flavonoids has advanced considerably in the last decade. Many flavonoids have been studied for their intestinal antiinflammatory activity which is only logical, since the gastrointestinal tract is naturally exposed to them. However, their potential therapeutic application in inflammation is not restricted to this organ and extends to other sites and conditions, including arthritis, asthma, encephalomyelitis, and atherosclerosis, among others.

Effects of berberine on human rheumatoid arthritis fibroblast-like synoviocytes

Activated rheumatoid arthritis fibroblast-like synoviocytes (RAFLSs) play an important role in the initiation and progression of rheumatoid arthritis (RA). Rapid proliferation and defective apoptosis of RAFLSs are two main mechanisms contributing to synovial hyperplasia. Berberine, the major constituent of Coptidis Rhizoma, has been widely used as an antitumor and anti-inflammation agent. Here we show that berberine significantly inhibited cell proliferation of serum-starved human RAFLSs in a dose-dependent manner. Cell cycle analysis of berberine-treated RAFLSs indicated a cell cycle arrest at the G0/G1 phase. The inhibitory effects of berberine correlated with an induction of cyclin-dependent kinase (CDK) inhibitors Cip1/p21 and Kip1/p27 and a reduction of CDK2, CDK4 and CDK6, and cyclins D1, D2 and E. Furthermore, an apoptosis assay showed that berberine treatment increased apoptotic death of RAFLSs, which was associated with an increased expression of proapoptotic protein Bax and decreased expression of antiapoptotic proteins Bcl-2 and Bcl-xl, disruption of mitochondrial membrane potential, and activation of caspase-3, caspase-9 and poly (ADP-ribose) polymerase. Taken together, these results demonstrate that berberine exerts antiproliferative effects against RAFLSs, likely through deregulation of numerous cell cycle and apoptosis regulators, thus having potential therapeutic implications in the treatment of RA.

Blockade of Caspase-2 Activity Inhibits Ischemia/Reperfusion-Induced Mitochondrial Reactive Oxygen Burst and Cell Death in Cardiomyocytes

We previously showed that initiator caspases-2 and −8 are prominently activated in ischemia/reperfusion (I/R)-induced injury in cardiomyocytes, but while blockade of caspase-2 activity enhanced cell survival, blockade of caspase-8 activity did not protect cardiomyocytes. Because apoptotic death in these cells is characterized by a burst of reactive oxygen species (ROS) at reperfusion and their survival by inhibition of this burst, we examined the effects of blocking caspase-2 and caspase-8 activities on ROS production. Caspase-2 inhibition blocked the reperfusion-induced ROS burst, while inhibition of caspase-8 did not. We also examined effects of caspase inhibition on mitochondrial membrane potential (ΔΨm) and mitochondrial function and found that blocking caspase-2, but not caspase-8, allowed recovery of ΔΨm and mitochondrial functionality. Furthermore, knockdown of caspase-2 by small-interfering (si)RNA confirmed caspase-2 participation in cytochrome c release, which correlates with loss of ΔΨm and cell death in these cardiomyocytes.

Molecular targets of natural health products in arthritis

Patients with rheumatoid arthritis (RA) and osteoarthritis (OA) consume 'natural health products' (NHPs) whose therapeutic efficacy, toxicity and mechanisms of action are poorly understood. In a previous issue of Arthritis Research and Therapy, Haqqi and colleagues characterized IL-1-activated mitogen-activated protein kinase kinase 3 (MKK3) and p38-mitogen-activated protein kinase (MAPK) isoforms in human OA chondrocytes. The cartilageprotective mechanisms of pomegranate extract involve diminishing MKK3-activated p38α, JNK, NF-κB and Runx2 pathways, which regulate inflammatory proteins and cartilage-destroying proteases. Epigallocatechin- 3-gallate, resveratrol, curcumin and other NHP active ingredients suppress multiple inflammatory and catabolic molecular mediators of arthritis. Non-toxicity, reduced severity and incidence of arthritis in animal models warrant testing NHP active ingredients for preventing human OA and RA.

Resveratrol induces apoptosis MH7A human rheumatoid arthritis synovial cells in a sirtuin 1-dependent manner

Resveratrol, a phytoalexin, reduced the viability of MH7A cells, a human rheumatoid arthritis synovial cell line. In the apoptosis assay, resveratrol increased TUNEL-positive cells and stimulated H2A.X phosphorylation. Resveratrol disrupted mitochondrial membrane potentials in MH7A cells and stimulated cytochrome c release from the mitochondria to the cytosol. Resveratrol activated caspase-3 and caspase-9 but not caspase-8 in MH7A cells. Resveratrol upregulated the expression of the NAD-dependent deacetylase sirtuin 1 mRNA and downregulated the expression of the Bcl-X_L mRNA, and resveratrol-induced MH7A cell death, mitochondrial damage, and caspase-3/-9 activation were prevented by sirtinol, an inhibitor of sirtuin 1. The results of the present study show that resveratrol induces MH7A cell apoptosis by activating caspase-9 and the effector caspase-3 along mitochondrial disruption as a result of reduced Bcl-X_L expression, allowing cytochrome c release from the mitochondria into the cytosol, in a sirtuin 1-dependent manner. This suggests that resveratrol could suppress hyperplasia of synovial cells, a critical factor of rheumatoid arthritis.

Monitoring of long-term effects of resveratrol on cell cycle progression of human HeLa cells after administration of a single dose

Expression of the human papillomavirus-encoded oncoproteins E6 and E7 in human HeLa cervical carcinoma cells results in their escape from the proper control of the cell cycle progression. Therefore, their susceptibility to agents modulating cell cycle differs from that in cells in which the control of cell cycle regulation is intact. Recently, a number of experimental studies revealed that polyphenols, especially resveratrol, could exert a strong antiproliferative effect. Polyphenols (e.g., resveratrol or epicatechins), potent antioxidant agents, are abundant components of our diet and, therefore, may not only affect the proliferation of healthy cells in the organism but also modulate the action of distinct anticancer drugs. Indeed, it has been shown that resveratrol enhances the antimitotic effect exerted by roscovitine (ROSC), a potent cyclin-dependent kinase inhibitor, on human MCF-7 breast cancer cells. In the present contribution the action of resveratrol alone and in combination with ROSC on human HeLa cells was determined. Resveratrol inhibited proliferation of exponentially growing HeLa cells. Exposure of HeLa cells to 50 micromol/L resveratrol blocked cells in the S phase in a time-dependent manner. After 12 h the population of G(2)/M-phase cells completely disappeared, and during a further 12 h the frequency of S-phase cells markedly increased and reached approximately 90%. Thus, resveratrol synchronized HeLa cells in the S phase. After removal of resveratrol, synchronized HeLa cells rapidly progressed through the cell cycle. Four hours after medium change, more than 70% of cells moved into the G(2)/M phase. Moreover, resveratrol combined with ROSC enhanced the antiproliferative action of resveratrol.