Protective effects of fenofibrate and resveratrol in an aggressive model of rheumatoid arthritis in rats

Harnessing the Power of Polyphenols: A New Frontier in Disease Prevention and Therapy

There are a wide variety of phytochemicals collectively known as polyphenols. Their structural diversity results in a broad range of characteristics and biological effects. Polyphenols can be found in a variety of foods and drinks, including fruits, cereals, tea, and coffee. Studies both in vitro and in vivo, as well as clinical trials, have shown that they possess potent antioxidant activities, numerous therapeutic effects, and health advantages. Dietary polyphenols have demonstrated the potential to prevent many health problems, including obesity, atherosclerosis, high blood sugar, diabetes, hypertension, cancer, and neurological diseases. In this paper, the protective effects of polyphenols and the mechanisms behind them are investigated in detail, citing the most recent available literature. This review aims to provide a comprehensive overview of the current knowledge on the role of polyphenols in preventing and managing chronic diseases. The cited publications are derived from in vitro, in vivo, and human-based studies and clinical trials. A more complete understanding of these naturally occurring metabolites will pave the way for the development of novel polyphenol-rich diet and drug development programs. This, in turn, provides further evidence of their health benefits.

Potential Role of Dietary Phenolic Compounds in the Prevention and Treatment of Rheumatoid Arthritis: Current Reports

Rheumatoid arthritis (RA) is a complex illness with both hereditary and environmental components. Globally, in 2019, 18 million people had RA. RA is characterized by persistent inflammation of the synovial membrane that lines the joints, cartilage loss, and bone erosion. Phenolic molecules are the most prevalent secondary metabolites in plants, with a diverse spectrum of biological actions that benefit functional meals and nutraceuticals. These compounds have received a lot of attention recently because they have antioxidant, anti-inflammatory, immunomodulatory, and anti-rheumatoid activity by modulating tumor necrosis factor, mitogen-activated protein kinase, nuclear factor kappa-light-chain-enhancer of activated B cells, and c-Jun N-terminal kinases, as well as other preventative properties. This article discusses dietary polyphenols, their pharmacological properties, and innovative delivery technologies for the treatment of RA, with a focus on their possible biological activities. Nonetheless, commercialization of polyphenols may be achievable only after confirming their safety profile and completing successful clinical trials.

"Cerastes snake venom as a promising approach in the management of complete Freund's adjuvant-induced rheumatoid arthritis in rats: Involvement of RANKL and JAK/STAT pathway"

ETHNOPHARMACOLOGICAL RELEVANCE

Cerastes cerastes is a snake found mainly in the Egyptian desert. Many studies were performed to explain the possible snake venom's pharmacological therapeutic effect in different autoimmune diseases. One of the most common auto-immune diseases is rheumatoid arthritis. Rheumatoid arthritis is characterized by a high release of pro-inflammatory and immune-modulatory cytokines. The reduction of these markers can indicate how effective is the administered drug.

AIM OF THE STUDY

This study aims to explore the potential pharmacological effects of cerastes venom in experimentally-induced RA in rats using Complete Freund's adjuvant - via different mechanisms - by assessing various tissue and serum parameters.

MATERIALS AND METHODS

The rats were assigned to negative control group, cerastes control group, positive control group, dexamethasone-treated group, infliximab-treated group, and cerastes-treated group. The study ended on the 20^th day when serum and tissue samples were prepared for further evaluation of reduced glutathione, malondialdehyde, rheumatoid factor, tumor necrosis factor-α, interleukin-6, and nuclear factor kappa-light-chain-enhancer of activated B cells as well as relative expression of phosphorylated Janus-kinase, phosphorylated signal transducers and activators of transcription, nuclear factor erythroid 2-related factor 2, and receptor activator of nuclear factor Kappa-B ligand. In addition, a histopathological examination of different groups' knees joints, and spleen was done.

RESULTS

The results showed a significant improvement of arthritis induced in the cerastes-treated group in contrast to the positive control group in all assessed parameters. In addition, significant improvement of arthritis was observed in the histopathological examination of different groups' knees joints, and spleen.

CONCLUSION

These results revealed that cerastes snake venom has potent anti-inflammatory and immunomodulatory effects and can be used in the management of arthritis.

Adjunctive therapy with lipid-lowering agents in COVID-19: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Many commonly used drugs were evaluated as repurposed treatment options since the emergence of the COVID-19 pandemic. The benefit of lipid-lowering agents has been controversial in this regard. In this systematic review, we assessed the effect of these medications as adjunctive therapy in COVID-19 by the inclusion of randomized controlled trials (RCTs).

METHODS

We searched four international databases including PubMed, the Web of Science, Scopus, and Embase for RCTs in April 2023. The primary outcome was mortality, while other efficacy indices were considered secondary outcomes. In order to estimate the pooled effect size of the outcomes, considering the odds ratio (OR) or standardized mean difference (SMD) and 95% confidence interval (CI), random-effect meta-analyses was conducted.

RESULTS

Ten studies involving 2,167 COVID-19 patients using statins, omega-3 fatty acids, fenofibrate, PCSK9 inhibitors, and nicotinamide as intervention compared to control or placebo, were included. No significant difference was found in terms of mortality (OR 0.96, 95% CI 0.58 to 1.59, p-value = 0.86, I² = 20.4%) or length of hospital stay (SMD -0.10, 95% CI -0.78 to 0.59, p-value = 0.78, I² = 92.4%) by adding a statin to the standard of care. The trend was similar for fenofibrate and nicotinamide. PCSK9 inhibition, however, led to decreased mortality and an overall better prognosis. Omega-3 supplementation showed contradicting results in two trials, suggesting the need for further evaluation.

CONCLUSION

Although some observational studies found improved outcomes in patients using lipid-lowering agents, our study found no benefit in adding statins, fenofibrate, or nicotinamide to COVID-19 treatment. On the other hand, PCSK9 inhibitors can be a good candidate for further assessment. Finally, there are major limitations in the use of omega-3 supplements in treating COVID-19 and more trials are warranted to evaluate this efficacy.

The effects of simvastatin and fenofibrate on malondialdehyde and reduced glutathione concentrations in the plasma, liver, and brain of normolipidaemic and hyperlipidaemic rats

The objective of study was to investigate the effects of different doses of simvastatin and fenofibrate on malondialdehyde (MDA) and reduced glutathione (GSH) in the plasma, liver, and brain tissue of male normolipidaemic and hyperlipidaemic rats. Normolipidaemic (Wistar) rats were receiving 10 or 50 mg/kg a day of simvastatin or 30 or 50 mg/kg a day of fenofibrate. Hyperlipidaemic (Zucker) rats were receiving 50 mg/kg/day of simvastatin or 30 mg/kg/day of fenofibrate. Control normolipidaemic and hyperlipidaemic rats were receiving saline. Simvastatin, fenofibrate, and saline were administered by gavage for three weeks. In normolipidaemic rats simvastatin and fenofibrate showed similar and dose-independent effects on plasma and brain MDA and GSH concentrations. Generally, plasma and brain MDA decreased, while brain GSH concentration increased. In hyperlipidaemic rats simvastatin did not affect plasma and brain MDA and GSH concentrations but significantly decreased liver GSH. Fenofibrate decreased plasma and liver MDA but increased brain MDA. In both rat strains fenofibrate significantly decreased liver GSH concentrations, most likely because fenofibrate metabolites bind to GSH. Our findings suggest that simvastatin acts as an antioxidant only in normolipidaemic rats, whereas fenofibrate acts as an antioxidant in both rat strains.

Resveratrol biotransformation and actions on the liver metabolism of healthy and arthritic rats

AIMS

To investigate the effects of resveratrol on glycogen catabolism and gluconeogenesis in perfused livers of healthy and arthritic rats. The actions of resveratrol-3-O-glucuronide (R3G) and the biotransformation of resveratrol into R3G was further evaluated in the livers.

MAIN METHODS

arthritis was induced with Freund's adjuvant. Resveratrol at concentrations of 10, 25, 50, 100 and 200 μM and 200 μM R3G were introduced in perfused livers. Resveratrol and metabolites were measured in the outflowing perfusate. Respiration of isolated mitochondria and activity of gluconeogenic enzymes were also evaluated in the livers.

KEY FINDINGS

resveratrol inhibited glycogen catabolism when infused at concentrations above 50 μM and gluconeogenesis even at 10 μM in both healthy and arthritic rat livers, but more sensitive in these latter. Resveratrol above 100 μM inhibited ADP-stimulated respiration and the activities of NADH- and succinate-oxidases in mitochondria, which were partially responsible for gluconeogenesis inhibition. Pyruvate carboxylase activity was inhibited by 25 μM resveratrol and should inhibit gluconeogenesis already at low concentrations. Resveratrol was significantly metabolized to R3G in healthy rat livers, however, R3G formation was lower in arthritic rat livers. The latter must be in part a consequence of a lower glucose disposal for glucuronidation. When compared to resveratrol, R3G inhibited gluconeogenesis in a lower extension and glycogen catabolism in a higher extension.

SIGNIFICANCE

the effects of resveratrol and R3G tended to be transitory and existed only when the resveratrol is present in the organ, however, they should be considered because significant serum concentrations of both are found after oral ingestion of resveratrol.

AMPK/SIRT1 Deficiency Drives Adjuvant-Induced Arthritis in Rats by Promoting Glycolysis-Mediated Monocytes Inflammatory Polarization

Background

Exact roles of many metabolic regulators in rheumatoid arthritis (RA) are to be clarified. This study aimed to further characterize the impacts of silent information regulator 1 (SIRT1) status changes on this disease.

Methods

Fluctuation pattern of SIRT1 expression in adjuvant-induced arthritis (AIA) rats was monitored using periodically collected white blood cells. Another bath of AIA rats were treated by SIRT1 agonist resveratrol. Blood from these rats was used to separate monocytes and plasma, which were subjected to polymerase chain reaction (PCR), enzyme linked immunosorbent assay (ELISA), and biochemical analyses. Clinical implication of SIRT1 activation was verified by treating AIA rat monocytes with SIRT1 agonist and overexpression vector in vitro.

Results

SIRT1 deficiency occurred in AIA rats, which was accompanied with down-regulation of interleukin 10 (IL-10) and arginase-1 (ARG-1). Resveratrol eased oxidative stress and increased IL-10 production in vivo. Results of ELISA analysis demonstrated that resveratrol attenuated AIA severity in rats. Furthermore, it restored the altered levels of triglyceride, lactate and pyruvate in blood. Resveratrol promoted IL-10 production, and suppressed glycolysis of AIA monocytes cultured in vitro. SIRT1 overexpression similarly reshaped differentiation profile of AIA monocytes, evidenced by changes in metabolism indicators, IL-10 production and AMP-activated protein kinase (AMPK) pathway status. Although overexpressing SIRT1 in normal cells did not affect glycolysis significantly, it attenuated AMPK antagonist-caused abnormality.

Conclusion

SIRT1 deficiency is implicated in AIA-related immune abnormality and metabolism alteration. Activating this signaling with resveratrol would impair the inflammatory polarization of monocytes, and consequently ease the severity of RA.

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.

Fenofibrate for COVID-19 and related complications as an approach to improve treatment outcomes: the missed key for Holy Grail

Introduction

Fenofibrate is an agonist of peroxisome proliferator activated receptor alpha (PPAR-α), that possesses anti-inflammatory, antioxidant, and anti-thrombotic properties. Fenofibrate is effective against a variety of viral infections and different inflammatory disorders. Therefore, the aim of critical review was to overview the potential role of fenofibrate in the pathogenesis of SARS-CoV-2 and related complications.

Results

By destabilizing SARS-CoV-2 spike protein and preventing it from binding angiotensin-converting enzyme 2 (ACE2), a receptor for SARS-CoV-2 entry, fenofibrate can reduce SARS-CoV-2 entry in human cells Fenofibrate also suppresses inflammatory signaling pathways, which decreases SARS-CoV-2 infection-related inflammatory alterations. In conclusion, fenofibrate anti-inflammatory, antioxidant, and antithrombotic capabilities may help to minimize the inflammatory and thrombotic consequences associated with SARSCoV-2 infection. Through attenuating the interaction between SARS-CoV-2 and ACE2, fenofibrate can directly reduce the risk of SARS-CoV-2 infection.

Conclusions

As a result, fenofibrate could be a potential treatment approach for COVID-19 control.

Leurieus quinquestriatus scorpion venom ameliorates adjuvant-induced arthritis in rats: Modulating JAK/STAT/RANKL signal transduction pathway

Leurieus quinquestriatus (LQ) is a type of Egyptian scorpions. Prior studies have established the potential use of scorpion venoms in treating several autoimmune diseases. Therefore, the current study investigates the possible pharmacological effect of LQ venom in CFA-induced arthritis - through different mechanisms - by assessing different serum and tissue parameters. This study was divided into two phases: phase I was conducted to determine the lowest therapeutic dose of LQ scorpion venom, whereas phase II investigated the potential therapeutic effect of the chosen dose of LQ venom on induced arthritis through different mechanisms. The Wistar albino rats were divided equally and randomly into normal control group, LQ control group, arthritis control group, infliximab-treated group, and LQ-treated group. On day 20, blood and tissue samples were collected for further analysis of serum and tissue biomarkers as well as histopathological examination. The results revealed a potential therapeutic effect of LQ venom on arthritic-induced rats through a significant decrease in Rheumatoid Factor, Janus Kinase, Signal transducers and activators of transcription, Receptor activator of nuclear factor Kappa-B ligand, Tumor Necrosis Factor-alpha, Interleukin-6, Nuclear factor kappa-light-chain-enhancer of activated B cells and Malondialdehyde by 57%, 66%, 64%, 62%, 75%, 59%, 38%, and 69%, respectively as well as a significant increase in reduced glutathione, and Nuclear factor erythroid 2-related factor 2 by 102% and 360%, respectively. Histopathological examination of knee joint and spleen also revealed a substantial improvement, indicating the possible utilization of LQ venom in the treatment of rheumatoid arthritis.

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.

The pharmacological assessment of resveratrol on preclinical models of rheumatoid arthritis through a systematic review and meta-analysis

Resveratrol/RES (3,5,4'-trihydroxy-trans-stilbene) is a natural compound found in many food items and red wine, which exhibits pleiotropic biological effects. Several preclinical studies evaluating the efficacy of RES in animal models of rheumatoid arthritis (RA) have been conducted, but the diversity of the experimental conditions and of their outcomes preclude definitive conclusions about RES's efficacy. We, therefore, performed a meta-analysis to assess its efficacy in mitigating experimental RA. We searched three databases until January 2021 and used the random-effects model for drawing inferences. Eighteen studies involving 544 animals were used in this study. Pooled analysis showed that experimental RA causes paw swelling (Hedge's g = 9.823, p = 0.000), increases polyarthritis score and arthritis index, and RES administration reduces paw volume (Hedge's g = -2.550, p = 0.000), polyarthritis score, and arthritis index besides amelioration in the histopathological score and cartilage loss. RA is accompanied by increased oxidative stress due to high malondialdehyde (MDA) level (p < 0.001) and low superoxide dismutase (SOD) activity (p = 0.002), and RES reduced MDA level (p < 0.001) and increased SOD activity (p < 0.001). Experimental RA exhibited an increase in pro-inflammatory cytokines viz. tumor necrosis factor (TNF)-α (p < 0.001), interleukin (IL)-6 (p = 0.002), and IL-1 (p < 0.001); however, insufficient quantitative data precluded us from assessing changes in the anti-inflammatory cytokine, IL-10. In experimental RA, RES decreased TNF-α (p < 0.001), IL-6 (p < 0.001) and IL-1 (p = 0.001) and increased IL-10. This meta-analysis suggests that RES can be a clinically effective therapy for RA, pending clinical trials.

Pharmacological support to anti-arthritic prospective of physostigmine: a new approach

Rheumatoid arthritis (RA) is a slowly progressing inflammatory autoimmune disease. Several features are involved in the RA pathogenesis in addition to environmental and genetic factors. Previously it has been reported that acetyl cholinesterase (AChE) activity is enhanced in old age and may contribute in the progression of RA. The current experimental work was projected to assess the activity of physostigmine (a cholinesterase inhibitor) for treatment of RA. In vitro and in vivo approaches were used for such evaluation. However, enzyme linked immunosorbent assays (ELISA) was performed to determine the concentrations of Prostaglandins E2 (PGE2) and tumor necrosis factor-α in arthritic rats after treatment with physostigmine. Moreover, anti-oxidant assays were employed to calculate the level of super oxide dismutase (SOD) and catalase peroxidase (CAT) in tissue of treated animals. The results claimed the dose dependent protective and stabilizing effect of physostigmine on denaturation of albumin (egg and bovine serum) protein and human red blood cell membrane, respectively, through in vitro studies. Furthermore, the physostigmine (10 and 20 mg/kg) significantly (p < 0.001) reduced the swelling of paw after induction of arthritis with formaldehyde or complete Freund's adjuvant (CFA) as compared to arthritic control animals. Moreover, significant (p < 0.001) reduction in the levels of inflammatory markers (PGE2 and TNF-α) at doses of 10 and 20 mg/kg of physostigmine has been observed in ELISA test. Likewise, there was a prominent rise in levels of SOD and CAT in animals treated with physostigmine. These findings pharmacologically conclude the anti-arthritic effect of physostigmine.

Phytochemical and In-Vivo Anti-Arthritic Significance of Aloe thraskii Baker in Combined Therapy with Methotrexate in Adjuvant-Induced Arthritis in Rats

Unlike other widely known Aloe species used for treatment of rheumatoid arthritis, this species suffers from a lack of sufficient studies on its biological and chemical characters. This is what drove us to perform this work to evaluate the in vivo anti-arthritic potential of its leaf ethanolic extract. The in vivo anti-arthritic activity of the leaf ethanolic extract at 100 and 200 mg/kg/day b.wt. was evaluated alone and in combination with methotrexate (MTX) using complete Freund's adjuvant. Serum levels of rheumatoid factor, anti-cyclic citrullinated peptide (anti-CCP), cytokines pro-inflammatory marker, inflammatory mediator serum levels, and oxidative stress mediators were analyzed, in addition to liver function. Orientin, isoorientin, β-sitosterol, its palmitate and its glucoside were isolated. The combined therapy of MTX and the leaf ethanolic extract (especially at 200 mg/kg b.wt.) group showed better activity compared to MTX alone. Moreover, the combined therapy provided additional benefits in lowering the liver toxicity by comparison to MTX alone. We concluded that a synergetic combination of the leaf ethanolic extract and MTX is beneficial in the management of rheumatoid arthritis with fewer side effects on liver function, as well as the possibility of the leaf extract to stand alone as an effective natural anti-arthritic agent.

Exploring the role of polyphenols in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, inflammatory and autoimmune disorder which is mainly characterized by inflammation in joints, bone erosions and cartilaginous destruction that leads to joint dysfunction, deformation, and/or permanent functional impairment. The prevalence of RA is increasing, incurring a considerable burden on healthcare systems globally. The exact etiology of RA is unknown, with various pathways implicated in its pathophysiology. Non-steroidal anti-inflammatory drugs (NSAIDs) including celecoxib, diclofenac and ibuprofen, disease-modifying anti-rheumatic drugs (DMARD) including azathioprine, methotrexate and cyclosporine, biological agents including anakinra, infliximab, and rituximab and immunosuppressants are used for symptomatic relief in patients with RA, but these medications have severe adverse effects such as gastric ulcers, hypertension, hepatotoxicity and renal abnormalities which restrict their use in the treatment of RA; new RA treatments with minimal side-effects are urgently required. There is accumulating evidence that dietary polyphenols may show therapeutic efficacy in RA through their antioxidant, anti-inflammatory, apoptotic, and immunosuppressant activities and modulation of the tumor necrosis factor-α (TNF-α), interleukin (IL)-6, mitogen-activated protein kinase (MAPK), IL-1β, c-Jun N-terminal kinase (JNK), and nuclear factor κ light-chain-enhancer of activated B cell (NF-κB) pathways. While resveratrol, genistein, carnosol, epigallocatechin gallate, curcumin, kaempferol, and hydroxytyrosol have also been studied for the treatment of RA, the majority of data are derived from animal models. Here, we review the various pathways involved in the development of RA and the preclinical and clinical data supporting polyphenols as potential therapeutic agents in RA patients. Our review highlights that high-quality clinical studies are required to decisively establish the anti-rheumatic efficacy of polyphenolic compounds.

Phytochemicals as Anti-Inflammatory Agents in Animal Models of Prevalent Inflammatory Diseases

Phytochemicals are known to have anti-inflammatory effects in vitro and in vivo, such as in inflammatory disease model systems. Inflammation is an essential immune response to exogenous stimuli such as infection and injury. Although inflammation is a necessary host-defense mechanism, chronic inflammation is associated with the continuous local or systemic release of inflammatory mediators, non-cytokine mediators, such as ROS and NO, and inflammatory cytokines are strongly implicated in the pathogenesis of various inflammatory disorders. Phytochemicals that exhibit anti-inflammatory mechanisms that reduce sustained inflammation could be therapeutic candidates for various inflammatory diseases. These phytochemicals act by modulating several main inflammatory signaling pathways, including NF-κB, MAPKs, STAT, and Nrf-2 signaling. Here, we discuss the characteristics of phytochemicals that possess anti-inflammatory activities in various chronic inflammatory diseases and review the molecular signaling pathways altered by these anti-inflammatory phytochemicals, with a focus on transcription factor pathways. Furthermore, to evaluate the phytochemicals as drug candidates, we translate the effective doses of phytochemicals in mice or rat disease models into the human-relevant equivalent and compare the human-relevant equivalent doses of several phytochemicals with current anti-inflammatory drugs doses used in different types of chronic inflammatory diseases.

The Basal Pharmacology of Palmitoylethanolamide

Palmitoylethanolamide (PEA, N-hexadecanoylethanolamide) is an endogenous compound belonging to the family of N-acylethanolamines. PEA has anti-inflammatory and analgesic properties and is very well tolerated in humans. In the present article, the basal pharmacology of PEA is reviewed. In terms of its pharmacokinetic properties, most work has been undertaken upon designing formulations for its absorption and upon characterising the enzymes involved in its metabolism, but little is known about its bioavailability, tissue distribution, and excretion pathways. PEA exerts most of its biological effects in the body secondary to the activation of peroxisome proliferator-activated receptor-α (PPAR-α), but PPAR-α-independent pathways involving other receptors (Transient Receptor Potential Vanilloid 1 (TRPV1), GPR55) have also been identified. Given the potential clinical utility of PEA, not least for the treatment of pain where there is a clear need for new well-tolerated drugs, we conclude that the gaps in our knowledge, in particular those relating to the pharmacokinetic properties of the compound, need to be filled.

Effects of Intra-Articular Resveratrol Injections on Cartilage Destruction and Synovial Inflammation in Experimental Temporomandibular Joint Osteoarthritis

PURPOSE

The aim of this study was to investigate the effects of intra-articular resveratrol injections on cartilage destruction and synovial inflammation in an experimental temporomandibular joint osteoarthritis (TMJ-OA) model.

MATERIALS AND METHODS

Freund's complete adjuvant injection method was used to construct the TMJ-OA model. Twenty-eight male Wistar rats were randomly placed into 4 groups: control (n = 4), TMJ arthritis (n = 8), low-dose intra-articular resveratrol (RES[L]; n = 8), and high-dose intra-articular resveratrol (RES[H]; n = 8). Intra-articular injections of resveratrol were performed 3 times at 1-week intervals, 1 week after the administration of a single dose of Freund's complete adjuvant to the TMJ. The effects of resveratrol on cartilage destruction and synovial inflammation were examined histopathologically. The histomorphometric examination revealed condylar cartilage and articular disc thickness. An apoptotic chondrocyte count was performed with terminal deoxynucleotidyl transferase dUTP nick end labeling staining, and matrix metalloproteinase 13 expression was evaluated through an immunohistochemical examination.

RESULTS

The thickness of the condylar cartilage in the RES(L) and RES(H) groups was statistically significantly greater than that in the control and TMJ arthritis groups (P < .05). The inflammation-induced articular disc thickening was significantly lower in the RES(L) and RES(H) groups (P < .05). The chondrocyte apoptosis in the RES(L) and RES(H) groups was significantly lower than that in the TMJ arthritis group (P < .05). The matrix metalloproteinase 13 expression in the RES(L) and RES(H) groups was obviously less than that in the TMJ arthritis group (P < .05).

CONCLUSIONS

The intra-articular resveratrol treatment exerted a curative effect by preventing the inflammation and cartilage destruction associated with TMJ-OA.

Wogonin ameliorate complete Freund's adjuvant induced rheumatoid arthritis via targeting NF-κB/MAPK signaling pathway

Rheumatoid arthritis (RA) is a chronic and accelerated autoimmune illness with proliferative and damaging synovitis, resulting in joint death and cartilage and bone erosion. This study focused on the potential therapeutic effect of wogonin on complete Freund's adjuvant (CFA) induced RA in rats and the underlying mechanisms. Arthritis was experimentally caused in rats by subcutaneously injecting 0.1 mL of CFA into the subplantar area of the left hind paw under moderate anesthesia on day zero. The regular oral doses of indomethacin/wogonin began on day zero and proceeded after injection to day 35. Wogonin reduced arthritic score considerably, enhanced body weight, and reduced paw thickness. Wogonin also boosted red blood cell considerably along with hemoglobin and reduced white blood cell count and erythrocyte sedimentation rate. Wogonin substantially improved an altered level of oxidative stress markers, antioxidant proteins, and inflammatory cytokines in a dose-dependent way. Wogonin inhibited p38 phosphorylation triggered by CFA and p65 nuclear translocation.

Anti-Inflammatory, Anti-Arthritic and Anti-Nociceptive Activities of Nigella sativa Oil in a Rat Model of Arthritis

This study investigated the preventive efficacy of the crude oil extracted from Nigella sativa seeds in a rat model of arthritis induced by using complete Freund’s adjuvant (CFA). Nigella sativa oil at 1.82 mL/kg or 0.91 mL/kg (corresponding to 1596 and 798 mg/kg, respectively) was orally administered for 25 days from the day of immunization. One immunized group was treated orally with indomethacin (3 mg/kg) as a reference drug. Body weight growth rate, paw swelling, arthritis score, mechanical allodynia, locomotor activity and anxiety-like behavior were observed, and the levels of Interleukin 6 (IL-6), C-reactive protein, albumin and total cholesterol in plasma were measured on days 15 and 25. Nigella sativa oil showed anti-inflammatory, anti-arthritic and anti-nociceptive activities that were significant as compared to untreated arthritic rats but less than indomethacin. These results indicated that Nigella sativa oil significantly attenuated adjuvant-arthritis in rats and the higher dose (1.82 mL/kg) prevented the development of arthritis with an inhibition of 56%.

Neuronal FcγRI mediates acute and chronic joint pain

Although joint pain in rheumatoid arthritis (RA) is conventionally thought to result from inflammation, arthritis pain and joint inflammation are at least partially uncoupled. This suggests that additional pain mechanisms in RA remain to be explored. Here we show that FcγRI, an immune receptor for IgG immune complex (IgG-IC), is expressed in a subpopulation of joint sensory neurons and that, under naïve conditions, FcγRI crosslinking by IgG-IC directly activates the somata and peripheral terminals of these neurons to evoke acute joint hypernociception without obvious concurrent joint inflammation. These effects were diminished in both global and sensory neuron-specific Fcgr1 knockout mice. In murine models of inflammatory arthritis, FcγRI signaling was upregulated in joint sensory neurons. Acute blockade or global genetic deletion of Fcgr1 significantly attenuated arthritis pain and hyperactivity of joint sensory neurons without measurably altering joint inflammation. Conditional deletion of Fcgr1 in sensory neurons produced similar analgesic effects in these models. We therefore suggest that FcγRI expressed in sensory neurons contributes to arthritis pain independently of its functions in inflammatory cells. These findings expand our understanding of the immunosensory capabilities of sensory neurons and imply that neuronal FcγRI merits consideration as a target for treating RA pain.

Evaluation of the antirheumatic effects of isoflavone-free soy protein isolate and etanercept in rats with adjuvant-induced arthritis

IMPACT STATEMENT

In view of the partial clinical benefit and significant toxicity of traditional rheumatoid arthritis (RA) treatments, there is a growing trend to use complementary therapy. The antiarthritic activity of soy is related to the effect of soy isoflavones. However, little is known about the antiarthritic activity of soy protein itself. This study demonstrates that soy protein isolate (SPI) and etanercept (ETN), a tumor necrosis factor-α (TNF-α) inhibitor, protect rats against the effects of adjuvant-induced arthritis (AIA) by reducing inflammation (TNF-α and matrix metalloproteinase-3), autoantibody production (anticyclic citrullinated peptide), and lipid peroxidation (malondialdehyde). Only SPI improved dyslipidemia accompanied by RA, giving it the advantage of reducing cardiovascular risk. Additionally, the severity of arthritis-induced pathology, including inflammatory infiltrates, synovial hyperplasia, pannus formation, synovial vascularity, and cartilage erosions, was reduced by both SPI and ETN. This research ascertains the possible antiarthritic effect of SPI, making it a recommended alternative therapy for RA.

Could Polyphenols Help in the Control of Rheumatoid Arthritis?

Rheumatoid arthritis (RA) is a chronic, systemic, joint-invading, autoimmune inflammatory disease, which causes joint cartilage breakdown and bone damage, resulting in functional impairment and deformation of the joints. The percentage of RA patients has been rising and RA represents a substantial burden for patients around the world. Despite the development of many RA therapies, because of the side effects and low effectiveness of conventional drugs, patients still need and researchers are seeking new therapeutic alternatives. Polyphenols extracted from natural products are effective on several inflammatory diseases, including RA. In this review polyphenols are classified into four types: flavonoids, phenolic acids, stilbenes and others, among which mainly flavonoids are discussed. Researchers have reported that anti-RA efficacies of polyphenols are based mainly on three mechanisms: their anti-inflammatory, antioxidant and apoptotic properties. The main RA factors modified by polyphenols are mitogen-activated protein kinase (MAPK), interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), nuclear factor κ light chain enhancer of activated B cells (NF-κB) and c-Jun N-terminal kinases (JNK). Polyphenols could be potent alternative RA therapies and sources for novel drugs for RA by affecting its key mechanisms.

Systemic treatment with resveratrol alleviates adjuvant arthritis-interstitial lung disease in rats via modulation of JAK/STAT/RANKL signaling pathway

Interstitial lung disease (ILD) is the most common pulmonary manifestation of Rheumatoid arthritis (RA) lung disease. The mechanism of RA-ILD remains obscure and more effective treatments are still needed. Resveratrol (RSV) a phytoalexin found with anti-inflammation and antioxidant activity. RSV has been reported to protect against RA. In current study, we evaluated the effects of RSV on RA-ILD and further explored the underlying mechanisms. We established the RA-ILD rat model by injecting Freund's complete adjuvant (FCA). After administration of RSV into RA-ILD rats, the disease parameters were assessed, inflammatory cytokines productions were analyzed, and the effects of RSV on JAK/STAT/RANKL were evaluated. Injection of FCA caused RA-ILD in rats, which had clear lung damage, fibrosis, and elevated pro-inflammatory cytokines in both serum and lung. RSV treatment significantly ameliorated the lung disease and prevented pro-inflammatory cytokines production. In addition, RSV inhibited JAK/STAT/RANKL signaling pathway in RA-ILD rats. RSV treatment alleviates RA-ILD in rats by inhibiting JAK/STAT/RANKL signaling pathway.

Resveratrol inhibits Src tyrosine kinase, STAT3, and Wnt signaling pathway in collagen induced arthritis model

Resveratrol, a phytochemical, acts several cellular signaling pathways and has anti-inflammatory potentials. The purpose of this study is to research the therapeutic effect of resveratrol in collagen-induced arthritis (CIA) model in rats and whether resveratrol affects the activities of signaling pathways those are potent pathogenic actors of rheumatoid arthritis. Arthritis was induced by intradermal injection of chicken type II collagen combined with incomplete Freund's adjuvant in Wistar albino rats. One day after the onset of arthritis (day 14), resveratrol (20 mg/kg/day) was given via oral gavage, until day 29. The paws of the rats were obtained for further analysis. Tissue Wnt5a, mitogen-activated protein kinase (MAPK), Src tyrosine kinase and signal transducer, and activator of transcription-3 (STAT3) mRNA expressions were determined by real-time polymerase chain reaction. Resveratrol ameliorated the clinical and histopathological (perisynovial inflammation and cartilage-bone destruction) findings of inflammatory arthritis. The tissue mRNA expressions of Wnt5a, MAPK3, Src kinase, and STAT3 were increased in the sham group compared to the control group. Resveratrol supplement decreased their expressions. The present study shows that Src kinase, STAT3, and Wnt signaling pathway are active in the CIA model. Resveratrol inhibits these signaling pathways and ameliorates inflammatory arthritis. © 2018 BioFactors, 45(1):69-74, 2019.

Cancer Stem Cells: Emergent Nature of Tumor Emergency

A functional analysis of 167 genes overexpressed in Krebs-2 tumor initiating cells was performed. In the first part of the study, the genes were analyzed for their belonging to one or more of the three groups, which represent the three major phenotypic manifestation of malignancy of cancer cells, namely (1) proliferative self-sufficiency, (2) invasive growth and metastasis, and (3) multiple drug resistance. 96 genes out of 167 were identified as possible contributors to at least one of these fundamental properties. It was also found that substantial part of these genes are also known as genes responsible for formation and/or maintenance of the stemness of normal pluri-/multipotent stem cells. These results suggest that the malignancy is simply the ability to maintain the stem cell specific genes expression profile, and, as a consequence, the stemness itself regardless of the controlling effect of stem niches. In the second part of the study, three stress factors combined into the single concept of "generalized cellular stress," which are assumed to activate the expression of these genes, were defined. In addition, possible mechanisms for such activation were identified. The data obtained suggest the existence of a mechanism for the de novo formation of a pluripotent/stem phenotype in the subpopulation of "committed" tumor cells.

Systemic treatment with resveratrol reduces the progression of experimental periodontitis and arthritis in rats

Rheumatoid arthritis and periodontitis are chronic inflammatory diseases which has been closely associated due to the nature of immune-inflammatory imbalance response. Resveratrol is a naturall product with biological proprieties that may promote immunomodulatory effects on host response. This study investigated resveratrol continuous administration effect on experimental periodontitis and arthritis progression in rats. Thirty-five rats were assigned to the following groups: 1-experimental arthritis + experimental periodontitis + placebo (RA+EP +PL) (n = 12); 2 -RA+EP+ ibuprofen (RA+PE+IB) (n = 11); 3-RA+EP+ resveratrol (RA+PE+RSV) (n = 11). After euthanasia, the specimens were processed for morphometric analysis of bone loss, and the gingival tissue surrounding the first molar was collected for quantification of inflammatory markers using a Luminex/MAGpix assay and anti-citrullinated protein antibody (ACCPA) levels were measured by ELISA assay. Serum level of rheumatoid factor (RF) was measured by ELISA assay. Paw edema was analyzed using a plethysmometer. Higher bone loss was observed in PL group, when compared to IB and RSV groups. RSV group presented higher IL-4 concentration than PL and IB groups. Resveratrol reduced RF serum levels and both IB and RSV decreased ACCPA gingival levels. Besides, paw swelling level was significantly lower in IB and RSV groups in the 21th day and only in RSV group in the 28th day. Histological analyzes showed smooth articular surface and higher width of the subchondral cortical in RSV group. Resveratrol showed modulatory effect and seems to reduce the inflammatory signs of arthritis and articular damage throughout the time.

Resveratrol prevents atrial fibrillation by inhibiting atrial structural and metabolic remodeling in collagen-induced arthritis rats

Rheumatoid arthritis (RA) causes atrial remodeling that induces the occurrence and maintenance of atrial fibrillation (AF). In this study, we explored the influence of RA on atrial fibrillation and the potential therapeutic effects of resveratrol in a rat model. The following three groups of female Wistar rats (8 weeks old) were used in this study: control, collagen-induced arthritis (CIA), and resveratrol. Rats in the CIA and resveratrol groups were injected twice with type II collagen in Freund's incomplete adjuvant. Three weeks after the second injection, resveratrol (10 mg kg^-1 day^-1) was administered for 4 weeks. Subsequently, atrial electrophysiological parameters were measured. Levels of inflammatory factors in the atria and serum were measured. Atrial histopathological changes were assessed using microscopy, and cardiomyocyte apoptosis and fibrosis were assessed using TUNEL and Masson's staining. Apoptosis-related and fibrosis-related proteins were assessed using Western blotting. Atrial adenosine triphosphate (ATP) and free fatty acid (FFA) levels were tested using ELISA. Glycogen accumulation and metabolism-related protein expression were assessed. AF inducibility and duration were markedly increased in CIA rats and were reduced by resveratrol. CIA also increased the atrial and serum IL-6 and TNF-a levels and induced atrial apoptosis and fibrosis, which were attenuated by resveratrol. Moreover, CIA induced the impairment of atrial energy metabolism by inhibiting the AMPK/PGC-1α pathway, which was reversed by resveratrol. Resveratrol protects against RA-induced atrial structural and metabolic remodeling, which may provide a new potential therapeutic treatment for RA-related AF.

A comprehensive review of the health perspectives of resveratrol

Many natural products present in our diet, including flavonoids, can prevent the progression of cancer and other diseases. Resveratrol, a natural polyphenol present in various fruits and vegetables, plays an important role as a therapeutic and chemopreventive agent used in the treatment of various illnesses. It exhibits effects against different types of cancer through different pathways. It additionally exerts antidiabetic, anti-inflammatory, and anti-oxidant effects in a variety of cell types. Furthermore, the cardiovascular protective capacities of resveratrol are associated with multiple molecular targets and may lead to the development of novel therapeutic strategies for atherosclerosis, ischemia/reperfusion, metabolic syndrome, and heart failure. Accordingly, this article presents an overview of recent developments in the use of resveratrol for the prevention and treatment of different diseases along with various mechanisms. In addition, the present review summarizes the most recent literature pertaining to resveratrol as a chemotherapeutic agent against multiple diseases and provides an assessment of the potential of this natural compound as a complementary or alternative medicine.

Anti-inflammatory effects of polyphenols in arthritis

Polyphenols have been extensively investigated with regard to their antioxidant, anti-inflammatory, and immunomodulant properties in many inflammatory chronic conditions. The aim of this review is to summarise how these compounds can modulate the inflammatory pathways which characterise the most prevalent arthropathies including osteoarthritis, rheumatoid arthritis and crystal-induced arthritis. Among polyphenols, epigallocatechin gallate, carnosol, hydroxytyrosol, curcumin, resveratrol, kaempferol and genistein have been the most widely investigated in arthritis. The most important results of the studies outlined in this article show how polyphenolic compounds are able to inhibit the expression and the release of a number of pro-inflammatory mediators and proteolytic enzymes, the activity of different transcriptional factors and the production of reactive oxygen species in vitro. Studies on animal models of rheumatoid arthritis, osteoarthritis and gout show interesting results in terms of reduced tissue damage, restored cartilage homeostasis, and decreased levels of uric acid, respectively. Despite the multiple protective effects of polyphenols, there are no dietary recommendations for patients affected by rheumatic diseases. Future studies, including intervention trials, should be conducted to determine the relevance of polyphenols consumption or supplementation in arthritis. © 2017 Society of Chemical Industry.

Nicorandil and theophylline can protect experimental rats against complete Freund's adjuvant-induced rheumatoid arthritis through modulation of JAK/STAT/RANKL signaling pathway

Signaling pathways are interesting fields of study of pathogenesis and treatment trials. We elucidated the possible protective effects of nicorandil (15mg/kg/day) and theophylline (20mg/kg/day) on experimentally-induced RA, focusing on the role of JAK (Janus Kinase) / STAT (Signal Transducer and Activator of Transcription) / RANKL (Receptor Activator of Nuclear factor-Kappa B Ligand) / cytokine signaling pathway. Four sets of experiments were performed. First, effect of test agents on normal animals was evaluated. Second, effect of test agents was evaluated on Complete Freund's Adjuvant (CFA; 0.3ml, s.c.)-induced RA to investigate anti-arthritic effect. Third, effect of test agents was evaluated on growth hormone (GH; 2mg/kg/day, s.c.)-induced stimulation of JAK/STAT/RANKL/cytokine signaling pathway to investigate the role of this signaling pathway in their anti-arthritic effect. Fourth, the effect of test agents was performed on CFA/GH-induced RA. To fulfill this purpose, serum anti-citrullinated peptide antibody (ACPA), interleukin-6 (IL-6), and cartilage oligomeric matrix protein (COMP), together with tissue JAK2, STAT3, RANKL, inducible and endothelial nitric oxide synthases (iNOS and eNOS) as well as macrophage inflammatory protein (MIP_1α) were estimated using ELISA, Western blotting and PCR techniques, confirmed by a histopathological study. Test agents significantly corrected JAK2, STAT3, RANKL and IL-6 values in animals receiving GH. Additionally, test agents could correct ACPA, IL-6, COMP, JAK2, STAT3, RANKL, iNOS, eNOS and MIP_1α levels compared with the respective CFA or CFA/GH controls. These results conclude that nicorandil and theophylline have good anti-arthritic effects related to modulation of JAK/STAT/RANKL signaling pathway. Further clinical trials are claimed.

Resveratrol Role in Autoimmune Disease-A Mini-Review

Autoimmune diseases are still considered to be pressing concerns due the fact that they are leaders in death and disability causes worldwide. Resveratrol is a polyphenol derived from a variety of foods and beverages, including red grapes and red wine. Anti-inflammatory, antioxidant, and antiaging properties of resveratrol have been reported, and in some animal and human studies this compound reduced and ameliorated the progression of autoimmune diseases, such as rheumatoid arthritis, systemic lupus erythematosus, psoriasis, inflammatory bowel disease, and type 1 diabetes mellitus. Thus, this review aims to summarize and critically analyze the role of resveratrol in the modulation of several organ-specific or systemic autoimmune diseases.

Managing Rheumatoid Arthritis with Dietary Interventions

Self-help by means of dietary interventions can help in management of various disorders including rheumatoid arthritis (RA), a debilitating autoimmune disease. Dietary interventions necessitate a widespread appeal for both patients as well as clinicians due to factors including affordability, accessibility, and presence of scientific evidences that demonstrate substantial benefits in reducing disease symptoms such as pain, joint stiffness, swelling, tenderness and associated disability with disease progression. However, there is still an uncertainty among the community about the therapeutic benefits of dietary manipulations for RA. In the present review, we provide an account of different diets and their possible molecular mechanism of actions inducing observed therapeutic benefits for remission and management of RA. We further indicate food that can be a potential aggravating factor for the disease or may help in symptomatic relief. We thereafter summarize and thereby discuss various diets and food which help in reducing levels of inflammatory cytokines in RA patients that may play an effective role in management of RA following proper patient awareness. We thus would like to promote diet management as a tool that can both supplement and complement present treatment strategies for a better patient health and recovery.

Resveratrol (3,5,4'-trihydroxystilbene) and its properties in oral diseases

Health promotion strategies and lifestyle changes are important in disease prevention. Oral health has received a large amount of attention previously as it is a fundamental component of general health and it contributes to the quality of life. Therefore, the study of associations between diet, health and the presence of bioactive compounds in food is receiving a substantial amount of attention. In the present review the effects and targets of a natural polyohenolic stilbenoid compound; resveratrol (3,5,4'-trihydroxystilbene; RSV) is assessed, and the future prospects for RSV in promoting oral health are considered. RSV is a phytoalexin, synthesized by a wide range of plants and abundantly extracted in grape skin, it has been purported to exert a multiplicity of anti-inflammatory, anti-viral, anti-microbial, estrogenic, anticancer, cardioprotective, neuroprotective and immunomodulatory functions. In this review, following an introduction documenting the biochemistry of RSV and RSV glucosides, the bioavailability and pharmacokinetics of RSV are described. Considering its multiple properties, the present review has focused on the potential benefits of RSV as an antioxidant and chemopreventive agent.

Granisetron and carvedilol can protect experimental rats againstadjuvant-induced arthritis

CONTEXT

Rheumatoid arthritis (RA), a disabling autoimmune disorder of the joints as well as other organs, affects about 1% of population. Unfortunately, all current treatments of RA cause severe gastrointestinal, renal and other complications.

OBJECTIVE

We aimed to evaluate the possible antiarthritic effects of a serotonin 5-HT₃ receptor blocker, granisetron, and a nonselective adrenergic receptor blocker, carvedilol, on complete Freund's adjuvant-induced RA in adult female albino rats.

MATERIALS AND METHODS

Rats were allocated into a normal control group, an arthritis control group, two reference treatment groups receiving dexamethasone (1.5 mg/kg/day) and methotrexate (1 mg/kg/day), and two treatment groups receiving granisetron (2.5 mg/kg/day) and carvedilol (10 mg/kg/day). Serum-specific rheumatoid, immunological, inflammatory and oxidative stress biomarkers were assessed. A confirmatory histopathological study on joints and spleens was performed.

RESULTS

Granisetron administration significantly improved all the measured biomarkers, with the values of rheumatoid factor, matrix metalloproteinase-3, cartilage oligomeric matrix protein, immunoglobulin G, antinuclear antibody and myeloperoxidase being restored back to normal levels. Carvedilol administration significantly improved all biomarkers, with serum MPO value restored back to normal levels.

DISCUSSION AND CONCLUSIONS

Serotonin 5-HT₃ receptor blockers and adrenergic receptor blockers, represented by granisetron and carvedilol, may represent new promising protective strategies against RA, at least owing to immune-modulator, anti-inflammatory and antioxidant potentials.

Dietary Phytochemicals: Natural Swords Combating Inflammation and Oxidation-Mediated Degenerative Diseases

Cumulatively, degenerative disease is one of the most fatal groups of diseases, and it contributes to the mortality and poor quality of life in the world while increasing the economic burden of the sufferers. Oxidative stress and inflammation are the major pathogenic causes of degenerative diseases such as rheumatoid arthritis (RA), diabetes mellitus (DM), and cardiovascular disease (CVD). Although a number of synthetic medications are used to treat these diseases, none of the current regimens are completely safe. Phytochemicals (polyphenols, carotenoids, anthocyanins, alkaloids, glycosides, saponins, and terpenes) from natural products such as dietary fruits, vegetables, and spices are potential sources of alternative medications to attenuate the oxidative stress and inflammation associated with degenerative diseases. Based on in vitro, in vivo, and clinical trials, some of these active compounds have shown good promise for development into novel agents for treating RA, DM, and CVD by targeting oxidative stress and inflammation. In this review, phytochemicals from natural products with the potential of ameliorating degenerative disease involving the bone, metabolism, and the heart are described.