Resveratrol alleviates inflammatory injury and enhances the apoptosis of fibroblast‑like synoviocytes via mitochondrial dysfunction and ER stress in rats with adjuvant arthritis

Resveratrol Attenuates Rheumatoid Arthritis Induce Neutrophil Extracellular Traps via TLR-4 Mediated Inflammation in C57BL/6 Mice

The objective of this study was to evaluate whether RSV inhibits neutrophil extracellular traps (NETs) that induce joint hyperalgesia in C57BL/6 mice after adjuvant-induced arthritis. A subplantar injection of Freund's complete adjuvant was administered to C57BL/6 mice on day 0 for immunization in the AIA model. Resveratrol (RSV, 25 mg/kg) was administered intraperitoneally once daily starting on day 22 and continuing for two weeks. The effects of mechanical hyperalgesia and edema formation have been assessed in addition to histopathological scoring. Mice were sacrificed on day 35 to determine cytokine levels and PADI4 and COX-2 expression levels. ELISA was used to quantify neutrophil extracellular traps (NETs) along with neutrophil elastase-DNA and myeloperoxidase-DNA complexes in neutrophils. An immunohistochemical stain was performed on knee joints to determine the presence of nuclear factor kappa B p65 (NF-kappaB p65). AIA mice were found to have higher levels of NET in joints and their joint cells demonstrated an increased expression of the PADI4 gene. Treatment with RSV in AIA mice (25 mg/kg, i.p.) significantly (P<0.05) inhibited joint hyperalgesia, resulting in a significant increase in mechanical threshold, a decrease in articular edema, a decrease in the production of inflammatory cytokines, increased COX-2 expression, and a decrease in the immunostaining of NF-kappaB. Furthermore, treatment with RSV significantly reduced the amount of neutrophil elastase (NE)-DNA and MPO-DNA complexes, which were used as indicators of NET formation (P<0.05). This study indicates that RSV reduces NET production and hyperalgesia by reducing inflammation mediated by PADI4 and COX-2. According to these data, NETs contribute to joint pain and resveratrol can be used to treat pain in RA through this pathway.

Oridonin Promotes Apoptosis in Rheumatoid Arthritis Fibroblast-like Synoviocytes Through PERK/eIF2α/CHOP of Endoplasmic Reticulum Stress Pathway

Oridonin (ORI), derived from Chinese herbs Rabdosia rubescens, has anti-inflammatory, proapoptotic, anticancer effects. Previous studies have found that ORI induces apoptosis in rheumatoid arthritis fibroblast synovial cells (RA-FLSs), but this mechanism is not clear. We will investigate the apoptosis mechanism of ORI on RA-FLSs. RA-FLSs were treated with various concentrations of ORI (0, 5, 10, 15, 20, 25, and 30 μM) for 24 h. CCK8, LDH, and hochest/PI assay determined the viability, cytotoxicity, and death of ORI on RA-FLSs. The endoplasmic reticulum probe was used to observe structural changes of endoplasmic reticulum in RA-FLSs. RNA expression was detected with RNA sequencing analysis and quantitative real-time PCR. The PERK/eIF2α/CHOP pathway protein of the endoplasmic reticulum was verified with Western Blot. Our results show that ORI induced the apoptosis of RA-FLSs from CCK8, LDH, and Hochest/PI. The endoplasmic reticulum distribution was altered in RA-FLSs after being treated with ORI. Bioinformatics analysis of RNA sequencing data found that 1453 genes were elevated. The PERK/eIF2α/CHOP pathway of the endoplasmic reticulum was regulated from the Gene ontology and KEGG analysis. The results of quantitative real-time PCR and Western blot analysis verified the regulation of PERK/eIF2α/CHOP pathway in RA-FLSs. Our data imply that the endoplasmic reticulum's PERK/eIF2α/CHOP signaling pathway is certainly implicated in the induction of RA-FLS apoptosis by ORI. This study has important implications for the pharmacological effects of ORI and the treatment of RA.

Systemic complications of rheumatoid arthritis: Focus on pathogenesis and treatment

As a systemic autoimmune disease, rheumatoid arthritis (RA) usually causes damage not only to joints, but also to other tissues and organs including the heart, kidneys, lungs, digestive system, eyes, skin, and nervous system. Excessive complications are closely related to the prognosis of RA patients and even lead to increased mortality. This article summarizes the serious complications of RA, focusing on its incidence, pathogenesis, clinical features, and treatment methods, aiming to provide a reference for clinicians to better manage the complications of RA.

Natural medicines of targeted rheumatoid arthritis and its action mechanism

Rheumatoid arthritis (RA) is an autoimmune disease involving joints, with clinical manifestations of joint inflammation, bone damage and cartilage destruction, joint dysfunction and deformity, and extra-articular organ damage. As an important source of new drug molecules, natural medicines have many advantages, such as a wide range of biological effects and small toxic and side effects. They have become a hot spot for the vast number of researchers to study various diseases and develop therapeutic drugs. In recent years, the research of natural medicines in the treatment of RA has made remarkable achievements. These natural medicines mainly include flavonoids, polyphenols, alkaloids, glycosides and terpenes. Among them, resveratrol, icariin, epigallocatechin-3-gallate, ginsenoside, sinomenine, paeoniflorin, triptolide and paeoniflorin are star natural medicines for the treatment of RA. Its mechanism of treating RA mainly involves these aspects: anti-inflammation, anti-oxidation, immune regulation, pro-apoptosis, inhibition of angiogenesis, inhibition of osteoclastogenesis, inhibition of fibroblast-like synovial cell proliferation, migration and invasion. This review summarizes natural medicines with potential therapeutic effects on RA and briefly discusses their mechanisms of action against RA.

Resveratrol from Dietary Supplement to a Drug Candidate: An Assessment of Potential

Resveratrol (RVT) is a well known phyto-chemical and is widely used in dietary supplements and botanical products. It shows a wide range of pharmacological/beneficial effects. Therefore, it can be a potential candidate to be developed as phyto-pharmaceutical. Multiple diseases are reported to be treated by the therapeutic effect of RVT since it has antioxidant, anti-cancer activity and anti-inflammatory activities. It also has a major role in diabetes, arthritis, cardiac disorder and platelet aggregation etc. The major requirements are establishments regarding safety, efficacy profile and physicochemical characterization. As it is already being consumed in variable maximum daily dose, there should not be a major safety concern but the dose needs to be established for different indications. Clinical trials are also being reported in different parts of the world. Physicochemical properties of the moiety are also well reported. Moreover, due to its beneficial effect on health it leads to the development of some intellectual property in the form of patents.

Dietary polyphenols for management of rheumatoid arthritis: Pharmacotherapy and novel delivery systems

Rheumatoid arthritis (RA) is a chronic, complex, systemic autoimmune disease causing chronic inflammation, swelling, and pain. It affects pulmonary and ocular physiology, gastrointestinal disturbance, skeletal disorders, and renal malfunctioning. Although conventional and biological drugs available to treat RA are potent and effective, they lead to life-threatening side effects and patient discomfort. Hence, alternative therapies are explored for their treatment which is safe, effective, and economical. Herbal drugs are widely used as an alternative therapy and some medicinal plants, especially dietary polyphenols proved their efficacy in treating RA. Polyphenols are secondary metabolites of plants possessing several pharmacological actions. They exert 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. Thus, polyphenols could be a promising option for the management of RA. Unfortunately, polyphenols suffer from poor bioavailability due to their physicochemical properties and incorporation into novel delivery systems such as liposomes, nanoparticles, nanoemulsions, micelles improved their oral bioavailability. This review article summarizes dietary polyphenols, their pharmacological actions and novel delivery systems for the treatment of RA. Nevertheless, the commercial translation of polyphenols could be only possible after establishing their safety profile and successful clinical trials.

Resveratrol and endoplasmic reticulum stress: A review of the potential protective mechanisms of the polyphenol

The endoplasmic reticulum (ER) is an organelle that performs a set of essential functions in cellular biology. These include synthesis of lipids, homeostasis of calcium, and controlling the folding of proteins. Inflammation and oxidative stress are two important reasons behind the accumulation of misfolded or unfolded proteins in the ER. In such circumstances, a series of measures are undertaken in the cell which are collectively called unfolded protein response (UPR). The aim of UPR is to reduce the burden of protein aggregates and promote survival. However, extended and unrestricted ER stress (ERS) can induce further inflammation and apoptosis. ERS and the UPR are involved in different diseases such as neurodegenerative and cardiovascular diseases. Resveratrol (RSV), a natural polyphenol, has well-documented evidence supporting its numerous biological properties including antioxidant, antiinflammatory, antiobesity, antidiabetic, and antiischemic activities. The compound is also known for its potential beneficial effects on cognitive function and liver, kidney, and lung health. In this review, the role of ERS in several pathological conditions and the potential protective effects of RSV are discussed. However, the scarcity of clinical data means that more research needs to be conducted to gain a lucid understanding of RSV's effects on endoplasmic reticulum stress (ERS) in humans.

Resveratrol Improves Bnip3-Related Mitophagy and Attenuates High-Fat-Induced Endothelial Dysfunction

Statin treatment reduces cardiovascular risk. However, individuals with well-controlled low-density lipoprotein (LDL) levels may remain at increased risk owing to persistent high triglycerides and low high-density lipoprotein cholesterol. Because resveratrol promotes glucose metabolism and mitigates cardiovascular disorders, we explored its mechanism of protective action on high-fat-induced endothelial dysfunction. Human umbilical venous endothelial cells were treated with oxidized LDL (ox-LDL) in vitro. Endothelial function, cell survival, proliferation, migration, and oxidative stress were analyzed through western blots, quantitative polymerase chain reaction, ELISA, and immunofluorescence. ox-LDL induced endothelial cell apoptosis, proliferation arrest, and mobilization inhibition, all of which resveratrol reduced. ox-LDL suppressed the activities of mitochondrial respiration complex I and III and reduced levels of intracellular antioxidative enzymes, resulting in reactive oxygen species overproduction and mitochondrial dysfunction. Resveratrol treatment upregulated Bnip3-related mitophagy and prevented ox-LDL-mediated mitochondrial respiration complexes inactivation, sustaining mitochondrial membrane potential and favoring endothelial cell survival. We found that resveratrol enhanced Bnip3 transcription through hypoxia-inducible factor 1 (HIF1) and 5' AMP-activated protein kinase (AMPK). Inhibition of AMPK and HIF1 abolished resveratrol-mediated protection of mitochondrial redox balance and endothelial viability. Together, these data demonstrate resveratrol reduces hyperlipemia-related endothelial damage by preserving mitochondrial homeostasis.

Neuroprotective Fragment C of Tetanus Toxin Modulates IL-6 in an ALS Mouse Model

Neuroinflammation plays a significant role in amyotrophic lateral sclerosis (ALS) pathology, leading to the development of therapies targeting inflammation in recent years. Our group has studied the tetanus toxin C-terminal fragment (TTC) as a therapeutic molecule, showing neuroprotective properties in the SOD1G93A mouse model. However, it is unknown whether TTC could have some effect on inflammation. The objective of this study was to assess the effect of TTC on the regulation of inflammatory mediators to elucidate its potential role in modulating inflammation occurring in ALS. After TTC treatment in SOD1G93A mice, levels of eotaxin-1, interleukin (IL)-2, IL-6 and macrophage inflammatory protein (MIP)-1 alpha (α) and galectin-1 were analyzed by immunoassays in plasma samples, whilst protein expression of caspase-1, IL-1β, IL-6 and NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) was measured in the spinal cord, extensor digitorum longus (EDL) muscle and soleus (SOL) muscle. The results showed reduced levels of IL-6 in spinal cord, EDL and SOL in treated SOD1G93A mice. In addition, TTC showed a different role in the modulation of NLRP3 and caspase-1 depending on the tissue analyzed. In conclusion, our results suggest that TTC could have a potential anti-inflammatory effect by reducing IL-6 levels in tissues drastically affected by the disease. However, further research is needed to study more in depth the anti-inflammatory effect of TTC in ALS.

Apoptosis Induction of Fibroblast-Like Synoviocytes Is an Important Molecular-Mechanism for Herbal Medicine along with its Active Components in Treating Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a known chronic autoimmune disease can cause joint deformity and even loss of joint function. Fibroblast-like synoviocytes (FLS), one of the main cell types in synovial tissues of RA patients, are key effector cells in the development of RA and are considered as promising therapeutic targets for treating RA. Herbal medicines are precious resources for finding novel agents for treating various diseases including RA. It is reported that induction of apoptosis in FLS is an important mechanism for the herbal medicines to treat RA. Consequently, this paper reviewed the current available references on pro-apoptotic effects of herbal medicines on FLS and summarized the related possible signal pathways. Taken together, the main related signal pathways are concluded as death receptors mediated apoptotic pathway, mitochondrial dependent apoptotic pathway, NF-κB mediated apoptotic pathways, mitogen-activated protein kinase (MAPK) mediated apoptotic pathway, endoplasmic reticulum stress (ERS) mediated apoptotic pathway, PI3K-Akt mediated apoptotic pathway, and other reported pathways such as janus kinase/signal transducers and activators of transcription (JAK-STAT) signal pathway. Understanding the apoptosis induction pathways in FLS of these herbal medicines will not only help clear molecular mechanisms of herbal medicines for treating RA but also be beneficial for finding novel candidate therapeutic drugs from natural herbal medicines. Thus, we expect the present review will highlight the importance of herbal medicines and its components for treating RA via induction of apoptosis in FLS, and provide some directions for the future development of these mentioned herbal medicines as anti-RA drugs in clinical.