Novel Anti-arthritic Mechanisms of Polydatin in Complete Freund’s Adjuvant-Induced Arthritis in Rats: Involvement of IL-6, STAT-3, IL-17, and NF-кB

Protective effects of polydatin against bone and joint disorders: the in vitro and in vivo evidence so far

Polydatin is an active polyphenol displaying multifaceted benefits. Recently, growing studies have noticed its potential therapeutic effects on bone and joint disorders (BJDs). Therefore, this article reviews recent in vivo and in vitro progress on the protective role of polydatin against BJDs. An insight into the underlying mechanisms is also presented. It was found that polydatin could promote osteogenesis in vitro, and symptom improvements have been disclosed with animal models of osteoporosis, osteosarcoma, osteoarthritis and rheumatic arthritis. These beneficial effects obtained in laboratory could be mainly attributed to the bone metabolism-regulating, anti-inflammatory, antioxidative, apoptosis-regulating and autophagy-regulating functions of polydatin. However, studies on human subjects with BJDs that can lead to early identification of the clinical efficacy and adverse effects of polydatin have not been reported yet. Accordingly, this review serves as a starting point for pursuing clinical trials. Additionally, future emphasis should also be devoted to the low bioavailability and prompt metabolism nature of polydatin. In summary, well-designed clinical trials of polydatin in patients with BJD are in demand, and its pharmacokinetic nature must be taken into account.

The Effect of Resveratrol in Sirt1/CST Pathway to Inhibit TNF-α Induced Inflammatory Response in Rat Primary Fibroblast-Like Synoviocytes

Rheumatoid arthritis has a significant impact on the life quality, but current pharmacological therapies have limitations. As a result, there is growing interest in exploring the potential of natural plant components to intervene in the development of rheumatoid arthritis. Resveratrol, a natural polyphenol and one of the main active components of the Chinese herbal medicine Polygonum cuspidatum, has emerged as a promising candidate for this purpose. In the present study, we investigated the role and mechanism of resveratrol in inhibiting inflammatory response in rat primary fibroblast-like synoviocytes. Tumor necrosis factor (TNF)-α was used to establish a model of inflammation, the Sirtuin1 selective inhibitor Selisistat (EX527) was used to inhibit Sirtuin1 activity, and small interfering RNA was used to silence cortistatin expression. The results showed that pre-treatment with resveratrol could time- and dose-dependently inhibit TNF-α induced cellular interleukin (IL)-1β and IL-6 secretion, and upregulate Sirtuin1 and cortistatin mRNA and protein expression in the range of 48 h, 100 µM. Selisistat (EX527) could attenuate resveratrol inhibited inflammatory response and upregulated cortistatin expression. Silencing cortistatin expression attenuated the effect of resveratrol on inhibiting inflammatory response, but did not affect its effect on upregulating Sirtuin1 expression. In conclusion, resveratrol effectively inhibited the TNF-α induced inflammatory response in fibroblast-like synoviocytes by a mechanism involving the Sirtuin1/cortistatin pathway.

Polydatin: Pharmacological Mechanisms, Therapeutic Targets, Biological Activities, and Health Benefits

Polydatin is a natural potent stilbenoid polyphenol and a resveratrol derivative with improved bioavailability. Polydatin possesses potential biological activities predominantly through the modulation of pivotal signaling pathways involved in inflammation, oxidative stress, and apoptosis. Various imperative biological activities have been suggested for polydatin towards promising therapeutic effects, including anticancer, cardioprotective, anti-diabetic, gastroprotective, hepatoprotective, neuroprotective, anti-microbial, as well as health-promoting roles on the renal system, the respiratory system, rheumatoid diseases, the skeletal system, and women's health. In the present study, the therapeutic targets, biological activities, pharmacological mechanisms, and health benefits of polydatin are reviewed to provide new insights to researchers. The need to develop further clinical trials and novel delivery systems of polydatin is also considered to reveal new insights to researchers.

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.

Novel anti-arthritic mechanisms of trans-cinnamaldehyde against complete Freund's adjuvant-induced arthritis in mice: involvement of NF-кB/TNF-α and IL-6/IL-23/ IL-17 pathways in the immuno-inflammatory responses

Trans-cinnamaldehyde (TCA), a natural cinnamaldehyde derivative of cinnamon oil, is known for anti-inflammatory, anti-bacterial, anti-fungal, anti-diabetic, and anti-cancer activities. However, no study has examined the protective mechanisms of TCA on complete Freund's adjuvant (CFA)-induced arthritis. Chronic arthritis was induced in mice by triple dose injection of 0.1 ml CFA in the first two days, then a treatment with TCA (100 mg/kg, i.p.) and the anti-arthritic drug; methotrexate (MTX, 0.75 mg/kg, i.p., 3 times/week) started from day 10 after CFA and continued till day 35.TCA ameliorated the CFA-induced arthritis features, indicated by the decrease in serum rheumatoid factor, paw swelling, arthritis index and the arthritis changes in limb histology. Additionally, TCA treatment showed anti-inflammatory actions through downregulation of TNF-α, NF-κB and COX-2 expressions and marked reduction in IL-1β, IL-6, IL-23 and IL-17 levels in inflamed paw tissues.Consequently, TCA can decrease arthritis progression and inhibit the immune/inflammatory responses initiated by TNF-α/IL-1β/IL-6/IL-23/IL-17 signals, via NF-κB modulation, almost to the same extent accomplished by MTX. Therefore, TCA could be a promising anti-arthritic drug.

Artificial intelligence-assisted development of in situ forming nanoparticles for arthritis therapy via intra-articular delivery

Intra-articular (IA) injection is grasping much interest due to the poor drug bioavailability at the targeted site of action which minimizes the effect of the orally administered moiety. Based on the integral role of non-steroidal anti-inflammatory drugs (NSAIDs) in the treatment of Rheumatoid Arthritis (RA), much effort is exerted to develop novel localized drug delivery systems to increase their bioavailability and minimize their side effects. Artificial intelligence (AI) is acquiring an increasing role in the design of experiments being an effective tool for saving both time and resources. Hence, the aim of this work was to develop, characterize and optimize targeted in-situ forming nano particles (ISNs) for IA delivery of piroxicam using Design^® Expert as an AI-based application where a 3³ full factorial experimental design was adopted. Morphological investigation, injectability, rheological studies, Fourier Transform Infrared Radiation (FTIR) as well as biological, histopathological, and biochemical examinations were performed to evaluate the optimized-ISNs. The optimized formulation, exhibiting a nano-sized particle size with a dense core, showed significant improvement in the histopathological findings compared to both the oral solution and the placebo. Additionally, the once-a-week IA administration of the optimized-ISNs proved a significant reduction in the protein expression of both STAT-3 and RANKL and the levels of anti-CCP and MCP-1 by almost 54 and 73%, respectively, coupled with a marked decline in the content of IL-17, MMP-3, NF-κB and TNF-α as compared to the positive control. In conclusion, the use of ISNs for intra-articular injection has demonstrated their effectiveness in piroxicam delivery for RA treatment.

Polydatin combats methotrexate-induced pulmonary fibrosis in rats: Involvement of biochemical and histopathological assessment

Polydatin (PD) is a polyphenolic compound found naturally in many fruits such as grapes. It has anti-oxidant and anti-inflammatory activities that are of paramount importance for its pharmacological actions. This study aimed to explore possible protective effects of PD against methotrexate (MTX)-induced pulmonary fibrosis in rats. A single oral dose of MTX (14 mg/kg) per week for 2 weeks caused a significant decrease in glutathione (GSH) content with a marked increase in transforming growth factor-beta (TGF-β), alpha-smooth muscle actin (α-SMA), pulmonary content of malondialdehyde (MDA), interleukin-1β (IL-1β), Hydroxyproline, tumor necrosis factor-alpha (TNF-α), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) as compared with the control group. Contrarily, daily administration of PD (25, 50, and 100 mg/kg, p.o.) for 14 days concomitantly with MTX ameliorated MTX-induced pulmonary fibrosis as indicated by mitigation of the previously mentioned biochemical parameters and histopathological changes in a dose-dependent manner. In conclusion, the protective effect of PD against pulmonary fibrosis induced by MTX in rats might be attributed to its anti-oxidant, anti-inflammatory as well as anti-fibrotic effects.

Co-treatment of Nimbolide augmented the anti-arthritic effects of methotrexate while protecting against organ toxicities

Prolonged exposure to the pharmacological doses of disease-modifying anti-rheumatic drugs (DMARDs) often results in major organ toxicities resulting in poor patient compliance. Methotrexate (MTX) is one of the commonly prescribed DMARDs for the treatment of arthritis, which results in vital organ dysfunction. To retain the anti-arthritic activity of MTX with the reduction in toxicities, combination therapies are warranted. Nimbolide (NMB) is a potent anticancer, anti-inflammatory and anti-fibrotic agent whose potential has been demonstrated in various pre-clinical models. Monoarthritis was developed with Complete Freund's Adjuvant in the knees of Wistar rats and treatment was given with either NMB (3 mg/kg/day) or MTX (2 mg/kg/week) alone or combination therapy (NMB + MTX). The anti-arthritic effects were evaluated by arthritic scoring, radiological imaging, synovial tissue proteins analysis, and histopathological staining. While hepato-renal toxicity was assessed in serum by evaluating the kidney and liver functional parameters, in tissues by oxidative-nitrosative stress markers, and pro-inflammatory cytokines levels. Histopathological analysis was performed to study the extent of tissue damage. Molecular studies like immunoblotting and immunohistochemistry were performed to understand the effect of combination therapy. We thereby report that monotherapy with either NMB or MTX exhibited significant anti-arthritic effects, while combination therapy resulted in augmented anti-arthritic effects with significant reduction in hepato-renal toxicity produced by MTX probably through anti-inflammatory and anti-oxidant effects. Therefore, our proposed combination of NMB and MTX may serve as a potential strategy for the effective management of arthritis.

Old dog, new tricks: Polydatin as a multitarget agent for current diseases

Polydatin (PD) is a natural single-crystal product that is primarily extracted from the traditional plant Polygonum cuspidatum Sieb. et Zucc. Early research showed that PD exhibited a variety of biological activities. PD has attracted increasing research interest since 2014, but no review comprehensively summarized the new findings. A great gap between its biological activities and drug development remains. It is necessary to summarize new findings on the pharmacological effects of PD on current diseases. We propose that PD will most likely be used in cardiac and cerebral ischaemia/reperfusion-related diseases and atherosclerosis in the future. The present work classified these new findings according to diseases and summarized the main effects of PD via specific mechanisms of action. In summary, we found that PD played a therapeutic role in a variety of diseases, primarily via five mechanisms: antioxidative effects, antiinflammatory effects, regulation of autophagy and apoptosis, maintenance of mitochondrial function, and lipid regulation.

Anti-inflammatory activity of different isolated sites of Chloranthus serratus in complete Freund's adjuvant-induced arthritic rats

Chloranthus serratus is a traditional Chinese medicine for treating arthritis and bruises. The aim of the present study was to investigate the anti-arthritic activities and possible associated mechanisms of different isolated sites of Chloranthus serratus (DISC) in adjuvant-induced arthritis (AA) rats. The therapeutic effects of the extracts were assessed through changes in body weights, swelling rates, arthritis indexes (AI) and organ indexes. The levels of nitric oxide (NO), malondialdehyde and superoxide dismutase were determined using one-step method, TBA method and hydroxylamine method, respectively; the levels of TNF-α, IL-1β, IL-6, prostaglandin E2, macrophage inhibitor factor-1, VEGF, immunoglobulin (Ig) G, IgM and IFN-γ in serum were determined using ELISA. Pathological changes and positive expression of VEGF in the ankle joints were investigated using hematoxylin-eosin staining and immunohistochemical staining, respectively. DISC treatment increased the weight gains and thymus indexes, and decreased the swelling rates, spleen indexes and AI in AA rats. The water isolated site (WA) and ethyl acetate isolated site (EA) significantly reversed complete Freund's adjuvant (CFA)-induced changes in the levels of NO, IL-6, TNF-α, IgG and IFN-γ, while the n-butanol isolated site (NB) only reversed the changes in IL-6 and IgG contents. Some changes in the chloroform isolated site group showed the same trend as those in the model group. The extracts relieved synovial hyperplasia, inflammatory cell infiltration and articular surface defects, and reduced the positive expression rate of VEGF in the synovial tissues of the AA rats to varying degrees. The WA exhibited the most marked effects, followed by the EA and NB, indicating that WA had optimal therapeutic effects on CFA-induced arthritic rats, which may be mediated by the oxidative stress and inhibition of inflammatory factors. C. serratus may serve as a potential candidate for the treatment of rheumatoid arthritis.

β-Sitosterol-loaded solid lipid nanoparticles ameliorate complete Freund's adjuvant-induced arthritis in rats: involvement of NF-кB and HO-1/Nrf-2 pathway

Rheumatoid arthritis (RA), autoimmune disease that is categorized via chronic inflammation manifestation, obesity, cardiovascular risk and even enhanced the mortality and affect the 0.3 and 1% of population worldwide. The current experimental study was scrutinize the anti-arthritic effect of β-sitosterol loaded solid lipid nanoparticles (SLN) against complete Fruend adjuvant (CFA)-induced arthritis via dual pathway. Double emulsion solvent displacement method was used for the preparation of β-sitosterol solid lipid nanoparticles (SLN). CFA was used to induce arthritis and rats were divided into different groups for 28 days. Biochemical, anti-inflammatory, pro-inflammatory cytokines and inflammatory mediator were estimated, respectively. Receptor activator of nuclear factor kappa-B ligand (RANKL), signal transducer and activator of transcription-3 (STAT3) nuclear factor erythroid 2–related factor 2 (Nrf₂), Heme Oxygenase-1(HO-1) and Nuclear factor-κB (NF-κB) expression were estimated. β-sitosterol-SLN significantly (p < .001) reduced the paw edema, arthritic index and increased the body weight. β-sitosterol-SLN increased the redox status of synovium {reduce the malonaldehyde (MDA) and increase superoxide dismutase (SOD), glutathione (GSH) and catalase (CAT)} level and reduced the cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-2, interleukin-6, interleukin-16, interleukin-17 and increased level of interleukin-10, Transforming growth factor beta (TGF-β). β-sitosterol-SLN significantly (p < .001) reduced the level of cyclooxygenase-2 (COX-2), prostaglandin E₂ (PGE₂), vascular Endothelial Growth Factor (VEGF) and NF-κB. β-sitosterol-SLN significantly increased the expression of HO-1,Nrf₂ and decreased the expression of NF-κB, RANKL, STAT3. In conclusion, β-sitosterol SLN showed the antiarthritic effect via suppression of NF-kB and activation of HO-1/Nrf-2 pathway.

Modified Simiaowan prevents articular cartilage injury in experimental gouty arthritis by negative regulation of STAT3 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Modified Simiaowan (MSW) is a traditional Chinese medicine formula that is composed of six herbs. It has been widely used in the treatment of gouty arthritis.

AIM OF THE STUDY

This study was designed to investigate the effect of MSW on gouty arthritis and explore the possible mechanisms.

MATERIAL AND METHODS

The rat gouty arthritis model was established by intra-articular injection of Monosodium Urate (MSU) crystal, and then treated with MSW for 5 days. The perimeter of the knee joints was measured in a time-dependent manner and serum samples were collected for the detection of TNF-α, IL-1β, and IL-6 protein levels by ELISA. The protein expressions of MMP-3, TIMP-3, STAT3, and p-STAT3 in cartilage tissues and C28/I2 cells were detected by Western blot, and the levels of proteoglycan in primary chondrocytes and cartilage tissues were determined by toluidine blue staining. In addition, AG490 and IL-6 were used in vitro to explore the function of IL-6/STAT3 pathway in the protective effect of MSU.

RESULTS

MSW reduced the joint swelling rate in gouty arthritis model and inhibited MSU induced up-regulation of IL-1β, TNF-α, and IL-6 protein levels in serum and synovial fluid. IL-1β induced an increase in p-STAT3 and MMP-3 protein expression in C28/I2 cells, as well as a decrease in TIMP-3. MSW serum inhibited the protein expression changes induced by IL-1β in vitro. Furthermore, inhibition of STAT3 signaling negated the effect of MSW serum on p-STAT3, MMP-3, and TIMP-3 protein levels in C28/I2 cells. MSW also increased the content of proteoglycan significantly both in vivo and in vitro.

CONCLUSION

Our data indicated that MSW protected rats from MSU-induced experimental gouty arthritis and IL-1β/IL-6/STAT3 pathway played an essential role in the protective effect of MSU against GA.

Effect of interleukin-6, -17, -21, -22, and -23 and STAT3 on signal transduction pathways and their inhibition in autoimmune arthritis

Rheumatic diseases are complex autoimmune diseases which include among others rheumatoid arthritis (RA), juvenile idiopathic arthritis (JIA), and psoriatic arthritis (PsA). These diseases are characterized by prolonged and increased secretion of inflammatory factors, eventually leading to inflammation. This is often accompanied by persistent pain and stiffness in the joint and finally bone destruction and osteoporosis. These diseases can occur at any age, regardless of gender or origin. Autoimmune arthritis is admittedly associated with long-term treatment, and discontinuation of medication is associated with unavoidable relapse. Therefore, it is important to detect the disease at an early stage and apply appropriate preventative measures. During inflammation, pro-inflammatory factors such as interleukins (IL)-6, -17, -21, -22, and -23 are secreted, while anti-inflammatory factors including IL-10 are downregulated. Research conducted over the past several years has focused on inhibiting inflammatory pathways and activating anti-inflammatory factors to improve the quality of life of people with rheumatic diseases. The aim of this paper is to review current knowledge on stimulatory and inhibitory pathways involving the signal transducer and activator of transcription 3 (STAT3). STAT3 has been shown to be one of the crucial factors involved in inflammation and is directly linked with other pro-inflammatory factors and thus is a target of current research on rheumatoid diseases.

Umbelliferone Ameliorates Complete Freund Adjuvant-Induced Arthritis via Reduction of NF-κB Signaling Pathway in Osteoclast Differentiation

Osteoclasts, bone-resorbing somatic cells, are directly responsible for bone destruction during rheumatoid arthritis. Complete Freund adjuvant (CFA) is a widely used animal model using rodents for studying rheumatoid arthritis (RA), which effectively manifests serious cartilage destruction and progressive bone erosion, affecting synovial joints and serious joint dysfunction. It was considered that joint injury in RA is induced through systemic inflammation pathway. Umbelliferone (UF), a coumarin derivative of Agele marmilosa, possesses anti-inflammatory activity. In the current study, we scrutinize the effect of umbelliferone on CFA-induced arthritis model and explore the possible mechanism on bone destruction. Intradermal administration of CFA (0.05 mL) was to induce RA manifestations in the experimental rats and the same oral administration of UF was received. The anti-arthritic activity of UF was determined by its inhibitory activity on various biochemical markers, viz., pro-inflammatory, inflammatory, antioxidant enzymes, and hematological parameters elevated during RA condition. We also estimated the mRNA expression of osteoclast parameters. Obtained result disclosed significant reduction in the paw edema and increment of the body weight after UF administration. UF reduce the inflammatory mediatory such as COX-2, PGE₂, NF-kB, and VEGF; pro-inflammatory cytokines include TNF-α, IL-1β, IL-6, IL-10, and IL-17 significantly. Moreover, UF treatment significantly reduced the osteoclast number via modulating the RANKL/RANK/OPG ratio. Furthermore, administration of umbelliferone significantly (P < 0.001) suppressed the NF-κB and VEGF. Collectively, our results indicated the novel role of umbelliferone in osteoclastogenesis and proved that umbelliferone is a modern therapeutic tool as a natural agent for treating arthritis and other autoimmune disorders with bone degradation.

Antitumor activity of flavonoids from Alpinia officinarum hance on gastric cancer

Introduction: To investigate antitumor activity and mechanism of flavonoids from Alpinia officinarum Hance against gastric cancer. Methods: Transplanted mouse fore-stomach carcinoma (MFC) tumor mice were divided into six groups: control group, model group, low dose (20 mg/kg), middle dose (40 mg/kg), and high dose (80 mg/kg) groups of TFAO and 5-Fu group. Mice were treated with TFAO or 5-Fu for 14 days, except those of control and model group. Tumor inhibitory rate, spleen, and thymus index were calculated. Contents of proliferating cell nuclear antigen, MMP-9, vascular endothelial growth factor, IL-1β, IL-6, and IL-17 in serum were detected. Effect of galangin on BGC-823 cell growth was detected. Cell apoptosis and cell cycle distribution were measured. Enzyme activity of Caspase-3, Caspase-8, and Caspase-9 was detected. Western blot was used to detect STAT3, Bcl-2, Bax, Caspase-3, Caspase-8, Caspase-9, CyclinB1, and CyclinD1 protein expression in BGC-823 cell. Results: Compared with model group, tumor weight of mice decreased significantly ( p < .01) in 5-Fu group, low dose, middle dose, and high dose group of TFAO; thymus index of mice decreased significantly ( p < .05) in 5-Fu group; and spleen index decreased significantly ( p < .05) in low dose and middle dose groups of TFAO. Compared with model group, levels of PCNA, MMP-9, IL-1β, and IL-6 in serum of mice decreased obviously ( p < .01) in all administration groups; levels of VEGF in serum of mice decreased obviously ( p < .01) in low dose and high dose group of TFAO and 5-Fu group; and levels of IL-17 in serum of mice decreased significantly ( p < .01) in low-dose and middle-dose groups of TFAO and 5-Fu group. Galangin could inhibit BGC-823 cell growth; accelerate apoptosis; block cell cycle; increase cell Caspase-3, Caspase-8, and Caspase-9 enzyme activity; upregulate expression of Caspase-3, Caspase-8, Caspase-9, and Bax; and downregulate expression of STAT3, CyclinB1, CyclinD1, and Bcl-2 protein. Conclusion: Flavonoids from A. officinarum showed antitumor activity in gastric cancer. Mechanisms may be associated with inhibition of tumor angiogenesis, tumor cell proliferation, and cancer-associated inflammation.

Anti-inflammatory effects of the root, stem and leaf extracts of Chloranthus serratus on adjuvant-induced arthritis in rats

Context: Chloranthus serratus [(Thunb.) Roem. et Schult, (Chloranthaceae)] is a folk medicine used for the treatment of rheumatoid arthritis.Objective: The aim of this study was to investigate anti-arthritic effects of the ethanol extracts of the roots (ER), stems (ES) and leaves (EL) of C. serratus on adjuvant arthritis rats and related mechanisms.Materials and methods: The rats were immunized by intradermal injection of complete Freund's adjuvant (CFA, 0.18 mL) into the right hind feet, and received intragastric administrations of the ER, ES and EL (2.07, 1.61 and 0.58 g/kg/d, respectively) for 14 days. The anti-arthritic activity was assessed by swelling rates, serum indicators, antioxidant capacity, histopathological and immunohistochemical analyses.Results: The LD₅₀ of the ER, ES and EL was higher than 10.35, 8.05 and 2.90 g/kg/p.o., respectively. Extract treatments decreased swelling rates, tumour necrosis factor-alpha (TNF-α), vascular endothelial growth factor (VEGF), interleukin 1 beta (IL-1β), migration inhibitory factor 1 (MIF-1), immunoglobulin G (IgG) and immunoglobulin M (IgM) levels and positive expression of VEGF in the arthritic rats (p < 0.01 or p < 0.05). The ER significantly decreased NO (3.91 ± 0.61 µmol/L), IL-6 (75.67 ± 16.83 pg/mL) and malondialdehyde (MDA) (2.28 ± 0.32 nmol/mL) contents and clearly increased IFN-γ (2082 ± 220.93 pg/mL) and superoxide dismutase (SOD) (601.98 ± 38.40 U/mL) levels. The ES and EL did not reverse the changes in some indicators. All the extracts alleviated inflammatory cell infiltration and synovial cell proliferation. Among them, the ER was the most pronounced.Discussion and conclusions: ER exerts the most promising effects, as shown by inhibiting the releases of inflammatory cytokines and enhancing antioxidant capacity, which provides a scientific basis for further research on C. serratus and its clinical applications.

Chronotherapy targeting cytokine secretion attenuates collagen-induced arthritis in mice

OBJECTIVE

Diurnal variation of symptoms are observed in rheumatoid arthritis, especially in productions of cytokines that show peak concentrations during mid night. In contrast, cytokines of collagen-induced arthritis (CIA) mice increase in daytimes under Mid-light condition. By using chronotherapy, differences in drug efficacies according to administration time of Baricitinib, a wide ranged cytokine blocker, were examined in CIA mice.

METHODS

CIA mice were administered a dose of 3 mg/kg of Baricitinib once a day at zeitgeber time (ZT) 0 or ZT12 for 21 days. Arthritis scores, histopathology and factors related to joint destruction in sera were examined. Phosphorylation of STAT3 in liver, expressions of cytokines in spleen, and Interleukin (IL)-6 and tumor necrosis factor (TNF)-α in sera were measured.

RESULTS

In CIA mice, diurnal variations were observed both in expressions of cytokines and phosphorylation of STAT3. Arthritis scores of ZT0/12 group decreased from day3 as compared to untreated mice, and those of ZT0 group significantly decreased as compared to ZT12 group from day12. Pathological findings, immunohistochemistry of cytokines and Receptor activator of nuclear factor kappa-Β ligand (RANKL)/osteoprotegerin ratio in sera well reflected results of arthritis scores. Diurnal variation of STAT3 phosphorylation was suppressed in ZT0 group. At ZT2, expressions of IL-6/Interferon-γ/TNF/granulocyte-macrophage colony-stimulating factor in ZT0 group were significantly decreased as compared to untreated mice, though not in ZT12 group. In ZT0 group, IL-6 and TNF-α in sera were decreased for longer time than that in ZT12 group.

CONCLUSION

Chronotherapy using Baricitinib targeting cytokine secretions is effective in CIA mice. Clinical applications of chronotherapy can be expected to enhance the drug efficacy.

Wasp Venom Possesses Potential Therapeutic Effect in Experimental Models of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disease. Wasp venom (WV), which is considered as a traditional folk medicine in Jingpo nationality in Yunnan, China, relieves rheumatoid arthritis. The current study aimed to investigate the effect of wasp venom ameliorating rheumatoid arthritis symptoms in experimental rats. We established a model of type II collagen- (CII-) induced arthritis (CIA) in SD rats and examined the inhibition of inflammation and autoimmune response. The antiarthritic effects of WV were evaluated through the paw swelling, and histopathological score and histopathology changes of the affected paw were assessed. The anti-inflammation effects were assayed by the level of IL-6, TNF-α, IL-1β, and the number of inflammatory cells in peripheral blood. The alteration of the T cell subset ratio in the spleen of rats was detected by flow cytometry, and at the same time, the viscera index and immune serum globulin levels were evaluated. The results suggested that various doses of WV (0.125, 0.25, and 0.5 mg/kg) significantly alleviated paw swelling and arthritis score in CIA rats with the untreated control (P < 0.05). WV (0.25 and 0.5 mg/kg) relieved synovial tissue lesions of ankle joints and histopathology scores of synoviocyte hyperplasia and inflammatory cell infiltration with vehicle group (P < 0.05). Regarding immunological regulation, 0.5 mg/kg WV lowered the immune serum globulin levels (P < 0.05), and we further found that WV (0.5 mg/kg) suppressed the immune response of Th cells, while enhancing the functions of Tc cells and Treg cells in spleen cells markedly (P < 0.05). The immunosuppressive action of WV displayed was analogous to its inhibitory effect on IL-1β, TNF-α, IL-8, IL-6, COX-2, and PGE2 levels in rat serum. In conclusion, these findings demonstrated that WV exhibited antiarthritic activity, which might be associated with their inhibitory effects on immunoregulation and anti-inflammatory action.

Neutralization of interleukin-17A alleviates burn-induced intestinal barrier disruption via reducing pro-inflammatory cytokines in a mouse model

Background

The intestinal barrier integrity can be disrupted due to burn injury, which is responsible for local and systemic inflammatory responses. Anti-inflammation strategy is one of the proposed therapeutic approaches to control inflammatory cascade at an early stage. Interleukin-17A (IL-17A) plays a critical role in inflammatory diseases. However, the role of IL-17A in the progression of burn-induced intestinal inflammation is poorly understood. In this study, we aimed to investigate the effect of IL-17A and associated pro-inflammatory cytokines that were deeply involved in the pathogenesis of burn-induced intestinal inflammatory injury, and furthermore, we sought to determine the early source of IL-17A in the intestine.

Methods

Mouse burn model was successfully established with infliction of 30% total body surface area scald burn. The histopathological manifestation, intestinal permeability, zonula occludens-1 expression, pro-inflammatory cytokines were determined with or without IL-17A-neutralization. Flow cytometry was used to detect the major source of IL-17A⁺ cells in the intestine.

Results

Burn caused intestinal barrier damage, increase of intestinal permeability, alteration of zonula occludens-1 expressions, elevation of IL-17A, IL-6, IL-1β and tumor necrosis factor-α (TNF-α), whereas IL-17A neutralization dramatically alleviated burn-induced intestinal barrier disruption, maintained zonula occludens-1 expression, and noticeably, inhibited pro-inflammatory cytokines elevation. In addition, we observed that the proportion of intestinal IL-17A⁺Vγ4⁺ T subtype cells (but not IL-17A⁺Vγ1⁺ T subtype cells) were increased in burn group, and neutralization of IL-17A suppressed this increase.

Conclusions

The main original findings of this study are intestinal mucosa barrier is disrupted after burn through affecting the expression of pro-inflammatory cytokines, and a protective role of IL-17A neutralization for intestinal mucosa barrier is determined. Furthermore, Vγ4⁺ T cells are identified as the major early producers of IL-17A that orchestrate an inflammatory response in the burn model. These data suggest that IL-17A blockage may provide a unique target for therapeutic intervention to treat intestinal insult after burn.

Inhibition of NET formation by polydatin protects against collagen-induced arthritis

BACKGROUND

Rheumatoid arthritis (RA) is a systematic, inflammatory, autoimmune disease, associated with a high number of disabilities. Increasing evidence has demonstrated that neutrophil extracellular trap (NET) formation plays a significant role in the pathogenesis and progression of RA. In this study, we have aimed to investigate the effects of polydatin (PD) on NET formation and its effects on disease activity in a collagen-induced arthritis (CIA) mouse model.

METHODS

In the presence of PD or vehicle, neutrophils isolated from RA patients and mice were treated with phorbol 12-myristate 13-acetate (PMA) for 4 h, and NET formation investigated. For in vivo experiments, PD was administered intraperitoneally (45 mg/kg per day) to collagen-induced arthritis (CIA) mice. The incidence and severity of collagen-induced arthritis were assessed and NET deposition tested.

RESULTS

In vitro, PD significantly suppressed NET formation of neutrophils from RA patients. Consistently, decreased NETs were observed in PD treated bone marrow-derived neutrophils. In CIA mouse model, PD treatment delayed the onset of arthritis and attenuated arthritis severity. Compared with vehicle-treated CIA mice, the deposition of NETs in ankle joints was also reduced in PD-treated CIA mice.

CONCLUSION

In this study, we found that PD treatment markedly inhibited NET formation and protected CIA mice from the development of arthritis. These findings suggest that inhibition of NET formation by PD may serve as a novel mechanism for the treatment of RA.

Vardenafil and cilostazol can improve vascular reactivity in rats with diabetes mellitus and rheumatoid arthritis co-morbidity

Endothelial dysfunction and vascular reactivity defects secondary to metabolic and immunological disorders carry risk of serious cardiovascular complications. Here, the effects of the phosphodiesterase (PDE) inhibitors vardenafil and cilostazol were examined against rheumatoid arthritis (RA)/diabetes mellitus (DM)-co-morbidity-induced endothelial dysfunction and vascular reactivity defects. After setting of RA/DM-co-morbidity model, rats were divided into a normal control group, an RA/DM-co-morbidity group, and two treatment groups receiving oral vardenafil (10 mg/kg/day) and cilostazol (30 mg/kg/day) for 21 days after RA/DM-co-morbidity induction. Aorta was isolated for biochemical estimations of the pro-inflammatory vasoconstrictor molecules angiotensin-II (Ang-II) and endothelin-1 (ET-1), the adhesion molecules P-selectin and vascular cell adhesion molecule-1 (VCAM-1), the energy sensor adenosine-5'-monophosphate-activated protein kinase (AMPK), and the vasodilator anti-inflammatory molecule vasoactive intestinal peptide (VIP) using enzyme-linked immunosorbent assay (ELISA) and western blot analysis. Immunohistochemical estimations of endothelial nitric oxide synthase (eNOS) and matrix metalloproteinase (MMP)-2 were performed coupled with histopathological examination using routine hematoxylin and eosin (H&E) and special Masson trichrome staining. The in vitro study was conducted using aortic strips where cumulative concentration response curves were done for the endothelium-dependent relaxing factor acetylcholine and the endothelium-independent relaxing factor sodium nitroprusside after submaximal contraction with phenylephrine. Vardenafil and cilostazol significantly improved endothelial integrity biomarkers in vivo supported with histopathological findings in addition to improved vasorelaxation in vitro. Apart from their known PDE inhibition, up-regulation of vascular AMPK and eNOS coupled with down-regulation of Ang-II, ET-1, P-selectin, VCAM-1 and MMP-2 may explain vardenafil and cilostazol protective effect against RA/DM-co-morbidity-induced endothelial dysfunction and vascular reactivity defects.

Polydatin promotes the osteogenic differentiation of human bone mesenchymal stem cells by activating the BMP2-Wnt/β-catenin signaling pathway

Steroid-induced osteonecrosis of the femoral head (SONFH) is a refractory disease induced by glucocorticoids. Marrow mesenchymal stem cells (MSCs) differentiate into multiple bone matrix cells and have been used as cell-based therapies to treat ONFH. However, the osteogenesis of MSCs isolated from patients with SONFH is significantly decreased. Polydatin has been widely used in traditional Chinese remedies due to its multiple pharmacological actions. As shown in our previous study, Polydatin protects from oxidative stress and promotes BMSC migration. However, little is known about its role in BMSC (Bone marrow mesenchymal stem cells) osteogenesis; therefore, we further investigated the effect and mechanism of Polydatin in hBMSC osteogenesis. The ability of Polydatin to promote the proliferation and osteogenic differentiation of hBMSCs was determined using the MTT assay, ALP staining and the ALP activity assay. Next, qPCR and western blotting were performed to measure the levels of genes and proteins related to the osteogenesis of hBMSCs. Then, the effect of Polydatin on the nuclear translocation of β-catenin was determined using immunofluorescence staining. Polydatin (30 μM) markedly enhanced the proliferation of hBMSCs and alkaline phosphatase (ALP) activity. Additionally, it also significantly upregulated the expression of osteogenic genes (Runx2, osteopontin, DLX5, osteocalcin, collagen type I and BMP2) and components of the Wnt signaling pathway (β-catenin, Lef1, TCF7, c-jun, c-myc and cyclin D). These osteogenesis-potentiating effects of Polydatin were blocked by Noggin, an inhibitor of the BMP pathway, and DKK1, an inhibitor of the Wnt/β-catenin pathway. However, DKK1 did not affect Polydatin-induced BMP2 expression. Based on our results, Polydatin promotes the proliferation and osteogenic differentiation of hBMSCs through the BMP2-Wnt/β-catenin signaling pathway.