SKLB023 blocks joint inflammation and cartilage destruction in arthritis models via suppression of nuclear factor-kappa B activation in macrophage

Development and characterization of trans-anethole-containing solid lipid microparticles: antiinflammatory and gastroprotective effects in experimental inflammation

The present study prepared, optimized, and characterized solid lipid microparticles that contained trans-anethole (SLMAN), evaluated their antiinflammatory activity in acute and chronic inflammation models, and investigated their effects on the gastric mucosa in arthritic rats. The microparticles were obtained by a hot homogenization process and characterized by physicochemical analyses. The acute inflammatory response was induced by an intradermal injection of 0.1 ml of carrageenan solution (200 μg) in the hind paw. The rats were treated orally with a single dose of SLMAN 1 h before induction of the inflammatory response. The chronic inflammatory response was induced by the subcutaneous application of 0.1 ml of complete Freund's adjuvant suspension (500 µg) in the hind paw. SLMAN was orally administered, starting on the day of arthritis induction, and continued for 21 days. The results showed that SLMAN was obtained with good encapsulation efficiency. Treatment with SLMAN at doses of 25 and 50 mg/kg was as effective as trans-anethole (AN) at a dose of 250 mg/kg on acute and chronic inflammatory responses. Histological analyses showed that treatment with SLMAN did not aggravate lesions in the gastric mucosa in arthritic rats. These results indicated that treatment with SLMAN at a dose that was 5-10 times lower than non-encapsulated AN exerted an inhibitory effect on acute and chronic inflammatory responses, suggesting the better bioavailability and efficacy of microencapsulated AN without aggravating lesions in the gastric mucosa in arthritic rats.

A New Peracetylated Oleuropein Derivative Ameliorates Joint Inflammation and Destruction in a Murine Collagen-Induced Arthritis Model via Activation of the Nrf-2/Ho-1 Antioxidant Pathway and Suppression of MAPKs and NF-κB Activation

Oleuropein (OL), an olive tree secoiridoid and its peracetylated derivate (Per-OL) have exhibited several beneficial effects on LPS-stimulated macrophages and murine experimental systemic lupus erythematosus (SLE). This study was designed to evaluate dietary Per-OL in comparison with OL supplementation effects on collagen-induced arthritis (CIA) murine model. Three-weeks-old DBA-1/J male mice were fed from weaning with a standard commercial diet or experimental enriched-diets in 0.05 % (w/w) OL, 0.05% and 0.025% Per-OL. After six weeks of pre-treatment, arthritis was induced by bovine collagen type II by tail base injection (day 0) and on day 21, mice received a booster injection. Mice were sacrificed 42 days after the first immunization. Both Per-OL and OL diets significantly prevented histological damage and arthritic score development, although no statistically significant differences were observed between both compounds. Also, serum collagen oligomeric matrix protein (COMP), metalloprotease (MMP)-3 and pro-inflammatory cytokines levels were ameliorated in paws from secoiridoids fed animals. Mitogen-activated protein kinases (MAPK)s and nuclear transcription factor-kappa-B (NF-κB) activations were drastically down-regulated whereas nuclear factor E2-related factor 2 (Nrf2) and heme-oxygenase-1 (HO-1) protein expressions were up-regulated in those mice fed with OL and Per-OL diets. We conclude that both Per-OL and its parent compound, OL, supplements might provide a basis for developing a new dietary strategy for the prevention of rheumatoid arthritis.

Mixed micelles loaded with the 5-benzylidenethiazolidine-2,4-dione derivative SKLB023 for efficient treatment of non-alcoholic steatohepatitis

Background: SKLB023, a novel 5-benzylidenethiazolidine-2,4-dione based-derivative, specifically inhibits inducible nitric oxide synthase and shows promise for treating non-alcoholic steatohepatitis (NASH). However, its poor water solubility and low bioavailability limits its clinical use. Here the drug was loaded into phosphatidylcholine-bile salt-mixed micelles (PBMM/SKLB023) to overcome these limitations. Methods: PBMM/SKLB023 was developed using a simple co-precipitation method, and formulation parameters were optimized. The pharmacokinetics of PBMM/SKLB023 were investigated in Wistar rats, and therapeutic efficacy was assessed in a mouse model of NASH induced by a diet deficient in methionine- and choline. Results: PBMM/SKLB023 particles were 11.36±2.08 nm based on dynamic light scattering, and loading the drug into micelles improved its water solubility 300-fold. PBMM/SKLB023 inhibited proliferation and activation of HSC-T6 cells more strongly than free SKLB023. PBMM/SKLB023 showed longer mean retention time and higher bioavailability than the free drug after intravenous injection in Wistar rats. In the mouse model of NASH, PBMM/SKLB023 alleviated hepatic lipid accumulation, inflammation, and fibrosis to a significantly greater extent than free SKLB023. Conclusion: PBMM/SKLB023 shows therapeutic potential for treating NASH and liver fibrosis.

Protective effects of SKLB023 on a mouse model of unilateral ureteral obstruction by the modulation of gut microbiota

Renal interstitial fibrosis is the common pathway underlying the progression of chronic kidney disease (CKD) to end-stage renal disease (ESRD) and the corresponding therapies are limited. Quantitative and qualitative alterations in gut microbiota are noted in patients with CKD and ESRD. In our previous study, SKLB023 exhibited antifibrotic effects by interfering TGF-β1/Smad3 signaling in obstructive nephropathy. However, it remained unclear that oral administration of SKLB023 drives the alteration of gut microbiota to attenuate renal fibrosis. In the study, the marked inflammation and interstitial fibrosis were found in the kidney tissues of unilateral ureteral obstruction (UUO) mice. While treatment with SKLB023 significantly alleviated renal interstitial fibrosis and reduced serum proinflammatory cytokines TNF-α, IL-6 levels. Importantly, SKLB023 derived the modulation of gut microbiota with the increasing similarity between the composition of gut microbiota in the control and UUO. The number of Turicibacter and Candidatus_Arthromitus was significantly decreased following UUO surgery and recovered by SKLB023, which positively correlated with pro-inflammatory cytokine expression. These results indicated the potential relationship between the antifibrotic benefits of SKLB023 and gut microbiota alteration, which provided new insights into drug therapy via gut microbiota modulation in obstructive nephropathy.

Renal fibrosis is the common pathway underlying the progression of CKD to ESRD and quantitative and qualitative alterations in gut microbiota are noted in patients with CKD. Our results indicated SKLB023 drives the alteration of gut microbiota to attenuate renal fibrosis.

SKLB023 protects mice against acute liver injury by inhibiting proinflammatory cytokine production in both T cells and macrophages

Acute liver failure is a severe clinical syndrome accompanied with excessive inflammatory response. Our previous study demonstrated that SKLB023, a novel thiazolidinedione derivative, showed potent anti-inflammatory activity in rheumatoid arthritis. The purpose of the present study is to evaluate the protective effect of SKLB023 on lipopolysaccharide (LPS)/D-GalN-induced liver failure and to explore the underlying molecular mechanisms. Our results showed that SKLB023 significantly improved mortality and liver injury as indicated by reduced serum levels of aminotransferases and alleviated pathological damage. Additionally, SKLB023 decreased the percentage of activated T cells and macrophages as well as the serum levels of cytokines in vivo. Furthermore, SKLB023 decreased levels of TNF-α and IL-6 secreted from liver macrophages (Kupffer cells) stimulated by LPS in vitro. Our results indicated that the protective effects of SKLB023 were associated with its significant impact on the inflammatory cytokines, which were produced by both T cells and macrophages.

A novel thiazolidinedione derivative SKLB023 offers a potent therapeutic strategy for the treatment of acute liver failure.

SKLB023 as an iNOS inhibitor alleviated liver fibrosis by inhibiting the TGF-beta/Smad signaling pathway

Nonalcoholic steatohepatitis (NASH)-related liver fibrosis has been suggested to be a physiological consequence of chronic hepatic injury, necrosis, inflammation and unbalanced intrahepatic lipid metabolism. Accumulated evidence demonstrates that inducible nitric oxide synthase (iNOS) is highly expressed in advanced liver fibrosis, and the knockout of iNOS inhibits the progression of hepatic fibrosis. In our previous study, (Z)-N-(3-chlorophenyl)-2-(4-((2,4-dioxothiazolidin-5-ylidene)methyl)phenoxy)acetamide (SKLB023), a novel small-molecule inhibitor of iNOS, blocked joint inflammation and cartilage destruction in arthritis. However, the role and function of SKLB023 in liver fibrosis have not been fully elucidated. In the present study, methionine- and choline-deficient (MCD) diet-induced NASH mice and LX-2 hepatic stellate cells were chosen to investigate the pharmacological effects of SKLB023 against liver fibrosis and the associated mechanism. Our results show that SKLB023 significantly alleviated MCD diet-induced liver injury, lipid accumulation and liver fibrosis. SKLB023 could suppress the activation of hepatic stellate cells by interfering with TGF-β/Smad pathways. Importantly, SKLB023 inhibited the level of TGF-β1 and Smad2/3 phosphorylation by blocking the expression of iNOS. These results suggest that SKLB023 might be an effective drug candidate for the treatment of liver fibrosis.

Macrophage migration inhibitory factor (MIF) inhibitor, Z-590 suppresses cartilage destruction in adjuvant-induced arthritis via inhibition of macrophage inflammatory activation

BACKGROUND

Macrophage migration inhibitory factor (MIF) is a pleiotropic pro-inflammatory mediator that is involved in the progression of rheumatoid arthritis (RA). Previously, we demonstrated a small molecule compound 3-[(biphenyl-4-ylcarbonyl) carbamothioyl] amino benzoic acid (Z-590) could inhibit MIF activity with docking-based virtual screening and experimental evaluation.

METHODS

The LPS activated RAW264.7 macrophage cells were used to determine the anti-inflammatory effects of Z-590 in vitro. A rat adjuvant-induced arthritis (AIA) model was used to determine the anti-arthritic effects of Z-590 in vivo.

RESULTS

MIF inhibitor Z-590 significantly inhibited the production of NO, TNF-α and IL-6 in LPS-activated RAW 264.7 macrophage cells and markedly inhibited LPS-induced expression of TNF-α, IL-6, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Z-590 also significantly reduced paw edema, serum level of TNF-α, IL-6 and spleen index in the adjuvant-induced arthritis (AIA) rat model. Furthermore, Z-590 markedly ameliorated joint inflammation and articular cartilage damage in AIA rat model.

CONCLUSION

MIF inhibitor Z-590 possesses potent anti-arthritic activity through suppression of macrophage activation, and could be a potential therapeutic treatment for RA.

SKLB023 hinders renal interstitial fibrosis in obstructive nephropathy by interfering TGF-β1/Smad3 signaling

Renal fibrosis is the principal process underlying the progression of chronic kidney disease to end-stage renal disease. It is a relatively uniform response involving glomerulosclerosis, tubulointerstitial fibrosis and changes in renal vasculature. A considerable number of studies have confirmed that inducible nitric oxide synthase (iNOS) was highly expressed in renal interstitial fibrosis and the overexpression of iNOS played a negative role in kidney disease progression. In our previous study, SKLB023 as a novel small-molecule inhibitor of iNOS, blocked joint inflammation and cartilage destruction in arthritis. However, the pharmacological role and function of SKLB023 in renal fibrosis remained poorly understood. In the study, oral administration of SKLB023 (25 and 50 mg per kg per day) for 7 day exhibited potent anti-fibrotic effects against the model UUO using the pathological assessment of H & E and Masson's trichrome staining. SKLB023 inhibited the expression of α-SMA, col I, col IV, fibronectin and further decreased iNOS expression as well as TGF-β1/Smad3 phosphorylation in the injured kidney tissues of UUO mice. Similarly, SKLB023 suppressed in vitro features of fibrosis in TGF-β1-induced NRK-49F by the inhibition of the corresponding fibrotic protein expression. These findings confirmed that SKLB023 hindered renal interstitial fibrosis by interfering with TGF-β1/Smad3 signaling, highlighting that SKLB023 has potential in therapeutic strategies.

The novel small-molecule inhibitor of iNOS (SKLB023) hindered renal interstitial fibrosis in vivo and in vitro by interfering with TGF-β1/Smad3 signaling, highlighting that SKLB023 has potential in the therapeutic strategy for renal fibrosis.

The Anti-Inflammatory Activity of Toonaciliatin K against Adjuvant Arthritis

Toonaciliatin K is a natural limonoid purified from the Toona ciliata Roem. var. ciliata (Meliaceae). This study is to reveal the inflammatory suppression effect of toonaciliatin K and further the intrinsic mechanism. Firstly, anti-inflammatory effect of toonaciliatin K was evaluated in lipopolysaccharide- (LPS-) induced RAW264.7 cells. RT-PCR results indicated that the mRNA expressions of TNF-α, IL-6, and IL-1β were downregulated by toonaciliatin K. The toonaciliatin K inhibited TNF-α, IL-6, and IL-1β levels stimulated by LPS. Furthermore, LPS elicited the excess iNOS and COX-2 mRNA and protein production and toonaciliatin K attenuated the excess production. Western blot assay demonstrated that MAPK and NF-κB signaling pathways play critical roles in the toonaciliatin K's anti-inflammatory activity. Secondly, toonaciliatin K inhibited carrageenan-induced paw edema in rats. Thirdly, toonaciliatin K alleviated the paw swelling and improved arthritis clinical scores in the adjuvant arthritis rats. Toonaciliatin K decreased the proinflammatory cytokines levels and Mankin scores in adjuvant arthritis rats. The HE staining, safranin O-fast green, and toluidine blue staining results demonstrated that toonaciliatin K alleviated the histological changes of paw, for example, pannus formation, focal loss of cartilage, bone erosion, and presence of extra-articular inflammation. Hence, toonaciliatin K is a promising agent for treatment of arthritis.

Fish Oil and Adjuvant-Induced Arthritis: Inhibitory Effect on Leukocyte Recruitment

Fish oil, a rich source of n-3 fatty acids, has been studied for its beneficial effects in many diseases. Recent studies have shown the robust anti-inflammatory activity of fish oil (FO), when administered orally to rats, in models of acute inflammation. Herein, we investigated if treatment with fish oil preparation (FOP) could interfere with the recruitment of leukocytes into the joint cavity of arthritic rats. We also evaluated the effect of treatment on rolling behavior and leukocyte adhesion in vivo and on leukocyte chemotaxis in vitro. Treatment with FOP (75, 150, and 300 mg/kg) initiated on the day of induction of arthritis (day 0) and maintained for 21 days reduced the total number of leukocytes recruited into the joint cavity, the number of rolling and adhered leukocytes in arthritic rats, and leukocyte migration in response to stimulation with N-formyl-methionyl-leucyl-phenylalanine (fMLP) and leukotriene B4 (LTB4). Together, our data provide evidence that FOP plays an important inhibitory role in the recruitment of leukocytes into the joint cavity of arthritic rats.

Decreased severity of collagen antibody and lipopolysaccharide-induced arthritis in human IL-32β overexpressed transgenic mice

Interleukin (IL)-32, mainly produced by T-lymphocytes, natural killer cells, epithelial cells, and blood monocytes, is dominantly known as a pro-inflammatory cytokine. However, the role of IL-32 on inflammatory disease has been doubtful according to diverse conflicting results. This study was designed to examine the role of IL-32β on the development of collagen antibody (CAIA) and lipopolysaccharide (LPS)-induced inflammatory arthritis. Our data showed that the paw swelling volume and clinical score were significantly reduced in the CAIA and LPS-treated IL-32β transgenic mice compared with non-transgenic mice. The populations of cytotoxic T, NK and dendritic cells was inhibited and NF-κB and STAT3 activities were significantly lowered in the CAIA and LPS-treated IL-32β transgenic mice. The expression of pro-inflammatory proteins was prevented in the paw tissues of CAIA and LPS-treated IL-32β transgenic mice. In addition, IL-32β altered several cytokine levels in the blood, spleen and paw joint. Our data indicates that IL-32β comprehensively inhibits the inflammation responses in the CAIA and LPS-induced inflammatory arthritis model.

Anti-inflammatory and anti-arthritic effects of Guge Fengtong Formula: in vitro and in vivo studies

Rheumatoid arthritis (RA) is the most common inflammatory arthritis and a major cause of disability. Presently, the clinical therapeutic medicines for inflammatory and arthritic diseases are unsatisfactory due to severe adverse effects or ineffectiveness. The Guge Fengtong formula (GGFT), containing the standardized extracts of Dioscoreae Nipponicae Rhizoma, Spatholobi Caulis, and Zingiberis Rhizoma, has long been used for RA treatment by Chinese doctorsin China. However, the detailed anti-inflammatory and anti-arthritic activity of GGFT has not been reported so far. In the present work, we aimed to evaluate the anti-inflammatory and anti-arthritic effects of GGFT using three in vivo animal models, and tried to uncover its preliminarythe underlying mechanism of action mechanism in RAW 264.7 macrophages. The obtained results indicated that GGFT significantly attenuated ear edema, decreased carrageenan-induced paw edema, reduced the arthritis score, and reversed the weight loss of the complete Freund's adjuvant (CFA)CFA-injected rats. Additionally, marked decrease of in synovial inflammatory infiltration and synovial lining hyperplasia in the joints and decline of inflammatory factors (TNF-α and IL-1β) in the serum were observed in the GGFT-treated rats. In lipopolysaccharide-activated RAW264.7 macrophages, GGFT reduced the production of NO, PGE2, and IL-6, and inhibited the expression of iNOS, COX-2, and NF-κB expression. Our results demonstrated that GGFT possessed considerable anti-inflammatory activity and have had potential therapeutic effects on adjuvant induced arthritis in rats, which provided providing experimental evidences for its traditional application in the treatment of RA and other inflammatory diseases.

Dietary extra virgin olive oil attenuates kidney injury in pristane-induced SLE model via activation of HO-1/Nrf-2 antioxidant pathway and suppression of JAK/STAT, NF-κB and MAPK activation

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by a widespread organ involvement. Recent studies have suggested that extra virgin olive oil (EVOO) might possess preventive effects on this immunoinflammation-related disease. However, its role in SLE remained unknown. In this work, we evaluated the effects of EVOO diet in a pristane-induced SLE model in mice. Three-month-old mice received an injection of pristane or saline solution and were fed with different experimental diets: sunflower oil diet or EVOO diet. After 24weeks, mice were sacrificed, spleens were collected and kidneys were removed for immunoinflammatory detections. The kidney expression of microsomal prostaglandin E synthase 1, heme oxygenase 1 (HO-1), nuclear factor E2-related factor 2 (Nrf-2), mitogen-activated protein kinases (MAPKs), Janus kinase/signal transducer and activator of transcription (JAK/STAT) and nuclear transcription factor-kappa B (NF-κB) pathways were studied by western blotting. In addition to macroscopic and histological analyses, serum matrix metalloproteinase 3 (MMP-3) levels and proinflammatory cytokines production in splenocytes were evaluated by enzyme-linked immunoassay. We have demonstrated that EVOO diet significantly reduced renal damage and decreased MMP-3 serum and PGE2 kidney levels as well as the proinflammatory cytokines production in splenocytes. Our data indicate that Nrf-2 and HO-1 protein expressions were up-regulated in those mice fed with EVOO and the activation of JAK/STAT, MAPK and NF-κB pathways were drastically ameliorated. These results support the interest of EVOO as a beneficial functional food exerting a preventive/palliative role in the management of SLE.

Effects of simvastatin, ezetimibe, and their combination on histopathologic alterations caused by adjuvant-induced arthritis

The objective of the present study was to investigate the effects of monotherapy with simvastatin or ezetimibe compared with those of an ezetimibe + simvastatin combination on the histopathologic aspects of arthritis induced by Complete Freund's Adjuvant in rats. The characteristics of diarthrosis were analyzed 7 and 28 days after arthritis induction with regard to the regularity and integrity of articular cartilage, the presence of leukocytes in blood vessels at the inflammation site, and the cytokine levels in articular tissue. Monotherapy with simvastatin or ezetimibe and the ezetimibe + simvastatin combination effectively reduced the cytokine levels (interleukin-6 and tumor necrosis factor) and articular lesions that are characteristic of this experimental disease. Although the results did not reveal significant differences between the monotherapy and the combined therapy, they suggest that these drugs have considerable antiinflammatory properties, as reflected by an attenuation of articular cartilage lesions mediated by a reduction in the levels of proinflammatory cytokines.