Investigation of toll-like receptor (TLR) 4 inhibitor TAK-242 as a new potential anti-rheumatoid arthritis drug.

BACKGROUND: Proper blocking of toll-like receptor (TLR) activation during disease progression has been reported to have inhibitory effect on the pathogenesis of rheumatoid arthritis (RA). We tested whether the TLR4 inhibitor TAK-242 had potential as a remedy for rheumatoid arthritis. METHODS: The therapeutic effect of TAK-242 was tested in vitro using the human rheumatoid fibroblast-like synoviocyte (FLS) line MH7A or primary human FLS and in an adjuvant-induced arthritis (AIA) rat model. RESULTS: TAK-242 dose dependently inhibited the increased expression of IL-6, IL-8, MMP-1, and VEGF in LPS-stimulated MH7A cells. It also inhibited the expression of IL-6 and IL-8 in poly(I:C), TLR3 activator-stimulated primary FLS, but not in IL-1ß-stimulated primary FLS. These findings suggest that TAK-242 blocks a specific signaling pathway to some degree. Further, TAK-242 slightly inhibited mobilization of NF-κB into nuclei. In the AIA rat model, TAK-242 significantly reversed the body weight and paw thickness of AIA rats to the normal state at a dose of 5 mg/kg, but not at 3 mg/kg, and reduced the increased serum level of IL-6 and VEGF in AIA rats. It also significantly ameliorated inflammatory symptoms of joint tissues at day 21 of treatment, according to histology and RT-PCR. CONCLUSIONS: Based on the drug repositioning concept, TAK-242, which is used for the treatment of TLR4-mediated inflammatory diseases, shows potential for cost-effective development as a remedy for rheumatoid arthritis or to control the progression of RA.

Triphala herbal extract suppresses inflammatory responses in LPS-stimulated RAW 264.7 macrophages and adjuvant-induced arthritic rats via inhibition of NF-κB pathway.

This study sought to explore the mechanism of anti-inflammatory effect of triphala in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages and in adjuvant-induced arthritic rats. In stimulated RAW 264.7 cells, triphala (100-300 µg/ml) significantly suppressed production of inflammatory mediators (e.g. TNFα, IL-1ß, IL-6, MCP-1, VEGF, NO, PGE2), intracellular free radicals and release of lysosomal enzymes (e.g. acid phosphatase, ß-galactosidase, N-acetyl glucosamindase and cathepsin D) in a dose-related manner. With triphala, mRNA levels of genes for pro-inflammatory TNFα, IL-1ß, IL-6 and MCP-1, inflammatory iNOS and COX-2 enzymes and NF-κBp65 were down-regulated in the stimulated cells; in contrast, there was up-regulation of heme oxygenase-1 (HO-1) expression. Western blot analyses revealed that triphala suppressed the protein expression of NF-κB p65 and p-NF-κB p65 in the stimulated cells, which subsequently reduced over-expression of TNFα, IL-17, iNOS and COX-2 in a manner similar to that observed with BAY 11-7082, an IκB kinase inhibitor. Immunofluorescence analysis revealed inhibition of p-NF-κB p65 nuclear translocation and COX-2 protein expression caused by triphala. Consistent with these findings, the animal studies presented confirmed that triphala exhibited anti-inflammatory effects in a rat adjuvant-induced arthritis model by reducing of inflammatory mediator (e.g. IL-17, COX-2 and RANKL) expression via inhibition of NF-κB activation. Taken together, the results here demonstrated that triphala has potential anti-inflammatory applications that could be used for the treatment of inflammatory disorders, including rheumatoid arthritis.

Targeting inflammatory mediators with ferulic acid, a dietary polyphenol, for the suppression of monosodium urate crystal-induced inflammation in rats.

AIMS: The aim of this study was to investigate the anti-inflammatory effect of ferulic acid, a dietary phenol, on monosodium urate (MSU) crystal-induced inflammation in rats, an experimental model for acute gouty arthritis. For the purpose of comparison, colchicine was used as a reference drug. MAIN METHODS: Paw edema, levels/activities of elastase, lysosomal enzymes (acid phosphatase and ß-galactosidase), nitric oxide, lipid peroxidation, antioxidant status and pro-inflammatory cytokines (tumor necrosis factor alpha (TNF-α) and interleukin (IL)-1ß), and histology of ankle joints were evaluated in rats with MSU crystal-induced inflammation. The messenger RNA (mRNA) expression of pro-inflammatory cytokines (TNF-α and IL-1ß), NLRP3 (nucleotide oligomerization domain (NOD)-like receptor family, pyrin domain containing 3) inflammasomes, caspase-1, and the transcription factor nuclear factor kappa B p65 (NF-κB p65) was determined by real-time polymerase chain reaction (PCR) analysis. The protein expression of NF-κB p65 and TNF-α was detected by immunohistochemical analysis. Further, a molecular docking analysis was conducted to determine the ligand efficiency of ferulic acid towards NF-κB, apoptosis-associated speck-like protein containing a CARD (PYCARD/ASC), NLRP3, and pro-caspase-1. KEY FINDINGS: In the joint homogenate of rats with MSU crystal-induced inflammation, treatment with ferulic acid (30mg/kg body weight (b.wt)) decreased paw edema; the level/activity of elastase, lysosomal enzymes, nitric oxide, lipid peroxidation, and pro-inflammatory cytokines (TNF-α and IL-1ß); and the mRNA expression of NLRP3 inflammasomes, caspase-1, pro-inflammatory cytokines, and NF-κB p65. In addition, the protein expression of NF-κB p65 and TNF-α was also found to be significantly decreased. However, the antioxidant status (superoxide dismutase (SOD) and catalase (CAT)) were found to be increased. The molecular docking analysis showed that ferulic acid exhibited significant ligand efficiency towards pro-caspase-1, NF-κB, PYCARD/ASC, and NLRP3. SIGNIFICANCE: Our findings demonstrate the potential anti-inflammatory effect of ferulic acid on MSU crystal-induced inflammation in rats.

The anti-inflammatory effect of triphala in arthritic-induced rats.

CONTEXT: Triphala, an Indian Ayurvedic herbal formulation which contains Terminalia chebula Retz. (Combretaceae), Terminalia bellerica (Gaertn.) Roxb. (Combretaceae) and Emblica officinalis L. (Phyllanthaceae), is used for treating bowel-related complications, inflammatory disorders, and gastritis. OBJECTIVE: To determine the anti-arthritic effect of triphala in arthritis-induced rats. For comparison purpose, the non-steroidal anti-inflammatory drug indomethacin was used. MATERIALS AND METHODS: Arthritis was induced in Wistar albino rats by intradermal injection of complete Freund's adjuvant (0.1 ml) into the foot pad of right hind paw. Triphala (100 mg/kg b wt, i.p.) was administered from day 11 to 18 after the administration of complete Freund's adjuvant. The activities/levels of lysosomal enzymes, glycoproteins, antioxidant status, and lipid peroxidation were determined in the paw tissues of arthritic rats. In addition, the inflammatory mediators were also measured in both the serum and the paw tissue of arthritic rats. RESULTS: The levels/activities of lipid peroxidation (∼41.5%), glycoproteins (hexose ∼43.3%, hexosamine ∼36.5%, and sialic acid ∼33.7%), lysosomal enzymes (acid phosphatase ∼52.4%, ß-galactosidase ∼22.9%, N-acetyl ß-glucosaminidase ∼22.1%, and cathepsin-D ∼27.7%) were found to be decreased and the antioxidant status (SOD ∼75.6%, CAT ∼62.7%, GPx ∼55.8%, GST ∼82.1%, and GSH ∼72.7%) was increased in the paw tissues of triphala-treated arthritic rats. In addition, the inflammatory mediator levels in serum (TNF-α ∼75.5%, IL-1ß âˆ¼99%, VEGF ∼75.2%, MCP-1 ∼76.4%, and PGE2 ∼69.9%) and in paw tissues (TNF-α ∼71.6%, IL-1ß âˆ¼75.5%, VEGF ∼55.1%, MCP-1 ∼69.1%, and PGE2 ∼66.8%) were found to be suppressed. CONCLUSION: Triphala has a promising anti-inflammatory effect in the inflamed paw of arthritis-induced rats.

An experimental study to investigate the impact of p-coumaric acid, a common dietary polyphenol, on cadmium chloride-induced renal toxicity.

Cadmium, a well-known environmental pollutant and a toxic transitional metal causes severe damage to many organs, such as liver, kidney, lungs, heart, etc. The current study has been designed to assess the impact of p-coumaric acid, a common dietary polyphenol on cadmium chloride-induced renal toxicity in rats. Therefore, the activities of membrane bound ATPases, mitochondrial TCA cycle and electron transport chain enzymes, gluconeogenic and glycolytic enzymes, and glycogen content were estimated in kidney tissue homogenates of control and experimental rats. In addition, the serum levels of glucose and pro-inflammatory cytokines, such as TNF-α and IL-1ß were also estimated. The cadmium chloride administered rats (3 mg per kg per b. wt per s.c.) showed significant decrease in the levels of membrane bound ATPases, mitochondrial TCA cycle and electron transport chain enzymes, glycolytic enzymes, and glycogen content as compared with controls. Conversely, the levels of glucose, gluconeogenic enzymes and pro-inflammatory cytokines (TNF-α, and IL-1ß) were found to be increased. However, the administration of p-coumaric acid (100 mg per kg per b. wt per s.c.) along with the cadmium chloride significantly modulated these biochemical and immunological changes to near normal, as compared to cadmium chloride treated rats. Thus, the results provide strong evidence that p-coumaric acid has a protective action against cadmium-induced renal toxicity in rats.

Hepatoprotective and antioxidant effects of gallic acid in paracetamol-induced liver damage in mice.

OBJECTIVES: The aim of this research paper was to investigate the hepatoprotective and antioxidant effects of gallic acid in paracetamol-induced liver damage in mice. METHODS: In the present study, the hepatoprotective and antioxidant effects of gallic acid were evaluated against paracetamol-induced hepatotoxicity in mice and compared with the silymarin, a standard hepatoprotective drug. The mice received a single dose of paracetamol (900 mg/kg body weight i.p.). Gallic acid (100 mg/kg body weight i.p.) and silymarin (25 mg/kg body weight i.p.) were administered 30 min after the injection of paracetamol. After 4 h, liver marker enzymes (aspartate transaminase, alanine transaminase and alkaline phosphatase) and inflammatory mediator tumour necrosis factor-alpha (TNF-alpha) were estimated in serum, while the lipid peroxidation and antioxidant status (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase and glutathione) were determined in liver homogenate of the control and experimental mice. KEY FINDINGS: Increased activities of liver marker enzymes and elevated TNF-alpha and lipid peroxidation levels were observed in mice exposed to paracetamol (P < 0.05), whereas the antioxidant status was found to be depleted (P < 0.05) when compared with the control group. However gallic acid treatment (100 mg/kg body weight i.p.) significantly reverses (P < 0.05) the above changes by its antioxidant action compared to the control group as observed in the paracetamol-challenged mice. CONCLUSIONS: The results clearly demonstrate that gallic acid possesses promising hepatoprotective effects.

Inhibition of monosodium urate crystal-induced inflammation by withaferin A.

PURPOSE: Gouty arthritis is a characteristically intense acute inflammatory reaction resulting from the formation of sodium urate crystals in the joint cavity. In the present study, the effect of withaferin A, a steroidal lactone was investigated on monosodium urate crystal-induced inflammation in mice; an experimental model for gouty arthritis and compared it with that of the non-steroidal anti-inflammatory drug, indomethacin. METHODS: Paw volume and levels/activities of lysosomal enzymes, lipid peroxidation, anti-oxidant status and inflammatory mediator TNF-alpha were determined in control and monosodium urate crystal-induced mice. The levels of beta-glucuronidase and lactate dehydrogenase were also measured in monosodium urate crystal-incubated polymorphonuclear leucocytes (PMNL). RESULTS: Paw volume, the levels of lysosomal enzymes, lipid peroxidation, and inflammatory mediator tumour necrosis factor-alpha were found to be increased significantly and the activities of antioxidant status were in turn decreased in monosodium urate crystal-induced mice; however these changes were reverted back to near normal levels in withaferin A (30 mg/kg/b.wt, i.p.) treated monosodium urate crystal-induced mice. In addition, beta-glucuronidase and lactate dehydrogenase level were reduced in withaferin A (100microg/ml) treated monosodium urate crystal-incubated polymorphonuclear leucocytes. CONCLUSION: The present findings clearly indicated that withaferin A exerted a strong anti-inflammatory effect against gouty arthritis.