Amelioration of collagen-induced arthritis in female dark agouti rats by glucosamine treatment

Effects of low-level laser therapy and therapeutic ultrasound on Freund's complete adjuvant-induced knee arthritis model in rats

OBJECTIVES

The aim of this study was to evaluate and monitor the effect of low-level laser therapy (LLLT) and therapeutic ultrasound (TU) alone, or combined with intra-articular prednisolone (P) in Freund's complete adjuvant (FCA)-induced knee arthritis model in rats.

MATERIALS AND METHODS

A total of 56 adult male Wistar rats were divided into seven groups: control (C), disease control (RA), P, TU, LLLT (L), P + TU (P+TU), P + LLLT (P+L) groups. The skin temperature, radiography, joint volume, serum rheumatoid factor (RF), interleukin (IL)-1β, serum tumor necrosis factor-alpha (TNF-α), and histopathological evaluation of joint were performed.

RESULTS

Thermal imaging and radiographic examination provided results consistent with the severity of the disease. The mean joint temperature (°C) was the highest in the RA (36.2±1.6) group on Day 28. The P+TU and P+L groups significantly decreased radiological scores at the end of the study. The rat serum TNF-α, IL-1β, and RF levels in all groups were significantly higher compared to the C group (p<0.05). Compared to the RA group, serum TNF-α, IL-1β, and RF levels were significantly lower in the treatment groups (p<0.05). The P+TU and P+L group was showed minimal chondrocyte degeneration and cartilage erosion and mild cartilage fibrillation and mononuclear cell infiltration of synovial membrane compared to the P, TU, and L group.

CONCLUSION

The LLLT and TU effectively reduced inflammation. In addition, a more effective result was obtained from the use of LLLT and TU combined with intra-articular P. This result may be due to insufficient dose of LLLT and TU, thus further studies should be focus on at higher dose ranges on FCA arthritis model in rats.

Pre-clinical Investigation of Protective Effect of Nutraceutical D-Glucosamine on TNBS-induced Colitis

The level of precursors involved in the biosynthesis of glycosaminoglycan (GAG), glucosamine synthase, and N-acetyl glucosamine (NAG), are significantly reduced in inflammatory bowel disease (IBD). This results in deficient GAG content in mucosa, which eventually disrupts the gut wall integrity, provoking abnormal immunological responses. This is characterized by colossal liberation of inflammatory mediators including tumor necrosis factor-alpha (TNF-α), interleukins (IL), and reactive oxygen species provoking colonic inflammation. D-glucosamine (D-GLU) is reported to suppress oxidative stress, and pro-inflammatory cytokines and acts as a starting material for biosynthesis of NAG. The potential of D-GLU and its combination with mesalamine (5-ASA) was investigated in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-instigated IBD in Wistar rats. Standard and test drugs were given orally for five days to separate groups of rats. Colonic inflammation was evaluated by disease activity score rate (DASR), colon/body weight ratio, colon length, diameter, colon pH, histological injury and score. Inflammatory biomarkers IL-1β, TNF-α, along with reduced glutathione (GSH), and malondialdehyde (MDA) were assessed. Combination of D-GLU +5-ASA significantly ameliorated severity of colonic inflammation by lowering DASR (P < 0.001) and colon/body weight ratio (P < 0.001), restored the colonic architecture and suppressed the histopathological score (P < 0.001), along with the absence of major adverse reactions. The combination suppressed the levels of inflammatory markers (P < 0.001) and MDA (P < 0.001) while enhancing GSH level (P < 0.001). In comparison to individual 5-ASA and D-GLU, combination of drugs significantly diminished colitis severity through their combined anti-inflammatory and antioxidant effects by acting on multiple targets simultaneously. The combination holds remarkable potential in the management of IBD.

Glucosamine for the Treatment of Osteoarthritis: The Time Has Come for Higher-Dose Trials

Although clinical trials with glucosamine in osteoarthritis have yielded mixed results, leading to doubts about its efficacy, the utility of glucosamine for preventing joint destruction and inflammation is well documented in rodent models of arthritis, including models of spontaneous osteoarthritis. The benefit of oral glucosamine in adjuvant arthritis is markedly dose dependent, likely reflecting a modulation of tissue levels of UDP-N-acetylglucosamine that in turn influences mucopolysaccharide synthesis and the extent of protein O-GlcNAcylation. Importantly, the minimal oral dose of glucosamine that exerts a detectible benefit in adjuvant arthritis achieves plasma glucosamine levels similar to those achieved when the standard clinical dose of glucosamine, 1.5 g daily, is administered as a bolus. The response of plasma glucosamine levels to an increase in glucosamine intake is nearly linear. Remarkably, every published clinical trial with glucosamine has employed the same 1.5 g dose that Rottapharm recommended for its proprietary glucosamine sulfate product decades ago, yet there has never been any published evidence that this dose is optimal with respect to efficacy and side effects. If this dose is on the edge of demonstrable clinical efficacy when experimental design is ideal, then variations in the patient populations targeted, the assessment vehicles employed, and the potency of glucosamine preparations tested could be expected to yield some null results. Failure to employ bolus dosing may also be a factor in the null results observed in the GAIT study and other trials. Clinical studies evaluating the dose dependency of glucosamine's influence on osteoarthritis are long overdue.

Cardamonin (2',4'-dihydroxy-6'-methoxychalcone) isolated from Boesenbergia rotunda (L.) Mansf. inhibits CFA-induced rheumatoid arthritis in rats

Boesenbergia rotunda (L.) Mansf. had been traditionally used as herbs to treat pain and rheumatism. Cardamonin (2',4'-dihydroxy-6'-methoxychalcone) is a compound isolated from Boesenbergia rotunda (L.) Mansf.. Previous study had shown the potential of cardamonin in inhibiting the release of pro-inflammatory cytokines such as tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) in vitro. Thus, the possible therapeutic effect of cardamonin in the rheumatoid arthritis (RA) joints is postulated. This study was performed to investigate the anti-arthritic properties of cardamonin in rat model of induced RA, particularly on the inflammatory and pain response of RA. Rheumatoid arthritis paw inflammation was induced by intraplantar (i.pl.) injection of complete Freund's adjuvant (CFA) in Sprague Dawley rats. Using four doses of cardamonin (0.625, 1.25, 2.5, and 5.0mg/kg), anti-arthritic activity was evaluated through the paw edema, mechanical allodynia and thermal hyperalgesia responses. Enzyme-linked immunosorbent assay (ELISA) was carried out to evaluate the plasma level of TNF-α, IL-1β, and IL-6. Histological slides were prepared from the harvested rat paws to observe the arthritic changes in the joints. Behavioral, biochemical, and histological studies showed that cardamonin demonstrated significant inhibition on RA-induced inflammatory and pain responses as well as progression of joint destruction in rats. ELISA results showed that there was significant inhibition in TNF-α, IL-1β, and IL-6 levels in plasma of the cardamonin-treated RA rats. Overall, cardamonin possesses potential anti-arthritic properties in CFA-induced RA rat model.

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

Context Fibrates were reported to have anti-inflammatory effects while the naturally occurring polyphenol resveratrol was traditionally known as a potent antioxidant agent. Objective The effects of fenofibrate and resveratrol were investigated on complete Freund's adjuvant (CFA)-induced rheumatoid arthritis (RA) in adult female albino rats. Materials and methods Rats were divided into a normal control group, an arthritis control group receiving CFA, two reference treatment groups receiving dexamesathone (1.5 mg/kg/day) and methotrexate (1 mg/kg/day), and two treatment groups receiving fenofibrate (100 mg/kg/day) and resveratrol (10 mg/kg/day) for seven consecutive days. Assessment of RA was performed by measuring serum rheumatoid factor (RF), matrix metalloprotinease-3 (MMP-3) and cartilage oligomeric matrix protein (COMP) as specific rheumatoid biomarkers, immunoglobulin G (IgG) and antinuclear antibody (ANA) as immunological biomarkers, tumour necrosis factor-alpha (TNF-α) and interleukin-10 (IL-10) as immunomodulatory cytokines, myeloperoxidase (MPO) and C-reactive protein (CRP) as inflammatory biomarkers and malondialdehyde (MDA) and glutathione (GSH) as oxidative stress biomarkers, supported by a histopathological study on joints and spleens. Results Serum RF, MMP-3, COMP, IgG, ANA, TNF-α, MPO, CRP and MDA were decreased to about 36, 56, 66, 65, 9, 35, 24, 44 and 31% by fenofibrate, and to about 37, 59, 44, 70, 5, 30, 23, 33 and 28% by resveratrol treatments, respectively. Alternatively, serum IL-10 and GSH were significantly increased to about 215 and 251% by fenofibrate and to about 225 and 273% by resveratrol treatments, respectively. Discussion and conclusion Fenofibrate and resveratrol protect against RA, possibly through their immunomodulatory, anti-inflammatory and antioxidant potential.

Ramipril and haloperidol as promising approaches in managing rheumatoid arthritis in rats

Rheumatoid arthritis (RA) is a challenging autoimmune disorder, whose treatments usually cause severe gastrointestinal, renal and other complications. We aimed to evaluate the beneficial anti-arthritic effects of an angiotensin converting enzyme (ACE) inhibitor, ramipril and a dopamine receptor blocker, haloperidol, on Complete Freund's Adjuvant-induced RA in adult female albino rats. 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 ramipril (0.9 mg/kg/day) and haloperidol (1 mg/kg/day). Serum rheumatoid factor, matrix metalloprotinease-3 (MMP-3) and cartilage oligomeric matrix protein as specific rheumatoid biomarkers, serum immunoglobulin G and antinuclear antibody as immunological biomarkers, serum tumor necrosis factor alpha (TNF-α) and interleukin-10 (IL-10) as immunomodulatory cytokines, serum myeloperoxidase and C-reactive protein as inflammatory biomarkers, as well as malondialdehyde and glutathione reduced (GSH) as oxidative stress biomarkers were assessed. A histopathological study on joints and spleens was performed to support the results of biochemical estimations. Ramipril administration significantly corrected all the measured biomarkers, being restored back to normal levels except for MMP-3, TNF-α and IL-10. Haloperidol administration restored all the measured biomarkers back to normal levels except for TNF-α, IL-10 and GSH. In conclusion, ACE inhibitors represented by ramipril and dopamine receptor blockers represented by haloperidol may represent new promising protective strategies against RA, at least owing to their immunomodulatory, anti-inflammatory and antioxidant potentials.