Effect of Carnosine in Experimental Arthritis and on Primary Culture Chondrocytes.

Carnosine's (CARN) anti-inflammatory potential in autoimmune diseases has been but scarcely investigated as yet. The aim of this study was to evaluate the therapeutic potential of CARN in rat adjuvant arthritis, in the model of carrageenan induced hind paw edema (CARA), and also in primary culture of chondrocytes under H2O2 injury. The experiments were done on healthy animals, arthritic animals, and arthritic animals with oral administration of CARN in a daily dose of 150 mg/kg b.w. during 28 days as well as animals with CARA treated by a single administration of CARN in the same dose. CARN beneficially affected hind paw volume and changes in body weight on day 14 and reduced hind paw swelling in CARA. Markers of oxidative stress in plasma and brain (malondialdehyde, 4-hydroxynonenal, protein carbonyls, and lag time of lipid peroxidation) and also activity of gamma-glutamyltransferase were significantly corrected by CARN. CARN also reduced IL-1alpha in plasma. Suppression of intracellular oxidant levels was also observed in chondrocytes pretreated with CARN. Our results obtained on two animal models showed that CARN has systemic anti-inflammatory activity and protected rat brain and chondrocytes from oxidative stress. This finding suggests that CARN might be beneficial for treatment of arthritic diseases.

Hyperbilirubinemia decreases physiological markers in adjuvant-induced arthritis.

There is evidence that a higher serum level of bilirubin (BIL) may be a protective factor for autoimmune diseases. We examined the effect of BIL supplementation in adjuvant-induced arthritis (AIA) where oxidative stress, inflammation and inadequate immune response are present. Male Lewis rats were randomized into groups: CO - control, AIA - untreated adjuvant-induced arthritis, AIA-BIL - adjuvant-induced arthritis administrated BIL (200 mg/kg b.w. daily i.p. during 14 days). Change of hind paw volume in the AIA-BIL group in comparison to the AIA group was significantly decreased after BIL administration. In CO and AIA groups we found almost untraceable levels of BIL. In the AIA-BIL group hyperbilirubinemia was observed. BIL administration significantly decreased plasma levels of C-reactive protein and ceruloplasmin in the AIA-BIL group in comparison to the AIA group. The values of white and red blood cells, hemoglobin and hematocrit were significantly decreased in AIA-BIL after BIL supplementation. Organs like spleen and thymus had a lower weight in AIA-BIL than in AIA. Histological findings showed decreased or even absent damage in hind paw joint of AIA-BIL animals. We observed an immunomodulatory effect of BIL on AIA development, which may also have a novel pharmacological impact.

Inhibition of oxidative stress in brain during rat adjuvant arthritis by carnosine, trolox and novel trolox-carnosine.

Carnosine (CARN) is an anti-glycating agent able to quench superoxide, and to neutralize 4-hydroxynonenal. Trolox-carnosine (CARN-T) was synthesized because of its resistance against degradation and to improve CARN antioxidant capacity. We evaluated the impact of trolox (TRO), CARN and its derivative CARN-T on oxidative stress (OS) in brain during rat adjuvant arthritis (AA). The experiments were done on healthy, control arthritic and arthritic animals with administration of CARN 150 mg/kg b.w., TRO 41 mg/kg b.w. and CARN-T 75 mg/kg b.w. in a daily dose during 28 days. Antioxidants did not affect the body weight on day 14, but on day 28 TRO enhanced the weight reduction. On day 14 and 28 CARN-T and TRO reduced arthritic score. IL-1beta, MCP-1 and MMP-9 were measured in plasma on day 14. MCP-1 was decreased by CARN-T and TRO. All antioxidants reduced IL-1beta and MMP-9 levels. Malondialdehyde, 4-hydroxynonenal and protein carbonyls were increased in brain. CARN, CARN-T and TRO prevented higher lipid and protein oxidation in brain. CARN and CARN-T caused no weight reduction like TRO that has an advantage in inflammatory arthritis. Moreover the antioxidants administered had a similar therapeutic effects on arthritic score, markers of inflammation in plasma and OS in brain.

Quercetin reduced inflammation and increased antioxidant defense in rat adjuvant arthritis.

Novel therapies for rheumatoid arthritis also include the use of naturally occurring compounds possessing antioxidant properties. In the present work, the effects of oral administration of quercetin were investigated in a rat model of adjuvant arthritis. Arthritis was induced by a single intradermal injection of heat-inactivated Mycobacterium butyricum in incomplete Freund's adjuvant. The experimental groups were treated with an oral daily dose of 150 mg/kg b.w. of quercetin for 28 days. Results indicated that quercetin was able to ameliorate all markers of inflammation and oxidative stress measured. Quercetin lowered levels of interleukin-1ß, C-reactive protein, and monocyte chemotactic protein-1 and restored plasma antioxidant capacity. In addition, quercetin inhibited the enzymatic activity of pro-inflammatory 12/15-lipoxygenase in lung and liver and increased the expression of heme oxygenase-1 in joint and lung of arthritic rats. Finally, quercetin inhibited the 2-fold increase of NF-қB activity observed in lung, liver and joint after induction of arthritis.

Chondroitin sulfate effect on induced arthritis in rats.

OBJECTIVE: Rodent models of osteoarthritis and rheumatoid arthritis are useful tools to study these disease processes. Adjuvant arthritis (AAR) is a model of polyarthritis widely used for preclinical testing of antiarthritis substances. We report the effect of two different doses of highly purified chondroitin sulfate (CS) pharmaceutical grade in the AAR animal model after oral administration. DESIGN: AAR was induced by a single intradermal injection of heat-inactivated Mycobacterium butyricum in incomplete Freund's adjuvant. The experiments included healthy animals, untreated arthritic animals, arthritic animals having been administered 300 or 900 mg/kg of CS daily, 14 days before AAR induction until the end of the experiment (day 28), arthritic animals having been administered 300 or 900 mg/kg of CS daily, from day 1 until the end of the experiment. RESULTS: CS was capable of significantly reducing the severity of arthritis along with oxidative stress, a consequence of chronic inflammatory processes occurring in AAR. The CS pre-treatment regimen was effective throughout the whole subacute phase, while treatment from day 1 proved effective only in the chronic period. The effects were confirmed by improved total antioxidant status and γ-glutamyltransferase activity. CS administered under a pre-treatment regimen was also able to reduce the production of pro-inflammatory cytokines, C-reactive protein in plasma, phagocytic activity and the intracellular oxidative burst of neutrophils. CONCLUSIONS: CS proved to be effective in slowing down AAR development and in reducing disease markers, thus supporting its beneficial activity as a drug in humans.