The protective effect of chondroitin sulfate on induced arthritis in rats.

The protective effect of chondroitin sulfate on induced arthritis in rats

The protective effect of chondroitin sulfate on induced arthritis in rats

The protective effect of chondroitin sulfate on induced arthritis in rat

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

Pinosilvin administered in monotherapy and in combination with methotrexate reduces oxidative stress in adjuvant arthritis rat model

Rheumatoid arthritis (RA) is a common severe joint disease that involves all age groups. This is one of the conditions in which oxidative stress (OS) has been shown to play a role by regulating the progression of the inflammatory response. Adjuvant arthritis (AA) is a rat model of autoimmune erosive arthritis widely used to evaluate etiopathogenetic mechanisms in RA as well as for testing anti-inflammatory drugs. Pinosylvin (PIN), 3,5-dihydroxy-trans-stilbene, is an analogue of resveratrol mainly found in the heartwood of Pinus sylvestris. The aim of the present study was to examine the eventual antioxidant and anti-inflammatory effect of PIN on the progression of AA in rats in monotherapy and in combination with methotrexate (MTX). AA was induced by a single intradermal injection of heat-inactivated Mycobacterium butyricum in incomplete Freund’s adjuvant. The experiments included healthy animals, arthritic animals not treated, arthritic animals treated with MTX, with PIN, and with a combination of PIN and MTX. The two latter groups received a daily oral dose of 50 mg/kg b.w. of PIN, either alone or with MTX in an oral dose of 0.4 mg/kg b.w. twice a week during 28 experimental days. Our data demonstrated that PIN potentiated both the anti-arthritic (decrease of hind paw volume) and the antioxidant effect of MTX (TBARS in plasma). The level of inflammatory protein CRP in plasma and activity of GGT in spleen were not improved by addition of PIN to MTX due to the prominent effect of MTX alone on these parameters. Arthritic animals showed increased OS, also evaluated as plasma levels of isoprostanes. PIN alone or in combination with MTX strongly reduced isoprostane levels (about 50%). Anti-inflammatory and antioxidant functions have been attributed to heme oxygenase (HO-1). Our data show a significant decline in HO-1 (about 40%) in the lung from AA rats. In these animals, PIN alone increased the levels of HO-1 by about 30% more than MTX. Moreover, the combination therapy was the most effective in increasing the levels of HO-1 (3-fold in respect to AA values). Finally, activated NF-B plays an important role in the expression of pro-inflammatory genes. In our model, we observed a marked increase in NF-B in the lung and liver from AA animals. This increase was strongly reduced by PIN alone as well as in combination with MTX. These results suggest that the anti-inflammatory activity of PIN can be mediated by suppression of NF-B activation. In conclusion, PIN is able to reduce OS in AA rat model. In fact, the combined administration of PIN and MTX suppressed arthritic progression more effectively than did MTX alone. This natural compound may then be useful in the treatment of rheumatoid arthritis. Acknowledgement: VEGA 2/0045/11, APVV-052-10, CNR/SAV bilateral project 2010-2012: In vitro and in vivo models of arthritic processes for studying the mechanisms of inflammation and oxidative stress link-up. New perspectives for arthritis therapy. Pinosylvin used in this study was prepared by Prof. Jan Šmidrkal (Institute of Chemical Technology, Prague, Czech Republic) and Ing. Juraj Harmatha, PhD (Institute of Organic Chemistry and Biochemistry, Academy of Sciences of Czech Republic)

Oxidative impairment of plasma and skeletal muscle sarcoplasmic reticulum in rats with adjuvant arthritis - effects of pyridoindole antioxidants

OBJECTIVES: To study possible oxidation of proteins and lipids in plasma and sarcoplasmic reticulum (SR) from skeletal muscles and to assess the effects of pyridoindole antioxidants in rats with adjuvant arthritis (AA) and to analyze modulation of Ca-ATPase activity from SR (SERCA). METHODS: SR was isolated by ultracentrifugation, protein carbonyls in plasma and SR were determined by ELISA. Lipid peroxidation was analyzed by TBARS determination and by mass spectrometry. ATPase activity of SERCA was measured by NADH-coupled enzyme assay. Tryptophan fluorescence was used to analyze conformational alterations. RESULTS: Increase of protein carbonyls and lipid peroxidation was observed in plasma of rats with adjuvant arthritis. Pyridoindole antioxidant stobadine and its methylated derivative SMe1 decreased protein carbonyl formation in plasma, effect of stobadine was significant. Lipid peroxidation of plasma was without any effect of pyridoindole derivatives. Neither protein oxidation nor lipid peroxidation was identified in SR from AA rats. SERCA activity from AA rats increased significantly, stobadine and SMe1 diminished enzyme activity. Ratio of tryptophan fluorescence intensity in SR of AA rats increased and was not influenced by antioxidants. CONCLUSION: Plasma proteins and lipids were oxidatively injured in rats with AA; antioxidants exerted protection only with respect to proteins. In SR, SERCA activity was altered, apparently induced by its conformational changes, as supported by study of tryptophan fluorescence. Stobadine and SMe1 induced a decrease of SERCA activity, elevated in AA rats, but they did not affect conformational changes associated with tryptophan fluorescence

Effect of nonanimal high- and low-molecular-mass chondroitin sulfates produced by a biotechnological process in an animal model of polyarthritis

BACKGROUND/AIMS: We planned to report on the effect of two nonanimal chondroitin sulfates (CSs) with different molecular masses produced using an innovative biotechnological process in an adjuvant arthritis animal model. METHODS: The experiments included healthy animals, untreated arthritic animals and arthritic animals having been administered 900 mg/kg of either of the two CS samples daily. Arthritic score, γ-glutamyltransferase (GGT) activity in hind paw joint tissue homogenates, plasmatic C-reactive protein (CRP) and pro-inflammatory cytokines IL-1β and IL-6 were assayed. RESULTS AND CONCLUSIONS: Low-molecular-mass (LMM) CS significantly reduced the arthritic score by up to about 30% from 14 to 28 days. In contrast, no significant differences were observed for high-molecular-mass (HMM) CS, even if a trend in its capacity to decrease the arthritic score by up to about 11% was observed. Additionally, LMM CS was able to significantly decrease GGT activity by approximately 31% and plasmatic CRP levels by about 9%. Both nonanimal CS samples were effective in reducing plasmatic levels of proinflammatory cytokines. A greater efficacy was also observed for LMM CS compared with a pharmaceutical-grade CS of extractive origin, while the efficacy of the HMM CS sample was found to be rather similar. The greater effect of LMM CS in reducing arthritic parameters may be related to its lower molecular mass with respect to HMM CS and natural CS

Modulation of methotrexate efficacy by green tea polyphenols in rat adjuvant arthritis

Background: Green tea catechins are widely employed as dietary supplements to restore the oxidative state in adjuvant-induced arthritic rats, a model for human rheumatoid arthritis. Methotrexate is the first line antirheumatic drug. The present study aimed to investigate if a decaffeinated extract (GreenSelect®, GS) of tea polyphenols can ameliorate methotrexate treatment in rat adjuvant arthritis. Methods: The study lasted 28 days and included healthy animals administered with GS (daily dose of 200 mg/kg), untreated arthritic rats and arthritic rats treated with: GS, methotrexate in single treatment or in combination with GS. Arthritic score and changes in body weigh were measured during the treatment while inflammatory markers (monocyte chemotactic protein-1, IL-17 and inducible NO-synthase mRNA) and biochemical parameters (gamma-glutamyltransferase and heme oxygenase-1) at the end of the treatment. Results: The association between GS and methotrexate was less efficient in ameliorating the arthritic score compared to methotrexate alone. GS did not improve the inflammatory and biochemical markers except for monocyte chemotactic protein-1 and negatively affected the body weight. GS did not increase the plasma antioxidant capacity, suggesting a pro-oxidant effect. Conclusions: The results suggest that long-term administration of GS may inhibit the therapeutic action of methotrexate in arthritic rats

Activity of pinosylvin administered in monotherapy and in combination with methotrexate on the development of rat adjuvant arthritis

Oxidative stress (OS) has been implicated in various pathological conditions involving several diseases and aging. Rheumatoid arthritis (RA) is a common severe joint disease that involves all age groups. The pathogenesis of RA is associated predominantly with the formation of free radicals at the site of inflammation. However, knowledge on the role of OS in the progression of RA is scarce and the link between OS and inflammation status in arthritis should be more precisely investigated. Pinosylvin (PIN), 3,5-dihydroxy-trans-stilbene, is mainly found in the heartwood of Pinus sylvestris. PIN used in this study was synthesized in the Institute of Organic Chemistry and Biochemistry, Academy of Sciences, Prague, Czech Republic by Ing. Juraj Harmatha, PhD. The aim of the present study was to examine the effect of PIN on the progression of adjuvant-induced arthritis (AA) in rats in monotherapy and in combination with methotrexate (MTX), which is a classical immunosuppressant drug. AA was induced by a single intradermal injection of heat-inactivated Mycobacterium butyricum in incomplete Freund’s adjuvant. The experiments included healthy animals, arthritic animals not treated, arthritic animals treated with MTX, with PIN, and with a combination of PIN and MTX. The two latter groups received a daily oral dose of 50 mg/kg b.w. of PIN, either alone or with MTX in an oral dose of 0.4 mg/kg b.w. twice a week during 28 experimental days. We found that PIN potentiated both the antiarthritic (decrease of hind paw volume) and the antioxidant effect of MTX (reduction of plasmatic levels of TBARS). Activity of GGT in spleen, level of MCP-1 and CRP in plasma were not improved by addition of PIN to MTX due to the prominent effect of MTX alone on these parameters. Arthritic animals showed increased OS, evaluated as plasma levels of isoprostanes. PIN alone or in combination with MTX strongly reduced isoprostane levels (about 50%). On the contrary, a significant decline in Nrf2-regulated antioxidant defences, such as hemeoxygenase-1 (HO-1), was observed in the lung (about 40%) but not in the liver from AA rats. In the AA lung, PIN alone increased the levels of HO-1 by about 30% more than MTX. Moreover, the combination therapy was the most effective in increasing the levels of HO-1 (3-fold in respect to AA values). OS can also activate NF-B, which plays a critical role in the transcription of proinflammatory genes. Our data showed a marked increase in NF-B in the lung and liver from AA animals. This increase was strongly reduced by PIN alone as well as in combination with MTX. Our results suggest that the anti-inflammatory activity of PIN is mediated by suppression of NF-kB activation in the liver and lung of arthritic animals. In summary, combined administration of PIN and MTX suppressed arthritic progression in rats more effectively than did MTX alone. This natural compound is able to reduce OS in vivo and may help improve the treatment of rheumatoid arthritis. Acknowledgement: VEGA 2/0045/11, APVV-0315-07, CNR/SAV bilateral project 2010-2012: In vitro and in vivo models of arthritic processes for studying the mechanisms of inflammation and oxidative stress link-up. New perspectives for arthritis therapy