Markers of inflammation and oxidative stress studied in adjuvant-induced arthritis in the rat on systemic and local level affected by pinosylvin and methotrexate and their combination

Abstract

Oxidative stress (OS) is important in the pathogenesis of autoimmune diseases such as rheumatoid arthritis (RA) and its experimental model – adjuvant arthritis (AA). Antioxidants are scarcely studied in autoimmunity, and future analyses are needed to assess its effects in ameliorating these diseases. Although there are studies about antioxidants effects on the course of RA, their role in combination therapy has not yet been studied in detail, especially on extra-articular manifestations of AA. During the 28-d administration of pinosylvin (PIN) in monotherapy and in combination with methotrexate (MTX) to AA rats, we evaluated the impact of the treatment on selected parameters. The experiment included: healthy controls, untreated AA, AA administered 50 mg/kg b.w. of PIN daily p.o., AA administered 0.4 mg/kg b.w. of MTX twice weekly p.o. and AA treated with a combination of PIN+MTX. AA was monitored using: hind paw volume, C-reactive protein, monocyte chemotactic protein-1 (MCP-1), thiobarbituric acid reactive substances (TBARS) and F2-isoprostanes in plasma, γ-glutamyltransferase activity in spleen, activity of lipoxygenase (LOX) in lung, heme oxygenase-1 (HO-1) and nuclear factor kappa B (NF-κB) in liver and lung. PIN monotherapy significantly improved the activation of NF-κB in liver and lung, HO-1 expression and activity of LOX in the lung, MCP-1 levels in plasma (on 14th d) and plasmatic levels of F2-isoprostanes. An important contribution of PIN to MTX effect was the reduction of OS (an increase of HO-1 expression in lung and reduction of plasmatic TBARS) and decrease of LOX activity in the lung.

• Autoimmunity
• antioxidants
• combination therapy
• extra-articular manifestation
• rheumatoid arthritis

Acknowledgements

We wish to thank 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) for the synthesis and analysis of pinosylvin for this experiment.

Declaration of interest

We wish to confirm that there are no known conflicts of interest associated with this publication and there has been no other significant financial support for this work that could have influenced its outcome. We confirm that the manuscript has been read and approved by all named authors and that there are no other persons who satisfied the criteria for authorship but are not listed. We further confirm that the order of authors listed in the manuscript has been approved by all of us.

This study was supported by grants: APVV-031507, APVV-0052-10, VEGA 2/0045/11 and performed in the frame of two SAS-CNR bilateral projects coordinated by Dr. Bauerova (Slovakia) and Dr. Russo (Italy): “Phytochemicals in ameliorating rheumatoid arthritis therapy: from preclinical studies to clinical applications” and “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”.