The petroleum ether fraction of Celastrus paniculatus Willd. seeds demonstrates anti-arthritic effect in adjuvant-induced arthritis in rats

Celastrus paniculatus (CP) Willd. is a plant indigenous to India with medicinal properties. It is used in the ayurvedic treatment of inflammatory ailments such as rheumatoid arthritis. The present study was designed to investigate the therapeutic efficacy of the petroleum ether fraction (PCP) obtained from CP seeds on adjuvant-induced arthritis in rats.Arthritis was induced in Sprague–Dawley rats by immunization with Freund's complete adjuvant (FCA). Arthritis severity was evaluated by arthritis score, paw volume, tibiotarsal joint thickness, body weight, dorsal flexion pain, motility test, stair climbing ability and index of thymus and spleen. Moreover, histopathology of knee joints supported by haematological analysis was used to assess the anti-arthritic action of PCP. The levels of superoxide dismutase (SOD), glutathione (GSH), catalase (CAT), nitric oxide (NO) and malondialdehyde (MDA) in liver were also assessed. Serum samples were collected for estimation of aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP). In addition, cytokines such as tumour necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) were estimated in plasma.PCP significantly alleviated arthritic progression with regards to paw swelling, arthritic score, immune organ indices, hyperalgesic effect and body weight. This phenomenon was correlated with significant suppression of overproduction of inflammatory cytokines (TNF-α and IL-6), oxidant stress markers (MDA and NO) and cellular enzyme (AST, ALT and ALP) levels versus arthritic rats without treatment. Moreover, PCP restored the decreased levels of SOD, CAT and GSH.Our results suggest that the anti-arthritic properties of PCP may be due to immunosuppressive effects, cytokine regulation, antioxidant effects and bone-protective activities.