Anti-inflammatory and antioxidant activities of Costus afer Ker Gawl. hexane leaf fraction in arthritic rat models

Ethnopharmacological relevance: Costus afer Ker Gawl is an indigenous tropical African medicinal plant used as therapy in the treatment of inflammatory ailments such as rheumatoid arthritis. This study was designed to evaluate the anti-inflammatory and antioxidant activities of the hexane fraction of C. afer leaves (CAHLF). Materials and methods: The anti-inflammatory effect of varying doses of CAHLF on carrageenan, arachidonic acid, and formaldehyde induced arthritis in male albino rats' models were investigated in order to study the acute inflammatory phase. Complete Freund's Adjuvant (CFA)-induced arthritis model was used to study the chronic inflammatory phase. Two known anti-inflammatory drugs, Diclofenac sodium (non-steroidal anti-inflammatory drug [NSAID]) and prednisolone (glucocorticoid [steroidal drug]) were used as standards for comparison. Various biochemical indices viz. superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), reduced glutathione (GSH) and malondialdehyde (MDA), aspartate amino transferase (AST), alanine amino transferase (ALT), alkaline phosphatase (ALP), total bilirubin (TB), total protein (TP), globulin and albumin levels were assayed using spectrophotometric methods. Results: Control animals in which arthritis have been induced using carrageenan, arachidonic acid, formaldehyde or CFA showed significant increases (P < 0.05) in paw edema when compared with normal animals. Treatment of the arthritis induced rats with CAHLF significantly (P < 0.05) suppressed the edema, in vivo antioxidant study showed that CAHLF treated animals had a significantly (P < 0.05) elevated GSH level, SOD, CAT and GST activities while MDA levels were significantly (P < 0.05) reduced in the plasma, liver, kidney and brain. CAHLF treated rats had a significantly (P < 0.05) reduced plasma AST, ALT and ALP. Plasma TP, globulin, TB levels were reduced while albumin levels were elevated in CAHLF treated animals. Conclusions: CAHLF possesses substantial anti-inflammatory and antioxidant activities against inflammatory diseases especially arthritis. It could be considered as a choice candidate in pharmaceutical anti-inflammatory drug development. (C) 2014 Elsevier Ireland Ltd. All rights reserved.