In vivo antiarthritic activity of the ethanol extracts of stem bark and seeds of Calophyllum inophyllum in Freund’s complete adjuvant induced arthritis

Context: Calophyllum inophyllum Linn. (Clusiaceae) (CI) is traditionally used to treat pain, inflammation, eye disorders and rheumatism. Objective: The present study evaluates the antiarthritic activity of the ethanol extract of the stem bark (ESBCI) and seeds (ESCI) of Calophyllum inophyllum in Freund’s adjuvant induced arthritic Wistar albino rat model. Materials and methods: ESBCI and ESCI were screened for in vitro anti-inflammatory activity by proteinase inhibition and membrane stabilization assays. Acute oral toxicity studies were conducted according to OECD-425 guidelines. Antiarthritic activity of ESBCI and ESCI at the dose of 250 mg/kg/p.o. was evaluated by Freund’s adjuvant induced arthritic rat model. Results: ESBCI and ESCI have shown maximum inhibition at 250 μg/mL in proteinase inhibition and haemolysis assays. The LD50 of ESBCI and ESCI was found to be greater than 5000 and 2000 mg/kg/p.o., respectively. In Freund’s adjuvant induced arthritic rat model ESBCI, ESCI and Diclofenac treatment have shown 28.57, 36.36, and 43.51% as maximum reduction in rat paw oedema volume respectively when compared with the arthritic control rats. ESBCI and ESCI treatment at the dose level of 250 mg/kg/p.o. normalized the altered haematological and biochemical parameters of arthritic control rats. Histological and radiological evaluation confirmed the antiarthritic effect of ESBCI and ESCI. Discussion: ESBCI and ESCI were found to show significant antiarthritic activity evidenced with clinical, biochemical, histological and radiological evaluations. Conclusion: The present study indicates the antiarthritic activity of ESBCI and ESCI, however its mechanism of action has to be studied in the future