Protective effect of sub-fraction of methanolic extract of Calotropis procera latex in FCA induced arthritic rats

The latex of the plant Calotropis procera has been reported to exhibit potent anti-inflammatory and anti-arthritic properties in various animal models. In the present study, the methanolic extract of latex of this plant was subjected to column chromatography and 11 fractions were separated using solvents of increasing polarity. In a preliminary screening, fraction No. 9 (F9) out of these 11 fractions was found to exhibit anti-inflammatory property and was further evaluated for its efficay in FCA induced arthritis model. Arthritis was induced by single intra-articular injection of 0.1 ml of 0.1% of Freund's Complete Adjuvant (FCA). The F9 (50 & 150 mg/kg) and diclofenac (5 mg/kg) were given orally 1 hr before injecting FCA and then daily for next 3 days. Parameters like joint diameter, functional disability (motility & dorsal flexion pain), levels of inflammatory markers (myeloperoxidase & nitric oxide), oxidative stress markers (superoxide dismutase & catalase) and tissue histology were measured. The efficacy of F9 was compared with standard anti-inflammatory drug diclofenac. The F9 showed a dose-dependent inhibition of joint inflammation and normalized the functional disability, levels of inflammatory markers and oxidative stress markers and the effect was comparable to that of diclofenac. The treatment of F9 was also found to maintain the tissue integrity in arthritic rats in comparison to that of arthritic control rats. Our results suggests that F9 has the therapeutic potential to be used in the treatment of various arthritic conditions. The charcterization (HPLC) and purification of the F9 has to be done in our future studies.