Protective effect of latex of Calotropis procera in Freund's Complete Adjuvant induced monoarthritis.

The protective effect of latex of Calotropis procera in Freund's Complete Adjuvant (FCA) induced monoarticular arthritis was evaluated in rats. Arthritis was induced by a single intra-articular injection of 0.1 mL of 0.1% FCA in the right ankle joint. The effect of dried latex (DL, 200 and 400 mg/kg) and its methanol extract (MeDL, 50 and 500 mg/kg) following oral administration was evaluated on joint inflammation, hyperalgesia, locomotor function and histology at the time of peak inflammation. The effects of DL and MeDL were compared with antiinflammatory drugs phenylbutazone (100 mg/kg), prednisolone (20 mg/kg), rofecoxib (20 and 100 mg/kg) and immuno-suppressant methotrexate (0.3 mg/kg). Daily oral administration of DL and its methanol extract (MeDL) produced a significant reduction in joint inflammation (about 50% and 80% inhibition) and associated hyperalgesia. The antihyperalgesic effect of MeDL was comparable to that of rofecoxib. Both DL and MeDL produced a marked improvement in the motility and stair climbing ability of the rats. The histological analysis of the arthritic joint also revealed significant reduction in oedema and cellular infiltration by MeDL that was comparable to that of rofecoxib. Thus, our study suggests that the latex of C. procera has the potential to be used as an antiarthritic agent. Copyright © 2008 John Wiley & Sons, Ltd.