Protective Effect of Proteins Derived from Seed Explant Cultures of Calotropis procera in a Preclinical Model of Arthritis

Abstract

Proteins isolated from the in vitro cultures of callus and roots developed from the germinating seed explants of Calotropis procera were evaluated for their protective effect in a rat model of arthritis at 1 and 5 mg/kg doses in two independent sets of experiments comprising of respective controls. Joint swelling, functional parameters, markers of inflammation, oxidative stress, tissue histology, and cyclooxygenase-2 expression in these rats were compared with those treated with the standard anti-inflammatory drug diclofenac on day 3. Both callus and root proteins produced a dose-dependent reduction in joint swelling, and at the 5-mg/kg dose, their inhibitory effect was more pronounced (57 and 55 % inhibition) than that of diclofenac (42 and 46 % in two sets). Both of the protein fractions alleviated functional limitations in arthritic rats and normalized the levels of prostaglandin E 2 , tumor necrosis factor- α , and other biochemical markers of inflammation and oxidative stress, maintained tissue architecture, and suppressed cyclooxygenase-2 expression compared to arthritic controls. This study demonstrates that the proteins derived from the in vitro culture of C. procera explants have potential in the treatment of arthritis.