Levels of various serum proteins were found to change in adjuvant induced arthritis. Increased levels of a glycoprotein with an apparent molecular weight of 72 kDa (Gp A72) were observed in the sera of arthritic rats. Gp A72 is an acidic glycoprotein with a pI of 5.1. Gp A72 also showed antitryptic activity. The appearance of Gp A72 in the serum preceded the onset of paw inflammation in arthritic rats and persisted in the chronic phase. Oral administration of the antiinflammatory spice principles-capsaicin (from red pepper) and curcumin (from turmeric) lowered the levels of Gp A72 by 88 and 73% respectively with concomitant lowering of paw inflammation in arthritic rats.