Effect of Plumbagin on collagen type II induced arthritis. Arthritis was induced in two groups (5 per each group) of mice by injecting collagen type II (CII) along with complete Freund's adjuvant (CII+CFA). Control group with CFA alone. Booster dose was given on day 21. One arthritic group was treated with Plumbagin (PZE-6) another treated with olive oil alone. Retroorbital sera were collected at 3, 5, 7 week intervals for the estimation of anti-type II collagen antibody (IgG) by ELISA. Bars represent means±SEM from n = 5. p-value≤0.05 was significant.