Effect of Plumbagin on Con A induced T cell proliferation in collagen Type II induced arthritis. Two groups of DBA/1 mice immunized with 0.1 ml of bovine type II collagen intradermally at the base of the tail. Booster dose was given on day 21. Normal group did not receive any injection. Test group was treated intraperitoneally with Plumbagin. Control group was treated with vehicle alone. At the end of the experiment mice were sacrificed, and Spleenic T lymphocytes isolated from arthritic mice, Plumbagin treated mice and normal mice were incubated with 1μg and 2μg of Con A and maintained the conditions similar to the previous culture experiments. Cultures were pulsed with 0.5 μci of radioactive thymidine per well and the incorporation of radioactivity was measured in scintillation counter after 18 hours of incubation. Native T cells without Con A stimulation served as blank. p-value≤0.05 was significant.