Anti-Inflammatory Effects of Ursolic Acid Figure 3. Ursolic acid inhibits cytokine secretion by T cells and macrophages. Lymphocytes were pre-treated with different concentrations of UA for 4 h before stimulation with Con A (5 mg/ml) (A) or anti-CD3/anti-CD28 mAb (B) for 24 h at 37uC. Vehicle treated cells served as control. The concentration of cytokines in the culture supernatant was estimated using ELISA. (C) UA inhibits anti-CD3/anti-CD28 induced cytokine secretion by CD4+T cells. Purified CD4+T cells were pre-treated with different concentrations of UA for 4 h before stimulation with anti-CD3/anti-CD28 mAb for PLoS ONE | www.plosone.org 6 February 2012 | Volume 7 | Issue 2 | e31318