Effects of Ursolic Acid and Oleanolic Acid on NO Production.Figure 6 shows the effects of ursolic acid and oleanolic acid on Nitric oxide production in the LPS-stimulated RAW264.7 cells. These results indicated that ursolic acid (7.5 μM) inhibited LPS-stimulated NO production (decrease from 38.45 ( 1.77 to 8.72 ( 1.56 nM) and showed no cytotoxicity (data not shown) in RAW 264.7 cells (Figure 6A). The concentrations used in the present study were consistent with those used in other studies examining the antiinflammatory effect of ursolic and oleanolic acids in RAW264.7 cells (23). However, oleanolic acid did not inhibit LPS-stimulated