Bioassay-guided separation of the proinflammatory constituents from the roots of Euphorbia kansui

In view of the toxic inflammatory reaction induced by Euphorbia kansui roots, a traditional Chinese medicine used for the treatment of edema, ascites, and asthma, the 95% ethanol extract was found to have a significant stimulating effect on inflammatory cells. Bioassay-guided separation of the 95% ethanol extract from the roots of E. kansui led to the isolation of five diterpenoids whose structures were identified by H-1, C-13 NMR spectroscopy and HR-ESI-MS as kansuinine B (1), kansuinine A (2), kansuiphorin C (3), 3-O-benzoyl-20-deoxyingenol (4), and 3-O-(2'E,4'Z-decadienoyl)-20-O-acetylingenol (5). The proinflammatory effect of compounds 1-5 was evaluated in vitro in models of inflammation using exoteric mice splenic lymphocytes (SPL) and rat peritoneal macrophages (PM phi). Compounds 1, 2, and 5 markedly promoted SPL proliferation and NO production by PM phi at concentrations from 0.78 to 12.50 mu g/mL. Hence the three compounds are believed to be important proinflammatory components of the roots of E. kansui.