Topical anti-inflammatory activity of Solenostemma argel leaves

The topical anti-inflammatory activity of Solenostemma argel Hayne leaves was evaluated using the Croton oil ear test in mice. A bioassay-guided fractionation procedure led to a highly active chloroform extract: at 300 μg/cm2, it induced 73% oedema reduction, while the reference drug indomethacin (100 μg/cm2) induced 56% reduction. The extract contained a new pregnene glycoside (1, solenoside A) and the known 14β,15α-dihydroxy-Δ4pregnene-3,20 dione (2), kaempferol-3-O-glucoside (3) and kaempferol-3-O-rutinoside (4). Their structures were determined by ID and 2D NMR experiments as well as HRMS. Compounds 2 and 4 showed anti-inflammatory activity comparable to that of indomethacin.