Anti-human immunodeficency virus activities of proteins from 17 species of plants

In order to find new anti human immunodeficiency virus (HIV) ribosome inactivating proteins (RIPs), the anti HIV activities of 47 RIPs and crude proteins from 17 species of plants were examined by the following measurements: 1) the inhibition of syncytia formation; 2) the protection of HIV 1 infected cell;3) inhibition of HIV 1 infected cell fusion in coculture;4) reduction of p24 antigen expression and numbers of HIV antigen positive cells in acutely and chronically infected culture. Among 47 proteins, trichosanthin (TCS) (SI=193.3) from Trichosanthes kirilowii, protein fractions Ⅴ (SI=243) and Ⅵ (SI>1200) from Trichosanthes damiaoshanesis were found to obviously inhibit syncytia formation induced by HIV 1. Crotin Ⅰ from Croton tiglium, luffin from Luffa cylinarica , RIPs from odgsonia macrocarpa and Entada phaseoloides showed slightly inhibition of the syncytia formation (SI<50). Crude protein extracts from Trichosanthes Ovigera, Momordica macrophylla and an unnamed plant growing in