Diterpenoids from Euphorbiaceae with Potent Anti-CHIKV and Anti-HIV Activities: Are these Antiviral Properties Correlated?

In the course of our ongoing program focusing on the characterization of anti-CHIKV (Chikungunya virus) compounds from higher plants, we found that several diterpenoids possessing daphnane, tigliane or jatrophane carbon skeletons, isolated from various Euphorbiaceae species were potent and selective inhibitors of the CHIKV replication. Since some daphnane-type and tigliane-type diterpenoids, such TPA and Prostratin, are well known to possess anti-HIV activities, we evaluated the antiviral activity of compounds isolated, as well as commercially available phorbol esters on HIV-1 and HIV-2 viruses. The results of this biological survey, still under investigation, indicate that potent anti-CHIKV diterpenoids possess also anti-HIV activities. Chikungunya virus (CHIKV) is an alpha virus (Togaviridae) that is transmitted to humans mainly by Aedes aegypti and A. albopictus mosquitoes, while HIV virus is a lentivirus (Retroviridae). Although there is no apparent relationship between these viruses, the mechanism of action by which diterpenoids would act could involve similar targets for the two viruses. We will report in this communication the main structural characteristics of the diterpenoids isolated and their antiviral activities on CHIKV, SINV (Sindbis virus), SFV (Semliki forest virus) and HIV viruses.