Screening of 25 Euphorbiaceae for their in vitro cytotoxic activity against two cancer cell lines

Twenty five plant species belonging to the Euphorbiaceae family were obtained from growing plants from “Tropical Plant Factory” project - ULiege/InBioS, from Meise Botanic Garden collections, from “Observatoire du Monde des Plantes” - ULiege and from our pharmacognosy lab collection. A total of 40 samples were collected and dichloromethane as well as methanol crude extracts were prepared from each of them. Their cytotoxic activity was evaluated in vitro on two human cancerous cell lines (MDA-MB-231 breast carcinoma and A2058 melanoma), using the Presto Blue assay. The activities were classified into three levels according to the IC50 (promising : < 10µg/ml ; moderate: 10-50µg/ml ; weakly or not active : > 50µg/ml). Almost all the tested species were found cytotoxic towards the A2058 melanoma cells with a promising cytotoxic activity detected for 10 of them (Jatropha gossypiifolia, Euphorbia griffithii, Euphorbia grandicornis, Euphorbia ingens, Euphorbia tirucalli, Euphorbia esula, Euphorbia candelabrum, Euphorbia lathyris, Jatropha curcas, Euphorbia paganorum), while 13 species were moderately active. On the contrary, none of the tested Euphorbiaceae species was found highly active against MDA-MB-231 breast carcinoma cells, while ten of them showed only moderate cytotoxic properties against this cell line. Our results indicate a potent cytotoxicity and selectivity against melanoma cancer cells for active extracts obtained from Euphorbiaceae plants.