Abstract

Natural products are a very productive source of leads for the development of medicines. Seven Brazilian Asteraceae adult plants were randomly chosen. The current study was designed to evaluate the antiprotozoal and cytotoxic activities in vitro of 21 extracts obtained. Phytochemical properties of the most active extracts also were checked. Cytotoxic activity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method against human tumor cell lines (HCT-116, OVCAR 8 and SF-295). The antiprotozoal activity was evaluated against Trichomonas vaginalis, Entamoeba histolytica and Giardia lamblia.None of the extracts showed antiprotozoal activity. However, 76% of the extracts displayed moderate to high in vitro cytotoxic activities against human cancer cell which suggests that they are a promising source of anticancer compound, since none of the extracts showed hemolytic activity. Terpenoids, flavonoids, saponins, tannins, besides other compound classes, were identified and may be responsible for their antitumor activity. Cytotoxic assays indicate the anticancer potential of Asteraceae species from Brazil.

Key words: Drug prospecting, Antiprotozoal agents, Cytotoxicity, Drug screening assays, Brazilian plant.