6D) as compared to epimastigotes ( Fig. 6B); only 6.5% of the epimastigotes treated with 2.44 μg/ml melittin were TUNEL-positive as compared to 47.8% of the trypomastigotes treated with 0.14 μg/ml melittin. Furthermore, only 8% of the epimastigotes that were treated with 1.22 μg/ml (half IC50) were TUNEL-positive as compared to 49.7% of the trypomastigotes that were treated with half LD50. The data obtained with the ultrastructural

techniques and fluorescent markers strongly suggested that the mechanisms of cell death triggered by the melittin peptide in the epimastigote and trypomastigote T. cruzi forms were autophagy and apoptosis, respectively. Natural products (such as animal venom) and their derivatives represent more than 30% of the pharmaceuticals currently on the market (Kirkpatrick, 2002) and are the major sources of innovative DAPT nmr therapeutic agents for diseases caused by bacteria, parasites and fungi (Altmann, 2001). Following this approach, animal venom has been screened as a potential agent for the treatment of neglected parasitic diseases (Gonçalves et al., 2002; Adade et al., 2011; Brand et al., 2006; Toyama et al., 2006; Passero et al., 2007; Adade et al., Src inhibitor 2012). For instance, honeybee venom has been used as a chemotherapy against arthritis (Park et al., 2004), rheumatism (Kwon et al., 2002), back pain (Chen et al., 2006) and cancerous tumors (Huh et al.,

2010; Wang et al., 2009; Park et al., 2011). Melittin is the principal toxic component in A. mellifera venom, and few studies have examined its antiparasitic effects ( Díaz-Achirica et al., 1998; Chicharro et al., 2001; Luque-Ortega et al., 2003; Alberola et al., 2004; Pérez-Cordero et al., 2011; Park and Lee, 2010). Thus far, the three studies that have investigated the lytic effects of melittin on T. cruzi only considered the epimastigote and trypomastigote forms of the parasite, without characterize the melittin effects over parasites morphology ( Azambuja et al.,

1989; Jacobs et al., 2003; Fieck et al., 2010). Our group previously published the effects of crude A. mellifera venom on all T. cruzi developmental forms, and we focused on the differences Glutamate dehydrogenase in the cell death phenotypes displayed by treated parasites ( Adade et al., 2012). Thus, the current study aimed to (i) evaluate melittin as the main component responsible for the A. mellifera venom trypanocidal activity and consequently the distinct cell death profiles observed; (ii) investigate the capacity of the isolated peptide to act on the intracellular amastigotes; and finally, (iii) investigate the toxicity of melittin against epithelial cells and mice resident macrophages, cells which were not previously tested in the literature and are important in the control of the parasite at different stages of Chagas disease, to verify the possibility of its use as a hybrid in future assays.