**4. Biological Studies**

The basis of the apparent selectivity of Jaburetox and Soyuretox towards certain organisms without affecting others is not well understood. As mentioned before, studies of acute toxicity injecting or feeding Jaburetox in murine models resulted in no effect [57]. Standardized in vitro assays indicated that Jaburetox did not cause cito- or genotoxicity in human and other mammalian cell lines [70]. Regarding Soyuretox, embryotoxicity assays in the zebrafish model demonstrated the lack of effect of the peptide on several developmental and behavioral parameters [64]. On the other hand, both peptides presented potent insecticidal and antimicrobial effects (discussed in the following subsections). A possible explanation for this selectivity could be related to the fact that

these peptides have more affinity for certain types of membrane lipids than others. Thus, the presence of these and possibly other molecules in susceptible cells could be necessary for the peptide to act upon. The biosecurity profile of Jaburetox seems promising since, in addition to the lack of toxic effects observed so far in vertebrates, a risk assessment study could not identify potential adverse reactions associated to the peptide [65]. Finally, the amino acid sequences of Jaburetox, Soyuretox and their homologs are present in ureases and these enzymes are abundant in several edible plants, including some that are eaten raw [71,72].
