Pharmaceutics from frogs

Frogs produce chemicals in their skin glands that can be of great interest for the pharmaceutical industry. During her PhD research Geisa Evaristo developed techniques to better analyze these compounds.

In her PhD thesis, which Geisa Evaristo will defend next month at the faculty of Applies Sciences, the researcher describes methods using mass spectrometry that help characterize the so-called bioactive peptides that frogs produce as a defense mechanism against bacterial infections, for example. Evaristo worked together with researchers from the Natural Drug Discovery Laboratory of  Queen’s University in Belfast, Northern Ireland.

“Although the complete genome of a frog species has been mapped, the analysis of frog peptides remains difficult,” the researcher says. The difficulty lies in the fact that during evolution each frog species has gathered its own set of bioactive peptides encoded in its genes, and that many of these peptides undergo a posttranslational modification, meaning the peptides are being modified by enzymes.

In addition to the interesting biological activities, the skin secretions can also be used for the taxonomical classification of the frogs. This is not an unimportant task, considering that each year new species are discovered.

Evaristo studied the Chinese odorous frog (Odorrana schmackeri), the African frog (Kassina senegalensis), the European fire bellied toad (Bombina variegata) and two Brazilian tree-frog species (Phyllomedusa burmeisteri and Phyllomedusa rohdei). 

For further reading (in Dutch): 'Ze kwaken vrolijk verder'