A Comparative Study of the Biological Activity of Skin and Granular Gland Secretions of Leptodactylus latrans and Hypsiboas pulchellus from Argentina

Abstract

The potential of the skin of anuran amphibians as a new source of bioactive peptides was investigated . For this purpose, the study collected data in the mid-eastern region of Argentina. Two anuran amphibian species were studied which belong to the Hylidae and Leptodactylidae families, Leptodatylus latrans (Ll) and Hypsiboas pulchellus (Hp). Two methods for the extraction of bioactive components were compared in their effectiveness: solvent extraction (SE) and transcutaneous amphibian stimulation (TAS). Two different approaches were used to study the extracts: i) the direct analysis of the complete samples by MALDI-TOF-MS, and ii) the characterization of bioactive fractions obtained by HPLC and analyzed by MS. The results show that not only the composition of the samples obtained by SE and TAS is different but also their antimicrobial activity. In this sense, only the extracts obtained from Ll and Hp by SE inhibited the growth of Mycobacterium tuberculosis H37Rv. The inhibitory activity of the extracts against the butyrylcholinesterase enzyme (BChE) was also investigated. Samples of Ll showed low percentages of inhibition whereas in Hp samples, the inhibition was moderate (40 -44%). The results suggest that the inhibitory activity of Hp is related to the presence of low molecular weight compounds.