Análise química, atividade antibacteriana e toxicidade da secreção glandular de Rhinella jimi (Stevaux, 2002)

Abstract

Bufonids have parotoid glands that produce important secretions in the passive defense process, they are activated through mechanical pressure, like the bite of some predator. In them, alkaloids, proteins, peptides, steroids and amines were identified, with important pharmacological functions. Rhinella jimi (Stevaux, 2002) is anuran amphibian popularly known as the "cururu toad" and are among the 47 species of amphibians cited with ethnozoological and zooterapeutic use. In this way the present work aims to analyze and compare the chemical composition of the glandular secretion of the species Rhinella jimi; Evaluate its action against bacteria of standard and multiresistant strains; To analyze the effect of secretion combined with antibacterial drugs. The animals were captured by active collection, anesthetized and then had the parotoid glands pressed for removal of the secretion. To identify cutaneous secretion, reverse phase high performance liquid chromatography (RP-HPLC) was used in a binary HPLC system, and mass spectrometry. Standard strains were used to determine the Minimum Inhibitory Concentration (MIC) and, for antibiotic modulating activity, the clinical isolates Escherichia coli 06, Pseudomonas aeruginosa 03 and Staphylococcus aureus 10. The modulatory activity was evaluated by the microdilution method in broth and Had aminoglycosides (amikacin and gentamicin) and β-lactams (Imipenem and Oxacillin) as antibiotics. The results showed similar profiles in the three samples studied, the peaks of 205 m/z, 203 m/z, 401 m/z, 403 m/z, 387 m/z, corresponding respectively to bufotenin, dehydrobufotenin, marinobufagine, telocinobufaline and bufalin. Secretions when used alone had no effect on the bacterial strains tested, but in combination with antibiotics they had a significant reduction of MIC in both aminoglycosides and β-lactams. Glandular secretion of Rhinella jimi demonstrated clinically relevant results at modulation. This is an interesting alternative since it can serve as a starting point for the production of new pharmaceutical compositions or a complement to existing antibiotics.