AUTHOR=Patriota Leydianne L. S. , Procópio Thamara F. , de Souza Maria F. D. , de Oliveira Ana Patrícia S. , Carvalho Lidiane V. N. , Pitta Maira G. R. , Rego Moacyr J. B. M. , Paiva Patrícia M. G. , Pontual Emmanuel V. , Napoleão Thiago H. 

TITLE=A Trypsin Inhibitor from Tecoma stans Leaves Inhibits Growth and Promotes ATP Depletion and Lipid Peroxidation in Candida albicans and Candida krusei

JOURNAL=Frontiers in Microbiology

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.00611

DOI=10.3389/fmicb.2016.00611

ISSN=1664-302X

ABSTRACT=<p><italic>Tecoma stans</italic> (yellow elder) has shown medicinal properties and antimicrobial activity. Previous reports on antifungal activity of <italic>T. stans</italic> preparations and presence of trypsin inhibitor activity from <italic>T. stans</italic> leaves stimulated the investigation reported here. In this work, we proceeded to the purification and characterization of a trypsin inhibitor (TesTI), which was investigated for anti-<italic>Candida</italic> activity. Finally, in order to determine the potential of TesTI as a new natural chemotherapeutic product, its cytotoxicity to human peripheral blood mononuclear cells (PBMCs) was evaluated. TesTI was isolated from saline extract by ammonium sulfate fractionation followed by ion exchange and gel filtration chromatographies. Antifungal activity was evaluated by determining the minimal inhibitory (MIC) and fungicide (MFC) concentrations using fungal cultures containing only yeast form or both yeast and hyphal forms. <italic>Candida</italic> cells treated with TesTI were evaluated for intracellular ATP levels and lipid peroxidation. Cytotoxicity of TesTI to PBMCs was evaluated by MTT assay. TesTI (39.8 kDa, pI 3.41, <italic>K</italic><sub>i</sub> 43 nM) inhibited similarly the growth of both <italic>C. albicans</italic> and <italic>C. krusei</italic> culture types at MIC of 100 μg/mL. The MFCs were 200 μg/mL for <italic>C. albicans</italic> and <italic>C. krusei</italic>. Time-response curves revealed that TesTI (at MIC) was more effective at inhibiting the replication of <italic>C. albicans</italic> cells. At MIC, TesTI promoted reduction of ATP levels and lipid peroxidation in the <italic>Candida</italic> cells, being not cytotoxic to PBMCs. In conclusion, TesTI is an antifungal agent against <italic>C. albicans</italic> and <italic>C. krusei</italic>, without toxicity to human cells.</p>