Anadenanthera colubrina (VELL.) Brenan: Perfil químico e atividade anticandida, antibiofilme, antitumoral e citotóxica

Abstract

Introduction: Studies on the biological properties of plant extracts are important for new natural therapeutic formulations development. Objective: This study investigated the chemical profile and antifungal, antibiofilm, antitumoral and cytotoxic activities of the hydroalcoholic extract of the Anadenanthera colubrina (Vell.) Brenan bark. Materials and Methods: The chemical composition was investigated by High Performance Liquid Chromatography (HPLC) and Gas Chromatography Coupled to Mass Spectrometer (GC-MS). In the antimicrobial analyzes, microdilution assays were carried out in broth for Minimum Inhibitory Concentration (MIC) determination, with and without sorbitol, and Minimum Fungicidal Concentration (CFM). For the antibiofilm activity analysis two concentrations of the extract (500 μg/mL and 1000 μg/mL) on C. albicans biofilm were tested and posterior morphological evaluation in both inverted optical and fluorescence microscopy. The crude extract and fractions antiproliferative activity, on human tumor cell lines and non-tumor cells, were evaluated by the Suforrodamine B method. The tests on fibroblasts and pre-osteoblasts were evaluated. carried out by the MTT [3- (4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide] assay. Results: The A. colubrina extract revealed the presence of flavonoids, triterpenes, steroids and phenolic acids. It had strong antifungal activity on the standard strains and moderate activity for clinical strains. In the presence of sorbitol, the MIC was equal to or greater than 2000 μg/mL. The extract also presented antibiofilm activity, with evident reduction in the number of CFU/mL and morphological alterations. In relation to the antitumor activity, it presented a non-specific cytostatic effect, with a reduction in cell proliferation for all tested tumor lines and keratinocytes, with no evidence of cytocidal effect up to 250 μg/mL. The dichloromethane:methanol fraction showed a cytocidal effect on the PC-3, NCI-H460 and NCI/ADR-RES. No cytotoxic effect of the extract was observed up to the concentrations of 62.5 μg/mL in the macrophages, 60 μg/mL for fibroblasts and 90 μg/mL for pre-osteoblasts. Conclusions: The A. colubrina extract reveals predominance of phenolic compounds, with significant antifungal activity against Candida and antibiofilm action, resulting from the probable interaction with the cell wall of C. albicans. It presents low toxicity on human tumor cell lines and non-tumor cells, with cytocidal effect on tumor cells, through its dichloromethane:methanol fraction.