Towards the development of an optimized extract of Phytolacca tetramera fruits with anti-Candida effect.

BUTASSI, E.; ZOU, S; SVETAZ, L.; IVANCOVICH, J.; WOLFENDER, J; ZACCHINO, S.

Rosario

Congreso; 4ta Reunión Internacional de Ciencias Farmacéuticas (RICiFa); 2016

Facultad de Ciencias Bioquímicas y Farmacéuticas (UNR) y Facultad de Ciencias Químicas (UNC)

Previous studies on Phytolacca tetramera Hauman (Phytolaccaceae) berries showed that its methanolic (MeOH), dicloromethanic (DCM) and butanolic (BuOH) extracts possessed moderate antifungal activity against Candida albicans and other fungal spp. The bioassay-guided fractionation of the BuOH extract led to the isolation of three monodesmosidic triterpenoid saponins [phytolaccosides (Phyt) B, E and F)] of which, Phyt B showed to act by thickening of the fungal cell wall. Since the wall is absent in mammalian cells, the attack of this target represents an ideal mode of action of antifungal agents that will be non-toxic for human beings. Due to this clinically important mode of action, the aim of this work was to advance in the preparation of a chemically optimized P. tetramera berries-antifungal extract. First of all, the contribution of selected extracts? constituents to the antifungal activity was determined by using a supervised multiple linear regression Partial Least Square (PLS) model. The variables were extracts? chemical components (variable X) and extracts? log(1/IC50) (Y) against C. albicans (sensitive to azoles) and C. glabrata, an intrinsically low azole-susceptible yeast. Results showed that phytolaccagenin (Phy) had higher influence on the activity than phytolaccoside B while phytolaccoside E showed lower influence in the activity. Based on these results, Phy and PhytB were chosen as biomarkers of the extracts and were quantified in each of the extracts by UHPLC chromatography carried out on a Waters Acquity UPLC® system with Waters Quattro micro API Tandem Quadrupole MS, with a validated method. Results showed that the DCM, MeOH and BuOH berries? extracts possess the marker compounds (Phy:PhytB) in the ratios (0.7826:1); (0.3801:1) and (0.0186:1) respectively being the first proportion the one that showed the best activity.