Polyphenols enhance ATPase activity but not ATPase-driven lipophillic compound transport in rat liver membranes

DE ATHAYDE MONCORVO, A; SALAZAR, PB; MORERO, R; DUPUY, F; MINAHK, C

Santiago del Estero

Congreso; XLIV Reunión Anual SAB 2015; 2015

Sociedad Argentina de Biofísica

Biological membranes are complex and highly dynamic structures, responsible for critic functions such as maintaining an internal environment, transport of different molecules and signal reception and transduction. It is becoming increasingly evident that there is a important relationship between the physicochemical features of a membrane (which are highly regulated in living systems) and their biological properties. Therefore, the presence of membranes-active substances, able to modulate their physicochemical properties, could activate or inhibit biological processes. Polyphenols, plant secondary metabolites characterized by the presence of phenolic groups, are potential candidates for this role. In this work, the ability of four chemically different polyphenols (resveratrol, naringenin, epigallocatechin gallate and enterodiol) to interact and modulate the viscosity and to modify biological activities were studied.Binding assays evidenced that polyphenols are indeed capable to interact with rat liver membranes. Furthermore, fluorescence anisotropy studies show that the presence of polyphenols was able to subtly modulate the viscosity of the aforementioned membranes. Enterodiol and, to a lesser extent, resveratrol were able to increase ATPase activity of rat liver membranes on in vitro assays, as determined by Ames-Chem method. Interestingly, no activation on unspecific translocation of the fluorescent membrane probe TMA-DPH was observed in the presence of all four polyphenols studied.Results presented in this work indicate that polyphenols are not only able to closely interact with biological membranes; but also suggest that at least ATPase activity is significantly enhanced in their presence. Nevertheless, further studies will be needed to elucidate whether the modulation of the ATPase activity is directly linked to fluidity changes induced by these phenolic compounds.