Electrophysiological evidence of the effect of natural polyphenols upon the human higher brain functions.

OBJECTIVE: Several natural polyphenols exert effects upon the cardiovascular as well as nervous system. In vitro and animal studies suggest that polyphenols may potentially affect the human cognitive function. The aim was to study the effect of Provinols™, the polyphenolic compounds isolated from red wine, upon the human higher brain functions.

MATERIAL AND METHODS: The accuracy of space memory was assessed by means of visually-guided and memory-guided saccadic eye movements. The EEG and blood pressure were registered also. The healthy undergraduates served as subjects. They were divided into the control, placebo and Provinols™ groups. The amplitudes of saccades, EEG spectral density, evoked potentials time-locked to saccadic onset and blood pressure were analyzed in control condition and 2 hours later, after administration of placebo, Provinols™ (4 mg/kg of body weight) or nothing.

RESULTS: After the Provinols™ administration the memory-guided saccades were significantly more accurate and the significant decrease in the slow EEG bands, alpha power mainly, was registered over the broad regions of temporo-parietal cortex. No changes in saccadic eye movement related potentials as well as in blood pressure were found after the single dose Provinols™ administration.

CONCLUSIONS: Even a single dose of the Provinols™ was able to affect positively the space memory for limited time duration. The improvement in space memory function and/or the positive role of attentional mechanisms may be taken into account mainly. More sensitive analysis of the particular participation of attentional and memory components demands the further study.