(-)-Epigallocatechin-3-O-gallate (EGCG) reverses caffeine-induced anxiogenic-like effects

This study was designed to determine whether (-)-epigallocatethin-3-O-gallate (EGCG) could reverse caffeine-induced anxiogenic-like effects in animals. In mice, EGCG antagonized the caffeine-induced reduction in both the open arm entry number and time-spent in open arm on elevated plus-maze. In addition, EGCG also antagonized the caffeine-induced reduction in both the central zone distance and central zone time-spent on an open field apparatus, respectively. Electroencephalogram (EEG) was recorded from the rat anterior cerebral cortex. Caffeine increased the power density-ratios of fast (FW: 8.00-20.00 Hz) and slow (SW: 0.75-8.00 Hz) frequency spectrum bands in these EEG recordings. However, EGCG reduced the caffeine-induced increase of FW/SW ratios. Thus, EGCG reverses caffeine-induced anxiogenic-like effects. We also provide additional evidence that the EEG FW/SW (or SW/FW) ratios can be a useful tool for the prediction of anxiogenic and/or anxiolytic effects in an animal model. (C) 2010 Elsevier Ireland Ltd. All rights reserved.