Abstract
We investigated whether coffee and its components (caffeine and chlorogenic acid) reduce stress in rats. In vivo microdialysis was used to characterize the effects of coffee, stress, and their interaction on the serotonergic and dopaminergic systems. Immobilization of the rats for 100min markedly increased the hippocampal levels of dopamine (DA) and serotonin (5-HT). Thereafter, 100min of rest restored the levels of DA and 5-HT to basal values. Treatment with 33mg/kg instant coffee (equivalent to the amount contained in one cup of coffee) or 1.7mg/kg caffeine (equivalent to one cup of coffee) reduced the second restraint-induced increase of the neurotransmitters, especially 5-HT. On the other hand, neither saline nor 1.7mg/kg chlorogenic acid (equivalent to one cup of coffee) reduced the increases. These results suggest that coffee administration helps to relax rats subjected to restraint-induced stress, and that this effect could be due to caffeine. Taken together, these findings suggest that coffee has a modulating effect on the stress response in rats.
