Fig. 1.

Suppression of adrenal hypertrophy in stressed mice. Mice consumed a CE-2 powder diet containing theanine, Arg, caffeine, and EGCG for seven days (single rearing for six days and confrontational rearing for one day). Mice ingested feed that contained the following components: theanine 10 μM, Arg 4 μM, caffeine 86 μM, and EGCG 63 μM. The mice of the pre-treated group that did not experience confrontational housing were used as a standard. The stress-reducing effect of tea components was compared among five groups, as follows: group 1 included mice fed a diet without any tea component; group 2 included mice fed a diet containing theanine and Arg; group 3 included mice fed a diet containing theanine, Arg, caffeine and EGCG; group 4 included mice fed a diet containing 2.5-fold more theanine and Arg, and the same amount of caffeine and EGCG as group 3; group 5 included mice fed a diet containing 5-fold more theanine and Arg, and the same amount of caffeine and EGCG as group 3. Bars indicate the mean ± SEM (n = 4; * p < 0.05).