Abstract
Green tea leaves of Camellia sinensis L. contain 2-4% (dry weight: DW) caffeine, whereas Camellia ptilophylla Chang, called
cocoa tea, contains about 4% (DW) theobromine instead of caffeine. Methylxanthines such as caffeine, theobromine, and theophylline
are generally known to induce a diuresis. Recently, several reports have suggested that epigallocatechin gallate (EGCG) may
influence the effects of caffeine. The above-mentioned Camellia contain up to about 10% (DW) of EGCG in addition to caffeine or
theobromine. Therefore, in this study, we evaluated whether the diuretic activity in rats induced by oral administration of caffeine and
theobromine (5 mg/kg body weight: b.w.) was affected by the coexistence of EGCG (10 mg/kg b.w.).
