Abstract
In this study, we conducted a double-blind placebo-controlled cross-over study in order to examine the stress reducing effects of ingestions of γ-aminobutyric acid (GABA), Apocynum Venetum Leaf Extract (AVLE), and concurrent ingestion of both samples. Changes in the concentration of salivary chromogranin A (CgA) and cortisol, scores of a questionnaire, after a stress inducing mental task following every intake were monitored. We found significant differences on CgA activity among the samples. Subjects administered with GABA+AVLE exhibited a significantly less increase in CgA concentration compared with that of placebo condition. This result suggested that concurrent ingestion of GABA and AVLE might be able to reduce mental stress in humans more than single intakes.
