Behav Brain Res. 1997 Feb; 83(1-2): 135-41.

Candidates for cognitive enhancer extracted from medicinal plants: paeoniflorin and tetramethylpyrazine.

Watanabe H.

Research Institute for Wakan-Yaku (Oriental Medicines), Toyama Medical and Pharmaceutical University, Japan.

A traditional Chinese medicine, Shimotsu-to, consisting of four herbs: Japanese angelica root, cnidium rhizome, peony root and rehmannia root, has been reported to improve spatial working memory in rats. The present results indicate that Paeoniflorin and tetramethylpyrazine (TMP) extracted from peony root and cnidium rhizome, respectively, are candidates for cognitive enhancer.