Is Sour Taste of Paeoniae Radix Phantom?

—Stringent Action and Muscle Relaxant Action—

Abstract

It is theoretically thought that Paeoniae Radix (shakuyaku) has a sour taste and astringent action in traditional Chinese medicine. To examine the practical taste of shakuyaku, 12 volunteers sampled the decoction of Paeoniae Radix Rubra (sekishaku) and Paeoniae Radix Alba (byakushaku). Each volunteer determined how sekishaku and byakushaku taste among “five tastes” : sweet, salty, bitter, sour, or spicy. Most volunteers chose bitter taste and none of them chose sour taste as the foremost taste of shakuyaku. At least in the modern age, shakuyaku may have little sour taste. In this article we discussed the astringent action and the muscle relaxant action of shakuyaku with reference to the sour taste.