ABSTRACT
Ginger rhizomes have been widely used as a cooking spice and herbal remedy to treat a variety of conditions. Fresh and dried gingers are used for different clinical purposes in traditional Chinese medicine (Kampo). Fresh ginger (Zingiberis Recens Rhizoma; Sheng Jiang in Chinese; Shoga in Japanese) is used as antiemetic, antitussive, or expectorant, and is used to induce perspiration and dispel cold, whereas dried ginger (Zingiberis Rhizoma; Gan Jiang in Chinese) is used for stomachache, vomiting, and diarrhea accompanied by cold extremities and faint pulse (Bensky and Gamble, 1986). Dried ginger, either simply dried in the shade (Gan Sheng Jiang, or simply Gan Jiang in Chinese; Shokyo in Japanese) or processed ones that are heated in pans or with hot sand (Rhizoma Zingiberis Preparata: Pao Jiang in Chinese) are often used in China. The simply dried ginger and the processed ginger are not clearly differentiated in clinical use. On the other hand, different types of dried gingers have been used in traditional Japanese medicine, such as dried ginger (Shokyo in Japanese, as shown above) and steamed and dried ginger (Zingiberis Siccatum Rhizoma; Kankyo in Japanese). Steamed and dried ginger is rarely used in traditional Chinese medicine. Here we describe the “simply dried ginger” as “dried ginger” (Shokyo), and the “steamed and dried ginger” as “steamed ginger” (Kankyo). Gingerols and shogaols are identified as the main components of dried ginger (Shokyo) and steamed ginger (Kankyo), respectively (Aburada, 1987). However, before we conducted this study, little was known about the scientific reasons why Shokyo and Kankyo are used for different clinical purposes.
