From ancient times, the crude drug rhubarb (Da-huang in Chinese, Daio in Japanese) has been processed using liquor in various ways in China. There are mainly three ways of processing it ; liquor-soaking, liquor-dipping and liquor-frying. Today, the liquor-fried rhubarb, appropriately named ‘liquor rhubarb’, is widely used. But it is not clear why use of the rhubarb processed with liquor began. Thus, we researched ancient literature published after the Jin and Yuan dynasties, when medical treatment was done based on the theories. We found that the ‘liquor-soaked rhubarb’ was used as a depurative, while the ‘liquor-dipped rhubarb’ was used as a purgative or a digestive. ‘Liquor-fried rhubarb’ use began after the Ming dynasty, and its medicinal effect was expected to be the same as the two processed rhubarbs of earlier periods.
distilled alcoholic beverage ; Rhubarb ; Today ; dalton ; Japanese language

Processing methods for the crude drugs shokyo (fresh ginger) and kankyo (dried ginger) have been different in China and Japan, although the reasons for this have not been clear. In this study, we revealed a historical transition in the processing methods for shokyo and kankyo.
We found that the name shokyo had been used for fresh ginger rhizome in China since the end of the Hou han dynasty. The name had also been used for shokyo in Japan, whereas the term shokyo was then applied to dried ginger in the Japanese pharmacopoeia during the Meiji era. With kankyo, on the other hand, several dif ferent processing methods existed in China. For example, ginger fermented in a ceramic pot after being soaked in running water and dried was called kankyo, and was strongly associated with the property ‘hot’. However, we supposed that simply dried ginger, which has the property ‘warm’, came to be called as kankyo exclusively from the middle of the Qing dynasty. Meanwhile, only ginger dried with lime after being steamed was called kankyo in Japan. We also found that ginger whitened with lime was produced and sold in pharmacies because of a description by Shizhen Li, to the effect that “white ginger has higher quality”. This controversial method has been changed to one without the use of lime since the Meiji era.

In traditional Chinese medicine, crude drugs are sometime processed and prepared for specific purposes. Rhubarb (Da-huang in Chinese; Daio in Japanese) has been processed by dipping or soaking it in huangjiu (Chinese fermented wine). However, the pharmacologic significance of this liquor processing has not been elucidated thoroughly. In this report, we describe how processing with ethanol altered the levels of the principal compounds in rhubarb: sennoside A, sennoside B, aloe-emodin, rhein, emodin, chrysophanol, physcion, lindleyin, isolindleyin, and total tannins. Liquor-dipping, dipping rhubarb in 16% ethanol for 30 seconds, did not affect the content of sennosides. Thus, the purgative effect of rhubarb is likely to be preserved. Liquor-soaking, soaking rhubarb in ethanol for 12 to 24 hours, the content of sennosides and tannins decreased and the content of anthraquinones increased. Liquor-soaking of rhubarb may increase its anti-bacterial and anti-inflammatory effects, thereby improving blood stasis. These results are in agreement with the descriptions in medicinal literatures published since the Jin and Yuan Dynasties.

Since ancient times in China, decocting times have been adjusted to improving objective medicinal effects. In medical texts, decocting times are dictated by the amount of water that is reduced. And in this report, we surveyed rhubarb (Chinese, Da-huang ; Japanese, Daio) formulation decocting times described in the earliest Shang-han-lun and Jin-gui-yao-lue texts, from the amount of water changed. We found that rhubarb decocting times could be divided into four 10-, 20-, 30- and 50-minute groups when rhubarb is decocted with other crude drugs, while when rhubarb is put in water after other crude drugs, decocting times could be divided into four 1-, 5-, 10- and 20-minute groups. Next, when we prepared rhubarb decoctions using unprocessed rhubarb and processed rhubarb, and compared change in the principal compounds eluted into those decoctions, we found that 80% or more of the principal compounds were eluted into a decoction when either unprocessed or processed rhubarb were decocted for 30 minutes. It was therefore clear that, in ancient times, rhubarb formulations were decocted for 10 to 30 minutes so that not all of the principle compounds would elute, or given 50 minutes to allow all the principle compounds to elute. Meanwhile, it was also clear that rhubarb was put in water1to 20 minutes before decocting finished, to adjust the amount of principle compound eluted.