Quick and easy preparation method for Kampo formula decoctions (part 4): IPCD method for rhubarb and aconite root

Abstract

Aim: The immersing powdered crude drugs (IPCD) method has been developed as a quick, easy and high-yielding method for preparing decoctions. Given that the extraction process is different from the conventional decoction method, the safety of this method should be carefully examined. In the present study, the amounts of the diester alkaloids of aconite root, the tuberous root of Aconitum carmichaeli, and sennoside A of rhubarb, the rhizome of Rheum palmatum, were determined in the IPCD immersion. Both of these compounds have strong physiological activities and have been suggested to be decomposed during the decoction process. Methods: The amounts of marker compounds in the IPCD immersion prepared from processed or unprocessed aconite root or rhubarb were measured and compared with those prepared using the conventional decoction method. Results: The amount of sennoside A extracted with the IPCD method was 1.1-fold increased compared with that from the conventional method. No diester alkaloids were detected in the IPCD immersion prepared from processed aconite root, whereas for unprocessed aconite root, the amount of diester alkaloids extracted from the IPCD immersion was 8.8-fold higher than that from the conventional decoctions. Conclusion: The IPCD method can be safely used on rhubarb or well-processed aconite root under the same conditions as other less-powerful crude drugs, whereas precautions are required for unprocessed aconite root.

Comparison of the conventional and immersing powdered crude drugs (IPCD) methods for color and extraction of quantitative indicator ingredients in the Kampo formula decoction of daiokanzoto

“…While the conventional method takes 30 min, the IPCD method takes only 4 min, greatly reducing the preparation time. Although some studies claim that the IPCD extraction method is as effective as the conventional method, there is still room for clarification [ 4 – 7 ]. In addition, because the Kampo formula decoction is a mixture of known and unknown components/substances, it is impossible to compare the extracted amounts of all components/substances by the conventional and IPCD methods.…”

“…The IPCD method yielded considerably more sennoside A (2 times), and more glycyrrhizic acid (1.5 times) than the conventional method (60 min). Previously, the IPCD method was reported to have a higher extraction efficiency for sennoside A (approximately 1.1–1.2 times) [ 7 ]. Strictly speaking, in the conventional decoction method described [ 4 , 7 , 13 ], Kampo formula decoction is started by adding crude drugs to cold water and then boiled for 30 min.…”

“…Previously, the IPCD method was reported to have a higher extraction efficiency for sennoside A (approximately 1.1–1.2 times) [ 7 ]. Strictly speaking, in the conventional decoction method described [ 4 , 7 , 13 ], Kampo formula decoction is started by adding crude drugs to cold water and then boiled for 30 min. However, in this study, the water was boiled and then the crude drugs were added and heated for 30 min since the time it takes for the cold water to become boiled water varies greatly depending on the temperature of the cold water and the room temperature of the laboratory.…”

“…The conventional method of decoction preparation was modified the method previously documented [ 4 , 7 , 13 ] and used an electric Kampo formula decoction heater pot (My New Mycon Torobi-ranran, EKSA-10, Tochimoto-Tenkaido Co.). Commercially available crude drugs were used as it is, without any treatment.…”

“…Furthermore, the conventional decoction method is very inconvenient and adds to the burden of patients. Therefore, to save time and effort, Fueki et al developed the immersing powdered crude drugs (IPCD) method as a quick, simple, and high-yielding method for preparing decoctions [ 4 – 7 ]. The IPCD method is a newly developed decoction method in which powdered crude drugs are immersed in boiling water to extract components.…”