α-starch and glycyrrhizin denature the acrid raphides of Pinellia tuber in traditional processing

Abstract

Objective: Pinellia tuber, the dried tuber of Pinellia ternata, causes severe acrid irritation in the mouth and throat when swallowed in its raw form. Based on the theory of traditional Chinese medicine, this acridity is reduced by heating or processing using ginger, licorice, alum, or lime. Although these detoxification methods have been known since ancient times, only little is known about the mechanisms by which they detoxify Pinellia tubers. In the present study, we aimed to reveal the effectiveness of α-starch, and glycyrrhizin in licorice for the detoxification of Pinellia tubers.Methods: Previously, we found that intact raphides of raw Pinellia tuber have a lipophilic character, and denaturation of the raphides reduced their lipophilicity and acridity. Accordingly, we developed a raphide denaturation assay (RDA) to quantify the degree of denaturation of raphides by measuring the absorbance of the petroleum ether (PE) layer comprising the raphides. The effect of α-starch or the decoction of licorice (the root and stolon of Glycyrrhiza uralensis) on raphide denaturation was then determined using this assay.Results: The treatment of raphides with α-starch markedly enhanced heat denaturation of the raphides. Licorice decoction, glycyrrhizin, and glycyrrhetinic acid significantly denatured raphides in a calcium-dependent manner at high pH. Glycyrrhizin and glycyrrhetinic acid are also attached to the denatured raphides.Conclusions: α-starch in Pinellia tubers contributes to detoxification by heating. In the traditional processing method for Pinellia tubers using licorice and lime, glycyrrhizin in licorice and calcium ions play important roles in denaturing raphides.

Keywords

α-Starch / Glycyrrhizin / Pinellia ternata / Processing / Raphide

References

[[1]] Pharmaceutical and Medical Device Regulatory Science Society of Japan. The Japanese Pharmacopoeia. 18th ed. Tokyo: Jiho; 2021.

[[2]] ISO/TR23022:2018. Traditional Chinese medicine — Controlled vocabulary index on Japanese Kampo formulas and indication codes for products.SO/TR23022:2018. Traditional Chinese medicine — Controlled vocabulary index on Japanese Kampo formulas and indication codes for products. Geneva: International Organization for Standardization; 2018.

[[3]] Chinese Pharmacopoeia Commission. The 2020 Edition of Pharmacopoeia of the People’s Republic of China. Beijing: Chemical Industry Press; 2020.

[[4]] The Japanese Society for Oriental Medicine. Introduction to Kampo, Japanese Traditional Medicine. Tokyo: Elsevier Japan; 2005.

[[5]] Nakajima-Ohyama KC, Shizusawa Y, Tanimukai H. Usefulness of hangekobokuto (Banxia-houpo-tang) to treat panic disorder in patients with bipolar disorder: a case report. Tradit Kampo Med 2021;8(3):238-241.

[[6]] Fueki T, Makino T, Matsuoka T, et al. Development of a quick highyield method for the preparation of decoctions, inspired by the “zhu san fa” of the Song period (Part 2) — Easy method to separate muddy residue from decoctions—. Kampo Med 2016;67(2):114-122.

[[7]] Zhong LY, Wu H, Zhang KQ, et al. Study on irritation of calcium oxalate crystal in raw Pinellia ternata. Chin J Chin Materia Medica 2006;31(20):1706-1710.

[[8]] Wu H, Zhong L, Zhang L, et al. The study on the toxicity of the calcium oxalate raphide in Pinellia Tuber and its binding protein. Proceedings of the 5th Academic Conference of 2nd session and the 3rd Member Congress for Four Famous Crude drugs of Huaiqing Research Forum in China Association of Chinese Medicine, Processing of Chinese Medicine Branch; 2007.

[[9]] Yu HL, Wu H, Zhang XD, et al. Irritant stability of raphides and tubers from Pinellia ternate. J Chin Med Materials 2010;33(6):903-907.

[[10]] Liu Y, Ota M, Fueki T, et al. Historical study for the differences of processing of Pinellia ternata tuber between China and Japan. Front Pharmacol 2022;13:892732.

[[11]] Bensky D, Clavey S, Stöger E. Chinese Herbal Medicine: Materia Medica. 3rd ed. Seattle: Eastland Press; 2004.

[[12]] Wu H, Yu H, Ge X, et al. The common detoxification processing mechanism of poisonous Araceae herbal medicines. China (Ninxia) Ethnic Medicine International Forum 2014:301-312.

[[13]] Fueki T, Tanaka K, Obara K, et al. The acrid raphides in tuberous root of Pinellia ternata have lipophilic character and are specifically denatured by ginger extract. J Nat Med 2020;74(4):722-731.

[[14]] Fueki T, Nose I, Liu Y, et al. Oxalic acid in ginger specifically denatures the acrid raphides in the unprocessed dried tuber of Pinellia ternata. Acupunct Herb Med 2022;2(1):33-40.

[[15]] Wu H, Li W, Han H, et al. Study of irritating ingredients in Pinellia ternata. China J Chin Mat Med 1999;24(12):725-730.

[[16]] Yu H, Zhu F, Wu G. Toxic proteins on raphides from Pinellia ternata and Pinellia pedatisecta. Chin J Tradit Chin Med Pharm 2011;26(5):1037-1042.

[[17]] Yu H, Wang W, Wu H, et al. Effect of processing on toxic components lectin from four kinds of Araceae toxic medicines. China J Chin Mat Med 2019;44(24):5398-5404.

[[18]] Sharon N, Lis H. Lectines. Berlin: Springer Science & Business Media; 2003.

RIGHTS & PERMISSIONS

2023 Acupuncture and Herbal Medicine