Sulfur Fumigation Processing of Traditional Chinese Medicinal Herbs: Beneficial or Detrimental?

Winnie Lai Ting Kan,Bin Ma,Ge Lin

doi:10.3389/fphar.2011.00084

Abstract

Majority of traditional Chinese medicine (TCM) herbs need to undergo post-harvesting processing to convert raw material into the form readily used for prescription. In general, processing procedures are either according to China Pharmacopeia or based on traditional methods. Recently sulfur fumigation is increasingly used to replace traditional sun-drying for its pesticidal and anti-bacterial properties in a cheap and convenient manner. However, to date information on effects of sulfur fumigation on herbal safety and efficacy are limited. This article addresses potential destructive effects of sulfur fumigation on herbal efficacy and safety through reviewing currently available information. Since recently increased numbers of studies have demonstrated that sulfur fumigation-induced dramatic changes in chemical profiles of various sulfur-fumigated herbs, consequent alteration of efficacy, and/or potential incidence of toxicity are suspected. Therefore comprehensive investigations on effects of sulfur fumigation on toxicity, chemical profiles, pharmacokinetics, and bioactivities of TCM herbs are timely to provide scientific basis for standardization and regulation of this currently common but potentially harmful processing method.

Highlights

In the traditional Chinese medicine (TCM) practice, a personalized Chinese Materia Medica, usually in a mixed form, is prescribed to individual patients (Chan, 1995; Ye and He, 2010)
The compound formula consists of a complementary combination of various TCM materials, including medicinal herbs, animals, and minerals, which contain multiple bioactive compounds and interact synergistically with each other for enhanced efficacy at multiple targets (Tomlinson et al, 2000; Kan et al, 2008)
Studies showed that 78% of patients admitted to hospital for acute cardiovascular diseases used natural health products, and of them 20% used herbal products and 9% consumed TCM herbs (Alherbish et al, 2011)

Summary

INTRODUCTION

In the traditional Chinese medicine (TCM) practice, a personalized Chinese Materia Medica, usually in a mixed form, is prescribed to individual patients (Chan, 1995; Ye and He, 2010). Several articles have reported and reviewed the general practice of the conventional processing methods recommended by Pharmacopeia of PRC and its beneficial effects of enhancing efficacy and reducing adverse effect/toxicity of TCM herbs via the alteration of chemical profiles of the herbs (Yu et al, 2005; Li et al, 2010a; Shaw, 2010; Zhao et al, 2010; Chang et al, 2011). The results revealed that contents of the major furocoumarins were significantly reduced and at least 60% of imperatorin and almost all of oxypeucedanin was lost due to sulfur fumigation (Wang et al, 2009b) To further confirm these chemical changes, the herb was directly treated with sulfur dioxide in a mimic processing procedure.

Formation of peoniflorin sulfonate

Findings

Formation of two ginsenoside