In samples from Chinese medicine clinics and pharmacies in Taipei, from 372 traditional Chinese medicines 2.42% were adulterated [1]. In material from herbal markets in China, adulterants were detected in 3.7-13.3 % of the cases [2]. Public health issues due to confusion with toxic herbs have been increasing [3], why there is an urgent need for proper authentication.
Chromatographic fingerprints are a powerful tool for identification [4]. Mixing up Aristolochiae fangchi radix and Stephaniae tetradrae radix can be avoided by simple TLC tests [5]. Toxicological risks occur also from mixing up Arenebia euchroma (Ruan Zicao), low in toxic pyrrolizidine alkaloids (PAs), with Lithospermum erythrorhizon (Ying Zicao) or Onosma paniculata (Dian Zicao), both high in PAs. By DNA and HPTLC fingerprint analysis, they can be discriminated [6]. Also, confusion of Acanthopanacis gracilistyli Cortex (Wu Jiapi) and Eleutherroocci senticosi radix (Ci Wu Jia) with Periplocae sepiae Cortex (Xiang Jiapi) is hazardous, because periplocin, the major constituent of Xiang Jiapi is a potent cardenolide [7],[8]. Other adulterations are more of therapeutic relevance, like mixing up different Angelica roots [9] and Lonicerae japonicae Flos (Jinyinhua) [10]. They can be detected by chromatographic or DNA analysis.
Expensive Chinese herbs are adulterated for commercial reasons. Near-infrared (NIR) spectroscopy has been suggested for differentiation of various grades of Panax ginseng (Ren Shen) [11], and for identifying adulterants of Panax notoginseng (Sanqi) [12], as well as for authentication of Cordiceps sinensis [13]. By using species-specific nucleotide signatures, adulteration of Cistanches Herba (Rou Cong Rong) can be detected [14].
