How to compete with adulterations in Chinese medicine

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].

• References

• 1 Chen WJ. Adulteration of the traditional Chinese medicines in Taipei city. Altern Integ Med 2014; 3: 3 .
• 2 Han JP, Pang XH, Liao BS, Yao H, Song JY, Chen SL. An authenticity survey of herbal medicines from markets in China using barcoding. Sci Rep 2015; 6: 18723 .
• 3 Stegelmeier BL, Brown AW, Welch KD. Safety concerns of herbal products and traditional Chinese herbal medicines: dehydropyrrolizidine alkaloids and aristolochic acid. J Appl Toxicol 2015; 35 (12) : 1433-1437.
• 4 Wagner H, Bauer R, Melchart D, Xiao PG, Staudinger A. Chromatographic fingerprint analysis of herbal medicines - thin-layer and high performance liquid chromatography of chinese drugs. Wien: Springer-Verlag; 2015
• 5 Wu KM, Farrelly JG, Upton R, Chen J. Complexities of the herbal nomenclature system in traditional Chinese medicine (TCM): lessons learned from the misuse of Aristolochia-related species and the importance of the pharmaceutical name during botanical drug product development. Phytomedicine 2007; 14 (04) : 273-9.
• 6 Kretschmer N, Durchschein C, Heubl G, Pferschy-Wenzig EM, Kunert O, Bauer R. Discrimination of zicao samples based on DNA analysis and HPTLC fingerprints. Submitted.
• 7 Awang DV. Siberian ginseng toxicity may be case of mistaken identity. CMAJ 1996; 155 (09) : 1237.
• 8 Wagner S. Bioassay-guided isolation of cytotoxic compounds from Chinese medicinal plants with special focus on Periploca sepium and Caesalpinia sappan PhD Thesis, Faculty of Natural Sciences. University of Graz; 2012
• 9 Zschocke S, Liu JH, Stuppner H, Bauer R. Comparative study of roots from Angelica sinensis and related umbelliferous drugs by means of TLC, HPLC and LC-MS analysis. Phytochem Anal 1998; 9: 283-290.
• 10 Gao Z, Liu Y, Wang X, Song J, Chen S, Ragupathy S, Han J, Newmaster SG. derivative technology of dna barcoding (nucleotide signature and SNP double peak methods) detects adulterants and substitution in Chinese patent medicines. Sci Rep. 2017; 7 (01) : 5858.
• 11 Zhang Y, Chen J, Lei Y, Zhou Q, Sun S, Noda I. Evaluation of different grades of ginseng using Fourier-transform infrared and two-dimensional infrared correlation spectroscopy. J Mol Struct 2010; 974 (01) : 94-102.
• 12 Chen H, Tan C, Lin Z, Li H. Quantifying several adulterants of notoginseng powder by near-infrared spectroscopy and multivariate calibration. Spectrochim Acta A Mol Biomol Spectrosc 2019; 211: 280-286.
• 13 Moon BC, Kim WJ, Park I, Sung G-H N P. Establishment of a PCR Assay for the Detection and Discrimination of Authentic Cordyceps and Adulterant Species in Food and Herbal Medicines. Mol 2018; 23 (08) : 1932.
• 14 Wang XY, Xu R, Chen J, Song JY, Newmaster SG, Han JP, Zhang Z, Chen SL. detection of cistanches herba (Rou Cong Rong) medicinal products using species-specific nucleotide signatures. Front Plant Sci 2018; 9: 1643 .