Because of wrongly labelled plant material and different local names, the exact identification of plant material stays a challenge in herbal medicine. Mix-ups can trigger serious health problems and undesired side effects due the fact that plants have different chemical compositions [1]. In China, Zicao is a commonly used herbal medicine, which represents the dried roots of plants from the genera Onosma, Arnebia, and Lithospermum, all belonging to the Boraginaceae family. All these roots contain red colored shikonin derivatives with various pharmacological properties [2]. Moreover, they contain pyrrolizidine alkaloids in low (Arnebia) or high (Onosma and Lithospermum) concentrations, which are well known for their hepatotoxic properties [3]. That is why there is an instant need for unambiguous identification of these roots. Despite of local names, which are used on medicinal markets (Ying Zicao for Lithospermum erythrorhizon, Dian Zicao for Onosma paniculata, and Ruan Zicao Arnebia euchroma), confusions of these species are common.
In this study, we developed a simple HPTLC method to distinguish the different Zicao species unambiguously. Various Zicao samples from different places in China were purchased and identified by DNA analysis (ITS1, trnL-F). By HPTLC, we identified a blue fluorescent zone as a marker compound by which the species can be exactly identified and a safe application in TCM can be ensured.
Acknowledgements: The Austrian Science Fund for the financial support (FWF, P27505).
References:
[1] Stegelmeier, B. L., Brown, A. W., & Welch, K. D. Safety concerns of herbal products and traditional Chinese herbal medicines: dehydropyrrolizidine alkaloids and aristolochic acid. J. Appl. Toxicol. 2015; 35(12): 1433-1437.
[2] Hu Y, Jiang Z, Leung KS, Zhao Z. Simultaneous determination of naphthoquinone derivatives in Boraginaceous herbs by high-performance liquid chromatography. Anal Chim Acta. 2006; 577(1): 26-31.
[3] Roeder, E. Medicinal plants in China containing pyrrolizidine alkaloids. Pharmazie 2000; 55(10): 711-726.