Identification of herbal substances in finished herbal medicinal products

Because of the diversity of botanical products in the market it is necessary to look for complementary methods that may also be useful to retrace herbal substances. We are evaluating the potential of PCR-related techniques and NMR-fingerprinting focussing on herbal substances from therapeutic systems of non-European origin and selected plant families e.g. Lamiaceae and Ranunculaceae. A challenging topic is the authentification of the herbal substance in products containing rhizomes of Black Cohosh (Cimicifuga racemosa). This perennial plant is native to North America and is of major importance in the US dietary supplements market [1]. In Europe, a monograph on Cimicifugae rhizoma is under development by the HMPC at the EMA [2]. Reports have been published on the occurrence of rare toxic liver disease after application of products containing Cimicifugae rhizoma. One hypothesis to explain this toxicity is based on possible contaminations with other species. Therefore, we analysed commercial samples using a PCR-based method targeting the ITS-region. Contaminations with Acer rubrum, Morus murrayana and Collinsonia canadensis were detected in few samples. These plants are also native to North America. In a second approach, the samples were extracted with dichlorine methanol and a metabolomic fingerprinting via H-NMR-measurements in combination with PCA was accomplished to further prove the identity of the respective samples. The data derived from NMR-profiling demonstrate that the contaminations are only due to minor traces of contaminating material.

References: 1. Kan He et al. (2006)J Chromatogr A. 2006 April 21; 1112(1–2): 241–254.

2. www.ema.europa.eu, HMPC, European community monographs, draft monograph Cimicifugae rhizoma, 2010.