Macroscopic authentication of Chinese materia medica (CMM): A UK market study of seeds and fruits

This small-scale macroscopic and quantitative authentication study, the first of its kind in the UK and elsewhere, assesses the identity and purity (excluding pesticides and heavy metals) of a selection of Chinese materia medica (CMM) seeds and fruits on the UK market. 25 fruit and seed CMM were chosen based on their inclusion in the Chinese Pharmacopoeia (2010, referred hereafter as 'official species'), maximum dimension of 10 mm, and regular use in Traditional Chinese Medicine (TCM) practice in the UK according to UK practitioners. In 2012 samples were obtained from six TCM wholesale traders and eight retail dispensaries in southeast England. Macroscopic identity and purity testing was undertaken drawing on expertise at the Royal Botanic Gardens, Kew and its collection of vouchered CMM reference drugs, herbarium specimens and published identification texts. Of the 25 CMM requested from suppliers, 23 were obtained, represented by 211 samples. 191 samples were identified as being sourced from the correct drug; 20 were identified as sourced from unofficial species. Of the 191 correct samples, 5 displayed major contamination by other plant material, stones, earth, etc. (defined as >5% of sample volume), and 12 had minor contamination (2-5%). 95% of samples derived from medicinally cultivated plants were sourced from an official species, 5% were contaminated; in contrast, 78% of wild-sourced CMM samples were sourced from an official species, and 14% showed contamination. These results aim to guide the further development of good practice in TCM herbal drug quality control, for which suggestions are provided.

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