Heterogeneity of Chinese medical herbs in Singapore assessed by fluorescence AFLP analysis.

Abstract

There are conflicting records on the identity of Chinese medical herbs, and it is known that different plant materials are used under the same common names in different regions in China. However, there is no study on the genetic heterogeneity of medical herbs in any market outside of China. In this report, Chinese medical herbs under common names Radix Quinquefolii (American Ginseng or Xiyangshen), Radix Astragali (Huangqi), Radix Notoginseng (Tianqi), Coxtex Cinnamomum (Guipi), Radix Isatidis (Banlangen), Radix Codonopsis (Dangshen) and Radix Rehmannia (Shengdi) were collected from three independent herbal shops in Singapore and their DNAs were isolated and subjected to fluorescence Amplified Fragment Length Polymorphism (AFLP) analysis. While samples for Radix Quinquefolii and Radix Astragali were homogenous genetically [similarity index (SI) = 0.85-1.00] across the three shops, genetic heterogeneity was found for the other herbs (SI < 0.7). For example, four samples of Radix Codonopsis were of three distinct patterns (SI < 0.6). Our results highlight the situation that genetically distinct herbal materials are labeled and marketed under the same common names in an international market of Chinese medical herbs, which may contribute to inconsistency in quality and efficacy.