Submitted to: Planta Medica
Publication Type: Peer reviewed journal
Publication Acceptance Date: 4/24/2005
Publication Date: 12/5/2005
Citation: Techen, N., Khan, I.A., Pan, Z., Scheffler, B.E. 2006. The use of polymerase chain reaction (pcr) for the identification of ephedra dna in dietary supplements. Planta Medica. 72: 241-247. Interpretive Summary: Ephedra sinca Stapf, commonly known in the USA just as Ephedra, has been a popular dietary supplement because the plant tissue contains the active compound ephedrine. Ephedrine is known to enhance athletic performance and promote weight loss. The consumption of Ephedra is a controversial issue because of evidence of possible permanent injury or death caused by improper use. Due to health concerns, the FDA prohibited the sale of dietary supplements containing any Ephedra species or ephedrine alkaloids in April 2004. This manuscript deals with the development of methods and a DNA marker that can be used to identify the presence of any Ephedra species in plant mixtures such as those found in common dietary supplements, like herbal teas. This paper illustrates that the DNA maker is specific to Ephedra species and can be used to distinguish between them and other closely related plant species. Experimental data demonstrates that in plant mixtures, like herbal teas, that the presence of Ephedra tissue can be detected even when the mixture is contains as little as 1/1000 part Ephedra tissue.
Technical Abstract: As part of an continuing research effort to develop chemical and genetic authentication profiles of botanicals an investigation was performed with the goal to detect, identify and verify Ephedra sinca Stapf DNA in dietary supplements such as plant mixtures and tablets/capsules. We amplified and sequenced the chloroplast psbA-trnH spacer from 21 Ephedra spp. and from two of their closest relatives Gnetum gnemon L. and Welwitschia mirabilis Hook. Based on sequence comparisons, we identified regions unique to all of the Ephedra spp. samples analyzed. We concluded that the psbA-trnH spacer sequence could be used as a molecular marker. Based on this spacer sequence, we designed Ephedra spp. specific primers that can help to identify Ephedra spp. DNA in plant mixtures containing as little as 1/1,000 part of Ephedra spp. tissue. We used DNA extraction method that allows for quick DNA isolation from plant mixtures for PCR analysis.