Rapid and sensitive authentication of Polygonum multiflorum (He-Shou-Wu) of Chinese medicinal crop using specific isothermal nucleic acid amplification

Abstract

Polygoni Multiflori Radix (PMR) is well-known valuable medicinal crop and has been reported to have many biological functions for medical applications. For preventing the problem of PMR adulteration in the herbal market, in this study, a DNA-based molecular method, loop-mediated isothermal amplification (LAMP), was developed for the authentication of PMR. A set of newly designed LAMP primer was developed based on the internal transcribed spacer (ITS) sequences of ribosomal DNA. The results demonstrated that amplicon of PM genomic DNA was amplified successfully using specific LAMP primers when the sample contained PM genomic DNA. By contrast, the adulterants of PMR did not exhibit DNA amplification when LAMP was performed. Compared with the traditional polymerase chain reaction (PCR), the isothermal DNA amplification by LAMP demonstrated 10-fold higher sensitivity and required half the time of PCR. The PMR samples with 3-times, 6-times repeated processing, autoclave steaming, and γ-ray irradiation were also can be authenticated by LAMP. However, the PMR sample with conventional 9-times repeated processing was not authenticated by LAMP.In conclusion, the specific DNA amplification method for the authentication of PMR presented herein was sensitive, specific, and rapid under isothermal condition. The findings are useful for application of PMR authentication on-site in the herbal market. This also demonstrates the method’s potential application for the authentication of other herbal crops in the future.