Identification of ginseng radix in Chinese medicine preparations by nested PCR-DNA sequencing method and nested PCR-restriction fragment length polymorphism

Abstract

Ginseng Radix, the dried root of Panax ginseng, is easily confused with other herbs of the Panax species by appearance. In Chinese medicine preparations, it is difficult to identify misuse of Ginseng Radix. In this study, the nested PCR and DNA sequencing methods were established for the identification of Ginseng Radix, whereas the combination of nested PCR and restriction fragment length polymorphism (RFLP) could differentiate Ginseng Radix from other Panax species and thus certify the use of impure raw material of Ginseng Radix in Chinese medicine preparations. Nested PCR and DNA sequencing methods were applied to verify ginseng ingredients in the preparations. Of the 58 samples analyzed, 48 samples contained P. ginseng, 8 P. quinguefolius, and 2 P. notoginseng. Utilizing restriction enzyme BstYI and DdeI, nested PCR products of the samples were digested for restriction fragment lengths of polymorphism (RFLP). It was proven that 23 of the 58 samples contained a mixture of Ginseng Radix and Panacis quinquefolii Radix. Twenty-five samples contained pure raw material of Ginseng Radix. Ginseng components of 10 samples were confirmed using a substitute of P. quinguefolius or P. notoginseng. The RFLP results were consistent with those of the sequencing method results.