Application of barcode high-resolution melting for rapid authentication of the medicinal plant Psammosilene tunicoides

Abstract

Psammosilene tunicoides is an important herb used in traditional Chinese medicine. It has been proved to benefit the stomach and treat rheumatism and gout. On the market, this herbal medicine is frequently adulterated by the related species Silene viscidula. Correct identification of P. tunicoides is important to ensure herbal quality, safety, authenticity and health for consumers. However, the identification of the P. tunicoides and S. viscidula species is complicated because of their morphological similarities. Therefore, a reliable method to authenticate these two medicinal plants is needed. In this study, the ITS2 barcode region coupled with high-resolution melting (Bar-HRM) was evaluated as a novel approach for differentiating P. tunicoides from its adulterant S. viscidula. Our findings showed that Bar-HRM not only detected the adulteration, but also quantified the most common admixture. Bar-HRM sensitivity in adulterant detection was assessed by analysing samples mixed with different proportions of S. viscidula and P. tunicoides control. The results are presented as a linear regression with R2 = 0.9852, which implied the capability of the method to detect adulteration. This study is significant to verify the authenticity for better quality control of this herbal species.