Rapid authentication of the medicinal crop Cirsium setosum and discrimination from its adulterants in herbal markets via polymerase chain reaction integrated with a lateral flow assay (PCR-LFA)

Abstract

Cirsium setosum (CS) is a frequently used medicinal crop in Chinese herbal medicine (CHM) and is recorded as an authentic herbal plant in herbal pharmacopeia. Due to similar morphological features between CS and Cirsium japonicum (CJ), CS adulteration occurs in the herbal marketplace. To guarantee the safety and efficacy of CHM usage, authentication of CHM is a crucial step in ensuring high-quality pharmaceutical production. In this work, a species-specific polymerase chain reaction-lateral flow assay (PCR-LFA) method for CS and CJ authentication was first developed. The CS- and CJ-specific PCR-LFA primer sets were designed based on the selected DNA barcode internal transcribed spacer (ITS) sequence via in silico analysis. After validation of primer specificity, authentication of the primer set for CS and CJ identification was successful, as was visualization of the detection results via LFA. The sensitivity of PCR-LFA for CS and CJ authentication was determined to be 0.1 fg and 1 pg, respectively. When PCR-LFA was applied for commercial CS products, 25 % of the adulterants in the claimed commercial CS samples was found to be CJ during the investigation of CS adulteration. In conclusion, a species-specific PCR-LFA for CS authentication was successfully established. This method is not only used for species authentication but can also be applied to commercial products for authenticity assays for quality control in pharmaceutical manufacturing.