Investigating the authenticity of Ophiopogonis Radix and its Chinese patent medicines by using a nucleotide signature

Ophiopogonis Radix (Maidong), derived from the dried root tuber of Ophiopogon japonicus (Thunb.) Ker Gawl., has been widely used in the treatment of chronic inflammatory and cardiovascular diseases. However, Ophiopogonis Radix is often adulterated with some species because of morphological similarities. Adulterants circulating in herbal markets are a latent threat to the clinical safety and consumers' interest. We aimed to develop a nucleotide signature for identification of Ophiopogonis Radix and its Chinese patent medicines. A total of 255 ITS2 sequences representing 39 species and 4 varieties were used to develop a nucleotide signature of Ophiopogonis Radix. The nucleotide signature was used to investigate 17 commercial crude drugs and eight batches of Chinese patent medicines. A 69 bp nucleotide signature unique to Ophiopogonis Radix was found. The survey revealed that 2 of 17 crude drug samples were adulterants detected as Liriopes Radix (Shanmaidong). Fortunately, no adulterants were detected in the eight batches of Chinese patent medicines. The newly developed nucleotide signature could be efficiently applied to identify Ophiopogonis Radix and its Chinese patent medicines, aiding in the authentication, quality control, and supervision of processed products in herbal markets.