Identification of cysteine-rich peptides as novel molecular markers for authentication of radix et rhizoma clematidis.

Abstract

Radix et Rhizoma clematidis (RRC) or 威灵仙, from the Ranunculaceae family, is traditionally prescribed for treating rheumatoid arthritis and glandularis erythematosa. Presently, more than 70 plant species are sold as 威灵仙. This jeopardizes safe and effective use of the herb, and highlights the need for authentication and quality control. Currently, chemical-based markers for authentication of this herb are limited to saponins.

We hypothesize that Cysteine-rich peptides (CRPs), like saponins, are components of plant biologics with therapeutic potential. Moreover, we speculate that CRPs can serve as novel molecular markers for herbal authentication. The Mass Spectrometry-Ultra Performance Liquid Chromatography (MS-UPLC) method was used for the preliminary screening of CRPs in RRC. Herein; we report the discovery of two novel heat- and enzyme-stable CRPs with mass of 4376Da and 4541Da, containing three and five disulphide bonds, respectively. We investigated the expression of the two CRPs in granule and dried-herb forms from four different sources. Both CRPs showed no significant difference in expression between granule and dried-herb samples (p> 0.05). We also noted that expression of CRPs was generally consistent in all eight samples. We conclude that CRPs have the potential to be novel markers for herbal authentication.