Screening and Identification of Anti-Gout Components From Herb Pair Combining Ultrafiltration-HPLC-MS, On-Line HPLC-2,2′-Azinobis(3-Ethylbenzothiazoline-6-Sulfonic Acid)-MS and In Silico Analysis: Case Study by Smilacis Glabrae Rhizoma–Dioscoreae Spongiosae Rhizoma

Smilacis Glabrae Rhizoma–Dioscoreae Spongiosae Rhizoma (SGR-DSR), a herb pair used in traditional Chinese medicine (TCM), has definite curative effect on the clinical treatment of gout. To screen and identify the anti-gout ingredients from SGR-DSR. In this study, an integration strategy combining ultrafiltration-high performance liquid chromatography-mass spectrometry (UF-HPLC-MS) and on-line HPLC-2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS)-MS were proposed and applied for the rapid screening and identification of anti-gout components (xanthine oxidase [XOD] inhibitors and free radical scavengers) from SGR-DSR. As a result, 35 compounds with both potential XOD inhibitor activity and free radical scavenging activity were screened from the herbal pair. Among them, 18 active components were verified by in vitro activity assays. Astilbin showed better XOD inhibition activity and ABTS^•+ scavenging ability with the inhibition rates of 73.76% and 81.56% at 80 µM, respectively. In addition, the molecular docking simulation calculation results showed that all the 18 components had good binding ability with XOD. This study indicated that herb pair with clear clinical efficacy of TCM was a promising source for anti-gout ingredients, and the integration screening strategy provides rapid and effective identification method of anti-gout ingredients from complex herb pairs.