Revealing the anti-inflammatory ingredients in wine-processed Radix et Rhizoma Rhei using immobilized cysteinyl leukotriene receptor type 1 as the stationary phase

Abstract

Despite the tremendous progress of wine-processed Radix et Rhizoma Rhei (Jiudahuang, JDH) in removing toxic heat from the blood in the upper portion of the body for hundreds of years, the deep understanding of its functional material basis of the anti-inflammatory ingredients remains unclear due to the lack of high specific and efficient methods. Herein, taking Cysteinyl leukotriene receptor type 1(CysLT1R) as the target protein, we established a chromatographic method based on the immobilized CysLT1R using haloalkane dehalogenases (Halo) at the C-terminus of the receptor in one step. After careful characterization by X-ray photoelectronic spectroscopy, immune-fluorometric analysis, and chromatographic investigations, the immobilized receptor was used to screen the anti-inflammatory ingredients in JDH. Aloe-emodin, rhein, emodin, chrysophanol, and physcion were identified as the main anthraquinone exerting anti-inflammatory effects in the drug. The association constants for the five compounds to bind with the receptor were calculated as (0.30 ± 0.06)× 105, (0.35 ± 0.03)× 105, (0.46 ± 0.05)× 105, (1.05 ± 0.14)× 105, and (1.66 ± 0.17)× 105 M−1 by injection amount-dependent method. Meanwhile, hydrogen bonds were identified as the main driving force for the five compounds to bind with CysLT1R by molecular docking. Based on these results, we believe that the immobilized receptor chromatography preserves historic significance in revealing the functional material basis of the complex matrices.