In order to solve the problem of weak correlation between quality control components and efficacy of Glycyrrhizae Radix et Rhizoma, this study detected the interaction between small molecular chemical components of Glycyrrhizae Radix et Rhizoma and total proteins of various organs of mice by fluorescence quenching method to screen potential active components. The 27 chemical components in Glycyrrhizae Radix et Rhizoma were detected by HPLC and their deletion rates in 34 batches of Glycyrrhizae Radix et Rhizoma were calculated. Combined with the principle of component effectiveness and measurability, the potential quality markers(Q-markers) of Glycyrrhizae Radix et Rhizoma were screened. RAW264.7 macrophage injury model was induced by microplastics. The cell viability and nitric oxide content were detected by CCK-8 and Griess methods. The levels of inflammatory factors(TNF-α, IL-1β, IL-6, CRP) and oxidative stress markers(SOD, MDA, GSH) were detected by the ELISA method to verify the activity of Q-markers. It was found that the interaction strength between different chemical components and organ proteins in Glycyrrhizae Radix et Rhizoma was different, reflecting different organ selectivity and 18 active components were screened out. Combined with the signal-to-noise ratio of the HPLC chromatographic peaks and between-run stability of the components, seven chemical components such as liquiritin apioside, liquiritin, isoliquiritin apioside, isoliquiritin, liquiritigenin, isoliquiritigenin and ammonium glycyrrhizinate were finally screened as potential Q-markers of Glycyrrhizae Radix et Rhizoma. In vitro experiments showed that Q-markers of Glycyrrhizae Radix et Rhizoma could dose-dependently alleviate RAW264.7 cell damage induced by microplastics, inhibit the secretion of inflammatory factors, and reduce oxidative stress. Under the same total dose, the combination of various chemical components could synergistically enhance anti-inflammatory and antioxidant effects compared with the single use. This study identified Q-markers related to the anti-inflammatory and antioxidant effects of Glycyrrhizae Radix et Rhizoma, which can provide a reference for improving the quality control standards of Glycyrrhizae Radix et Rhizoma.
Keywords: Glycyrrhizae Radix et Rhizoma; fluorescence quenching; macrophage; microplastics; quality markers.