Quercetin and Quercitrin Attenuates the Inflammatory Response and Oxidative Stress in LPS-Induced RAW264.7 Cells: In Vitro Assessment and a Theoretical Model.

Jie Tang,Ping Diao,Lidan Xiong,Li Li,Xiaohong Shu

doi:10.1155/2019/7039802

Abstract

Background Nowadays, atmospheric pollutants, ultraviolet rays, and other factors cause the imbalance of cell redox, resulting in skin oxidative damage. There is an interaction between inflammatory response and oxidative stress, which often involve networks of reactions and serve to amplify each other. Quercetin and quercitrin, with strong antioxidant and anti-inflammatory properties, were widely applied in cardiovascular disease, osteoporsis, pulmonary disease, etc. However, the regulation mechanism of quercetin and quercitrin on various inflammatory skin diseases is still not clear. Purpose In this study, quercetin and quercitrin were used to investigate whether they had anti-inflammatory and anti-ROS effects. Besides, theoretical calculation method was also adopted to preliminarily explore the mechanism of the anti-inflammatory and antioxidant effects of these two substances. Methods CCK-8 assay was employed to investigate the cytotoxicity. The concentration of NO measured by Griess Reaction System. Moreover, the inflammatory factors (TNF-α, IL-1β, and IL-6) were reduced in LPS-stimulated RAW264.7 cells were tested by ELISA kits. The trend of ROS changes was detected by DCFH-DA method. Finally, the mechanism of the anti-inflammatory and antioxidant effects of these two substances was carried out by DMol3 package in Materials Studio. Results CCK-8 assay results guided that the safe concentration of quercetin and quercitrin was lower than 15.0 μg/mL and 22.4 μg/mL, respectively. Also, the concentration of NO could significantly be inhibited by quercetin and quercitrin. Besides, the ELISA results showed that TNF-α, IL-1β, and IL-6 were reduced in LPS-stimulated RAW264.7 cells after interfering with quercetin and quercitrin. The trend of ROS changes was similar to that of inflammatory factors. Finally, the theoretical calculation illustrated that the oxygen atom on B rings may be the main site of electron cloud density changes, which may suggest a possible mechanism for the anti-inflammatory and ROS scavenging effects of quercetin and quercitrin. Conclusions This experiment shows that LPS can induce the overactivating of macrophages and the activated macrophages can subsequently induce inflammatory storms and oxidative stress. Both quercetin and quercitrin can inhibit LPS-induced macrophage inflammation and oxidative stress by experiment and theoretical calculations.

Highlights

Oxidative stress refers to the imbalance of oxidation and antioxidation in the body under the attack of harmful stimulating factors [1]
In order to study the anti-inflammatory effects of quercetin and quercitrin, we chose these three concentrations (3.0, 0.3, 0.03 μg/mL for quercetin; 4.5, 0.45, 0.045 μg/mL for quercitrin) for further investigation
Effects of Quercetin and Quercitrin on the Production of nitric oxide (NO) in LPS-Induced RAW264.7 Cells. e RAW264.7 cells were exposed to various concentrations of quercetin and quercitrin and induced with LPS (2 μg/ml). e NO concentrations are shown in Figure 3. e amount of NO released by RAW264.7 cells increased significantly when exposed to LPS, and the treatment with positive control (DEX, 10 μg/mL), quercetin, and quercitrin significantly decreased the LPS-induced NO production in RAW264.7 cells

Summary

Background

Atmospheric pollutants, ultraviolet rays, and other factors cause the imbalance of cell redox, resulting in skin oxidative damage. ere is an interaction between inflammatory response and oxidative stress, which often involve networks of reactions and serve to amplify each other. Theoretical calculation method was adopted to preliminarily explore the mechanism of the anti-inflammatory and antioxidant effects of these two substances. The ELISA results showed that TNF-α, IL-1β, and IL-6 were reduced in LPS-stimulated RAW264.7 cells after interfering with quercetin and quercitrin. The theoretical calculation illustrated that the oxygen atom on B rings may be the main site of electron cloud density changes, which may suggest a possible mechanism for the anti-inflammatory and ROS scavenging effects of quercetin and quercitrin. Is experiment shows that LPS can induce the overactivating of macrophages and the activated macrophages can subsequently induce inflammatory storms and oxidative stress Both quercetin and quercitrin can inhibit LPSinduced macrophage inflammation and oxidative stress by experiment and theoretical calculations

Introduction

Experimental

Results

Discussion