Quercetin-Loaded Microcapsules Ameliorate Experimental Colitis in Mice by Anti-inflammatory and Antioxidant Mechanisms

Quercetin (<b>1</b>) is an anti-inflammatory and antioxidant flavonoid. However, the oral administration of <b>1</b> did not lead to beneficial effects in experimental animal colitis models, which involve cytokines and oxidative stress. A possible explanation is that the absorption profile of <b>1</b> prevents its activity. Therefore, it was reasoned that the controlled release of <b>1</b> would improve its therapeutic effect. Thus, the therapeutic effect and mechanisms of <b>1</b>-loaded microcapsules in acetic acid-induced colitis in mice were evaluated. Microcapsules were prepared using pectin/casein polymer and <b>1</b>. The oral administration of <b>1</b>-loaded microcapsules decreased neutrophil recruitment, attenuated histological alterations, and reduced macroscopical damage, edema, and IL-1β and IL-33 production in the colon samples. Microcapsules loaded with <b>1</b> also prevented the reduction of anti-inflammatory cytokine IL-10 and the antioxidant capacity of the colon. These preclinical data indicate that pectin/casein polymer microcapsules loaded with <b>1</b> improved the anti-inflammatory and antioxidant effects of <b>1</b> compared to the nonencapsulated drug. Therefore, quercetin seems to be a promising active molecule in inflammatory bowel disease if provided with adequate controlled release