Dandelion extract suppresses reactive oxidative species and inflammasome in intestinal epithelial cells

Abstract

Dandelion (Taraxacum spp.) has received increasing attention in western countries due to its health beneficial properties and pharmaceutical functions. In the current study, we evaluated compounds extracted from different parts of dandelion. Dandelion leaf had the highest, while root had the lowest level of total phenolic and flavonoid contents. Using HPLC, eleven phenolic acids and flavonoids were identified, among which chicoric acid was the main component in all parts of dandelion. Consistent with the total content of phenolics and flavonoids, leaf extract had the highest total antioxidant and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity. Dandelion leaf extract at 400μg/ml suppressed reactive oxygen species (ROS) in HT-29 cells induced by hydrogen peroxide, equivalent to the ROS scavenging activity of 20μg/ml of pure chicoric acid. Importantly, both leaf extract and chicoric acid mitigated inflammatory signaling NF-κB p65 and cyclooxygenase-2 activity induced by lipopolysaccharide, demonstrated by suppressed LRR and PYD domains-containing protein 3 (NLRP3) inflammasome activation and caspase-1 activity, as well as NLRP3 inflammasome–mediated interleukin (IL)-1β and IL-18 secretion. In conclusion, dandelion extract inhibited inflammasome activation through ROS scavenging and anti-inflammatory activity; and chicoric acid, a major component of dandelion, is mainly responsible for the beneficial effects.