Abstract:

Human umbilical vein endothelial cells were pretreated with quercetin and its metabolite quercetin-3-Oglucuronide
for 30 min, and then incubated with 100 μmol/L palmitic acid. Palmitic acid stimulation led to reactive
oxygen species (ROS) production with collapse of mitochondrial membrane potential (Δψm). Quercetin and quercetin-
3-O-glucuronide inhibited ROS overproduction and effectively restored Δψm, demonstrating their chemoprotection of
mitochondrial function through antioxidative actions. Also, quercetin and quercetin-3-O-glucuronide inhibited ROSassociated
inflammation by inhibition of interleukin-6 and tumor necrosis factor-α production with suppression of IKKβ/
NF-κB phosphorylation. Therefore, quercetin and quercetin-3-O-glucuronide can inhibit oxidative stress and inflammation.
The results of this study indicate that the relationship between food containing quercetin and human health may be due to the
anti-oxidative stress and anti-inflammation activities of its metabolite in the endothelial cells.

Key words: quercetin, quercetin-3-O-glucuronide, reactive oxygen species, inflammation