Quercetin accumulation by chronic administration causes the caspase-3 activation in liver and brain of mice

Quercetin is an excellent antioxidant that has a variety of side effects. This study investigated whether the chronic administration of quercetin in mice induces apoptosis. Mice were divided randomly into three treatment groups. Quercetin was administered orally to two of three groups at 100 and 250 mg/kg body weight (BW) for 18 days. The serum quercetin level increased in a dose-dependent manner, although the quercetin levels in the liver and brain were lower than in serum. Nevertheless, quercetin induced apoptosis in both the liver and brain, as evidenced by increased caspase-3 expression and activity. Quercetin-induced apoptosis seems to be associated with quercetin accumulation. Moreover, with quercetin accumulation, the brain was more susceptible to apoptosis than the liver. In conclusion, quercetin administration at a high dose may lead to apoptosis in the liver and brain of mouse.