Quercetin is a principal flavonoid compound and an excellent free-radical-scavenging antioxidant that promotes apoptosis. In vitro it shows some antitumor activity in oral cancer and leukemia. Cultured skin and prostate cancer cells showed significant mortality (compared to nonmalignant cells) when treated with a combination of quercetin and ultrasound. Note that ultrasound also promotes topical absorption by up to 1,000 times, making the use of topical quercetin and ultrasound wands an interesting proposition.
High dietary intake of fruits and vegetables is associated with reduction in cancer, and some scientists, such as Gian Luigi Russo at the Institute of Food Sciences in Italy, suspect quercetin may be partly responsible. Research shows that quercetin influences cellular mechanisms in vitro and in animal studies. According to the American Cancer society, “there is no reliable clinical evidence that quercetin can prevent or treat cancer in humans”.
Quercetin inhibits multiple pathways involved in interleukin 6 secretion from human lung fibroblasts and activity in bronchial epithelial cell transformation induced by benzo[a]pyrene diol epoxide.
quercetin, a dietary compound having preventive properties for lung cancer, decreased BPDE-stimulated IL-6 secretion from human lung fibroblasts through inhibition of the NF-κB and ERK pathways