Mechanisms of Cancer-killing by Quercetin; A Review on Cell Death Mechanisms.

Cancer drug resistance has always been a serious issue regarding cancer research and therapy. Different cancers undergo different mutations, which may cause suppression of tumor suppressor genes, inhibition of apoptosis, stimulation of drug resistance mediators, and exhaustion of the immune system. The modulation of pro-death and survival-related mediators is an intriguing strategy for cancer therapy. Several nature-derived molecules, e.g., quercetin, have shown interesting properties against cancer through the modulation of apoptosis and autophagy mediators. Such molecules, e.g., quercetin, have been shown to stimulate apoptosis and other types of cell death pathways in cancers via the modulation of ROS metabolism. Quercetin may affect immune system function and trigger the expression and activity of tumor suppressor genes. Furthermore, it may suppress certain multidrug resistance mechanisms in cancer cells. This paper aims to review the effects of quercetin on various cell death mechanisms such as apoptosis, autophagic cell death, senescence, ferroptosis, and others.