Quercetin is a phytochemical that is part of the coloring found in the skins of apples and red onions. Quercetin may expel phlegm and arrest oughing, it can also be used as antiasthmatic. Quercetin has anticancer activity, inhibits PI3-kinase activity and slightly inhibits PIP Kinase activity, reduces cancer cell growth via type II estrogen receptors. Quercetin may inhibit histamine release from basophils and mast cells.Quercetin may control the spread of certain viruses within the body. Quercetin may help reduce tissue destruction. Quercetin may also be beneficial in the treatment of dysentery, gout, and psoriasis.