Quercetin
Quercetin is a plant pigment (flavonoid). It is present in a wide variety of plants and foods, including red wine, onions, green tea, apples, berries, and other fruits and vegetables. There is some evidence that quercetin can help protect against cardiovascular disease and cancer. As a result of its ability to assiststabilise the cells in the body that are responsible for histamine release, quercetin has both an anti infectious and an antihistamine effect.
Resources: Quercetin