Nature’s Defense (formerly AllerQuell)
Grape Seed Extract with Quercetin: This exceptional product has been formulated to help control both airborne allergies and mild food intolerance.
Grape Seed Extract
Grape seeds are a rich source of bioflavonoids known as proanthocyanidins. These powerful antioxidants are effective in the treatment of many problems, largely those due to aging and the effects of free radical action. The specific type of proanthocyanidins found in grape seeds are called “leucoanthocyanidins”. Leucoanthocyanidins from grape seed prevent the release and synthesis of compounds that promote inflammation and allergies such as histamine, serine protease, prostaglandins and leukotrienes.
Quercetin is a powerful anti-inflammatory agent, directly inhibiting a number of the processes that result in inflammation and associated allergic reactions. Unlike antihistamine drugs that block the binding of histamine to cellular receptors, quercetin actually inhibits the release of histamine and other inflammatory compounds in the first place.
Quercetin is a type of bioflavonoid that is widely distributed throughout the plant kingdom. It is found, for example, in yellow onion, broccoli, asparagus, kale, bell peppers, apple and tea. Quercetin is also found in a number of medicinal plants including bearberry, witch hazel, passionflower, eucalyptus and elder.
The release of histamine and other products of inflammation from both mast cells and basophils, is a basic pathological response in acute allergic situations. Researchers have concluded that quercetin is a potent inhibitor of mast cell and basophil degranulation because it blocks the cellular influx of calcium in these cells. This effectively stops the basic signal necessary for the occurrence of degranulation and associated histamine release.
Mast cells are found throughout the body and occur in the highest concentrations in the GI and respiratory tracts and the skin.ii Since quercetin is not well absorbed, it is believed to work primarily at the GI tract level, making it the ideal solution for individuals with mild food intolerance. In contrast to quercetin, the proanthocyanidins in grape seed extract are well absorbed, entering the blood stream rapidly. Here, they inhibit the release and synthesis of inflammatory chemicals such as histamines, prostaglandins and leukotrienes.