Elderberries contain organic pigments, tannin, amino acids, carotenoids, flavonoids, sugar, rutin, viburnic acid, vitaman A and B and a large amount of vitamin C. They are also mildly laxative, a diuretic, and diaphoretic. Flavonoids, including quercetin, are believed to account for the therapeutic actions of the elderberry flowers and berries. Used for its antioxidant activity, to lower cholesterol, improve vision, boost the immune system, improve heart health and for coughs, colds, flu, bacterial and viral infections and tonsilitis. Elderberry juice was used to treat a flu epidemic in Panama in 1995.