ZENITH NUTRITION’S PINE BARK EXTRACT: One of the most potent antixoxidants ever discovered, pine bark from the Eastern Pine, contains complex plant compounds known as proanthocyanidins. Proanthocyanidins are condensed tannins that are responsible for astringent character of fruits, berries, beans, and tea. These bioflavonoids are powerful antioxidants, giving benefits to the cardiovascular system and capillary health. They are potent, free radical scavengers that help the body reduce oxidative damage.