- The toxic principle is HYPERICIN (an bianthraquinone), it is present throughout the plant - Causes poisoning of different livestock (goat, sheep- ingest the plant) - Appears photosensitization and lesions when animals are exposed to sunlight - Manifestation of EDEMATOUS LESIONS: skin areas that are not / less covered with the hair (ears, nose, eyes) - Humans: EXPOSURE TO ULTRAVIOLET therapy it can ENHANCE THE PHOTOSENSITIZATION