Antioxidant marine algae phlorotannins and radioprotection: a review of experimental evidence.

Radiation has been widely used for cancer therapy in human medicine. However, the side effects of radiation are problematic and can limit its application. Radiation generates reactive oxygen species, leading to cell death via multiple signaling pathways. The blocking of certain signaling cascades using antioxidants represents a compensatory therapy of radiation-induced tissue injury. Although synthetic chemicals have been investigated in recent decades, anti-oxidants from natural resources have been searched for continuously. Among them, phlorotannins from marine algae, including Ecklonia cava, have been shown to protect cells from radiation-induced injury as well as oxidative stress. In the present review, the radioprotective capacity of phlorotannins derived from marine algae and the mechanisms involved are discussed.