The antioxidant is a nitrone known as PBN which may slow aging in the
brain. While the purpose of most antioxidants is to scavenge
destructive free radicals, the Science news article noted that some
free radicals are necessary "to eliminate invaders and unwanted
tissues [and] also to synthesize many important compounds, including
hormones". Unlike most antioxidants, PBN (which is being developed by
Centaur Pharmaceuticals) supposedly has the advantage that it does not
eliminate these useful functions of free radicals, only their harmful
effects.
Mark Crosby