Free radicals and reactive oxygen species in programmed cell death

Oxidative stress, originating from reactive oxygen species and free radical s provides a constant challenge to eukaryotic cell survival. While implicat ed in a number of degenerative diseases, some associated with aging and wit h aging itself, the manner and extent to which oxidative stress contributes to the initiation or implementation of programmed-cell death is problemati c. If oxidative stress is an important modulator of programmed-cell death, any ability intentionally to augment or inhibit it might ameliorate disease s in which the process is abnormally underactive or overactive.