a b s t r a c tParkin mutations produce Parkinson's disease (PD) in humans and nigrostriatal dopamine lesions related to increased free radicals in mice. We examined the effects of NP7, a synthetic, marine derived, free radical scavenger which enters the brain, on H 2 O 2 toxicity in cultured neurons and glia from wild-type (WT) and parkin null mice (PK-KO).NP7, 5-10 lM, prevented the H 2 O 2 induced apoptosis and necrosis of midbrain neuronal and glial cultures from WT and PK-KO mice. NP7 suppressed microglial activation and the H 2 O 2 induced drop-out of dopamine neurons . Furthermore, NP7 prevented the increased phosphorylation of ERK and AKT induced by H 2 O 2 . NP7 may be a promising neuroprotector against oxidative stress in PD.