The present study examined the effect of chelerlythrine, a protein kinase C (PKC) inhibitor, on 1-methyl-4-phenylpyridine (MPP+)-induced hydroxyl radicals (*OH) in rat striatum. Rats were anesthetized, and sodium salicylate (0.5 mM or 0.5 nmol/microl/min) was infused through a microdialysis probe to detect the *OH generation as reflected by the non-enzymatic formation of 2,3-dihydroxybenzoic acid (2,3-DHBA) in the striatum. Dopamine (DA)-selective neurotoxin, MPP+, infusion into the striatum of rats induces *OH formation, trapped as 2,3-DHBA. The application of chelerythrine, a potent and selective protein kinase C (PKC) inhibitor, suppressed MPP+ -induced *OH formation. The results in the present study suggests the protective effect of chelerythrine on *OH generation induced by MPP+.