We investigated the effects of a potent
antioxidant,
lycopene, on the
free radical-scavenging activity as evaluated by the DPPH test and lipid peroxidation in rat brain homogenates as well as
nitric oxide (NO) formation in cultured microglia stimulated by
lipopolysaccharide. In addition, we also investigated the
therapeutic effect of
lycopene in attenuating
ischemia/reperfusion
brain injury induced by middle cerebral artery (MCA) occlusion in rats.
Lycopene (1, 2 and 5 microM) exerted increased DPPH decolorization in the DPPH test, and increased inhibition of
iron-catalyzed lipid peroxidation (
TBARS formation) in rat brain homogenates in concentration-dependent manners. Furthermore,
lycopene (5 and 10 microM) significantly inhibited
nitrite production by about 31% and 61% in microglia stimulated by LPS, respectively. Rats which received
lycopene at a dosage of 4 mg/kg, but not at 2 mg/kg, showed significant
infarct size reductions compared with those which received the
solvent control (20%
Tween 80). In conclusion, we demonstrate a protective effect of
lycopene on ischemic
brain injury in vivo.
Lycopene, through its antioxidative property, mediates at least a portion of
free radical-scavenging activity and inhibits microglia activation, resulting in a reduction in
infarct volume in
ischemia/reperfusion
brain injury.