Objective Curcumin is a plant polyphenolic compound and a major component of spice turmeric （Curcuma longa）. It has been reported to possess free radical-scavenging, iron-chelating, and anti-inflammatory properties in dif- ferent tissues. Our previous study showed that curcumin protects MES23.5 dopaminergic cells from 6-hydroxydopamine （6-OHDA）-induced neurotoxicity in vitro. The present study aimed to explore this neuroprotective effect in the 6-OHDA-lesioned rat model of Parkinson＇s disease in vivo. Methods Rats were given intragastric curcumin for 24 days. 6-OHDA lesioning was conducted on day 4 of curcumin treatment. Dopamine content was assessed by high-performance liquid chromatography with electrochemical detection, tyrosine hydroxylase （TH）-containing neurons by immunohistochemistry, and iron-containing cells by Perls＇ iron staining. Results The dopamine content in the striatum and the number of TH-immunoreactive neurons decreased after 6-OHDA treatment. Curcumin pretreatment reversed these changes. Further studies demonstrated that 6-OHDA treatment increased the number of iron-staining cells, which was dramatically decreased by curcumin pretreatment. Conclusion The protective effects of curcumin against 6-OHDA may be attributable to the ironchelating activity of curcumin to suppress the iron-induced degeneration of nigral dopaminergic neurons.
