Fig. 3

Nrf2 signaling participated in ICA-mediated neuroprotection. Nrf2 KO mice were treated with ICA (60 mg/kg) daily for 10 consecutive days and a single intranigral injection of 6-OHDA (4 μg) in the left side of SN 3 days after ICA treatment. Then, mouse brains were harvested and the knockout efficiency was tested by western blotting (a). The mRNA and protein expressions of Keap1, HO-1, and NQO1 in midbrain were detected by real-time RT-PCR (b) and western blotting (c), respectively. The rotarod test and open-field test were performed (d, e). TH-positive neurons were measured by immunofluorescence staining (f). TH protein expression in mesencephalon was detected by western blot assay (g). The levels of DA, DOPAC, and HVA in striatal tissue were tested by UHPLC. The DA metabolite ratio [(DOPAC + HVA)/DA × 100] was computed (h). Results were mean ± SEM from 5 to 6 mice. *p < 0.05 compared with the control group. Scale bar = 200 μm