Figure 8

Diapocynin suppresses disease progression in the subacute MPTP mouse model of Parkinson’s disease (PD) and protects striatal neurotransmitter depletion in the chronic MPTP mouse model of PD. For disease progression study, mice were treated with MPTP (25 mg/kg/day) for 5 days. Diapocynin (300 mg/kg/day) treatment started on the 4th day of MPTP injection and continued for another 8 days. Mice were sacrificed 1 day after the last dose of diapocynin and striatal (A) dopamine, (B) 3,4-dihydroxyphenyl-acetic acid (DOPAC) and (C) homovanillic acid (HVA) were measured by high-performance liquid chromatography (HPLC). For chronic treatment, mice were treated with 2 doses of MPTP (25 mg/kg/day, s.c.) and 2 doses of probenecid (250 mg/kg/day, i.p.) per week for 5 weeks. Control mice received only saline. One week prior to MPTP/probenecid treatment, one group of mice received 3 doses of diapocynin (100 mg/kg/day, gavage) and this treatment continued for 12 consecutive weeks. Another batch of mice received 3 doses of diapocynin (100 mg/kg/day, gavage) in a week for consecutive 12 weeks. Immediately after treatment, mice were sacrificed and striatal (D) dopamine, (E) DOPAC and (F) HVA were measured by HPLC. Data are means ± SEM of 8 to 10 mice per group. ^*** P <0.001 vs the control group; ^** P <0.01 vs the MPTP group; ^* P <0.05 vs the MPTP group.