Diapocynin enters brain and attenuates MPTP-induced depletion of neurotransmitters. (A) Treatment schedule of MPTP-injected mice with diapocynin. (B) Mice were treated with two doses of diapocynin (100 and 150 mg/kg/day) and seven days after the last dose of MPTP treatment, striatal dopamine level was measured using high-performance liquid chromatography (HPLC). Quantification of diapocynin in the substantia nigra (SN) and striatum of mice. Mice were administered diapocynin (300 mg/kg/day) by oral gavage 24 h before MPTP treatment, and co-treatment with MPTP (25 mg/kg/day) was continued for 5 days, and post-treatment with MPTP (25 mg/kg/day) lasted 6 days. Seven days after the last injection of MPTP, SN and striatum were dissected out and quantified for diapocynin. (C) Standard curve of diapocynin standards ranging from 0.3 μg to 30 μg. (D) Quantification of diapocynin in SN and striatum. Seven days after the last MPTP treatment, striatal (E) dopamine, (F) 3,4-dihydroxyphenyl-acetic acid (DOPAC) and (G) homovanillic acid (HVA) were measured by HPLC. Data are means ± SEM of eight to ten mice per group. ***
P <0.001 versus the control group; *
P <0.05 vs the MPTP group; #
P <0.01 vs the MPTP group; a
P <0.01 vs the control group.