TABLE 4.

Stereological assessment of dopamine neuron numbers in the SN and TH staining intensity in the ST

Mice were treated with saline or MPTPp (25 mg/kg MPTP subcutaneous, 250 mg/kg probenecid intraperitoneal) every other day for 7 days (total four injections). MPTPp 7 day mice were terminated at 7 days and assessed using stereology for TH-positive neurons in the SN. Remaining groups were either given corn oil (MPTPp 14 days), C-DIM5 (MPTPp 14 days plus C-DIM5), C-DIM8 (MPTPp 14 days plus C-DIM8), or C-DIM12 (MPTPp 14 days plus C-DIM12) via daily oral gavage (50 mg/kg) for the following 7 days. After a total of 14 days, mice were used for stereology studies in the SN. Mean fluorescence intensity of TH expression in the ST as a representation of dopamine neuron terminal survival is presented for each treatment group as a percentage of control (SAL). Data are expressed as mean ± S.E.M. (n = 4 animals per group).

Treatment	SAL	MPTPp 7 Days	MPTPp 14 Days	MPTPp 14 Days Plus C-DIM5	MPTPp 14 Days Plus C-DIM8	MPTPp 14 Days Plus C-DIM12
TH + Neurons (SN)	11,434 ± 566	8,061 ± 1010*	5,689 ± 406*,†	8,556 ± 699*,‡	7,408 ± 2,587*	9,572 ± 823*,‡
TH Intensity (%Control) (ST)	100.0 ± 5.3	81.6 ± 3.5*	65.4 ± 2.6*	88.5 ± 3.9*,‡	89.3 ± 1.9*,‡	88.4 ± 0.6*,‡

C-DIM, para-phenyl subsitiuted diindolylmethane; MPTP, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyradine; MPTPp. 1-methyl-4-phenyl-1,2,3,6-tetrahydropyradine with probenecid; SN, substantia nigra; ST, striatum; TH, tyrosine hydroxylase.

^*P < 0.05 compared with saline control.

^†P < 0.05 compared with MPTPp 7 days.

^‡P < 0.05 compared with MPTPp 14 days.