Figure 12

Tocopherol supplementation reduces PQ (10 mg/kg b.w.)-induced TNF-α overexpression. TNF-α immunolocalization in SN, FC and hippocampus after PQ treatment with or without tocopherol supplementation (A, B and C respectively). Densitometric analyses of western blots indicate that tocopherol supplementation reduced expression levels of TNF-α significantly in SN, hippocampus, and FC of PQ-treated animals compared to PQ-treated animals without tocopherol. (A): TNF-α immunoreactivity of oval-shaped cells (microglia-macrophages) appeared in SN after PQ treatment (a), and this was reduced by α-tocopherol (b). (B): TNF-α immunopositivity appeared in microglia-like cells in FC after PQ treatment (a), and this was reduced by tocopherol (b). (C): TNF-α immunoreactivity appeared in both nucleated and non-nucleated areas of hippocampal regions CA1, CA3, and dentate gyrus (a, c and e respectively) after PQ treatment (b, d and f respectively). PQ treatment followed by tocopherol reduced TNF-α immunoreactivity in nucleated and non-nucleated areas of hippocampus (b, d and f respectively). (D): Densitometric analyses of western blots indicate that PQ treatment increased TNF-α expression levels in SN, FC and hippocampus compared to respective saline-treated control. Expression of TNF-α in the three regions remained unaltered after PQ treatment followed by tocopherol, compared to controls. Tocopherol did not alter TNF-α expression compared to saline-treated controls. β-Actin was used as a reference control in western blots. Data are presented as mean ± SEM. (n = 3). Asterisks (*) represents significant differeneces at a level of p < 0.05 (Student's t-test) for densitometric analyses. Magnification of IHC images is 40× and the scale bars = 40µm.