The mRNA expression of (A) TNF-α, (B) IL-1β, (C) IL-6, and (D) GDNF in the striatum was examined by real time RT-PCR. Abbreviations of groups of animals: control–saline-treated; PEG–vehicle-treated; MPTP–MPTP-intoxicated; i(20, 30, 40, or 50)+MPTP–IBD [20, 30, 40, or 50 mg/kg] and MPTP-treated; i(20, 30, 40, or 50)–IBD [20, 30, 40, or 50 mg/kg] treated. Data is given as the mean value ± SEM of five animals per group (* represents a significant difference relative to the control group, *p<0.05, **p<0.01; # represents a significant difference compared with the MPTP group, #p<0.05, ##p<0.01; ¤ differs from vehicle-treated animals, ¤p<0.05, ¤¤p<0.01. Mann Whitney U test).