Fig. 4

Role of κ-opioid receptor and neurokinin 1 receptor in GRe-mediated antioxidant potentials. Effects of neurokinin 1 receptor antagonist L-733,060 on Nor-B-mediated pharmacological activity in response to antioxidant effect of GRe against ROS formation (a), HNE (b), and protein carbonyl (c) levels induced by MA. Sal = saline, MA = methamphetamine 35 mg/kg, i.p., GRe = ginsenoside Re 20 mg/kg, i.p., Nor-B = Nor-binaltorphimine 3 or 6 mg/kg, i.p., L733 = L-733,060 5 or 10 mg/kg, i.p., ROS = reactive oxygen species, HNE = 4-hydroxynonenal, WT = wild type, DYN KO = prodynorphin knockout. Each value is the mean ± SEM of six animals (one-way ANOVA followed by Fisher’s LSD pairwise comparisons)