20-Hydroxyecdysone Protects against Oxidative Stress-Induced Neuronal Injury by Scavenging Free Radicals and Modulating NF-κB and JNK Pathways

A: Chemical structure of 20E. B: Concentration-dependent effect of H₂O₂ on cell viability in B35 neural cells. B35 neural cells were exposed to different concentrations of H₂O₂, and then cell viability was assessed 12 h later by an MTT assay. C: Inhibition of H₂O₂-induced decrease in cell viability by 20E in B35 neural cells. Cells were exposed to 20E at the concentrations of 25 to 400 µM for 24 h or were pretreated with 20E (25 to 400 µM) for 24 h prior to a 12 h incubation with H₂O₂. Cell viability was assessed, as measured by an MTT assay. D: Cell injury was assessed by testing LDH release. Cells were pretreated with 20E (50 or 400 µM) for 24 h before a 12 h incubation with H₂O₂, and then LDH release (% of total) was calculated as the percentage of LDH in the medium versus total LDH activity in the cells. Data are reported as the means ± S.D. from three independent experiments. Non-treated cells served as controls. ^# p<0.05 vs. Control, ^## p<0.01 vs. Control, ^*p<0.05 vs. H₂O₂ alone, ^**p<0.01 vs. H₂O₂ alone.