Figure 2.

(A) Comparison of the effects of 10 µM sterubin, eriodictyol, homoeriodictyol, hesperetin, sakuranetin, OHGK, chrysoeriol, or luteolin on basal tGSH levels and tGSH levels in the presence of 5 mM glutamate. tGSH levels were measured after 24 h with a chemical assay. Results are the average of three independent experiments. **** p < 0.0001 relative to control for cells not treated with glutamate; **** p < 0.0001, * p < 0.01 relative to cells treated with glutamate alone. One-way ANOVA followed by Tukey’s post test analysis. (B) HT22 cells were treated with 10 µM sterubin, eriodictyol, homoeriodictyol, hesperetin, sakuranetin, OHGK, chrysoeriol or luteolin for 4 h. Nuclei were prepared and examined by Western blotting for Nrf2 and ATF4. Representative blots are shown. Quantification of the results from 3 independent experiments is shown. The expression of each protein was normalized to the level of actin in the sample and the results are presented relative to the controls which were set at 1. **** p < 0.0001, *** p < 0.001 relative to control. One-way ANOVA followed by Tukey’s post test analysis. (C) HT22 cells were treated with 10 µM sterubin, eriodictyol, homoeriodictyol, hesperetin, sakuranetin, OHGK, chrysoeriol or luteolin for 8 h and whole cell extracts examined for two markers of Nrf2 activation, heme oxygenase 1 (HO-1) and p62, by Western blotting. Representative blots are shown. Quantification of the results from 3 independent experiments is shown. The expression of each protein was normalized to the level of actin in the sample and the results presented relative to the controls which were set at 1. ** p < 0.01, * p < 0.05 relative to control. One-way ANOVA followed by Tukey’s post test analysis.