Untransfected DI TNC1 astrocytes were treated with quercetin (A, B), or Ashwagandha (C, D), or Sutherlandia (E, F) or Açaí (G, H) extracts at the indicated concentrations for 6 h. Nrf2 (A, C, E,F) and HO-1 (B, D, F, H) expression was determined by Western blot analysis, as described in Methods. Representative blots and quantitative analysis (bar graphs) are shown. Results are expressed as the mean ± SEM (n=3-6) and analyzed by one-way ANOVA with Bonferroni post-tests, where *p<0.05, **p<0.01, ***p<0.001 vs. control.