Figure 5. Astaxanthin increased expression of NQO1, GCLM, HO-1 and GCLC mRNA. Cells were treated with 5, 10, and 20 µM astaxanthin (AST) for 24 h. Total RNA was extracted, and the amounts of NQO1, GCLM, HO-1 and GCLC mRNA amounts were quantified with real-time PCR and normalized to the corresponding amounts of β-actin mRNA. Data are shown as mean ± standard deviation (SD) (n=6); *p<0.05 versus control; **p<0.01 versus control.