Figure 5.

Effects of pretreatment with phytochemicals on the survival rates of Nrf2-homozygous mutant larvae exposed to NaAsO₂. (A) Survival assays using Nrf2-mutant larvae prepared from homozygous mutant parents. Larvae (3.5 dpf) were pretreated with (red; 50 µM cinnamaldehyde, 25 µM isoeugenol or 10 µM 6-MSITC) or without (gray, dotted) indicated phytochemicals. After pretreatment for 12 h, the solution was changed to 1.9 mM NaAsO₂ and survival was measured every 12 h for 48 h. (B) Determination of the optimal NaAsO₂ concentrations for survival analyses using Nrf2-mutant larvae. Larvae (4 dpf) were exposed to NaAsO₂ at concentrations of 1.3 to 1.9 mM for 48 h (1.3 (dark blue), 1.4 (red), 1.5 (light blue, dotted), 1.6 (green), 1.7 (yellow, dotted), 1.8 (purple), 1.9 mM (dark gray, dotted)). Survival rates were observed every 12 h. (C) Survival assays using a lower dose of NaAsO₂. Larvae (3.5 dpf) of Nrf2 mutant were pretreated with (red; 50 µM cinnamaldehyde, 25 µM isoeugenol or 10 µM 6-MSITC) or without (gray, dotted) indicated phytochemicals. After pretreatment for 12 h, the solution was changed to 1.4 mM NaAsO₂ and survival was measured every 12 h for 48 h.