FIGURE 1.

Radicals present in CS are responsible for UPR induction. MLE12 cells were exposed or not to the indicated concentrations of CSE (A), AC (B), HQ (C), H₂O₂ (D), and PN (E) for the indicated times. F, in indicated experiments AC, HQ, and CSE were added together with NAC. By the end of the incubation, cells were lysed, and lysates were checked for the presence of the phosphorylated form of eIF2α. Actin was used as a loading control (Con). Gels are representative from at least three repetitive experiments. G, graph represents quantitation of eIF2α phosphorylation. H, cell viability by the end of the exposure time was tested using a Neutral Red kit. I, MLE12 cells were exposed or not to HQ, AC, PN, H₂O₂, and 10% CS extract for 30 min, washed twice, and allowed to recover for indicated periods of time. Cells were counted by the end of indicated recovery times.