Fig. 2. α-LA protects against PQ-induced cytotoxicity. (A) Cell viability was determined in cells pretreated with 250, 500, or 1000 μM α-LA for 3 h followed by 1000 μM PQ exposure for 24 h. The data are presented as means ± SEM from four independent experiments. **P < 0.01 vs. the control group; ^##P < 0.01 vs. the PQ group. (B) Morphological changes in different treatment groups observed by phase contrast microscopy with original magnification ×10. Scale bar: 80 μm. Dead cells are pointed out with black arrows. Control: solvent, α-LA: 250 μM, PQ: 1000 μM, α-LA + PQ: 250 μM α-LA plus 1000 μM PQ.