approached significanceP =0.082
At 48 hours: 0 μM 1.000±0.031; 10 μM 0.732±0.049; 20 μM 0.661±0.052; 50 μM 0.384±0.047; all three concentrations were lower than control (all P <0.001), and the difference between 10 and 20 μM approached significance ( P =0.082), suggesting convergence with prolonged exposure.