Valproate reduced healing and migration rate of cells in mono (A & B) and multilayers (C & D). A. Mean ± standard deviations of wound areas (%) in monolayer cells. Wounds exposed to high concentration of valproate were significantly larger (*) than controls as early as 12 h of incubation and this difference was maximum by 24 h. Wounds exposed to low concentration of valproate were also larger than controls starting as early as 12 h of incubation but this difference was significant (**) only at 24 h of incubation. Differences in wound areas between the low and high valproate concentrations were not significant. B. Mean ± standard deviations of % migration rates (μm2/h) of cells in monolayer cells. Valproate at high and low concentrations changed the migration rate of cells throughout the course of assay. However, it was significantly reduced during 6 to 12 h and increased during 24 to 48 h. C. Mean ± standard deviations of wound areas (%) in multilayer cells. Wounds exposed to low concentration of valproate were significantly larger than controls at 3 h of treatments and this difference was at its maximum by 12 h of incubation. D. Mean ± standard deviations of % migration rates (μm2/h) of cells in multilayers. Both high and low concentrations of valproate inhibited migration rate of cells until 12 h. Symbols Monolayer wounds (○), Multilayer wounds (●), Control (-) or (□) High drug concentration (--) or (■), Low drug concentration (...) or (). *, ** p < 0.05.