Figure 4. Viability of human trabecular meshwork (hTM) cells. A:SA-2 dose-dependently increased the number of viable hTM cells and exhibited no toxicity up to 125 µM. The half maximal effective concentration (EC₅₀) was calculated to be 53.5 µM. B: SA-2 dose-dependently increased the number of viable hTM cells in the presence of tert-butyl hydroperoxide (TBHP, 300 µM). The EC₅₀ was calculated to be 0.38 µM. C: SA-2 dose-dependently protected hTM cells against TBHP (300 µM) and induced cell proliferation up to the 16 µM dose. hTM cell viability is represented as % of control. Experiments were performed in triplicate with n = 4 technical replicates. Values are expressed in mean ± standard error of the mean (SEM). *p<0.01, one-way analysis of variance (ANOVA).