Fig. 7.

TP protect cells against oxidative stress. (A) SAR of suppression of ROS formation by various TP. U937 cells were exposed to 10 nM TP for 24 h, incubated with 10 μM2′,7′-dichlorodihydrofluorescein diacetate for 30 min, and then challenged with 250 μM tert-butyl hydroperoxide for 15 min. Mean fluorescence intensity of 10⁴ cells was determined by flow cytometry. (B) TP-225 protects against photooxidative damage. Human retinal pigment epithelial cells (ARPE-19) were incubated with TP-225 for 24 h. They then were loaded with 25 μM all-trans-retinaldehyde for 2 h, exposed to UVA (340–400 nm) for 15 min, and finally incubated for an additional 18 h. Cell survival was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay.