N-Acetyl-L-cysteine Protects Human Retinal Pigment Epithelial Cells from Oxidative Damage: Implications for Age-Related Macular Degeneration

Figure 3

NAC protects against GSH depletion. RPE cells were treated with H₂O₂ (150, 200, and 250 μM) for 24 hours with or without NAC (500 μM) pretreatment for 2 hours. GSH levels in (a) No AMD () cells and (b) AMD () cells were calculated relative to the no treatment control (dotted line). (c) GSH content after NAC treatment was compared between No AMD (NA) cells and AMD (A) cells. (d) NAC protection was calculated as NAC+H₂O₂ relative to H₂O₂ alone. One-sample -tests were used to compare NAC treatment or H₂O₂ alone to no treatment in No AMD and AMD groups (a, b). Unpaired -tests were used to compare H₂O₂ to NAC+H₂O₂ treatments in (a, b). An unpaired -test was used to compare GSH content in NAC-treated No AMD cells to NAC-treated AMD cells in (c). Two-way ANOVA with Sidak’s post hoc was used to compare the effect of the disease state (No AMD vs. AMD) and H₂O₂ concentration in (d). Per: peroxide effect; Dis: disease effect; DxP: interaction between disease effect and peroxide effect. Data are the mean (±SEM). ^† denotes significance from the no treatment control, and denotes significance between conditions. and or ^††† were statistically significant.

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