Fig. 3. Intracellular GSH levels measured in untreated erythrocytes, or in 10 mM Mg²⁺-treated erythrocytes (control) or in H₂O₂ -treated (300 μM, 600 μM or 1mM) erythrocytes, with or without pre-exposure to 10 mM Mg²⁺ (10 mM Mg²⁺+ 300 μM H₂O₂ or 10 mM Mg²⁺+ 600 μM H₂O₂ or 10 mM Mg²⁺+ 1 mM H₂O₂). Bars represent the mean ± SD from at least 5 experiments, where 10 mM Mg²⁺ n.s. versus untreated erythrocytes; n.s. versus control.