(A and C) Intracellular reduced GSH evaluation after 24- and 48-hour treatment with BiZn or BSO on HK-2 cells. HK-2 cells were treated with BiZn (10 μM and 100 μM) or BSO (250 μM and 500 μM) for 24 or 48 hours. After monochlorobimane staining, the fluorescence produced by the cells was measured. (A) The fluorescence increased significantly in BiZn (100 μM)-treated HK-2 cells after 24 hours of incubation (n = 3, BiZn 100 μM vs. control group, 60 minutes **P < .01) and 48 hours of incubation (n = 3, BiZn 100 μM vs. control group, 60 minutes **P < .01). (B) Monitoring the GSH depletion effect of BSO on HK-2 cells for 24 hours of incubation (n = 3, BSO 250 and 500 μM vs. control group, 60 minutes ***P < .001) and 48 hours (n = 3, BSO 250 and 500 μM vs. control group, 60 minutes ***P < .001) of incubation. (C) The reduced GSH increased significantly in BiZn (10 μM and 100 μM)-treated HK-2 cells after 48 hours of incubation (n = 3, BiZn 10 μM and 100 μM vs. control group, ***P < .001). (D) The effects of BiZn and BSO on cisplatin-treated HK-2 cells were analyzed by XTT and neutral red uptake assay. HK-2 cells were pretreated with BiZn (10 μM and 100 μM) for 3 days before exposure to BSO (500 μM) and cisplatin (10 μM) for 48 hours. (C-a) Cell viability of HK-2 cells (XTT assay). (C-b) Cell viability of HK-2 cells (neutral red uptake assay) (compounds vs. control group or compounds vs. compounds group, **P < .01 and ***P < .001).