Curcumin Protects Human Keratinocytes against Inorganic Arsenite-Induced Acute Cytotoxicity through an NRF2-Dependent Mechanism
Figure 4
Curcumin treatment protects HaCaT cells against iAs3+-induced cytotoxicity. (a) Protocols for curcumin treatment and arsenic exposure in HaCaT cells. Confluence cells were either treated or not treated with curcumin for a total of 26 hr. After the first 6 hr (pretreatment), arsenic was added for the remaining 20 hr. (b) Effect of curcumin treatment on iAs3+-induced cytotoxicity. Cell viability was measured by MTT assay. Values are mean ± SD. . * versus untreated with the same iAs3+ exposure. Veh, vehicle. (c) Effect of curcumin treatment on iAs3+-induced apoptosis. Apoptotic cells were determined by flow cytometry. Annexin V-positive cells were quantified as apoptotic cells. . * versus iAs3+ exposure without curcumin treatment. (d) Immunoblotting of cleaved caspase-3 (CASP-3), PARP, and cleaved PARP. Vehicle, medium; iAs3+, cells exposed to 30 μM of iAs3+ for 20 hr; Cur + iAs3+, cells treated with 5 μM curcumin for 26 hr and exposed to 30 μM of iAs3+ for 20 hr. Whole cell lysates were used for analysis and β-ACTIN was used as loading control.
