Chemopreventive Doses of Curcumin Protect Cells from Cadmium Induced Oxidative Stress

Circumstantial evidence link the high levels of environmental pollutants to increased incidence of different chronic-degenerative diseases. Among these, the levels of heavy metals (HM) can certainly play a key role. On the other hand, a qualified literature highlights how different phytochemicals, normally present in the diet are able to interfere with HM metabolism helping to reduce tissue concentrations and their negative effects on health. Curcumin (Cur) appears of particular interest for its protective properties against cadmium (Cd) toxicity. HL-60 cells, differentiated in human monocyte/macrophage lineage by vitamin D analogue EB1089, were preincubated with low doses of Cur (1 ?M) and treated for 24 h with 15 ?M Cd. Cell viability was measured using CyQuant fluorescent dye. ROS (reactive oxygen species) and reduced glutathione (GSH) variations were assayed respectively by dichlorofluorescein-diacetate method and monochlorobimane probe. The bioavailability of Cur in HL-60 cells was successfully performed using RP-HPLC coupled with UV-Vis, MS/MS or MS/MSn. In differentiated HL-60 cells, the preincubation with 1 ?M Cur determined a significant 20% protection towards the cytotoxicity induced by Cd. The investigation of the mechanism of action evidenced that curcumin lowered ROS increase caused by Cd by increasing GSH intracellular levels. The antioxidant activity of Cur was strengthened by the detection of free curcumin inside the cells after 5 min of treatment.