OBJECTIVETo study the relationship between copper-induced apoptosis and reactive oxygen species (ROS) in BRL cells and the effect of curcumin, a plant-derived polyphenol, on copper-injured BRL cells.

METHODSBRL cells were treated with CuSO4 (100 micromol/L) or curcumin + CuSO4. The BRL cells without any treatment were used as controls. Flow cytometry was applied to detect the production of ROS with fluorescent probe DCFH-DA. MTT colorimetry was used to evaluate cell activity. Apoptosis was measured using Hoechst 33258 staining and Annexin V-FITC and propidiumiodide (PI) staining. JNK/SAPK protein level was detected using Western blot.

RESULTSROS levels (711.70 +/- 68.33 vs 87.22 +/- 7.58) and apoptosis rate (45.08 +/- 1.87% vs 8.23 +/- 2.56%) of BRL cells reached to a peak after 6 hrs of CuSO4 treatment, which were significantly higher than controls (P < 0.01). JNK/SAPK levels increased significantly after 6 hrs of CuSO4 treatment and peaked at 24 hrs of CuSO4 treatment compared with controls (P < 0.01). Curcumin pretreatment decreased significantly ROS and JNK/SAPK levels as well as the apoptosis rate when compared with the CuSO4-treated alone group (P < 0.01).

CONCLUSIONSCopper may induce apoptosis of BRL cells. ROS participated in apoptosis induced by copper. Curcumin produced protections on copper-injured BRL cells possibly by anti-oxidation and inhibition of p-JNK expression.