Fig. 5

Effect of wortmannin on the cytotoxicity of the combined treatment of As^III and Tetra. After the treatment with 10 μM As^III combined with 4 μg/ml Tetra in the presence or absence of 0.25 μM and 1.0 μM wortmannin, respectively, for 24 h (a) and 48 h (b), cell viability was determined by XTT assay as described under “Materials and methods”. Relative cell viability was calculated as the ratio of the absorbance at 450 nm of each treatment group against those of the corresponding untreated control group. ^†p < 0.0001 vs. control; ^∂p < 0.05, ^£p < 0.0001 vs. As^III + Tetra. As, As^III; Tetra, tetrandrine