Fig. 3
a-c Extracellular O2•− quantified by electrochemical method in melanoma A375 cells. A375 cells were exposed to UV (A), UVA (b) and UVB (c); Non-pretreatment: black line; α-tocopherol pre-treatment: blue line. O2•− generation during post-UVs irradiation quantified by electrochemical sensing: non-treatment (d) α-tocopherol pretreatment (e) (n = 3),* denotes P < 0.05,** denotes P < 0.01