Silymarin prevents UVB-induced DNA damage as determined by comet assay.

<p><b>(A),</b> NHEK were exposed to UVB (150 J/m²) radiation with and without the treatment with silymarin (20 µg/mL), as described under <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0021410#pone-0021410-g002" target="_blank">Fig. 2</a>. Keratinocytes were harvested 36 h after UVB irradiation, and UVB-induced DNA damage was determined using comet assay, as detailed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0021410#s2" target="_blank">Materials and methods</a>. The comet assay was used to determine UVB-induced DNA damage in the form of DNA fragmentation. <b>(B),</b> The tail of the comet was measured in each cell under microscope and expressed in µm as a mean±SD from at least 30 cells in each treatment group. ^¶Significant increase in tail length <i>versus</i> non-UVB-exposed control, p<0.001; ^*Significant decrease in tail length versus UVB alone, p<0.001.