Optimization of the alkaline comet assay for easy repair capacity quantification of oxidative DNA damage in PBMC from human volunteers using aphidicolin block.

Assessment of DNA repair capacity (DRC) upon ex vivo challenge of peripheral blood mononuclear cells (PBMC) with oxidative damage inducing agents, as evaluated by the comet assay, is widely used as biomarker to assess the antioxidant status in human studies. Here, the alkaline comet assay was now optimized for easy and time saving detection of repair capacity upon oxidative stress-induced DNA damage using the DNA polymerase inhibitor aphidicolin (APC) to block repair of hydrogen peroxide (HO) induced DNA damage. Addition of a DMSO-containing DNA damage stop solution was found suitable to replace washing steps for HO removal before APC block.

Normal human immune cells are sensitive to telomerase inhibition by Brassica-derived 3,3-diindolylmethane,partly mediated via ERα/β-AP1 signaling.

Scope: Indole-3-carbinol (I3C) and 3,3'-diindolylmethane (DIM) from Brassica plants are regarded as promising anticancer phytochemicals. The enzyme telomerase is a very attractive target for cancer therapeutics; in normal cells such as lymphocytes, it plays a decisive role for cell maintenance. The effect of I3C and DIM on telomerase in normal human immune cells (PBMC) was studied compared to leukaemia cells (HL-60).