Abstract
The anti-genotoxicity effect of aqueous extracts of Connarus ruber cortex was studied in cultured human cells and mice. Connarus extract decreased bi-nuclei cells with micronuclei (MNBNC) significantly in NER-proficient WTK1 cells that were exposed to MNU, MMC, or UVC and in NER-deficient XPL3KA cells (that is, in XP-C) that were exposed to MNU or MMC, but not UVC. The genotoxicity-suppressing effect was further studied by the comet assay. Connarus extract decreased DNA migration significantly in WTK1 cells that were exposed to MNU or UVC and in XPL3KA cells that were exposed to MNU but not UVC. In WTK1 cells, in contrast, DNA migration increased with the extract in the presence of DNA repair inhibitors (araC and HU), suggesting that the anti-genotoxic potential is due to an enhanced incision step of global genome repair (GGR) subpathways in NER. The anti-clastogenic effect of Connarus extracts was examined in mice using a micronucleus assay. ICR male mice that received Connarus extract from drinking water for 1 - 2 weeks were exposed to cigarette mainstream smoke with interval of 24 h for 1 week. The frequency of micronucleus decreased significantly in rats received Connaraus extract, showing that Connarus extract has in vivo anti-genotoxic potential caused by inhalation of cigarette smoke.
