Spanish honeys protect against food mutagen-induced DNA damage

Honey contains a variety of polyphenols and represents a good source of antioxidants, while the human diet often contains compounds that can cause DNA damage. The present study investigated the protective effect of three commercial honey samples of different floral origin (rosemary, heather and heterofloral) from Madrid Autonomic Community (Spain) as well as an artificial honey on DNA damage induced by dietary mutagens, using a human hepatoma cell line (HepG2) as in vitro model system and evaluation by the alkaline single-cell gel electrophoresis or comet assay.

Rosemary, heather and heterofloral honeys protected against DNA strand breaks induced by N-nitrosopyrrolidine (NPYR), benzo(a)pyrene (BaP) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), but none of the honey samples tested prevented DNA strand breaks induced by N-nitrosodimethylamine (NDMA). Heterofloral and heather (unifloral) honeys with higher phenolic content were most effective in protecting HepG2 cells against DNA damage induced by food mutagens. Heterofloral honey was more protective against NPYR and BaP, while heather honey was more protective against PhIP. Artificial honey did not show a protective effect against DNA damage induced by any of the food mutagens tested, indicating that the protective effects of honeys could not be due to their sugar components.

The results suggest that the protective effect of three kinds of Spanish honey of different floral origin could be attributed in part to the phenolics present in the samples. Honeys with higher phenolic content, i.e. heather and heterofloral honeys, were most effective in protecting against food mutagen-induced DNA damage in HepG2 cells. In addition, a possible synergistic effect between other minor honey components could also be involved.