Background

 Honey contains a variety of polyphenols and represents a good source of antioxidants. On the other hand, human diet often contains compounds that cause DNA damage. In the present study we 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 of an artificial honey on DNA damage induced by dietary mutagens, using a human hepatoma cell line (HepG2) as in vitro model system and evaluated by the alkaline single cell gel electrophoresis or comet assay.

Results

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

Conclusion

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