Mutual interactions among ingredients of betel quid in inducing genotoxicity on Chinese hamster ovary cells

The purpose of this study is to explore the mutual interactions among the chemical ingredients of betel quid including arecoline, sodium fluoride, catechin and glycyrrhizin in producing genotoxicity on Chinese hamster ovary (CHO) cells using the micronucleus method. Our results show that arecoline at a rather low concentration of 0.2–2 μM which could be in the oral cavity during betel quid chewing and NaF (0.8–2.4 mM) significantly elevated the number of micronucleated cells in a concentration-dependent manner. In addition, significant prolongation of cell cycles was observed by treatment with arecoline (≥2.0 μM) or NaF (2.4 mM) in CHO cells. Both catechin and glycyrrhizin could antagonize not only the increased micronucleated cells induced by arecoline and NaF but also the prolonged cell cycle induced by arecoline in CHO cells. This finding implies that the adjuvant ingredients, catechu and liquorice root extract provide not only a flavor but also an antagonist against the genotoxicity of arecoline and fluoride containing betel quid.