Effects of fusel oil on animal hangover models.

Fusel oil has been reported to have undesirable side effects such as hangover. However, the relationship between fusel oil and hangover has been investigated insufficiently. In this study, we investigated the effects of fusel oil and their ingredients contained in alcoholic beverages by using animal hangover models. Ethanol and fusel oil were simultaneously administered to Suncus murinus, and emetic responses were observed for 60 min. Ethanol and fusel oil were simultaneously administered to mice immediately after intake of saccharin solution; on the next day, the mouse's saccharin solution intake was measured. The volatile fraction (fusel oil) of whisky had no remarkable effect on ethanol-induced emetic responses in suncus. Whisky had the most suppressive effect on ethanol-induced conditioned taste aversion in mice among the various alcoholic beverages tested. The volatile fraction (fusel oil) of whisky suppressed the ethanol-induced conditioned taste aversion. In contrast, the nonvolatile fraction of whisky had no effect. The administration of isoamyl alcohol (5 mg/kg) and isoamyl acetate (10 and 40 microg/kg), ingredients of fusel oil, significantly suppressed the ethanol-induced conditioned taste aversion. The fusel oil in whisky had no effect on the ethanol-induced emetic response, but it suppressed taste-aversion behavior in animal models of hangover symptoms. These results suggest that the fusel oil in whisky alleviates hangover, contrary to the common belief.