The effect of honey on ethanol-induced increased vascular permeability changes was studied in the rat stomach. Sucralfate and allopurinol were used as standard gastroprotective and antioxidant drugs, respectively. Extravasation of intravenously administered Evans blue dye into the stomach following 30 min exposure to ethanol was used as an indicator of vascular permeability. The amounts of the extravasated. dye were quantified spectrophotometrically. Ethanol produced concentration and time-dependent increase in the extravasation of Evans blue. Oral administration of honey (0.078-0.625 g/kg) 30 min before ethanol dose-dependently attenuated ethanol-induced increased vascular permeability. Pretreatment with a sulfhydryl blocker, N-ethylmaleimide (0.050 g/kg, subcutaneously), caused enhancement of ethanol-induced vascular permeability changes. Treatment with N-ethylmaleimide before honey reduced the protective effects of honey. Similarly, sucralfate (0.031-0.250 g/kg) orally and allopurinol (0.025-0.050 g/kg) intravenously inhibited vascular permeability caused by ethanol and treatment with N-ethylmaleimide before sucralfate or allopurinol reduced their inhibitory effects. These results suggest that the protective effect of honey may be mediated through sulfhydryl-sensitive processes and it may also possess antioxidant properties. II is also suggested that endogenous sulfhydryl may facilate and mediate beneficial effects of gastroprotective and antioxidant drugs. (C) 1997 Elsevier Science Ireland Ltd.