Gastroprotective activity of caryophyllene oxide: The role of nitric oxide, prostaglandins and sulfhydryls

The present study was carried out to evaluate the gastroprotective effect of caryophyllene oxide, and investigate the gastroprotective mechanism. For this purpose, Wistar rats received vehicle, caryophyllene oxide (10-100 mg/kg) or carbenoxolone (1-100 mg/kg, used as the reference drug). Thirty minutes later absolute ethanol was given orally, and 2 h later the stomach was dissected and the damaged area measured. In other experiments, the rats received L-NAME (70 mg/kg, i. p.), indomethacin (10 mg/kg, s. c.), and N-ethylmaleimide (10 mg/kg, s. c.), before the administration of the caryophyllene oxide (100 mg/kg) or carbenoxolone (100 mg/kg). Two control groups were included in these evaluations. Again, thirty minutes later absolute ethanol was given orally, and 2 hours later the animals were sacrificed to measure the ulcer index. Treatment of rats with caryophyllene oxide and carbenoxolone elicited a dose-dependent gastroprotective effect. The gastroprotection observed with the administration of caryophyllene oxide was attenuated in rats pretreated with the inhibitors. This suggests that the gastroprotective mechanism of action of caryophyllene oxide involves NO, prostaglandins and sulfhydryl groups. In the case of carbenoxolone, the partial participation of NO, prostaglandins and sulfhydryls was observed.