The present study was designed to evaluate the
antioxidant effects of
oleuropein against oxidative stress in the hippocampal area of rats. We used seven experimental groups as follows: Control,
Propofol,
Propofol-
Ketamine (Pro.-Ket.),
Xylazine-
Ketamine (Xyl.-Ket.), and three
oleuropein-pretreated groups (Ole.-Pro., Ole.-Pro.-Ket. and Ole.-Xyl.-Ket.). The
oleuropein-pretreated groups received
oleuropein (15 mg/kg
body weight as orally) for 10 consecutive days.
Propofol 100 mg/kg,
xylazine 3 mg/kg, and
ketamine 75 mg/kg once as ip was used on the 11th day of treatment. Spatial memory impairment and
antioxidant status of hippocampus were measured via Morris water maze, lipid peroxidation marker, and
antioxidant enzyme activities. Spatial memory impairment and lipid peroxidation significantly increased in Xyl.-Ket.-treated rats in comparison to the control,
propofol, Ole.-Pro. and Ole.-Pro.-Ket. groups.
Oleuropein pretreatment significantly reversed spatial memory impairment and lipid peroxidation in the Ole.-Xyl.-Ket. group as compared to the Xyl.-Ket.-treated rats. There was no significant difference between the control and the
propofol group in lipid peroxidation and spatial memory status.
Superoxide dismutase and
catalase activities both significantly decreased in Xyl.-Ket.-treated rats when compared to the control,
propofol, Ole.-Pro., Ole.-Pro.-Ket., and Ole.-Xyl.-Ket. groups. In contrast,
glutathione peroxidase activity in Xyl.-Ket.-treated rats significantly increased as compared to the control,
propofol, Pro.-Ket., Ole.-Pro., and Ole.-Pro.-Ket. groups. We concluded that
xylazine in combination with
ketamine is an oxidative
anesthetic drug and
oleuropein pretreatment attenuates
cognitive dysfunction and oxidative stress induced by
anesthesia in the hippocampal area of rats. We also confirmed the
antioxidant properties of
propofol as a promising
antioxidant anesthetic agent.