Beneficial Effects of Piperine on Spatial Memory Impairment and Brain Lipid Peroxidation Increase Induced by Transient Cerebral Ischemia in Mice

Abstract

Effects of piperine, a major pungent alkaloid in pepper, on the cognitive

deficit and cerebral oxidative stress induced by cerebral ischemia were studied in

mice by using spatial memory task and measurement of lipid peroxidation in the

brain. Transient cerebral ischemia was induced by 20-min bilateral common

carotid artery occlusion (2VO) and the impairment of spatial learning and

memory was subsequently evaluated for 5 consecutive days by a Morris water

maze. The 2VO-mice displayed a delay in swimming time to find a hidden

platform (escape latency) when compared to sham-operated mice. The 5-day

intraperitoneal (i.p.) administration of piperine, at 0.1 and 0.5 mg/kg/day after the

2VO, markedly attenuated this cognitive deficit while the same administration at

higher doses (1 and 5 mg/kg/clay) showed lower preventive effect on the deficit.

Beneficial effects of piperine on spatial memory task were also found in normal

and sham-operated mice. However, the magnitude of effects was relatively small

comparing to that observed in 2VO mice. In addition, 5-day piperine

administration at all test doses did not show any significant effects on locomotor

activity of normal mice.

The brain lipid peroxidation (as measured by TBARS assay) of 2VO-mice

at 5 days after the occlusion was significantly increased when compared to

sham-operated mice. This increase was markedly attenuated by 5-day i.p.

administration of piperine at 0.1 and 0.5 mg/kg/day while the same administration

at higher doses (1 and 5 mg/kg/day) showed modest attenuation on the increase.

Moderate beneficial effects of piperine on brain lipid peroxidation were also

noticed in sham-operated mice.

Taken together, these results suggested that piperine administration had

beneficial effects on 2VO-induced cognitive deficit and brain lipid peroxidation

increase in mice. The close correlation between effects of piperine on both

indications of brain injury also implied that the attenuation of 2VO-induced

cognitive deficit may involve, at least partly, the antioxidant property of piperine.

Conceivably, piperine may be considerable for further study as a possible

adjunctive medication in the treatment of neurodegenerative disorders.