The pathophysiological mechanisms leading to neuronal injury in
middle cerebral artery occlusion (MCAO) model of
cerebral stroke are complex and multifactorial that form the bases of behavioral deficits and
inflammation mediated damage. The present study demonstrates the effect of
piperine pretreatment (10 mg/kg b wt, once daily p.o. for 15 days) on
cerebral ischemia-induced
inflammation in male Wistar rats. The right middle cerebral artery was occluded for 2 h followed by reperfusion for 22 h. A maximum
infarct volume (57.80 %) was observed in ischemic MCAO group. However,
piperine administration prior to
ischemia showed a significant reduction in
infarct volume (28.29 %; p < 0.05) and neuronal loss (12.72 %; p < 0.01). As a result of
piperine pretreatment, a significant improvement in behavioral outputs of MCAO rats (p < 0.05-0.01) was observed.
Piperine successfully reduced the level of proinflammatory
cytokines IL-1β,
IL-6 and TNF-α, in ischemic group (p < 0.01). Ischemic group brain has shown edematous morphology with vacuolated architecture and pyknotic nuclei in H & E staining which was successfully ameliorated by
piperine administration. Moreover,
piperine also succeeded in lowering the expression of COX-2, NOS-2, and NF-κB (p < 0.01). Both cytosolic and nuclear NF-κB were down-regulated in ischemic group pre-administered with
piperine (p < 0.01). The present study suggests that
piperine is able to salvage the ischemic penumbral zone neurons by virtue of its anti-inflammatory property, thereby limiting ischemic cell death.