Stroke is a leading cause of disability and death world-wide and there is currently a lack of effective treatments for
acute stroke.
D-Limonene is a common natural monocyclic
monoterpene possessing various activities. The present study aimed to evaluate the therapeutic efficacy of
D-limonene against
ischemia-associated cerebral injury in hypertensive SHRsp rats. Although systolic blood pressure was not altered by
ischemia,
D-Limonene decreased the systolic blood pressure of SHRsp rats following
stroke. Induction of
stroke resulted in increased escape latency time, decreased time spent in the target quadrant in the probe trial, decreased capacity to distinguish between familiar objects and novel objects, and increased
sensory neglect in the SHRsp rat, however these symptoms were significantly inhibited by
D-limonene.
D-limonene also decreased the
cerebral infarct size in the SHRsp rats following
stroke.
D-Limonene markedly decreased the
mRNA expression of interleukin-1β,
monocyte chemoattractant protein-1 and
cyclooxygenase-2 in SHRsp rats following
stroke. The
mRNA expression of
vascular endothelial growth factor in the brain of SHRsp rats following
stroke was significantly increased by
D-Limonene.
D-Limonene increased the activities of
superoxide dismutase and
catalase, decreased the
malondialdehyde level, increased
glutathione content and reduced the DHE-staining in SHRsp rats following
stroke. Overall, inhibition of cerebral
inflammation,
vascular remodeling and
antioxidant activities of
D-Limonene may be involved in the protective effects against
ischemia-induced damage in SHRsp rats. The present study identified
D-Limonene as a potential therapeutic candidate for treatment of
stroke-associated cerebral and vascular damage under conditions of
hypertension.