Study of the neuroprotective
role of pretreatment with hydroalcoholic extract of Dorema aucheri leaves by alteration
of the antioxidant capacity during cerebral ischemia-induced brain injury
It has been demonstrated that hydroalcoholic extract of Dorema
aucheri (DA) leaves, as one of the medicinal plants, has a powerful antioxidant
property. Since the excessive generation of reactive oxygen species (ROS) is
the principal mechanism of brain damage during ischemic stroke, this study aimed
to evaluate the neuroprotective effects of pretreatment with DA leaves extract against cerebral
ischemia-induced brain injury through alteration of the antioxidant capacity.
Methods: The experiment was conducted in three groups of rats as
follows; sham, control ischemic and pretreated ischemic groups. Rats were
hydroalcoholic extract of DA leaves at
dosage of 200mg/kg/day for fourteen days. Then, the middle cerebral artery of
right hemisphere was occluded for 90min to achieve cerebral ischemia. After 24hours
reperfusion, cerebral infarction and superoxide dismutase (SOD) and catalase activities
as well as malondialdehyde (MDA), glutathione and NOx contents were determined.
Results: Pretreatment with DA leaves extract considerably attenuated the cerebral
infarct volume both in cortex (63%) and striatum (75%) compared with control
ischemic group. Also, DA leaves extract significantly decreased the indexes of
oxidative stress, MDA (28%), and nitrosative stress, NOx (11%), in the ischemic
hemispheres compared with control ischemic group. Likewise, pretreatment with this
extract enhanced the antioxidant capacity of ischemic hemispheres by increasing
the glutathione content (7%) and the activities of SOD (16%) and catalase (46%).
Conclusion: The findings of this study indicate that pretreatment with
hydroalcoholic extract of DA leaves declines the cerebral ischemia-induced brain
injuries through alleviation of the brain antioxidant defense system.