ABSTRACT
Abstract White pepper (Piper nigrum L.) and long pepper (Piper longum L.) belong to family Piperaceae and are commonly used as household spices and traditional medicine worldwide, specifically in China and Southeast Asia. In Traditional Chinese Hui Medicine, these herbs are widely used for treatment of stroke. Our present study investigated effects of these herbs on inflammation in rat model with cerebral ischemia. After subjecting the rats to permanent middle cerebral artery occlusion (pMCAO) for 6 h, at doses of 100 and 200 mg/kg, dichloromethane fraction from white pepper and long pepper, respectively, was intragastrically administered once a day for seven consecutive days. Cerebral cortical and hippocampal tissues were collected after seven days. Superoxide dismutase, malonaldehyde, tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and IL-6 were measured by spectrophotometer. Phytochemical profile of dichloromethane fraction was determined through HPLC. Dichloromethane fraction exhibited anti-inflammatory activity by suppressing expression or production of IL-1β, IL-6, and TNF-α. By contrast, dichloromethane fraction showed activity against pMCAO injury by reducing oxygen-free radicals through increased superoxide dismutase activity and decreased malonaldehyde level. HPLC analysis revealed piperine as major component of dichloromethane fraction. These results show that dichloromethane fraction provides protection against cerebral ischemia. The possible mechanism is related to anti-inflammatory activity and reduction in oxygen-free radicals.
ABSTRACT
Objective To investigate the effect of hand twelve Jing-Well points bloodletting on blood-brain barrier (BBB) permeability in the early stage of focal cerebral ischemic injury in rats with permanent middle cerebral artery occlusion (pMCAO). Method Male Wister rats were randomized into sham operation, model and bloodletting groups. A model of middle cerebral artery occlusion was made by Longa's method. 2%Evans blue (EB) was injected into the caudal vein at three time points:5, 24 and 72 hrs after model making. EB exudation amount was assessed by measurement of EB absorbance in brain tissue to observe BBB permeability. Result Cerebral EB exudation amount was significantly higher in the model group of rats than in the sham operation group (P<0.01) and significantly lower in the bloodletting group than in the model group (P<0.01). Conclusion Hand twelve Jing-Well points bloodletting can reduce blood-brain barrier permeability in pMCAO rats. Its effect is highly significant at 24 and 72 hrs after ischemia.
ABSTRACT
Laboratory mice with Middle Cerebral Artery Occlusion (MCAO) represent the main animal models for ischemic stroke research. Appropriate anesthetic protocols are essential, as anesthetic agents might affect the central nervous system (CNS) and therefore interfere with the outcome of pre-clinical ischemic stroke studies. In the present study we sought to investigate whether isoflurane, a widely used inhalational anesthetic, has any effect on MCAO mice pretreated with simvastatin, a well-known neuroprotective compound, compared with the administration of injectable ketamine/xylazine combination. Forty adult C57Bl/6J mice randomly allocated into four groups underwent ischemic injury by permanent coagulation of the Middle Cerebral Artery (MCA): Group A (n=11) animals were anesthetized with ketamine/xylazine, Group B (n=9) with isoflurane, Group C (n=9) with ketamine/xylazine after pretreatment with simvastatin 2h before permanent Middle Cerebral Artery Occlusion (pMCAO) and Group D (n=11) with isoflurane after similar pretreatment with simvastatin. The potential neuroprotective effect of the anesthetics was evaluated in terms of brain infarct volumes and neuron death. No significant differences, both quantitatively and qualitatively, were detected in brain lesions measured up to 7 days after pMCAO when comparing isoflurane inhalational anesthesia to ketamine/xylazine injectable anesthesia. Group C mice (simvastatin-treated ketamine/xylazine) had a significantly reduced brain infarct volume compared to Group A mice (non-simvastatin ketamine/xylazine) (P<.0005). Similarly Group D mice (simvastatin-treated isoflurane) had a significantly reduced brain infarct volume compared to Group B mice (non-simvastatin isoflurane) (P<.0005). No difference between morphology and number of apoptotic neurons was detected due to the two different anesthetic regimens. These results demonstrated the safe use of the established anesthetic agent isoflurane in mice where simvastatin is investigated as a neuroprotective compound.
ABSTRACT
In order to study the therapeutic time window of dimethylaminoethyl ginkgolide B mesylate(XQ-1H) in the permanent focal ischemia of rat,we used the rat model of the permanent middle cerebral artery occlusion (pMCAO).Doses of 15.6,7.8 and 3.9 mg/kg of XQ-1 H were intravenously administered at 0.5,1,2,3 h after MCAO,respectively.Neurological scores,infarct sizes,water contents and pathological changes in each interval were determined at 72 h after MCAO.It was observed that XQ-1 H administered at 0.5 and 1 h after MCAO significantly reduced the cerebral infarct size and edema,and produced significant reductions in the neurological deficits.The protective effect of XQ-1H on the neuron cells was proved by pathological observations.In addition,the contents of MDA,lactate,and the activities of SOD were measured.Reduction in the contents of MDA and lactate and enhancement in the activities of SOD were attributed to the pretreatment of XQ-1H at 0.5 and 1 h.Our results showed that the therapeutic time window of XQ-1H extended for up to 1 h after MCAO.
ABSTRACT
Matrix metalloproteinases (MMPs) can degrade a wide range of extracellular matrix components. It has been reported that MMP-9 are activated after focal ischemia in experimental animals. (-)-Epigallocatechin-3-gallate (EGCG), a major constituent of green tea polyphenols, is a potent free radical scavenger and reduces the neuronal damage caused by oxygen free radicals. And it has been known that EGCG could reduce the infarction volume in focal brain ischemia and inhibit MMP-9 activity. To delineate the relationship between the anti-ischemic action and the MMP-9-inhibiting action of EGCG, we investigated the effect of EGCG on brain infarction and the activity of matrix metalloproteinase-9 induced by permanent middle cerebral artery occlusion (pMCAO) in ICR mice. EGCG (40 mg/kg, i.p. 15~30 min prior to MCAO) significantly decreased infarction volume at 24 hr after MCAO. GM 6001 (50 mg/kg, i.p. 15~30 min prior to MCAO), a MMP inhibitor, also significantly reduced infarction volume. In zymogram, MMP-9 activities began to increase at ipsilateral cortex at 2 hr after MCAO, and the increments of MMP-9 activities were attenuated by EGCG treatment. Western blot for MMP-9 also showed patterns similar to that of zymogram. These findings demonstrate that the anti-ischemic action of EGCG in mouse focal cerebral ischemia involves its inhibitory effect on MMP-9.
Subject(s)
Animals , Mice , Blotting, Western , Brain Infarction , Brain Ischemia , Brain , Extracellular Matrix , Free Radicals , Infarction , Infarction, Middle Cerebral Artery , Ischemia , Matrix Metalloproteinase 9 , Matrix Metalloproteinases , Mice, Inbred ICR , Middle Cerebral Artery , Neurons , Oxygen , Polyphenols , TeaABSTRACT
Objective To investigate the effects of focal mild hypothermia on apoptotic neurons and the expression of glutamate transporter(GLT-1)and metabotropic glutamate receptor(mGluR2/3)after cerebral ischemia in rats.Methods Eighty-eight adult rats were randomly divided into mild hypothermia group,normothermia group and control group.Unilateral permanent middle cerebral artery occlusion(pMCAO)was induced.In mild hypothermia group,the brain temperature of occlusive side was decreased and maintained for 3 h at(33?0.5)℃ with Sticking Focal Mild Hypothermia Instrument.The body temperature of normothermia group was maintained at(37?0.5)℃.3 h,6 h,12 h,24 h,3 d,7 d after cerebral ischemia,the expression of GLT-1 and mGluR2/3 around infarction cortex were determined by Western Blot.6 h,24 h,3 d,7 d after cerebral ischemia,TUNEL method was performed to label neuronal apoptosis.Results 24 h,3 d after cerebral ischemia of mild hypothermia group,24 h,3 d,7 d after cerebral ischemia of normothermia group,the apoptotic neurons around infarction core markedly increased comparing with 6 h after cerebral ischemia(all P