B R A I N R E S E A R C H 1 2 6 8 ( 2 0 0 9 ) 1 7 4 – 1 8 0

ava i l ab l e a t www.sc i enced i r ec t . com

www.e l sev i e r. com/ loca te /b ra in res

Research Report

Oxymatrine protects rat brains against permanent focalischemia and downregulates NF-κB expression

Ying Liu, Xiang-jian Zhang⁎, Chen-hui Yang, Hong-guang FanDepartment of Neurology, Second Hospital of Hebei Medical University. Shijiazhuang 050000, China

A R T I C L E I N F O

⁎ Corresponding author.E-mail address: zhang6xj@heinfo.net (X. Z

0006-8993/$ – see front matter © 2009 Elsevidoi:10.1016/j.brainres.2009.02.069

A B S T R A C T

Article history:Accepted 20 February 2009Available online 10 March 2009

Background: Oxymatrine is proven to protect ischemic and reperfusion injury in liver,intestine and heart, this effect is via anti-inflammation and anti-apoptosis. Whether thisprotective effect applies to ischemic injury in brain, we therefore investigate the potentialneuroprotective role of oxymatrine and the underlying mechanisms. Methods: Male,Sprague–Dawley rats were randomly assigned to four groups: permanent middle cerebralartery occlusion (pMCAO), high dose (pMCAO+oxymatrine 120 mg/kg), low dose (pMCAO+oxymatrine 60 mg/kg) and sham operated group. We used a permanent middle cerebralartery occlusion model and administered oxymatrine intraperitoneally immediately aftercerebral ischemia and once daily on the following days. At 24 h after MCAO, neurologicaldeficitwas evaluatedusing amodified sixpoint scale; brainwater contentwasmeasured;NF-κB expression was measured by immunohistochemistry, Western blotting and RT-PCR.Infarct volumewas analyzed with 2, 3, 5-triphenyltetrazolium chloride (TTC) staining at 72 h.Results: Comparedwith pMCAO group, neurological deficit in high dose groupwas improved(P<0.05), infarct volume was decreased (P<0.001) and cerebral edema was alleviated(P<0.05). Consistent with these indices, immunohistochemistry, Western blot and RT-PCRanalysis indicated that NF-κB expression was significantly decreased in high dose group.Low dose of oxymatrine did not affect NF-κB expression in pMCAO rats. Conclusions:Oxymatrine reduced infarct volume induced by pMCAO, this effect may be through thedecreasing of NF-κB expression.

© 2009 Elsevier B.V. All rights reserved.

Keywords:OxymatrineCerebral infarctionMiddle cerebral arteryNF-κB

1. Introduction

Ischemic stroke remains a leading cause of death anddisability worldwide. In acute stroke, neuron apoptosis andinflammation play an important role in tissue loss andneurological deficit. Oxymatrine (OMT) is the major quinoli-zidine alkaloid from the root of Sophora flavescens Ait (kushen).The structure of OMT is clear as shown in Fig. 1. It has beenproved that OMT has anti-inflammatory, anti-apoptosis, anti-tumor, anti-viral and anti-arrhythmic effects. OMT also exerts

hang).

er B.V. All rights reserved

a protective effect on ischemia or ischemia/reperfusiondamage in liver, intestine and heart (Jiang et al., 2005; Zhaoet al., 2008; Hong-Li et al., 2008). In the colitis induced bydextran sulfate sodium, OMT ameliorates the colonic inflam-mation through reducing expression of NF-κB in colonicmucosa (Zheng et al., 2005).

Nuclear factor-kappa B (NF-κB) is a ubiquitously expressedtranscription factor that regulates expression of genesinvolved in inflammation, cell survival and apoptosis (Małeket al., 2007). There are many evidences that NF-κB is

.

Fig. 1 – Chemical structure of OMT.

175B R A I N R E S E A R C H 1 2 6 8 ( 2 0 0 9 ) 1 7 4 – 1 8 0

upregulated following ischemia (Terai et al., 1996; Gabriel et al.,1999). Alsomany data suggest that inhibition of NF-κB reducesinfarction volume and develops less ischemic damage inpermanent ischemia especially; maybe NF-κB antagonists aretherapeutic agents for stroke (Shen et al., 2003; Schneider et al.,1999; Ueno et al., 2001; Xu et al., 2002; Nurmi et al., 2004a,b).

The aimof this studywas to investigatewhether OMThas aneuroprotective effect in the rat model of permanent middlecerebral artery occlusion (pMCAO) and the potential mechan-isms for its neuroprotection.

Fig. 2 – Effect of OMT on neurological deficit. The behavioralscores were significantly lower in high dose group thanpMCAO group (*P<0.05, Mann–Whitney test), but nosignificant difference was found between pMCAO group andlow dose group.

2. Results

2.1. OMT treatment and neurological deficit after pMCAOin rats

Neurological deficit was examined and scored on a 6-pointscale and Mann–Whitney U test analysis was conducted.Neurological deficit scores were significantly decreased byOMT at a dose of 120 mg/kg (P<0.05) versus saline-treatedpMCAO group. At a dose of 60 mg/kg, OMT reduced the scores,but did not reach a significance level (Fig. 2).

2.2. Effect of OMT on infarct volume in pMCAO rats

No infarction was observed in sham operated group, Fig. 3displayed the image of the untreated and treated animals at72 h after cerebral ischemia. In pMCAO group, an extensivelesion was developed in both striatum and lateral cortex. OMTtreatment (120 mg/kg) significantly reduced the %HLV from46.66±4.82 to 26.36±6.86 (P<0.001). There was no significantdifference in the infarct volume between pMCAO group andlow dose group (40.09±5.72). The neuroprotective effect ofOMT in high dose group was greater than that in low dosegroup (P<0.05).

2.3. Effect of OMT on cerebral edema

Cerebral water content was shown in Fig. 4. In the shamoperated group, water content was 77.68%±0.36% andincreased to 83.00%±0.49% at 24 h after occlusion. Comparedwith pMCAO group, water content markedly reduced to81.83%±0.42% (P<0.05) in high dose group, but no statisticalsignificance was observed in low dose group.

2.4. Effect of OMT on expression of NF-κB

Immunohistochemistry using antibodies against activatedp65/RelA subunits showed that the expression of NF-κB was

upregulated after ischemia. In sham operated animals, fewcells stained by p65 were seen in the cortex (Fig. 5A). 24 h afterthe injury, an intense staining of NF-κB was observed at bothcytoplasm and nucleus in the ischemic cortex (Fig. 5B). In highdose group, the number of cells labeled with NF-κB in thenucleus was decreased (P<0.05) and lots of cells were stainedonly in cytoplasm (Fig. 5C), the difference was not significantin low dose group (Fig. 5D).

Western blotting analysis of the NF-κB p65 in cytosolic andnuclear extracts from rat cortex (Figs. 6A–C). The NF-κB p65was rich in cytosolic fractions but poor in nuclear extractsfrom shamoperated group. In contrast, the protein level of NF-κB in pMCAO group was significantly enhanced in nuclearfraction and concurrently decreased in cytosol at 24 h afterischemia, indicating the translocation of these NF-κB subunitsfrom the cytosol to the nucleus. The increased protein level ofNF-κB in pMCAO group was decreased by intraperitonealinjection of OMT at a dose of 120 mg/kg significantly (P<0.01).

In agreement with other results, the mRNA expression ofNF-κB in the cortex of animals treated with either saline orOMT was increased after ischemia and suppressed by OMT atthe transcriptional level (Figs. 6D, E). The ischemia-inducedmRNA expression of NF-κB was attenuated by OMT at a doseof 120 mg/kg (P<0.05).

3. Discussion

Our study provided evidence that OMT was a potent neuro-protectants in brain ischemia. Here, our study showed thatadministration of 120 mg/kg OMT was sufficient to providesignificant neuroprotection against neurological injuryinduced by pMCAO. We supported this finding by bothhistological and neurological data: a reduction in the braininfarct volume and an attenuation of the neurological deficit,both of which are clinical features and related with the qualityof life after stroke. Also the post-ischemic protection intreatment groups was accompanied by alleviation in brainedema. At a dose of 60 mg/kg, OMT had no significantprotective effect, so the neuroprotective effect of OMT was

Fig. 3 – Effect of OMT on infarct volume. Part 1 Typical images of brain slices stained by TTC after 72 h occlusion indicated OMTinduced a neuroprotective effect for infarction volume. Slices are at 2 mm intervals in descending order from frontal pole(anterior to posterior). Part 2 OMT reduced percentage hemisphere lesion volume (%HLV). Data are expressed as mean±S.D.*P<0.001 versus pMCAO group. #P<0.05 versus high dose group.

176 B R A I N R E S E A R C H 1 2 6 8 ( 2 0 0 9 ) 1 7 4 – 1 8 0

dose dependant. The minimum effective dose of OMT may bebetween 120 and 60 mg/kg and need further study.

In conclusion, these results showed that OMT had bene-ficial effects for ischemia, if provided at a suitable dose.However, the potential mechanisms underlying the neuro-protection of OMT are not yet known. OMTmay ameliorate theinflammation through reducing TNF-α, IL-6 and ICAM-1, andactivate Bcl-2 to prevent apoptosis (Zheng et al., 2005; Jiang etal., 2005; Hong-Li et al., 2008), these genes and others that areregulated by NF-κB; maybe NF-κB is a potential mediator forthe protective effects of OMT.

NF-κB which plays a pivotal role in both inflammatoryresponse and cell survival regulates a vast number of genesincluding those encoding cytokines (IL-1α, IL-6, IL-8, TNF-α,MCP-1, interferon-γ), death and survival proteins (Bcl-2, Bcl-xl,Bcl-xs, Bax, p53, Myc, Fas), intercellular adhesion molecules

(ICAM), cyclooxygenase-2 (COX-2) and inducible nitric oxidesynthase (iNOS) (Małek et al., 2007).

As a regulator of death and survival proteins, NF-κB plays adual role for neuron survival in the central nervous system,dependent on the nature of the ischemic injuries (permanentversus transient, duration and severity of ischemia andreperfusion) (Duckworth et al., 2006; Hill et al., 2001; Schneideret al., 1999; Nurmi et al., 2004a,b), according to the idea ofClemens et al.: transient activation of NF-κB in neurons aidstheir survival after the ischemic insult and persistent activa-tion of NF-κBmakes neurons vulnerable to the ischemic insult(Clemens et al., 1998; Clemens et al., 1997).

In permanent ischemia, accumulating evidence supportsthe notion that elevated NF-κB contributes to ischemia-induced neurological injury (Sironi et al., 2006; Xu et al.,2002; Nurmi et al., 2004a,b; Zhang et al., 2008). Inhibiting NF-κB

Fig. 4 – Effect of OMT on brain edema in contralateral andipsilateral hemispheres. The water content of ipsilateralhemispheres was reduced in high dose group; whereas nodifference was found in contralateral hemispheres. Eachcolumn representsmean±S.D. *P<0.05 versus pMCAO group.

177B R A I N R E S E A R C H 1 2 6 8 ( 2 0 0 9 ) 1 7 4 – 1 8 0

activation by pyrrolidine dithiocarbamate and knockout p50subunit of NF-κB is protection and develops smaller infarct. Apivotal role of NF-κB is to regulate the genes of inflammatorymediators such as IL-1, TNF-a, IL-6, ICAM-1, iNOS and COX-2,all of which play an important role in ischemic brain damage(Zheng and Yenari, 2004; Yi et al., 2007). So inflammatorymechanism plays an important role in the ischemic braindamage related with elevated NF-κB.

Consistent with the investigation in other pathologies suchas colitis (Zheng et al., 2005), our study demonstrated that the

Fig. 5 – Effect of OMT on immunohistochemistry of NF-κB p65 ipositive cells increased in pMCAO group (B) than sham operated gthe cytoplasm (C). (D) Quantitative analysis of nuclear positive cepMCAO group.

expression of NF-κB in both protein and transcriptional levelswas reduced significantly by OMT at a dose of 120 mg/kg, butthe mechanism involved is not known and needed a furtherstudy.

In conclusion, our study has confirmed that OMT not onlyreduced infarct volume induced by pMCAO but also associatedwith the depressed expression of NF-κB. The elevated expres-sion of NF-κB is thought to be consistent with ischemia evokedneuron injury and death through inflammatory mechanism.These resultsmay indicate that the suppression of NF-κB afterischemia by administration of OMT is a potential mechanismfor its neuroprotection. In China, OMT called kushensu, hasbeen extensively used in clinical practice for treatment of viralhepatitis (Mao et al., 2004), cancer, cardiac diseases (such asviral myocarditis) and skin diseases (such as psoriasis andeczema). We suggest that OMT maybe a novel, effectivetherapeutic drug for the treatment of brain injury.

4. Experimental procedures

4.1. Animals

Male Sprague–Dawley rats, weighing 260 to 280 g wereprovided by Hebei Medical University. The protocol wasapproved by the institutional animal care and use committeeand the local experimental ethics committee. Rats were keptunder a 12/12 h light/dark cycle and given free access to foodand water. The animals were randomly divided into 4 groups(n=15 for each group): pMCAO group, high dose group(animals with pMCAO and 120 mg/kg OMT treatment), low

n cortex. At 24 h after the occlusion, the number of nuclearroup (A). In high dose group, lots of cells were stained only inlls. Each column represents mean±S.D., *P<0.001 versus

Fig. 6 – Effect of OMT on protein andmRNA expression of NF-κB p65.Western blotting analysis of NF-κB p65 in nuclear (A) andcytosolic (B) extracts from cortex. (C) Quantitative analysis the expression of nuclear protein. *P<0.01 versus pMCAO group.The expression of NF-κBmRNAwas increased in the ischemic cortex, OMT at a dose of 120mg/kg reduced the increase inducedby ischemia (D, E). #P<0.05 versus pMCAO group.

178 B R A I N R E S E A R C H 1 2 6 8 ( 2 0 0 9 ) 1 7 4 – 1 8 0

dose group (animals with pMCAO and 60 mg/kg OMT treat-ment) and sham operated group.

4.2. Permanent middle cerebral artery occlusion

During thewhole surgical period, the animalswere anesthetizedwith pentobarbital. Focal cerebral ischemia was induced by theintraluminal suture method originally described by Longa et al.(1989). Briefly, a nylon monofilament (diameter 0.234 mm) withits tip rounded by heating near a flame was introduced into theinternal carotid artery through a nick made in the externalcarotid artery and advanced 17–20 mm distally from thecommon carotid artery bifurcation to block the origin of middlecerebral artery.

4.3. Drug administration

OMT (Huike Botanical Development Co., Shananxi, China)with purity of more than 98%, was dissolved in saline toprepare concentrations of 40 mg/ml. For high dose group andlow dose group, OMT at doses of 60 and 120mg/kg (addedwithsaline to a total volume of 1ml) was administered respectivelyby intraperitoneal injection, immediately after cerebral ische-mia and once daily on the following days. In the case of thepMCAO and sham operated group, equal volume saline wasadministered in the same manner.

4.4. Neurologic deficit

A neurologic test was carried out by an examiner blinded tothe experimental groups at 24 h after pMCAO, all of 15 ratsfrom each group were assessed on a modified scoring system

that developed fromLonga et al. (1989) andDing et al. (2002), asfollows: 0, no deficits; 1, difficulty in fully extending thecontralateral forelimb; 2, unable to extend the contralateralforelimb; 3, mild circling to the contralateral side; 4, severecircling and 5, falling to the contralateral side.

4.5. Percentage hemisphere lesion volume (%HLV)

At 72 h after MCAO, the rats were sacrificed under deepanesthesia with an overdose of pentobarbital (n=6). Toquantify ischemic damage, brains were dissected and cutinto 5 coronal slices of 2-mm thickness, incubated in a 2%solution of TTC at 37 °C for 15 min and immersion-fixed in a4% paraformaldehyde. TTC-stained sections were photo-graphed and the digital images were analyzed using imageanalysis software (Image-Pro Plus 5.1). The lesion volume wascalculated by multiplying the area by the thickness of slices.To compensate for the effect of brain edema, %HLV wascalculated by the following equations, based on that used byTatlisumak et al. (1998) %HLV={[total infarct volume− (righthemisphere volume− left hemisphere volume)] / left hemi-sphere volume}×100%.

4.6. Brain water content

The rats (n=3) were anesthetized deeply with an intraperito-neal injection of pentobarbital and the brains were removed at24 h after pMCAO. A coronal brain slice (about 3 mm thick)4 mm from the frontal pole was cut and the slice was dividedinto the ipsilateral and contralateral hemispheres. Brainsamples were immediately weighed on an electronic balancetoobtainwetweight. Thenbrain samplesweredried in anoven

179B R A I N R E S E A R C H 1 2 6 8 ( 2 0 0 9 ) 1 7 4 – 1 8 0

at 100 °C for 24 h to obtain the dry weight. Brain water contentwas calculated as (wet weight–dry weight)×100/wet weight.

4.7. Histological preparation and NF-κBimmunohistochemistry

The brain were fixed in 4% paraformaldehyde in PBS over 24 hand subjected to standard histological processing for paraffin-embedded sections. 5 μ m thick paraffin sections were cut forimmunohistochemistry and then incubatedwith a rabbit anti-rat NF-κB antibody (1:100, Santa Cruz, CA) at 4 °C overnight.Expression of NF-κB was visualized by routine immunoperox-idase techniques. An examiner blinded to the experimentalgroups counted the cells labeled with NF-κB in the nucleithroughout 5 lesion regions randomly in the ischemic hemi-sphere cortex under a light microscope at 400×.

4.8. Western blotting

Preparation of cytosolic and nuclear extracts from the ipsilat-eral cerebral cortex of rats sacrificed immediately 24 h afterartery occlusion (n=3). The cytosolic and nuclear extracts wereprepared according to the manufacturer's instructions (Apply-gen Technologies Inc., Beijing). The protein concentrationswere determined using a BCA Protein Assay reagent kit(Novagen, Madison, WI). 50 μg of protein was separated bySDS/PAGE, transferred 2 h to PVDF membranes, the non-specific binding of antibodies was blocked with 5% non-fatdried milk in PBS and then incubated with the primaryantibodies at 4 °C overnight: a rabbit anti-rat NF-κB antibody,(1:100, Santa Cruz, CA) and rabbit anti-rat β-actin (1:100,Zhongshan Biotechnology, Beijing). After four washes withPBS containing 0.1% (v/v) Tween-20, the second antibodies(goat anti-rabbit, 1:3000, Rockland) were incubated withmembranes for 1 h at room temperature. The relative densityof bands was analysed using an imaging densitometer (LI-CORBioscience). The densitometric values were normalized withrespect to the values of β-actin immunoreactivity to correct forany loading and transfer differences between samples.

4.9. RNA isolation and reverse transcription-polymerasechain reaction (RT-PCR)

Total RNA was isolated from ischemic cortical hemisphereusing Trizol reagent (Invitrogen, Carlsbad, CA), collected 24 hafter pMCAO (n=3). Then RNA was transcribed with M-MLVreverse transcriptase and randomprimers (Promega,Madison,WI). For PCR amplification, GoTaq®GreenMasterMix (Promega,Madison, WI) and following primers were used: NF-κB P65, 5′-CGATCTGTTTCCCCTCATCT-3 ′ ( f o rward ) and 5 ′ -ATTGGGTGCGTCTTAGTGGT-3′(reverse); β-actin, 5′-GCCATG-TACGTAGCCATCCA-3′ (forward) and 5′-GAACCGCTCATTGCC-GATAG-3′ (reverse).The RT-PCR products were separated on 2%agarose gel and the intensity of each band was quantified usingSynGene software and expressed in arbitrary units.

4.10. Statistics

Except neurological deficit, the data were expressed as themean±S.D. Statistical analysis were made with ANOVA and

followed by Student–Newman–Keuls test for individual com-parisons of means. For neurological deficit, Mann–Whitney Utest was used for comparisons between two groups. Differ-ences were considered significant at P<0.05.

Acknowledgments

This work was funded by Hebei Province, No.:C2006000915; wethank technician Ruichun Liu and Hongran Wu for theirtechnical assistance and Dr. Yi Yang, Dr. Litao Li, Dr. Jing Yinand Dr. Yansu Guo for providing valuable suggestions.

R E F E R E N C E S

Clemens, J.A., Stephenson, D.T., Yin, T., Smalstig, E.B., Panetta,J.A., Little, S.P., 1998. Drug-induced neuroprotection fromglobal ischemia is associated with prevention of persistent butnot transient activation of nuclear factor-kappa B in rats.Stroke 29, 677–682.

Clemens, J.A., Stephenson, D.T., Dixon, E.P., Smalstig, E.B.,Mincy, R.E., Rash, K.S., Little, S.P., 1997. Global cerebralischemia activates nuclear factor-kappa B prior to evidence ofDNA fragmentation. Brain Res. Mol. Brain Res. 48, 187–196.

Ding, Y., Li, J., Rafols, J.A., Phillis, J.W., Diaz, F.G., 2002.Prereperfusion saline infusion into ischemic territory reducesinflammatory injury after transient middle cerebral arteryocclusion in rats. Stroke 33, 2492–2498.

Duckworth, E.A., Butler, T., Collier, L., Collier, S., Pennypacker, K.R.,2006. NF-kappaB protects neurons from ischemic injury aftermiddle cerebral artery occlusion in mice. Brain Res. 1088,167–175.

Gabriel, C., Justicia, C., Camins, A., Planas, A.M., 1999. Activation ofnuclear factor-kappaB in the rat brain after transient focalischemia. Brain Res. Mol. Brain Res. 65, 61–69.

Hill, W.D., Hess, D.C., Carroll, J.E., Wakade, C.G., Howard, E.F.,Chen, Q., Cheng, C., Martin-Studdard, A., Waller, J.L., Beswick,R.A., 2001. The NF-kappa B inhibitor diethyldithiocarbamate(DDTC) increases brain cell death in a transient middlecerebral artery occlusion model of ischemia. Brain Res. Bull.55, 375–386.

Hong-Li, S., Lei, L., Lei, S., Dan, Z., De-Li, D., Guo-Fen, Q., Yan, L.,Wen-Feng, C., Bao-Feng, Y., 2008. Cardioprotective effects andunderlying mechanisms of oxymatrine against ischemicmyocardial injuries of rats. Phytother. Res. 22, 985–989.

Jiang, H., Meng, F., Li, J., Sun, X., 2005. Anti-apoptosis effects ofoxymatrine protect the liver from warm ischemia reperfusioninjury in rats. World J. Surg. 29, 1397–1401.

Longa, E.Z., Weinstein, P.R., Carlson, S., Cummins, R., 1989.Reversiblemiddle cerebral artery occlusionwithout craniotomyin rats. Stroke 20, 84–91.

Małek, R., Borowicz, K.K., Jargiełło, M., Czuczwar, S.J., 2007. Role ofNF-κB in the central nervous system. Pharmacol. Rep. 59,25–33.

Mao, Y.M., et al., 2004. Capsule oxymatrine in treatment of hepaticfibrosis due to chronic viral hepatitis: a randomized, doubleblind, placebo-controlled, multicenter clinical study. World J.Gastroenterol. 10, 3269–3673.

Nurmi, A., Lindsberg, P.J., Koistinaho, M., Zhang, W., Juettler, E.,Karjalainen-Lindsberg,M.L.,Weih, F., Frank,N., Schwaninger,M.,Koistinaho, J., 2004a. Nuclear factor-kappaB contributesto infarction after permanent focal ischemia. Stroke 35, 987–991.

Nurmi, A., Vartiainen, N., Pihlaja, R., Goldsteins, G., Yrjänheikki, J.,Koistinaho, J., 2004b. Pyrrolidine dithiocarbamate inhibitstranslocation of nuclear factor kappa-B in neurons and

180 B R A I N R E S E A R C H 1 2 6 8 ( 2 0 0 9 ) 1 7 4 – 1 8 0

protects against brain ischaemia with a wide therapeutic timewindow. J. Neurochem. 91, 755–765.

Schneider, A., Martin-Villalba, A., Weih, F., Vogel, J., Wirth, T.,Schwaninger, M., 1999. NF-kappaB is activated and promotescell death in focal cerebral ischemia. Nat. Med. 5, 554–559.

Shen, W.H., Zhang, C.Y., Zhang, G.Y., 2003. Antioxidants attenuatereperfusion injury after global brain ischemia throughinhibiting nuclear factor-kappa B activity in rats. ActaPharmacol. Sin. 24, 1125–1130.

Sironi, L., Banfi, C., Brioschi, M., Gelosa, P., Guerrini, U., Nobili, E.,Gianella, A., Paoletti, R., Tremoli, E., Cimino, M., 2006.Activation ofNF-κBandERK1/2 after permanent focal ischemia isabolished by simvastatin treatment. Neurobiol. Dis. 22,445–451.

Tatlisumak, T., Carano, R.A., Takano, K., Opgenorth, T.J., Sotak,C.H., Fisher, M., 1998. A novel endothelin antagonist, A-127722,attenuates ischemic lesion size in rats with temporary middlecerebral artery occlusion: a diffusion and perfusion MRI study.Stroke 29, 850–857 (discussion 857–8).

Terai, K.,Matsuo, A.,McGeer, E.G.,McGeer, P.L., 1996. Enhancementof immunoreactivity for NF-κB in human cerebral infarctions.Brain Res. 739, 343–349.

Ueno, T., Sawa, Y., Kitagawa-Sakakida, S., Nishimura,M.,Morishita,R., Kaneda, Y., Kohmura, E., Yoshimine, T., Matsuda, H., 2001.Nuclear factor-kappa B decoy attenuates neuronal damage afterglobal brain ischemia: a future strategy for brain protection

during circulatory arrest. J. Thorac. Cardiovasc. Surg. 122,720–727.

Xu, L., Zhan, Y., Wang, Y., Feuerstein, G.Z., Wang, X., 2002.Recombinant adenoviral expression of dominant negativeIkappaBalpha protects brain from cerebral ischemic injury.Biochem. Biophys. Res. Commun. 299, 14–17.

Yi, J.H., Park, S.W., Kapadia, R., Vemuganti, R., 2007. Role oftranscription factors in mediating post-ischemic cerebralinflammation and brain damage. Neurochem. Int. 50,1014–1027.

Zhang, H.L., Gu, Z.L., Savitz, S.I., Han, F., Fukunaga, K., Qin, Z.H.,2008. Neuroprotective effects of prostaglandinA(1) in ratmodels of permanent focal cerebral ischemia are associatedwith nuclear factor-kappaB inhibition and peroxisomeproliferator-activated receptor-gamma up-regulation.J. Neurosci. Res. 86, 1132–1141.

Zhao, J., Yu, S., Tong, L., Zhang, F., Jiang, X., Pan, S., Jiang, H., Sun, X.,2008. Oxymatrine attenuates intestinal ischemia/reperfusioninjury in rats. Surg. Today 38, 931–937.

Zheng, Z., Yenari, M.A., 2004. Post-ischemic inflammation:molecular mechanisms and therapeutic implications. Neurol.Res. 26, 884–892.

Zheng, P., Niu, F.L., Liu, W.Z., Shi, Y., Lu, L.G., 2005.Anti-inflammatory mechanism of oxymatrine in dextransulfate sodium-induced colitis of rats. World J. Gastroenterol.11, 4912–4915.