Ischemia-reperfusion Injured Rats Research Articles

Inter-synergized neuroprotection of costunolide engineered bone marrow mesenchymal stem cells targeting system

Treatment of stroke remains difficult due to the unsatisfactory or unlocalized delivery of small molecule- and cell-based therapeutics in injured brain tissues. This is particularly the case for costunolide (Cos), which is highly neuroprotective and anti-inflammatory but finds great difficulty in reaching the brain. Here, we present that Cos induces the differentiation of bone marrow mesenchymal stem cells (bMSCs) into glia-like cells (C-bMSCs) capable of secreting neurotrophic factors and homing to injured brain tissues. By taking advantage of the homing effect, Cos and C-bMSCs were simultaneously funneled into the damaged brain by: (i) preparing Cos micelles (Cos-M) through entrapping Cos into the amphiphilic copolymer mPEG-PLGA [poly(ethylene oxide) monomethyl ether-poly(lactide-co-glycolide)], and (ii) incorporating Cos-M into C-bMSCs to give an intravenously injectable cell-like composite termed Cos@C-bMSCs, which displayed the inter-synergized neuroprotective efficacy in the cerebral ischemia reperfusion (CIR) injured rats. As desired, in the injured brain area, Cos@C-bMSCs simultaneously released Cos and C-bMSCs (glia-like cells) to repair the injured brain and to secret neurotrophic factors such as nerve growth factor (NGF). In view of the availability and reliability of autologous MSCs, the proof-of-concept design, development, and in vivo efficacy of Cos@C-bMSCs signify a movement in our management of brain damages.

Role of exogenous putrescine in the status of energy, DNA damage, inflammation, and spermidine/spermine-n(1)- acetyltransferase in brain ischemia-reperfusion in rats.

Objective(s): This study aims to investigate the role of putrescine against brain ischemia-reperfusion (IR) injured rats administered with 250 µmol/kg exogenous putrescine and highlight the IR-associated mechanisms in energy metabolism and inflammatory pathway. Materials and Methods:The rats were divided into six groups: 1-Sham group; 2-IR group, 30 min of ischemia and 30 min of reperfusion was performed with bilateral carotid occlusion (BCAO); 3-IPR group, a single oral dose of putrescine was administered at the start of the 30-minute reperfusion; while in the other treatment groups, 4 doses of putrescine were given within 12-hour intervals. After 30 min of reperfusion, the first dose was administered immediately in the IR-PI (group 4), after 3 hr in IR-PII (group 5), and after 6 hr in IR-PIII (group 6). Interleukin-6 (IL-6), Nuclear factor NF-kappa-B (NF-kB), Adenosine triphosphate (ATP), total Nitric oxide (NO), 8-hydroxyguanosine (8-OHdG), Spermidine/Spermin N-acetyltransferase (SSAT) levels were analyzed in brain tissues.Results:IR reduced brain ATP levels; however, putrescine treatment reversed this state. Brain NO and 8-OHdG levels, and NF-kB and IL-6 levels increased significantly in the IR group and these elevations were decreased in putrescine administered groups. SSAT levels were higher in the IR-PII group. The lowest levels were observed in the IR-PIII group. Conclusion:The exogenous putrescine supplementation after cerebral IR creates neuroprotective effects independent of the time of administration; according to conditions such as formation of radicals in the brain, the spread of the inflammation and the need for consumption of energy are considered as a whole.

Proteomics analysis of protein biomarkers in Astragalus membranaceus- and Astragaloside IV-treated brain tissues in ischemia-reperfusion injured rats

Background and aimAstragalus membranaceus (AM) is a major Chinese herb used in the treatment of stroke. Astragaloside IV (AS)is a component of AM. This study investigated the effects of AM on the protein expression through proteomics analysis in ischemia-reperfusion injured Sprague Dawley rats. Experimental procedureAn animal model of ischemia-reperfusion injury by occlusion of the right middle cerebral artery for 90 min followed by reperfusion for 24 h. The rats were intraperitoneally injected with AM or AS three times at 30 min, 1 day, and 2 days prior to the occlusion of the cerebral blood flow. ResultsAldolase C was overexpressed in the cortex, and Dihydrolipoamide dehydrogenase and Triose-phosphate isomerase were overexpressed in the hippocampus. ConclusionPretreatment with AM or AS can induce the overexpression of Aldolase C in the cerebral cortex and that of Dihydrolipoamide dehydrogenase and Triose-phosphate isomerase in the hippocampus, suggesting that both AM and AS may act as neuroprotectors through regulating the expression of Aldolase C, Dihydrolipoamide dehydrogenase and Triose-phosphate isomerase. However, the underlying neuroprotective mechanisms need more studies.

Biotransformation of natural hydroxycinnamic acids by gut microbiota from normal and cerebral ischemia-reperfusion injured rats: a comparative study.

Hydroxycinnamic acids (HAs) are widely spread in food and herbal medicines. The bioavailability of HAs largely depends on the absorption and metabolism in enterohepatic circulation, in which gut microbiota plays a vital role. The present research aims to investigate the metabolism of HAs by gut microbiota, together with the community changes of gut microbiota after cerebral ischemia-reperfusion (I/R) injury. The results showed that non-substituted cinnamic acid (NCA) and sinapic acid (SA) were stable to gut microbiota, while 4-hydrocinnamic acid (4-HA), caffeic acid (CA), and ferulic acid (FA) underwent decarboxylation and hydrogenation after anaerobic incubation. Time-course studies indicated that the gut microbiota from I/R injured rats can catalyze the same reaction, but with a decreased reaction rate. The 16S rRNA sequencing technique was applied to uncover the community changes of gut microbiota. In addition, the metabolites of the three HAs exhibited greater activity in scavenging the DPPH radical and protected PC12 cells against oxidative damage.

The effect of oxytocin and Kisspeptin-10 in ovary and uterus of ischemia-reperfusion injured rats

ObjectiveIschemia/reperfusion (I/R) injuries result in damage to endothelial and parenchymal cells. Oxytocin (OXY) stimulates uterine contraction during parturition and myoepithelial cells during suckling. OXY has been used as a protective antioxidant. Kisspeptin plays a key role in the central control of reproductive functions and onset of puberty. Recent studies show that these reproductive hormones have protective potential as antioxidant. The aim of this study is to investigate the potential protective effects of Kisspeptin and OXY as antioxidants on I/R injured ovary and uterus of female rats. Materials and methodsRats were separated into five groups. Group 1, is control group; Group 2, rats were subjected to ischemia followed by reperfusion. Group 3, OXY administration 30 min prior to I/R applied rats; Group 4, Kisspeptin administration 30 min prior to I/R applied rats; Group 5, OXY and Kisspeptin administration 30 min prior to I/R. Ovary and uterus were removed for histopathological and biochemical observations. Malondialdehyde, glutathione levels, and superoxide dismutase activities were analyzed in order to observe antioxidant potential of OXY and Kisspeptin. Hematoxylin and Eosin staining was applied for histopathologic scoring. ResultsStromal and granulosa cells in ovary, endometrial cells in uterus were damaged in I/R group. The cellular damage of ovary and uterus were reduced in OXY and Kisspeptin administered I/R group when compared to only Kisspeptin injected I/R group and I/R group. There is no significant difference between OXY and OXY + Kisspeptin injected I/R groups. MDA levels were decreased in Kisspeptin and/or Oxytocin applied I/R group compared to I/R group. SOD activity and GSH levels were increased in Kisspeptin and/or OXY applied I/R group compared to I/R group. ConclusionsThe present results suggest that exogenous application of oxytocin and kisspeptin can have antioxidant effects on the uterus and ovary.

Electro-acupuncture ameliorates cognitive impairment via improvement of brain-derived neurotropic factor-mediated hippocampal synaptic plasticity in cerebral ischemia-reperfusion injured rats.

A previous study by our group found that electro-acupuncture (EA) at the Shenting (DU24) and Baihui (DU20) acupoints ameliorates cognitive impairment in rats with cerebral ischemia-reperfusion (I/R) injury. However, the precise mechanism of action has remained largely unknown. The present study investigated whether brain-derived neurotropic factor (BDNF) mediates hippocampal synaptic plasticity as the underlying mechanism. Rats were randomly divided into three groups: The sham operation control (Sham) group, the focal cerebral ischemia-reperfusion (I/R) group, and the I/R with EA treatment (I/R+EA) group. The I/R+EA group received EA treatment at the Shenting (DU24) and Baihui (DU20) acupoints after the operation. EA treatment was found to ameliorate neurological deficits (P<0.05) and reduce the cerebral infarct volume (P<0.01). In addition, EA improved cognitive function in cerebral I/R-injured rats (P<0.05). Furthermore, EA treatment promoted synaptic plasticity. Simultaneously, EA increased the hippocampal expression of BDNF, its high-affinity tropomyosin receptor kinase B (TrkB) and post-synaptic density protein-95 (PSD-95) in the rats with cerebral I/R injury. Collectively, the findings suggested that BDNF-mediated hippocampal synaptic plasticity may be one mechanism via which EA treatment at the Shenting (DU24) and Baihui (DU20) acupoints improves cognitive function in cerebral I/R injured rats.

Levodopa improves learning and memory ability on global cerebral ischemia-reperfusion injured rats in the Morris water maze test

Previous studies have shown that levodopa (L-dopa) for 1–7days improved the consciousness level of certain patients who suffered from ischemia-reperfusion injury and were comatose for a long time period after cerebral resuscitation treatment. It also has an awakening effect on patients with disorders of consciousness. This study aimed to investigate whether L-dopa, which is used clinically to treat Parkinson's disease, might also ameliorate the behavior of rats following global cerebral ischemia-reperfusion injury. Fifty-six healthy adult male Sprague-Dawley rats were randomly divided into four groups: shamoperated, global cerebral ischemia mode, 25mg/kg/d L-dopa intervention, and 50mg/kg/d L-dopa intervention. The level of consciousness and modified neurological severity score (NSS) of the rats in each group were measured before reperfusion and 6, 24, and 72h and 1–4 weeks after reperfusion. The Morris water maze test was used to assess behavior of rats 1 week after reperfusion and 2 weeks after reperfusion in each group. The results showed that after global cerebral ischemiareperfusion injury, neurological deficits of rats are severe, and space exploration capacity and learning and memory capacity are significantly decreased. L-dopa can shorten the duration of coma in rats following global cerebral ischemia-reperfusion injury and improve the symptoms of neurological deficits and advanced learning and memory. In the range of the selected doses, the relationship between L-dopa and improvement of the neurological behavior in rats was not dose-dependent. Dopamine may be useful for treating severe ischemia-reperfusion brain injury.

Electroacupuncture ameliorates post-stroke learning and memory through minimizing ultrastructural brain damage and inhibiting the expression of MMP-2 and MMP-9 in cerebral ischemia-reperfusion injured rats.

The aim of the present study was to investigate the potential neuroprotective effects of electroacupuncture (EA) in the treatment of cerebral ischemia/reperfusion (I/R) injury, and to elucidate the association between this neuroprotective effect and brain ultrastructure and expression of matrix metalloproteinase (MMP)-2 and 9. Rats underwent focal cerebral I/R injury by arterial ligation and received in vivo therapeutic EA at the Baihui (DU20) and Shenting (DU24) acupoints. The therapeutic efficacy was then evaluated following the surgery. The results of the current study demonstrated that EA treatment significantly ameliorated neurological deficits and reduced cerebral infarct volume compared with I/R injured rats. Furthermore, EA improved the learning and memory ability of rats following I/R injury, inhibited blood brain barrier breakdown and reduced neuronal damage in the ischemic penumbra. Furthermore, EA attenuated ultrastructural changes in the brain tissue following ischemia and inhibited MMP-2/MMP-9 expression in cerebral I/R injured rats. The results suggest that EA ameliorates anatomical deterioration, and learning and memory deficits in rats with cerebral I/R injury.

Mizoribine inhibits the proliferation of renal stem/progenitor cells by G1/S arrest during renal regeneration.

Immunosuppressive agents are generally administered to treat kidney diseases. However, it is unclear whether renal stem/progenitor cells are directly affected by the immunosuppressive agents. We used normal rat kidney cells, ureteric bud cells and rat kidney stem/progenitor cells in this study. Mizoribine (MZR), cyclophosphamide (CPA) and cyclosporine (CyA) were added to the culture media of these cells. We evaluated the effects of these immunosuppressive agents on cell proliferation using an electrical cell-substrate impedance sensing system (ECIS) and their effects on the process of renal regeneration using the ischemia-reperfusion (I/R) injury rat model. The ECIS data showed that proliferation of each of the 3 types of cells was significantly suppressed by MZR. MZR treatment enhanced renal tubular injury in ischemia-reperfusion (I/R) injured rats, and significantly decreased levels of M-phase cells and Nestin-positive cells. These results suggested that MZR inhibits the cell cycle of renal stem/progenitor cells;thus, physicians should take note that MZR might affect not only inflammation but also renal regeneration.

Electroacupuncture enhances hippocampal NSCs proliferation in cerebral ischemia-reperfusion injured rats via activation of notch signaling pathway

The purpose of this study was to investigate the mechanisms by which electroacupuncture (EA) enhances hippocampal neural stem cells (NSCs) proliferation in cerebral ischemia-reperfusion (I/R) injured rats. A total of 72 male adult Sprague-Dawley rats were randomly divided into the sham operation control group (SC), the ischemia control group (IC) and the EA group. Middle cerebral artery occlusion (MCAO) was performed to establish the focal cerebral I/R injury model. Proliferation of hippocampal NSCs in cerebral I/R injured rats was determined by the Nestin immunohistochemical staining. Activation of the notch signaling pathway was detected by Western blotting and reverse transcription polymerase chain reaction analysis. The serum level of neurotrophic factors, e.g., the brain-derived neurotrophic factor (BDNF) and the Glial cell line-derived neurotrophic factor (GDNF), was measured using enzyme-linked immunosorbent assay (ELISA). The results showed that EA at Quchi (LI11) and Zusanli (ST36) acupoints significantly alleviated neurological deficits, reduced infarct volumes and promoted the proliferation of hippocampal NSCs in cerebral I/R injured rats. The crucial signaling molecules in the notch signaling pathway were activated and the secretion of BDNF and GDNF was increased upon EA. The protein and mRNA levels of Cyclin D1, Cdk4 and p-Rb were increased, while p21 and p27 transcripts were suppressed by notch signaling. These results suggest that the up-regulatory effect of EA on the notch signaling pathway and neurotrophic factor secretion may result in the promotion of NSCs proliferation and consequently a therapeutic effect on cerebral ischemia.

Electroacupuncture ameliorates cognitive impairment through inhibition of NF-κB-mediated neuronal cell apoptosis in cerebral ischemia-reperfusion injured rats

Cognitive impairment is a serious mental deficit following stroke that severely affects the quality of life of stroke survivors. Nuclear factor‑κB (NF-κB)-mediated neuronal cell apoptosis is involved in the development of post-stroke cognitive impairment; therefore, it has become a promising target for the treatment of impaired cognition. Acupuncture at the Baihui(DU20) and Shenting(DU24) acupoints is commonly used in China to clinically treat post‑stroke cognitive impairment; however, the precise mechanism of its action is largely unknown. In the present study, we evaluated the therapeutic efficacy of electroacupuncture against post-stroke cognitive impairment and investigated the underlying molecular mechanisms using a rat model of focal cerebral ischemia-reperfusion (I/R) injury. Electroacupuncture at Baihui and Shenting was identified to significantly ameliorate neurological deficits and reduce cerebral infarct volume. Additionally, electroacupuncture improved learning and memory ability in cerebral I/R injured rats, demonstrating its therapeutic efficacy against post-stroke cognitive impairment. Furthermore, electroacupuncture significantly suppressed the I/R-induced activation of NF-κB signaling in ischemic cerebral tissues. The inhibitory effect of electroacupuncture on NF-κB activation led to the inhibition of cerebral cell apoptosis. Finally, electroacupuncture markedly downregulated the expression of pro-apoptotic Bax and Fas, two critical downstream target genes of the NF-κB pathway. Collectively, our findings suggest that inhibition ofNF-κB‑mediated neuronal cell apoptosis may be one mechanism via which electroacupuncture at Baihui and Shenting exerts a therapeutic effect on post-stroke cognitive impairment.

Protective effect of polysaccharide from the root of Rhizoma Corydalis on focal ischemic cerebral infarct induced by middle cerebral artery occlusion in rats

To investigate the effect of polysaccharide from the root of Rhizoma Corydalis (YhPS-1) on focal cerebral infarct in ischemia-reperfusion injured rats, sixty Wister rats were randomly divided into six groups (n = 10): sham group, control group, YhPS-1-treatment groups (20, 40, and 80 mg/kg), and positive medicine breviscapine table group, respectively. The models of focal cerebral infarct and carotid thrombosis were established, and neurobehavioral scores, the area of cerebral infarct, water content of brain, clotting time and thrombosis time were used to evaluate the effect of YhPS-1. Experiments indicated that YhPS-1-treated groups significantly improved neurological deficits, reduced the area of cerebral infarct and brain water content, and prolonged clotting time and thrombosis time in comparison with control group. These findings suggested that YhPS-1 played a crucial protective role in cerebral ischemia-reperfusion injury. Key words: Polysaccharide of Rhizoma Corydalis, cerebral infarct, blood clotting time, thrombosis time, free radicals.

Electroacupuncture at the Quchi and Zusanli acupoints exerts neuroprotective role in cerebral ischemia-reperfusion injured rats via activation of the PI3K/Akt pathway

The PI3K/Akt pathway, a critical mediator of cell survival, is suppressed in cerebral ischemia/reperfusion (I/R) injury; therefore, it is a major focus in treatment of ischemic stroke. Acupuncture has long been used in China to clinically treat stroke. However, the precise mechanism of its neuroprotective activities remains largely unknown. Using a focal cerebral I/R injured rat model, in the present study we evaluated the invivo therapeutic efficacy of electroacupuncture and investigated the underlying molecular mechanisms. We found that electroacupuncture at Quchi (LI11) and Zusanli (ST36) acupoints on the contralateral paralyzed limb significantly improved neurological deficits and cerebral infarction. In addition, electroacupuncture profoundly activated PI3K/Akt signaling in ischemic cerebral tissues. Consequently, the upregulatory effect of electroacupuncture on PI3K/Akt activation resulted in the inhibition of cerebral cell apoptosis. Moreover, electroacupuncture increased the serum secretion levels of the PI3K activators BDNF and GDNF, as well as upregulated the anti-apoptotic Bcl-2/Bax ratio in ischemic cerebrum. Our data suggest that electroacupuncture at Quchi and Zusanli acupoints exerts neuroprotective function in ischemic stroke via activation of the PI3K/Akt pathway.

The Anti-Inflammatory Effect of Paeoniflorin on Cerebral Infarction Induced by Ischemia-Reperfusion Injury in Sprague-Dawley Rats

Paeoniflorin, a component in Paeonia lactiflora Pall, inhibits nuclear factor-kappaB expression in chronic hypoperfusion rat and has anti-inflammatory properties. Therefore, the aim of the present study was to investigate the effect of paeoniflorin on cerebral infarct, and the involvement of anti-inflammation. We established an animal model of cerebral infarct by occluding both the common carotid arteries and the right middle cerebral artery for 90 min, followed by reperfusion of 24 hours. The ratios of cerebral infarction area to total brain area, and neuro-deficit score were used as an index to observe the effects of paeoniflorin on cerebral infarct. ED1 (mouse anti rat CD68), interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), intercellular adhesion molecular-1 (ICAM-1), myeloperoxidase (MPO) immunostaining and apoptotic cells in the cerebral infarction region also were studied. The results indicated that both pre-treatment and post-treatment with paeoniflorin reduced the ratio of cerebral infarction area; pre-treatment with paeoniflorin also reduced the neurological deficit score. The counts of ED1, IL-1beta, TNF-alpha, ICAM-1 of microvessels and MPO immunoreactive cells and apoptotic cells were increased in the cerebral infarction region; however, these increases were reduced by Paeoniflorin pre-treatment. In conclusion, Paeoniflorin reduced cerebral infarct and neurological deficit in ischemia-reperfusion injured rats, suggesting that paeoniflorin may have a similar effect in humans and might be a suitable treatment for stroke. Paeoniflorin reduced cerebral infarct, at least in part, involves the anti-inflammatory properties.

Panax Notoginseng Burk Attenuates Impairment of Learning and Memory Functions and Increases ED1, BDNF and β-Secretase Immunoreactive Cells in Chronic Stage Ischemia-Reperfusion Injured Rats

Panax Notoginseng Burk (PN) has been reported to improve blood circulation, as well as learning and memory functions. The purpose of the present study was to investigate the effect of PN on learning and memory functions in chronic cerebral infarct rats. A cerebral infarct animal model was established by blocking the blood flow of both common carotid arteries and right middle cerebral artery for 90 min followed by reperfusion for 4 weeks. PN (0.5 g/kg) was administered orally 3 days per week for 4 weeks, whereas the control group provided bait and water only. The learning and memory functions were estimated by measuring how successful rats were able to negotiate an 8-arm radial maze test; the test was performed after operation once a week for 4 weeks. Finally, the rats were sacrificed and their brains were removed. The brains were sectioned and analyzed for ED1, glial fibrillary acid protein (GFAP), nuclear factor-kappaB, and brain derivative neurotrophin factor (BDNF) and beta-secretase by immunostaining. Cerebral infarct rats given PN were able to successfully navigate the 8-arm radial maze test four weeks after cerebral infarction. PN also increased ED1, BDNF and beta-secretase immunoreactive cells, but did not increase GFAP and NF-kappaB immunoreactive cells. PN attenuated the reduction in learning and memory functions induced by cerebral infarction in cerebral ischemia-reperfusion injured rats; it also increased the amount of activated microglia and BDNF. These data suggest that the effect of PN, at least in part, is closely related to the increase in BDNF that was generated by activated microglia. The effect that PN has on astrocytes, NF-kappaB and beta-secreatase immunoreactive cells requires further study.

Acupuncture Stimulation at Baihui Acupoint Reduced Cerebral Infarct and Increased Dopamine Levels in Chronic Cerebral Hypoperfusion and Ischemia-Reperfusion Injured Sprague-Dawley Rats

The Baihui acupoint has three Yang and five convergences; it is needled in order to activate spirit and resuscitate the brain in traditional Chinese medicine. Therefore, the purpose of the present study is to investigate the effect of acupuncture stimulation at the Baihui acupoint on cerebral infarct and dopamine levels. A chronic cerebral hypoperfusion animal model was established by permanent ligation of both common carotid arteries; a cerebral infarct animal model was established by blocking the blood flow of both common carotid arteries and the right middle cerebral artery for 90 min followed by reperfusion in Sprague-Dawly (SD) rats. The Baihui acupoint was stimulated for 20 min 3 days per week for 4 weeks. The cognitive and memory functions were evaluated by measuring the successful rates for rats to negotiate an 8-arm radial maze test; the test was performed after operation once a week for 4 weeks. Finally, the rats were sacrificed and their brains were removed; the dopamine levels in brain tissue were measured and the percentage of right to left hemisphere area was calculated. The results indicated that acupuncture stimulation (AS) did not increase the success rate of performing the 8-arm radial maze in chronic cerebral hypoperfusion and cerebral ischemia-reperfusion injured rat models. AS increased dopamine levels in the right cerebral cortex and hippocampus in the chronic cerebral hypoperfusion rats, and increased dopamine levels of the cerebral cortex in the cerebral ischemia-reperfusion injured rat's models. The neurological deficit score was similar between control and AS groups 24 hours after reperfusion, whereas the AS group comprised of ischemia-reperfusion injured rats had a greater percentage of right to left hemisphere area than the control group. In conclusion, AS at the Baihui acupoint for 4 weeks increased dopamine levels in the brain tissue of chronic cerebral hypoperfusion rats and of cerebral ischemia-reperfusion injured rats. The AS also reduced brain atrophy after cerebral infarct, suggesting that AS at the Baihui acupoint acts as neuroprotector. However, regular stimulation at the Baihui acupoint enhances cognition and memory functions need further study.

Sodium nitroprusside decreased leukotriene C4 generation by inhibiting leukotriene C4 synthase expression and activity in hepatic ischemia-reperfusion injured rats

The effects of NO on LTC4 generation during hepatic ischemia-reperfusion (I/R) are largely unclear. Sprague–Dawley rats were divided into control, I/R and sodium nitroprusside (SNP, 2.5, 5 and 10 μg/kg/min) + I/R groups. Liver was subjected to I/R injury, saline or SNP administered intravenously. The protein expressions of LTC4 synthesis enzymes including LTC4 synthase (LTC4S), microsomal glutathione- S-transferase (mGST)2 and mGST3 were detected with immunoblotting, the LTC4 synthesis enzymes’ activities and LTC4 content were measured by RP-HPLC, the mRNA expressions of inducible nitric oxide synthase (iNOS) and endogenous nitric oxide synthase (eNOS) in liver were measured by RT-PCR. Tissue injuries were assessed by serum ALT and AST and histological changes. Serum NO 2 − and liver tissue GSH were also examined. Compared with I/R group, SNP markedly decreased LTC4 content, LTC4S protein and iNOS mRNA levels, and the LTC4 synthesis enzymes’ activities ( P < 0.05), but significantly enhanced eNOS mRNA expression in liver ( P < 0.05). The decline in serum ALT, AST and NO 2 − levels ( P < 0.05) together with hepatic GSH elevation ( P < 0.05) in SNP + I/R groups were also observed. LTC4S expression in hepatocytes and sinusoidal endothelial cells in SNP + I/R groups was lower than that in I/R group. But no significant differences in the protein expressions of mGST3 and mGST2 existed between control, I/R and SNP + I/R groups ( P > 0.05). These results demonstrated that the decline in LTC4 production by SNP treatment during hepatic I/R could be partially resulted from SNP down-regulating the protein expression of LTC4S rather than mGST2 or mGST3 and its inhibiting the LTC4 synthesis enzymes’ activities.

Paeonol reduced cerebral infarction involving the superoxide anion and microglia activation in ischemia-reperfusion injured rats

Both Moutan cortex of Paeonia suffruticosa Andrews (MC) and the root of Paeonia lactiflora Pall (PL) are important Traditional Chinese herbs used commonly to treat inflammatory and pyretic disorders. Paeonol, a common component of MC causes anti-platelet aggregation and scavenges free radicals. Therefore, the aim of the present study is to investigate the effects of Paeonol on cerebral infarct. A total of 60 male Sprague–Dawley (SD) rats were studied. An animal model of cerebral infarct was established by occluding both common carotid arteries and the right middle cerebral artery for 90 min, followed by a 24 h period of reperfusion. The percentage of cerebral infarction area to total brain area in each piece of brain tissue, and neuro-deficit score were measured. Superoxide anion was determined by the number of lucigenin-chemiluminescence (CL) counts. ED1 (mouse anti rat CD68) and interleukin-1β (IL-1β) immunostaining in the cerebral infarction region were also investigated for activation of microglia. The results indicated that Paeonol 15 and 20 mg/kg pretreatment and 20 mg posttreatment reduced the cerebral infarction area; Paeonol 15 and 20 mg/kg pretreatment reduced the neuro-deficit score. In addition, Paeonol 20 mg/kg pretreatment reduced the lucigenin-CL counts at 2 h period of reperfusion. The number of ED1 and IL-1β immunoreactive cells also reduced in the cerebral infarction region; there were no significant changes in blood sugar levels. The results show that Paeonol reduced cerebral infarct and neuro-deficit in rat, suggesting Paeonol might play a similar role in reducing cerebral infarction in humans. Paeonol suppresses and scavenges superoxide anion, and inhibit microglia activation and IL-1β in ischemia-reperfusion injured rats.

Effect of salvia miltiorrhiza bunge on cerebral infarct in ischemia-reperfusion injured rats.

According to the theory of traditional Chinese medicine, cerebral infarction results from blood stasis, and the method of quickening the blood and dispelling stasis is used to treat cerebral infarct. salvia miltorrhiza bunge (SM) is a Chinese herb, which is considered to have an action of quickening the blood and dispelling stasis, and is frequently used to treat related disorders of blood stasis such as cerebrovascular accident and ischemic heart disease. The aim of the present study was to investigate the effect of SM on cerebral infarct in ischemia-reperfusion injured rats. A total of 30 Sprague-Dawley (SD) rats were studied. A model of focal cerebral infarct was developed by occluding both common carotid arteries and the right middle cerebral artery for 90 minutes. After 24 hours reperfusion, the rats were killed and the brain tissue was stained with 2, 3, 5-triphenyl-tetrazolium chloride (TTC). The areas of cerebral infarct were calculated, and lumino-chemiluminesence (CL) counts and lucigenin-CL counts of peripheral blood taken at this time were measured. The changes in the area of cerebral infarct were used as an index to evaluate the effect of SM on cerebral infarct. The results indicated that pretreatment with intraperitoneal injection of 30 mg/kg and 15 mg/kg SM reduced the area of cerebral infarct and also reduced the luminol-CL counts of peripheral blood in ischemia-reperfusion injured rats. This study has demonstrated that SM can reduce the area of cerebral infarct in ischemia-reperfusion injured rats, suggesting it may be useful in the treatment of cerebral infarct in humans. The therapeutic effect of SM may be partly due to its free radical scavenging activities.

A short history of acupuncture.

A short history of acupuncture.