[Role of SIRTs in cerebral ischemia reperfusion injury and targeted intervention of Chinese medicine].

Cerebral ischemia-reperfusion injury(CIRI) is a complex cascade process and seriously hinders the recovery of patients with acute ischemic stroke, which has become an urgent public health issue to be addressed. Silent information regulators(SIRTs) are a family of nicotinamide adenine dinucleotide(NAD~+)-dependent deacetylases, capable of deacylating the histone and non-histone lysine groups. Accumulating evidence has demonstrated that SIRTs are able to regulate the pathological processes such as oxidative stress, inflammatory response, mitochondrial dysfunction, and programmed cell death of CIRI through post-translational deacetylation, and exert the neuroprotection function. In this study, we reviewed the papers about the role and regulatory mechanisms of SIRTs in the pathological process of CIRI published in the past decade. Further, we summarized the research advance in the prevention and treatment of CIRI with Chinese medicine targeting SIRTs and the related signaling pathways. This review will provide new targets and theoretical support for the clinical application of Chinese medicine in treating CIRI during the occurrence of ischemic stroke.

Ameliorating Effects of ß-Glucan on Epigastric Artery Island Flap Ischemia-Reperfusion Injury.

BACKGROUND: Ischemia-reperfusion injury has been one of the culprits of tissue injury and flap loss after island flap transpositions. Thus, significant research has been undertaken to study how to prevent or decrease the spread of ischemia-reperfusion injury. Preventive effects of ß-glucan on ischemia-reperfusion injury in the kidney, lung, and small intestine have previously been reported. In this study, we present the ameliorating effects of ß-glucan on ischemia-reperfusion injury using the epigastric artery island-flap in rats. MATERIALS AND METHODS: Thirty Wistar-Albino rats were equally divided into three groups: sham, experimental model, and treatment groups. In the sham group, an island flap was elevated and sutured back to the original position without any ischemia. In the experimental model group, the same-sized flap was elevated and sutured back with 8 h of ischemia and consequent 12 h of reperfusion. In the treatment group, 50 mg per kilogram ß-glucan was administered to the rats using an orogastric tube for 10 d before the experiment. The same-sized flap is elevated and sutured back to its original position with 8 h of ischemia and 12 h of consequent reperfusion in the treatment group. Tissue biopsies were taken on the first day of the experimental surgery. Tissue neutrophil aggregation and vascular responses were evaluated by histological examinations. Tissue oxidant and antioxidant enzyme levels are evaluated biochemically after tissue homogenization. Topographic follow-up and evaluation of the flaps were maintained, and photographs were taken on the first and seventh day of the experimental surgery. RESULTS: Topographic flap survival was significantly better in the ß-glucan administered group. The neutrophil number, malondialdehyde, and myeloperoxidase levels were significantly lower while glutathione peroxidase and superoxide dismutase levels were significantly higher in the ß-glucan administered group respective to the experimental model group. CONCLUSIONS: Based on the results of our study, we can conclude that ß-glucan is protective against ischemia-reperfusion injury. Our study presents the first experimental evidence of such an effect on skin island flaps.

GJ-4 ameliorates memory impairment in focal cerebral ischemia/reperfusion of rats via inhibiting JAK2/STAT1-mediated neuroinflammation.

ETHNOPHARMACOLOGICAL RELEVANCE: Gardenia jasminoides J. Ellis (Fructus Gardenia) is a traditional Chinese medicine with diverse pharmacological functions, such as anti-inflammation, anti-depression, as well as improvement of cognition and ischemia brain injury. GJ-4 is a natural extract from Gardenia jasminoides J. Ellis (Fructus Gardenia) and has been proved to improve memory impairment in Alzheimer's disease (AD) mouse model in our previous studies. AIM OF THE STUDY: This study aimed to evaluate the therapeutic effects of GJ-4 on vascular dementia (VD) and explore the potential mechanisms. MATERIAL AND METHODS: In our experiment, a focal cerebral ischemia and reperfusion rat model was successfully developed by the middle cerebral artery occlusion and reperfusion (MCAO/R). GJ-4 (10 mg/kg, 25 mg/kg, 50 mg/kg) and nimodipine (10 mg/kg) were orally administered to rats once a day for consecutive 12 days. Learning and memory behavioral performance was assayed by step-down test and Morris water maze test. The neurological scoring test was performed to evaluate the neurological function of rats. 2,3,5-Triphenyltetrazolium chloride (TTC) staining and Nissl staining were respectively employed to determine the infarct condition and neuronal injury of the brain. Iba1 immunohistochemistry was used to show the activation of microglia. Moreover, the synaptic damage and inflammatory level were detected by Western blot. RESULTS: GJ-4 could significantly improve memory impairment, cerebral infraction, as well as neurological deficits of VD rats induced by MCAO/R. Further research indicated VD-induced neuronal injury was alleviated by GJ-4. In addition, GJ-4 could protect synapse of VD rats by upregulating synaptophysin (SYP) expression, post synaptic density 95 protein (PSD95) expression, and downregulating N-Methyl-D-Aspartate receptor 1 (NMDAR1) expression. Subsequent investigation of the underlying mechanisms identified that GJ-4 could suppress neuroinflammatory responses, supported by inhibited activation of microglia and reduced expression of inflammatory proteins, which ultimately exerted neuroprotective effects on VD. Further mechanistic study indicated that janus kinase 2 (JAK2)/signal transducer and activator of transcription 1 (STAT1) pathway was inhibited by GJ-4 treatment. CONCLUSION: These results suggested that GJ-4 might serve as a potential drug to improve VD. In addition, our study indicated that inhibition of neuroinflammation might be a promising target to treat VD.

Protection against acute cerebral ischemia/reperfusion injury by Leonuri Herba Total Alkali via modulation of BDNF-TrKB-PI3K/Akt signaling pathway in rats.

OBJECTIVE: To observe the brain protective effect of Leonuri Herba Total Alkali (LHA) on cerebral ischemia reperfusion injury in rats, so as to provide basis for clinical research. METHODS: Adult male SD rats were randomly assigned into sham group, middle cerebral artery occlusion/reperfusion (MCAO/R) group, and LHA + MCAO/R group (25 mg/kg, 50 mg/kg, and 100 mg/kg). Fourteen days before MCAO/R surgery, the rats in treatment groups were orally administered with LHA in ultrapure water once daily for 14 days, while rats in the sham and MCAO groups were given the same amount of saline in advance. After 1 h of administration on the 14th day, MCAO surgery was subjected. The neurological deficits, brain infarct volume, histopathology, immunofluorescence, inflammation indicators and the gene/protein expressions of BDNF-TrKB-PI3K/Akt signaling pathway in the rat brain tissue were evaluated 24 h after the MCAO/R-injury. RESULTS: It was found that rats in LHA pre-administration group showed significantly reduced neurological deficit scores, infarction volume, the serum levels of NSE and S100ß. Meanwhile, the content of Evans Blue (EB) in brain tissue from LHA group was decreased, as well as the levels of inflammatory cytokines and their gene levels. Moreover, LHA pre-administration inhibited the expression of CD44, GFAP, FOXO1 and promoted the expression of BDNF and NeuN. In addition, LHA pre-administration could up-regulate the protein expression of TrkB, p-PI3K, p-Akt, Bcl-2, and down-regulate the protein expression of Bax, and increase the level of Bcl-2/Bax. CONCLUSIONS: The study demonstrated that LHA pre-administration could regulate the PI3K/Akt pathway by increasing BDNF levels, and play a neuroprotective role in cerebral ischemia-reperfusion injury.

Proxeed plus salvage rat testis from ischemia- reperfused injury by enhancing antioxidant's activities and inhibition of iNOS expression.

Testicular torsion is an acute urological emergency condition that occurs due to obstruction of blood flow to the testicles which may result in ischemia and loss of testicular functions. This study examined the protective effects of Proxeed Plus (PP), a dietary supplement on testicular ischemia/reperfusion (I/R) injured rats using oxidative stress markers, hormonal levels, apoptotic parameters, histological and immunohistochemistry analysis at 4 h and after 7 days of reperfusion. The protective treatment of the I/R injured rats with PP at 1000 and 5000 mg/kg body weight (bw) resulted in significant increases in the serum and tissue antioxidative defense capacities (superoxide dismutase, reduced glutathione, catalase, glutathione-s-transferase, and glutathione peroxidase), sex hormones (luteinizing hormone, follicle-stimulating hormone, and testosterone), also reduce pro-oxidative markers (malondialdehyde and hydrogen peroxide), serum iNOS and apoptotic parameters (Caspase -3 and Caspase -9) in comparison to the results detected in the I/R untreated rats. It was also observed that PP ameliorated histological changes of I/R injured rats; increased spermatogenetic activity, seminiferous tubular diameter, Leydig cell mass, and reduced expressions of testicular inducible nitric oxide synthase (iNOS). Therefore, the therapeutic use of Proxeed Plus could be considered a promising approach in averting testicular damage against I/R injury.

Carthamus tinctorius L. Extract ameliorates cerebral ischemia-reperfusion injury in rats by regulating matrix metalloproteinases and apoptosis.

We investigate the protective effect of Carthamus tinctorius L. (CTL, also known as Honghua in China or Safflower) on cerebral ischemia-reperfusion and explored the possible mechanisms on regulating apoptosis and matrix metalloproteinases (MMPs). High-performance liquid chromatography method with diode array detection analysis was established to analyze the components of CTL. Middle cerebral artery occlusion rats model was established to evaluate Neurological Function Score and hematoxylin-eosin staining, as well as triphenyltetrazolium was used to examine the infarction area ratio. Transferase-mediated dUTP nick-end labeling was performed for the apoptosis. Apoptosis-related factors, including B-cell lymphoma-2 (Bcl-2), Bax and Caspase3, and MMPs-related MMP2, MMP9, tissue inhibitor of metalloproteinases 1 (TIMP1) in ischemic brain, were assayed by Western blot, reverse transcription polymerase chain reaction, and immunohistochemistry. The data showed that CTL (2, 4 g crude drug/kg/d) treatment could significantly reduce the ischemic damage in brain tissue and improve a significant neurological function score. In addition, CTL could also attenuate apoptosis degree of brain tissues and regulate Bcl-2, Bax, and Caspase 3 and also have a significant decrease on MMP-9 expression, followed by a significant increase of TIMP1 protein expression. These findings indicated that regulation of CTL on apoptosis and MMPs contributed to its protective effect on ischemia/reperfusion injury.

Metformin decreases testicular damages following ischaemia/reperfusion injury in rats.

The effects of metformin on a testicular torsion injury in adolescent rat testis after I/R were evaluated in the present study. Forty adolescent rats were divided into five groups with eight rats per group: a control group; a sham-operated group; an ischaemia group, where torsion was applied for 4 hr and testis was examined immediately after detorsion; an I/R group, where torsion was applied for 4 hr and the testis was examined 4 hr after detorsion; and an I/R + M group, where the metformin (300 mg/kg) administration was added to the identical procedures used for the I/R group. Spermatogenesis, basal membrane integrity and cleaved caspase-3 expression were assessed. The I/R + M group had a significantly higher Johnsen score than the I/R group (7.9 ± 0.1 vs. 7.5 ± 0.2; p < .001; F-value = 14.2). Failure of basal membrane integrity was highest in the ischaemia group (45 ± 5) compared to the other groups (control group, 20 ± 5; sham-operated group, 16.6 ± 2.8), but not different between the I/R + M (31.6 ± 12.5) and the I/R groups (25 ± 3.5). Cleaved caspase-3 expression was highest in the ischaemia group (73.5 ± 0.7), and significantly lower in the I/R + M group (33.4 ± 0.9) than the I/R group (58.5 ± 0.2; p < .05; F-value = 7.6). Metformin decreases testicular damage by exerting protection against the harmful effects of I/R on spermatogenesis and alleviating apoptosis in adolescent rat testis.

Inhibition of Autophagy Attenuated Intestinal Injury After Intestinal I/R via mTOR Signaling.

BACKGROUND: Intestinal ischemia/reperfusion (I/R) is a grave condition related to high morbidity and mortality. Autophagy, which can induce a new cell death named type II programmed cell death, has been reported in some intestinal diseases, but little is known in I/R-induced intestinal injury. In this study, we aimed to explore the role of autophagy in intestinal injury induced by I/R and its potential mechanisms. MATERIALS AND METHODS: The rats pretreated with rapamycin or 3-methyladenine had intestinal I/R injury. After reperfusion, intestinal injury was measured by Chiu's score, intestinal mucosal wet-to-dry ratio, and lactic acid level. Intestinal mucosal oxidative stress level was measured by malondialdehyde and superoxide dismutase. Autophagosome, LC3, and p62 were detected to evaluate autophagy level. Mammalian target of rapamycin (mTOR) was detected to explore potential mechanism. RESULTS: Chiu's score, intestinal mucosal wet-to-dry ratio, lactic acid level, malondialdehyde level, autophagosomes, and LC3-II/LC3-I were significantly increased, and superoxide dismutase level and expression of p62 were significantly decreased in intestinal mucosa after intestinal ischemia/reperfusion. Pretreatment with rapamycin significantly aggravated intestinal injury evidenced by increased Chiu's score, intestinal mucosal wet-to-dry ratio and lactic acid level, increased autophagy level evidenced by increased autophagosomes and LC3-II/LC3-I and decreased expression of p62, and downregulated expression of p-mTOR/mTOR. On the contrary, pretreatment with 3-methyladenine significantly attenuated intestinal injury and autophagy level and upregulated expression of p-mTOR/mTOR. CONCLUSIONS: In summary, autophagy was significantly enhanced in intestinal mucosa after intestinal ischemia/reperfusion, and inhibition of autophagy attenuated intestinal injury induced by I/R through activating mTOR signaling.

Electroacupuncture Inhibits Apoptosis of Peri-Ischemic Regions via Modulating p38, Extracellular Signal-Regulated Kinase (ERK1/2), and c-Jun N Terminal Kinases (JNK) in Cerebral Ischemia-Reperfusion-Injured Rats.

BACKGROUND Previous studies suggested that inhibition of apoptosis prevents the dysfunction of ischemia-reperfusion injury. In the pathogenesis of ischemia-reperfusion injury, JNK/ERK1/2 and p38 play an essential role in regulation of cell apoptosis. Electroacupuncture (EA), a form of acupuncture, has demonstrated superiority in preventing ischemia-reperfusion injury, but the underlying mechanism is unclear. In the present study, we explored the effects of electroacupuncture at Shenting (GV24) and Baihui (GV20) acupoints on focal cerebral ischemia-reperfusion (MCAO) rats, and explored whether JNK/ERK1/2- and p38-mediated cell apoptosis are involved. MATERIAL AND METHODS The rats were divided into a sham operation control group, an ischemia group, and an electroacupuncture group with acupuncture applied for 10 days (30 min per day). TTC staining was used to calculate the ischemic brain volume. TUNEL staining and transmission electron microscopy were used to detect cell apoptosis. Western blot analysis and Bio-Plex were used to detect JNK, p38, ERK1/2, Bcl-2, and Bax protein expression. RESULTS We found that electroacupuncture at day 10 significantly reduced cerebral infarction. In addition, electroacupuncture suppressed activation of JNK and p38, while enhancing the activation of ERK1/2 in the peri-ischemic regions. Consequently, the effect of electroacupuncture on these pathways resulted in the inhibition of apoptosis, which was demonstrated by TUNEL and transmission electron microscopy. We found that electroacupuncture upregulated the anti-apoptotic Bcl-2/Bax ratio in peri-ischemic regions. CONCLUSIONS Our findings suggest that inhibition of cell apoptosis via regulating multiple signaling pathways might be a mechanism whereby electroacupuncture has a positive therapeutic effect on post-stroke impairment.

Targeting Phosphodiesterase-5 by Vardenafil Improves Vascular Graft Function.

OBJECTIVES: Ischaemia reperfusion (IR) injury occurs during vascular graft harvesting and implantation during vascular/cardiac surgery. Elevated intracellular cyclic guanosine monophosphate (cGMP) levels contribute to an effective endothelial protection in different pathophysiological conditions. The hypothesis that the phosphodiesterase-5 inhibitor vardenafil would protect vascular grafts against IR injury by upregulating the nitric oxide-cGMP pathway in the vessel wall of the bypass graft was investigated. METHODS: Lewis rats (n = 6-7/group) were divided into Group 1, control; Group 2, donor rats received intravenous saline; Group 3, received intravenous vardenafil (30 µg/kg) 2 h before explantation. Whereas aortic arches of Group 1 were immediately mounted in an organ bath, aortic segments of Groups 2 and 3 were stored for 2 h in saline and transplanted into the abdominal aorta of the recipient. Two hours after transplantation, the implanted grafts were harvested. Endothelium dependent and independent vasorelaxations were investigated. TUNEL, CD-31, ICAM-1, VCAM-1, α-SMA, nitrotyrosine, dihydroethidium and cGMP immunochemistry were also performed. RESULTS: Compared with the control, the saline group showed significantly attenuated endothelium dependent maximal relaxation (Rmax) 2 h after reperfusion, which was significantly improved by vardenafil supplementation (Rmax control, 91 ± 2%; saline 22 ± 2% vs. vardenafil 39 ± 4%, p < .001). Vardenafil pre-treatment significantly reduced DNA fragmentation (control 9 ± 1%, saline 66 ± 8% vs. vardenafil 13 ± 1%, p < .001), nitro-oxidative stress (control 0.8 ± 0.3, saline 7.6 ± 1.3 vs. vardenafil 3.8 ± 1, p = .036), reactive oxygen species level (vardenafil 36 ± 4, control 34 ± 2 vs. saline 43 ± 2, p = .049), prevented vascular smooth muscle cell damage (control 8.5 ± 0.7, saline 4.3 ± 0.6 vs. vardenafil 6.7 ± 0.6, p = .013), decreased ICAM-1 (control 4.1 ± 0.5, saline 7.0 ± 0.9 vs. vardenafil 4.4 ± 0.6, p = .031), and VCAM-1 score (control 4.4 ± 0.4, saline 7.3 ± 1.0 vs. vardenafil 5.2 ± 0.4, p = .046) and increased cGMP score in the aortic wall (control 11.2 ± 0.8, saline 6.5 ± 0.8 vs. vardenafil 8.9 ± 0.6, p = .016). The marker for endothelial integrity (CD-31) was also higher in the vardenafil group (control 74 ± 4%, saline 22 ± 2% vs. vardenafil 40 ± 3%, p = .008). CONCLUSIONS: The results support the view that impairment of intracellular cGMP signalling plays a role in the pathogenesis of the endothelial dysfunction of an arterial graft after bypass surgery, which can effectively be prevented by vardenafil. Its clinical use as preconditioning drug could be a novel approach in vascular/cardiac surgery.

Salvianolic acid A attenuates ischemia reperfusion induced rat brain damage by protecting the blood brain barrier through MMP-9 inhibition and anti-inflammation.

Salvianolic acid A (SAA) is a water-soluble component from the root of Salvia Miltiorrhiza Bge, a traditional Chinese medicine, which has been used for the treatment of cerebrovascular diseases for centuries. The present study aimed to determine the brain protective effects of SAA against cerebral ischemia reperfusion injury in rats, and to figure out whether SAA could protect the blood brain barrier (BBB) through matrix metallopeptidase 9 (MMP-9) inhibition. A focal cerebral ischemia reperfusion model was induced by middle cerebral artery occlusion (MCAO) for 1.5-h followed by 24-h reperfusion. SAA was administered intravenously at doses of 5, 10, and 20 mg·kg-1. SAA significantly reduced the infarct volumes and neurological deficit scores. Immunohistochemical analyses showed that SAA treatments could also improve the morphology of neurons in hippocampus CA1 and CA3 regions and increase the number of neurons. Western blotting analyses showed that SAA downregulated the levels of MMP-9 and upregulated the levels of tissue inhibitor of metalloproteinase 1 (TIMP-1) to attenuate BBB injury. SAA treatment significantly prevented MMP-9-induced degradation of ZO-1, claudin-5 and occludin proteins. SAA also prevented cerebral NF-κB p65 activation and reduced inflammation response. Our results suggested that SAA could be a promising agent to attenuate cerebral ischemia reperfusion injury through MMP-9 inhibition and anti-inflammation activities.

Autodigestion by migrated trypsin is a major factor in small intestinal ischemia-reperfusion injury.

BACKGROUND: The pathophysiological role of pancreatic digestive hydrolases in intestinal ischemia-reperfusion (I/R) injury is still not clear. Here, we studied whether ischemia-induced injury to the small intestine can be explained by the autodigestion hypothesis. MATERIALS AND METHODS: Mesenteric I/R was induced in rats by superior mesenteric artery occlusion (90 min) and reopening (120 min). Thirty minutes before superior mesenteric artery occlusion, aprotinin (14.7 mg/kg), orlistat (5 mg/kg), and their combination or α1-proteinase inhibitor (60 mg/kg) were injected into the lumen of the small intestine. Systemic and vital parameters, intestinal microcirculation, and mucosal barrier function were monitored during the observation phase; markers of small intestinal injury, as well as trypsin-, chymotrypsin-, elastase-, and lipase-like activities in intestinal effluates were assessed at the end. RESULTS: The pattern of small intestinal injury correlated inversely with the local alterations in microvascular tissue perfusion and corresponded with the intestinal distribution of trypsin-like activity. Aprotinin almost completely inhibited trypsin-like activity (P < 0.05) and significantly reduced intestinal tissue injury. Combined with orlistat, it also increased the postischemic blood pressure (P < 0.05) but not the intestinal barrier function. Macroscopic as well as the histologic alterations were decreased by α1-proteinase inhibitor, which significantly improved postischemic blood pressure (P < 0.05). CONCLUSIONS: The I/R-induced pattern of small intestinal injury is likely to result from both local differences in tissue ischemia and the digestive activity of migrated pancreatic trypsin. Therefore, administration of aprotinin and orlistat into ischemic small intestines may be a therapeutic option in patients with a poor diagnosis.

Protective effect of gel form of gastric gavage applicated aloe vera on ischemia reperfusion injury in renal and lung tissue.

The aloe vera plant has become increasingly popular in recent years. This study aimed to research the effect of aloe vera to prevent renal and lung tissue damage in an experimental ischemia-reperfusion (I/R) injury model. The study included 21 male Wistar Albino rats, which were categorized into control group, n = 7 (no procedures), Sham group n = 7 (I/R); and aloe vera therapy group, n = 7 (aloe vera and I/R). Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and malondialdehyde (MDA) were evaluated from lung and kidney tissues for biochemical investigations. As histopathological, hematoxylin and eosin and anti-iNOS were also examined. In biochemical investigations, SOD, CAT, and GPx levels of the Sham group were found to be lower compared with the other groups (P < 0.05). The aloe vera therapy group was not statistically different from control groups but significantly different compared with the Sham group. In the same way, the MDA levels of kidney and lung tissues were statistically significant in the aloe vera therapy group, compared to the Sham group. In the Sham group, the peribronchial and perialveolar edema were observed in lung parenchyma. Also, excess interstitial hemorrhage, leukocyte infiltration, and alveolar wall thickening were identified in ischemic groups. The histopathological changes were much lighter than in the aloe vera therapy group. In renal tissues, excess epithelial cell deterioration, tubular desqumination, and glomerular atrophy were observed in the Sham group. The histopathological changes were markedly reduced in the aloe vera therapy  group. In the kidney and lung tissue, the level of iNOS activity in the Sham group was significantly higher than in the control and aloe vera therapy group. This study indicated that aloe vera is protective against oxidative damage formed by I/R in distant organs like the lungs and kidneys.

[JUN N-TERMINAL KINASES AND THEIR PHARMACOLOGICAL MODULATION OF ISCHE-MIC AND REPERFUSION INJURY OF THE BRAIN].

The article reviews the literature regarding the role of c-Jun-N-terminal kinases (JNK) and its inhibitors in brain damage in the settings of ischemia and reperfusion injury. The implication of JNK in signaling mechanisms involved in ischemia-reperfusion-induced cerebral injury are discussed. Described effects associated with JNK inhibition using synthetic and natural substances in experimental models of ischemic and reperfusion injury of the brain. Results of experimental studies demonstrated that JNK represent promising therapeutic targets for brain protection against ischemic stroke. However, multiple physiologic functions of various JNK family members do not allow for the systemic use of non-specific JNK inhibitors for therapeutic purposes. The authors conclude that the continuous search for selective inhibitors of JNK3 remains an important task.

Neuroprotection of Cilostazol against ischemia/reperfusion-induced cognitive deficits through inhibiting JNK3/caspase-3 by enhancing Akt1.

Cilostazol(CTL) is a phosphodiesterase inhibitor, which has been widely used as anti-platelet agent. It also has preventive effects on various central nervous system (CNS) diseases, including ischemic stroke, Parkinson's disease and Alzheimer disease. However, the molecular mechanism underlying the protective effects of CTL is still unclear, and whether CTL can prevent I/R induced cognitive deficit has not been reported. Transient global brain ischemia was induced by 4-vessel occlusion in adult male Sprague-Dawley rats. The open field tasks and Morris water maze were used to assess the effect of CTL on anxiety-like behavioral and cognitive impairment after I/R. Western blotting were performed to examine the expression of related proteins, and HE-staining was used to detect the percentage of neuronal death in the hippocampal CA1 region. Here we found that CTL significantly improved cognitive deficits and the behavior of rats in Morris water maze and open field tasks (P<0.05). HE staining results showed that CTL could significantly protect CA1 neurons against cerebral I/R (P<0.05). Additionally, Akt1 phosphorylation levels were evidently up-regulated (P<0.05), while the activation of JNK3, which is an important contributor to I/R-induced neuron apoptosis, was reduced by CTL after I/R (P<0.05), and caspase-3 levels were also decreased by CTL treatment. Furthermore, all of CTL's protective effects were reversed by LY294002, which is a PI3K/Akt1 inhibitor. Taken together, our results suggest that CTL could protect hippocampal neurons and ameliorate the impairment of learning/memory abilities and locomotor/ exploratory activities in ischemic stroke via a PI3K-Akt1/JNK3/caspase-3 dependent mechanism.

Inhibition of coagulation proteases Xa and IIa decreases ischemia-reperfusion injuries in a preclinical renal transplantation model.

Coagulation is an important pathway in the pathophysiology of ischemia-reperfusion injuries. In particular, deceased after circulatory death (DCD) donors undergo a no-flow period, a strong activator of coagulation. Hence, therapies influencing the coagulation cascade must be developed. We evaluated the effect of a new highly specific and effective anti-Xa/IIa molecule, with an integrated innovative antidote site (EP217609), in a porcine preclinical model mimicking injuries observed in DCD donor kidney transplantation. Kidneys were clamped for 60 minutes (warm ischemia), then flushed and preserved for 24 hours at 4°C in University of Wisconsin (UW) solution (supplemented or not). EP217609-supplemented UW solution (UW-EP), compared with unfractionated heparin-supplemented UW solution (UW-UFH) or UW alone (UW). A mechanistic investigation was conducted in vitro: addition of EP217609 to endothelial cells during hypoxia at 4°C in the UW solution inhibited thrombin generation during reoxygenation at 37°C in human plasma and reduced tumor necrosis factor alpha, intercellular adhesion molecule 1, and vascular cell adhesion molecule 1 messenger RNA cell expressions. In vivo, function recovery was markedly improved in the UW-EP group. Interestingly, levels of thrombin-antithrombin complexes (reflecting thrombin generation) were reduced 60 minutes after reperfusion in the UW-EP group. In addition, 3 months after transplantation, lower fibrosis, epithelial-mesenchymal transition, inflammation, and leukocyte infiltration were observed. Using this new dual anticoagulant, anti-Xa/IIa activity during kidney flush and preservation is protected by reducing thrombin generation at revascularization, improving early function recovery, and decreasing chronic lesions. Such an easy-to-deploy clinical strategy could improve marginal graft outcome.

Shengmai injection attenuates the cerebral ischemia/reperfusion induced autophagy via modulation of the AMPK, mTOR and JNK pathways.

Context Shengmai injection (SMI) is a patented Chinese medicine originated from the ancient Chinese herbal compound Shengmai san, which is used extensively for the treatment of cardiovascular and cerebrovascular disease in the clinic. Objective To determine the neuroprotective effect of SMI, we investigated the effect of SMI on cerebral ischemia/reperfusion (I/R) injury in mice as well as the mechanisms underlying this effect. Materials and methods Right middle cerebral artery was occluded by inserting a thread through internal carotid artery for 1 h, and then reperfused for 24 h in mice. The neuroprotective effects were determined using transmission electron microscopic examination, the evaluation of infarct volume, neurological deficits and water brain content. Related mechanisms were evaluated by immunofluorescence staining and western blotting. SMI was injected intraperitoneally after 1 h of ischemia at doses of 1.42, 2.84 and 5.68 g/kg. The control group received saline as the SMI vehicle. Results Results showed that SMI (1.42, 2.84 and 5.68 g/kg) could significantly reduce the infarct volume, SMI (5.68 g/kg) could also significantly improve the neurological deficits, decreased brain water content, as well as the neuronal morphological changes. SMI (5.68g/kg) could significantly inhibit the expression of autophagy-related proteins: Beclin1 and LC3. It also reduced the increase in LC3-positive cells. SMI (5.68 g/kg) remarkably inhibited the phosphorylation of adenosine monophosphate activated protein kinase (AMPK), and down-regulated the phosphorylation of mammalian target of rapamycin (mTOR) and Jun N-terminal kinase (JNK) after 24 h of reperfusion. Discussion and conclusion The results indicate that SMI provides remarkable protection against cerebral ischemia/reperfusion injury, which may be partly due to the inhibition of autophagy and related signalling pathways.

Electroacupuncture improves cognitive function through Rho GTPases and enhances dendritic spine plasticity in rats with cerebral ischemia-reperfusion.

The aim of the present study was to evaluate the effect of electroacupuncture (EA) on cognitive function following cerebral ischemia­reperfusion (I/R) injury, and to clarify the mechanism through which Rho GTPase is associated with EA analgesia modulation of dendritic spine plasticity. Rats were randomly divided into three groups: The sham surgery group, the middle cerebral artery occlusion (MCAO) model of ischemia group, and the MCAO with EA (MCAO+EA) treatment group. The MCAO+EA group received treatment with EA at points of Baihui (DU20) and Shenting (DU24) following surgery. It was demonstrated that treatment with EA significantly (P<0.05) protected the cognitive function of rats from impairment caused by cerebral I/R injury. Furthermore, EA treatment increased the density of dendritic spines in the hippocampus of cerebral I/R­injured rats. Simultaneously, EA increased the expression of cell division cycle 42, Ras­related C3 botulinum toxin substrate 1 and F­actin proteins. By contrast, EA treatment inhibited the expression of Ras homologous member A. Collectively, these findings suggest that Rho GTPases and dendritic spine plasticity are critical in mediating the effects of EA treatment at the points of Shenting and Baihui, and that EA protects against impairment of cognitive function following ischemic stroke.

Manitoba Lingonberry (Vaccinium vitis-idaea) Bioactivities in Ischemia-Reperfusion Injury.

Evidence for the efficacy of dietary interventions in protecting against cardiovascular disease has grown significantly, with flavonoids and anthocyanins receiving special attention. Lingonberry (Vaccinium vitis-idaea L.) is a good source of these compounds, and this study examined the protective effects of wild lingonberry found in Manitoba, Canada, against ischemia-reperfusion (IR) injury. Manitoba lingonberry contained 3793 ± 27 mg gallic acid equiv, 120,501 ± 7651 µmol trolox equiv, and 575 ± 20 mg cyanidin-3-glucoside equiv per 100 g dry weight, which correspond with high total phenolic content, antioxidant activity, and anthocyanin content, respectively. A complete methanolic extract and both anthocyanin-rich and phenolic-rich fractions inhibited apoptosis in H9c2 cells during simulated IR. Lingonberry extract and fractions significantly inhibited several markers of apoptosis induced by IR, including nuclei condensation, caspase-3 activation, and MAP kinase signaling. These results provide the first analysis of Manitoba lingonberry and highlight the mechanistic importance of dietary berry compounds for cardiovascular health.

Carvacrol alleviates ischemia reperfusion injury by regulating the PI3K-Akt pathway in rats.

BACKGROUND: Liver ischemia reperfusion (I/R) injury is a common pathophysiological process in many clinical settings. Carvacrol, a food additive commonly used in essential oils, has displayed antimicrobials, antitumor and antidepressant-like activities. In the present study, we investigated the protective effects of carvacrol on I/R injury in the Wistar rat livers and an in vitro hypoxia/restoration (H/R) model. METHODS: The hepatoportal vein, hepatic arterial and hepatic duct of Wistar rats were isolated and clamped for 30 min, followed by a 2 h reperfusion. Buffalo rat liver (BRL) cells were incubated under hypoxia for 4 h, followed normoxic conditions for 10 h to establish the H/R model in vitro. Liver injury was evaluated by measuring serum levels of alanine aminotransferase (ALT) and aspatate aminotransferase (AST), and hepatic levels of superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and malondiadehyde (MDA), and hepatic histology and TUNEL staining. MTT assay, flow cytometric analysis and Hoechst 33258 staining were used to evaluate the proliferation and apoptosis of BRL cells in vitro. Protein expression was examined by Western Blot analysis. RESULTS: Carvacrol protected against I/R-induced liver damage, evidenced by significantly reducing the serum levels of ALT and AST, histological alterations and apoptosis of liver cells in I/R rats. Carvacrol exhibited anti-oxidative activity in the I/R rats, reflected by significantly reducing the activity of SOD and the content of MDA, and restoring the activity of CAT and the content of GSH, in I/R rats. In the in vitro assays, carvacrol restored the viability and inhibited the apoptosis of BRL cells, which were subjected to a mimic I/R injury induced by hypoxia. In the investigation on molecular mechanisms, carvacrol downregulated the expression of Bax and upregulated the expression of Bcl-2, thus inhibited the activation of caspase-3. Carvacrol was also shown to enhance the phosphorylation of Akt. CONCLUSION: The results suggest that carvacrol could alleviate I/R-induced liver injury by its anti-oxidative and anti-apoptotic activities, and warrant a further investigation for using carvacrol to protect I/R injury in clinic.