Dakuan Gao

Resveratrol attenuates ischemic brain damage in the delayed phase after stroke and induces messenger RNA and protein express for angiogenic factors.

BACKGROUND It has been reported recently that resveratrol preconditioning can protect the brain from ischemia-reperfusion injury. However, it was unclear whether resveratrol administration after stroke was beneficial to the delayed phases after focal cerebral ischemia injury. This study investigated the effects and possible protective mechanism of resveratrol on the delayed phase after focal cerebral ischemia injury in mice. METHODS Mice were randomly assigned to five groups according to the time of administration of resveratrol. Control group mice received a corresponding volume of saline solution (0.9% NaCl) containing 20% hydroxypropyl h-cyclodextrin by gavage and were exposed to middle cerebral artery (MCA) occlusion and reperfusion injury. The treatment groups received resveratrol (50 mg/kg/d, gavage) until day 7. Ischemia group mice received their first dose 5 minutes before MCA ischemia, reperfusion group mice received their first dose 5 minutes before MCA reperfusion, first-day, group mice received their first dose 24 hours after MCA reperfusion, and third-day group mice received their first dose at 72 hours after MCA reperfusion. Brain injury was evaluated by triphenyltetrazolium chloride staining and neurologic examination 7 days after reperfusion. The microvascular cell number was examined with immunohistochemistry staining. Effect of resveratrol on matrix metalloproteinase-2 (MMP-2) and vascular endothelial growth factor (VEGF) gene expression was investigated with reverse transcriptase-polymerase chain reaction and Western blot. RESULTS The mean neurologic scores and infarct volumes of the ischemia and reperfusion groups were lower than that of the control group at 7 days after MCA reperfusion (P < .05). Immunohistochemistry staining showed significantly less reduction in the number of microvessels in the cortical area of mice of the ischemia and reperfusion groups compared with controls. The ischemic hemispheres of the ischemia and reperfusion groups showed significantly (P < .05) elevated levels of protein of MMP-2 and VEGF. CONCLUSIONS Resveratrol administration by gavage provided an important neuroprotective effect on focal cerebral ischemic injury in the delayed phase. The elevated MMP-2 and VEGF levels might be important in the neuroprotective effect of resveratrol administration by inducing angiogenesis.

Resveratrol protects primary cortical neuron cultures from transient oxygen‑glucose deprivation by inhibiting MMP‑9

It was recently shown that resveratrol exerts neuroprotective effects against cerebral ischemia in mice. The aim of the present study was to further confirm these effects in in vitro primary cortical neuron cultures with transient oxygen-glucose deprivation (OGD), and to investigate whether these effects are due to the inhibition of matrix metalloproteinase-9 (MMP-9) and of cell apoptosis. Neuronal primary cultures of cerebral cortex were prepared from BALB/c mice embryos (13-15 days). Cells from 14- to 16-day cultures were subjected to OGD for 3 h, followed by 21 h of reoxygenation to simulate transient ischemia. Different doses of resveratrol were added into the culture medium during the simulation of transient ischemia. The effect of the extracellular signal-regulated kinase (ERK) inhibitor U0126 was studied by adding U0126 (5 µg/µl, 4 µl) into the culture medium during transient ischemia; as a control, we used treatment of cells with 50 µM of resveratrol. Cell viability was investigated using the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) reduction assay. Cell apoptosis was assessed by flow cytometry. The effects of resveratrol on the expression of MMP-9 were analyzed by western blotting and reverse transcription-polymerase chain reaction (RT-PCR), while the levels of ERK, phosphorylated (p)-ERK, cleaved caspase-3, Bax and Bcl-2 were measured by western blotting. The results of the MTT assay showed that cell viability is significantly reduced by transient OGD. OGD induced cell apoptosis, the expression of Bax and the activation of caspase-3 and ERK, inhibited the expression of Bcl-2 and increased the expression of MMP-9, while these effects were reversed by treatment with resveratrol. The therapeutic efficacy of resveratrol was shown to be dose-dependent, with the most suitable dose range determined at 50-100 µM. Treatment with U0126 inhibited MMP-9 and Bax expression and caspase-3 activation, while it further promoted the expression of the anti-apoptotic molecule Bcl-2, suggesting that resveratrol inhibits MMP-9 expression and cell apoptosis by attenuating the activation of ERK1/2. In conclusion, OGD can induce apoptosis through canonical apoptotic signals and by regulating the expression of MMP-9; the anti-apoptotic activity of resveratrol and its inhibitory effect on MMP-9 expression contribute in the reduced activation of ERK.

Allicin protects rat cortical neurons against mechanical trauma injury by regulating nitric oxide synthase pathways.

Allicin, a small molecule that is responsible for the typical smell and most of the functions of garlic, possesses a broad spectrum of pharmacological activities and is considered to have therapeutic potential in many pathologic conditions. In the present study, we investigated the potential protective effect of allicin in an in vitro model of traumatic brain injury (TBI) using primary cultured rat cortical neurons. We found that allicin treatment significantly reduced mechanical trauma-induced lactate dehydrogenase (LDH) release and inhibited apoptotic neuronal death in a dose-dependent manner. These protective effects were observed even if allicin treatment was delayed to 2h after injury. Allicin significantly decreased the expression of inducible nitric oxide synthase (iNOS) and increased the phosphorylation of endothelial NOS (eNOS) but had no effect on neuronal NOS (nNOS) expression. Allicin-induced protection in cortical neurons was augmented by iNOS and nNOS antagonists and was partly reversed by blocking eNOS phosphorylation. In addition, allicin treatment inhibited the TBI-induced activation of ERK and further enhanced the phosphorylation of Akt in TBI-injured neurons. The Akt inhibitor LY294002 attenuated the allicin-induced increase in eNOS expression and phosphorylation, whereas the ERK inhibitor PD98059 had opposite effects on the expression of iNOS and eNOS. Pretreatment with LY294002 or PD98059 partly prevented or further enhanced allicin-induced neuroprotection, respectively. Collectively, these data demonstrate that allicin treatment may be an effective therapeutic strategy for traumatic neuronal injury and that the potential underlying mechanism involves Akt- and ERK-mediated regulation of NOS pathways.

Gross-total hematoma removal of hypertensive basal ganglia hemorrhages: A long-term follow-up

BACKGROUND AND PURPOSE Hypertensive basal ganglia hemorrhage (HBGH) accounts for 35%-44% of cases of hypertensive intracranial hemorrhage (ICH), which is one of the most devastating forms of cerebrovascular disease. In this study, intracerebral hematoma was evacuated with a burr hole craniectomy. The relationships of residue hematoma volume to brain edema, inflammation factors and the long-term prognosis of HBGH patients were studied. METHODS One hundred and seventy-six patients with HBGH were randomly divided into gross-total removal of hematoma (GTRH) and sub-total removal of hematoma (STRH) groups. The pre-operative and post-operative data of the patients in the two groups were compared. The pre-operative data included age, sex, hematoma volume, time from the ictus to the operation, Glasgow Coma Scale (GCS) scores, and the European Stroke Scale (ESS) scores. The post-operative information included edema grade, level of thromboxane B2 (TXB2), 6-keto-prostaglandin F1a (6-K-PGF1a), tumor necrosis factor-a (TNF-a) and endothelin (ET) in hematoma drainage or cerebral spinal fluid (CSF), ESS and Barthel Index (BI). RESULTS There was no statistical difference between the two groups (P>0.05) in the pre-operative data. The levels of TXB2, 6-K-PGF1a, TNF-a and ET in the GTRH group were significantly lower than those in the STRH group at different post-operative times. The ESS in the GTRH group increased rapidly after the operation and was higher than that in the STRH group. There was a significant difference between the two groups (P<0.05). The post-operative CT scan at different times showed that the brain edema grades were better in the GTRH group than in the STRH group. The BI was higher in the GTRH group than in the STRH group (P<0.05). CONCLUSIONS GTRH is an effective method to decrease ICH-induced injury to brain tissue. Such effect is related to decreased perihematomal edema formation and secondary injury by coagulation end products activated inflammatory cascade.

A randomized controlled study comparing omeprazole and cimetidine for the prophylaxis of stress-related upper gastrointestinal bleeding in patients with intracerebral hemorrhage

OBJECT Patients with intracerebral hemorrhage (ICH) are at high risk for severe stress-related upper gastrointestinal (UGI) bleeding, which is predictive of higher mortality. The aim of this study was to evaluate the effectiveness of omeprazole and cimetidine compared with a placebo in the prevention and management of stress-related UGI bleeding in patients with ICH. METHODS In a single-center, randomized, placebo-controlled study, 184 surgically treated patients with CT-proven ICH within 72 hours of ictus and negative results for gastric occult blood testing were included. Of these patients, 165 who were qualified upon further evaluation were randomized into 3 groups: 58 patients received 40 mg intravenous omeprazole every 12 hours, 54 patients received 300 mg intravenous cimetidine every 6 hours, and 53 patients received a placebo. Patients whose gastric occult blood tests were positive at admission (n = 70) and during/after the prophylaxis procedure (n = 48) were treated with high-dose omeprazole at 80 mg bolus plus 8 mg/hr infusion for 3 days, followed by 40 mg intravenous omeprazole every 12 hours for 7 days. RESULTS Of the 165 assessable patients, stress-related UGI bleeding occurred in 9 (15.5%) in the omeprazole group compared with 15 patients (27.8%) in the cimetidine group and 24 patients (45.3%) in the placebo group (p = 0.003). The occurrence of UGI bleeding was significantly related to death (p = 0.022). Nosocomial pneumonia occurred in 14 patients (24.1%) receiving omeprazole, 12 (22.2%) receiving cimetidine, and 8 (15.1%) receiving placebo (p > 0.05). In patients with UGI bleeding in which high-dose omeprazole was initiated, UGI bleeding arrested within the first 3 days in 103 patients (87.3%). CONCLUSIONS Omeprazole significantly reduced the morbidity of stress-related UGI bleeding in patients with ICH due to its effective prophylactic effect without increasing the risk of nosocomial pneumonia, but it did not reduce the 1-month mortality or ICU stay. Further evaluation of high-dose omeprazole as the drug of choice for patients presenting with UGI bleeding is warranted. Clinical trial registration no.: ChiCTR-TRC-12001871, registered at the Chinese clinical trial registry (http://www.chictr.org/en/proj/show.aspx?proj=2384).

Protective effects of hydrogen sulfide in a rat model of traumatic brain injury via activation of mitochondrial adenosine triphosphate-sensitive potassium channels and reduction of oxidative stress.

BACKGROUND Hydrogen sulfide (H2S) is considered an important neuromodulator in the central nervous system. We designed the present study to investigate the effects of exogenous H2S in a rat model of traumatic brain injury (TBI) and the mechanism(s) that underlie this effect. METHODS We induced a TBI model by controlled cortical impact injury. We intraperitoneally administered sodium hydrosulfide (NaHS) (an H2S donor) (3 mg/kg) or vehicle alone at 5 min after a TBI operation. We then measured the H2S level, brain edema, blood-brain barrier integrity, neurologic dysfunction, and lesion volume in all animals. Moreover, we assessed the role of mitochondrial adenosine triphosphate-sensitive potassium (mitoKATP)channels by intraperitoneal injection of the selective blocker 5-hydroxydecanoate before NaHS administration. In addition, we detected the levels of oxidative products and the activities of antioxidant enzymes in brain tissue. RESULTS Administration of NaHS significantly increased the H2S level of brain tissue in TBI-challenged rats. The TBI-challenged animals exhibited significant brain injuries, characterized by an increase of blood-brain barrier permeability, brain edema, and lesion volume, as well as neurologic dysfunction, which were significantly ameliorated by NaHS treatment. However, the protective effects of H2S in TBI could be abolished by the mitoK(ATP) channel blocker 5-hydroxydecanoate. Moreover, we found that NaHS treatment increased endogenous antioxidant enzymatic activities and decreased oxidative product levels in brain tissue of TBI-challenged rats. CONCLUSIONS Exogenous H2S administered at an appropriate dose can exert a protective effect against TBI via activation of mitoK(ATP) channels and reduction of oxidative stress.

The anti-inflammatory effects of D-allose contribute to attenuation of cerebral ischemia-reperfusion injury.

It has been proved that multiple independently lethal mechanisms are involved in cerebral ischemia-reperfusion injury. Inflammatory processes, mediated by activated leukocytes, have been implicated in the mechanisms of cerebral ischemia-reperfusion injury. In addition, the leukocytes accumulated in the perivascular areas during the inflammatory responses after reperfusion will transform oxygen to reactive free radicals, release cytotoxic products and vasoactive substances, which further promotes brain injury. So activated leukocytes play an important role in the pathophysiologic process of cerebral I/R injury. D-allose, a rare sugar produced from D-ribose, attracts increased attention from researchers in recent years. It has been proved that D-allose can produce inhibitory effects on activated leukocytes in liver, kidney and retina, including immunosuppressive effects, anti-inflammatory effects, as well as anti-oxyradical effects. Furthermore, recent research work of our colleagues has demonstrated that D-allose could attenuate cerebral I/R injury by anti-oxyradical effects. However, inflammatory responses play an important role in the mechanisms of cerebral I/R injury. So we hypothesize that D-allose might perform neuroprotection against cerebral ischemia-reperfusion injury by its anti-inflammatory effects.

Osthole attenuates spinal cord ischemia-reperfusion injury through mitochondrial biogenesis-independent inhibition of mitochondrial dysfunction in rats.

BACKGROUND Osthole, the main bioactive compounds isolated from the traditional Chinese medical herb broad Cnidium monnieri (L.) cusson, has been shown to exert spectrum of pharmacologic activities. The aim of this study was to investigate the potential neuroprotective effects of osthole against spinal cord ischemia-reperfusion injury in rats. MATERIALS AND METHODS Osthole was administrated at the concentration of 0.1, 1, 10, 50, or 200 mg/kg (intraperitoneally) 1 h before spinal cord ischemia. The effects on spinal cord injury were measured by spinal cord water content, infarct volume, hematoxylin and eosin staining, and neurologic assessment. Mitochondria were purified from injured spinal cord tissue to determine mitochondrial function. RESULTS We found that treatment with osthole (10 and 50 mg/kg) significantly decreased spinal cord water content and infarct volume, preserved normal motor neurons, and improved neurologic functions. These protective effects can be also observed even if the treatment was delayed to 4 h after reperfusion. Osthole treatment preserved mitochondrial membrane potential level, reduced reactive oxygen species production, increased adenosine triphosphate generation, and inhibited cytochrome c release in mitochondrial samples. Moreover, osthole increased mitochondria respiratory chain complex activities in spinal cord tissue, with no effect on mitochondrial DNA content and the expression of mitochondrial-specific transcription factors. CONCLUSIONS All these findings demonstrate the neuroprotective effect of osthole in spinal cord ischemia-reperfusion injury model and suggest that oshtole-induced neuroprotection was mediated by mitochondrial biogenesis-independent inhibition of mitochondrial dysfunction.

D-allose protects the blood brain barrier through PPARγ-mediated anti-inflammatory pathway in the mice model of ischemia reperfusion injury

Our early experiments confirmed that D-allose was closely involved in the blood brain barrier (BBB) protection from ischemia reperfusion (IR) injury, but the regulatory mechanism is not fully defined. In this study, we aimed to investigate the role of D-allose in the protection of BBB integrity and the relevant mechanisms involved in the mice model of middle cerebral artery occlusion and reperfusion (MCAO/Rep). D-allose was intravenously injected via a tail vein (0.2mg/g and 0.4mg/g, 1h before ischemia), GW9662 was intraperitoneal injected to the mice (4mg/kg) before inducing ischemia 24h. Pretreatment with D-allose ameliorated the neurological deficits, infarct volume and brain edema in brains of MCAO/Rep mice. D-allose inhibited cell apoptosis in the mice model of MCAO/Rep. We observed that D-allose remarkably decreased BBB permeability and prevented the reduction of ZO-1, Occludin and Claudin-5 in mice brains with MCAO/Rep injury. D-allose also repressed the levels of TNF-α, NF-κB, interleukin (IL)-1β and IL-8 in inflammatory responses. The increases of intercellular adhesion molecular-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and CD11b/CD18 were significantly inhibited by D-allose during the MCAO/Rep injury. And D-allose decreased the L-selectin and P-selectin levels after MCAO/Rep. Moreover, D-allose induced up-regulation of peroxisome proliferator-activated receptor γ (PPARγ), and down-regulation of TNF-α and NF-κB after MCAO/Rep, which were abolished by utilization of GW9662. In conclusion, we provided evidences that D-allose may has therapeutic potential against brain IR injury through attenuating BBB disruption and the inflammatory response via PPARγ-dependent regulation of NF-κB.

The microsurgical treatment of cranio-orbital tumors assisted by intraoperative electrophysiologic monitoring and neuronavigation

OBJECTIVE Total resection of cranio-orbital tumors without any major complications is still a challenge for neurosurgeons. Intraoperative electrophysiologic monitoring and neuronavigational system have been widely used in microneurosurgery, but their effects during microsurgical treatment of cranio-orbital tumors warrant further investigation. METHODS Thirty-eight patients with cranio-orbital tumors admitted to our hospital underwent microsurgery assisted by intraoperative electrophysiologic monitoring. We also simultaneously performed intraoperative neuronavigation in 20 patients. A retrospective review of clinical notes, operation records and prognoses of all patients was performed. RESULTS Gross total resection was achieved in 29 patients (76%), near total resection in 5 (13%), subtotal resection in 3 (8%) and partial resection in 1 (3%). With the helps of electromyogram (EMG) monitoring of levator palpebrae superioris (LPS) muscle and navigation system, no surgical damages to the oculomotor nerve and other important structures occurred. A follow-up study showed that 31 patients (82%) resumed normal lives (Glasgow Outcome Scale (GOS) score 5), 5 patients (13%) had independent lives (GOS score 4), and 2 patients (5%) were unable to live independently (GOS score 3). CONCLUSION Microsurgical treatment assisted by intraoperative electrophysiologic monitoring and neuronavigation might be a useful method for resection of cranio-orbital tumors, especially better for protection of the important cranial nerve and structure in the kull base.