Protective effect of paeoniflorin on nerve cells in APP/PS1 mice and its mechanism

AIM: To investigate the therapeutic and preventive effects of paeoniflorin (PF) on APP/PS1 mice, and to explore the possible mechanism. METHODS: Fifteen male 5-month-old APP/PS1 non-dominant mice were chosen as normal control group, 15 male 5-month-old APP/PS1 double transgenic mice were used as model group, and 15 male 5-month-old APP/PS1 double transgenic mice treated with 5 mg/kg PF by intraperitoneal injection were allocated in administation group. The learning and memory ability of the mice in each group was detected by Morris water maze. The apoptosis was assessed by TUNEL fluorescence staining. The protein expression of PI3K, Akt, p-PI3K, p-Akt, caspase-3, caspase-9, Bcl-2 and Bax in cerebral cortex and hippocampus was detected by Western Blot. The protein expression levels and distribution of caspase-3 and caspase-9 were detected by immunohistochemistry. RESULTS: (1) Compared with normal control group, the learning and memory ability declined in APP/PS1 model group. Compared with APP/PS1 model group, PF obviously improve the ability of learning and memory in mice. (2) Compared with normal control group, the apoptosis of nerve cells in APP/PS1 model group significantly increased and distributed in wider areas, while that in PF group was reduced (P<0.05). (3) Compared with APP/PS1 model group, PF could significantly lower pro-apoptotic factors, caspase-3, caspase-9 and Bax (P<0.05), and increase the expression of anti-apoptotic factors, p-PI3K, p-Akt and Bcl-2 (P<0.05). CONCLUSION: PF can up-regulate the expression of Bcl-2 and down-regulate the expression levels of caspase-9, caspase-3 and Bax via the activation of PI3K/Akt pathway, thereby inhibiting the nerve cell apoptosis and protecting the nerve cells, so as to treat neurodegenerative diseases.     

Intervention of hydrogen on memory damage induced by chronic hypoxia-hypercapnia in rats

AIM: To investigate the effects of hydrogen on the memory damage caused by chronic hypoxia-hypercapnia in rats. METHODS: Twenty-four SD rats trained by eight-arm radial maze test were randomly divided into 3 groups:normal control group (NC), hypoxia-hypercapnia+saline group (MS) and hypoxia-hypercapnia+ hydrogen group (MH). The rats in the latter 2 groups were placed in a closed cabin for 8 h/day,6 days/week and lasted for 4 weeks, in which O₂ was 9％-11％ and CO₂ was 5％-6％. In every time after the animals were out of the cabin, the MS rats were intraperitoneally injected with saline (5 mL/kg) and the MH rats were intraperitoneally injected with hydrogen solution at the same dose. The learning and memory function, the activity of superoxide dismutase (SOD), the content of malondialdehyde (MDA) and 8-hydroxydeoxyguanosine (8-OHdG) were examined after the cabin training. The ultramicrostructures of hippocampus were also observed. RESULTS: (1) Compared with NC group, the number of working memory errors, the total errors, the content of hippocampus 8-OHdG and serum MDA in MS and MH groups were higher and the activity of serum SOD was lower (P<0.05). The hippocampus structure was destroyed and some degree of edema and more apoptosis in the neurons were obserued in MS group and MH group. (2) Compared with MS group, the number of working memory errors(WME), the total errors, the content of hippocampus 8-OHdG and serum MDA were lower and the activity of serum SOD was higher in MH group (P<0.05). In MH group, the morphology of hippocampus structures kept nearly normal arrangement and the only mild edema and fewer apoptosis in the neurons were found. CONCLUSION: Hydrogen may attenuate chronic hypoxia-hypercapnia-induced memory damage in rats by inhibiting apoptosis of the neurons and decreasing detrimental free radicals reaction.     

Influence of APP17 peptide on the study ability,memory and NT-3, NGF expression of the hippocampus neurons D-galactose induced brain aging model mice

AIM:To observe the influence of beta-amyloid precursor protein (APP17) on the study ability, memory and the expression of neurotrophin-3 (NT-3), nerve growth factor(NGF)in the hippocampus neuron of the model mice. METHODS: Mice brain aging model were produced with D-galactose(D-gal), the model mice were given hypodermic injection of APP17 peptide. APP17 peptide is the 319-335 peptide sequence of beta-amyloid precursor protein. Eight weeks later, the animals were observed by water labyrinth test and immunohistochemistry assay. RESULT:(1) The whole time needed and total times of wrong response for the D-gal group mice to complete the whole course of the water labyrinth test is significantly higher than the normal control group. (2) The expression of NT-3, NGF in the hippocampus neurons of the mice in APP17 peptide group is significantly higher than that of the normal control group and D-gal mice group, P＜0.01. CONCLUSIONS: The study ability, memory and the expression of NT-3, NGF in hippocampus neurons decreased in the D-gal induced brain aging model mice; APP17 peptide protected the study ability and memory of the model mice and in increasing the expression of NT-3, NGF in the hippocampus neurons.     

Effect of BDNF expression in cerebral cortex and hippocampus on ability of learning and memory in APP/PS1 transgenic mice

AIM: To investigate the expression changes of brain-derived neurotrophic factor (BDNF) in the cerebral cortex and hippocampus and their effects on the ability of learning and memory in the wild-type (WT) mice and APP/PS1 transgenic mice. METHODS: WT mice and APP/PS1 transgenic mice were selected as study subjects. Aβ plaques, apoptosis rate and BDNF expression in the cerebral cortex and hippocampus of WT mice and APP/PS1 transgenic mice were detected by the methods of Congo red staining, TUNEL, immunofluorescence and Western blot. The abilities of learning and memory were determined by Morris water maze test. RESULTS: The Aβ plaques appeared in the cerebral cortex and hippocampus of APP/PS1 transgenic mice, and the number of Aβ plaques in 12-month-old mice was larger than that in 6-month-old mice (P<0.05). The number of apoptotic neurons in the cerebral cortex and hippocampus of 12-month-old APP/PS1 transgenic mice was larger than that of WT mice (P<0.01). The expression level of BDNF in the cerebral cortex and hippocampus of WT mice was higher than that of APP/PS1 transgenic mice (P<0.01). The Morris water maze test showed that the escape latency in APP/PS1 transgenic mice was longer than that in WT mice, and the times across the platform quadrant in 60 s was less than that in WT mice (P<0.01). The swim-tracking path of APP/PS1 transgenic mice was disordered and irregular. CONCLUSION: The expression of BDNF in the cerebral cortex and hippocampus of APP/PS1 transgenic mice was lower than that of WT mice, accompanied by increased neuronal apoptosis and decreased spatial learning and memory ability. The decrease in learning and memory ability may be related to decreased BDNF expression in the cerebral cortex and hippocampus of APP/PS1 transgenic mice, leading to increased neuronal apoptosis, which may be one of the pathological mechanisms of Alzheimer disease.     

Effect of curcumin on scopolamine-induced memory impairment in mice

AIM:Scopolamine blocks cholinergic transmission and impairs learning and memory in mice. The purpose of this study was to evaluate the memory-improving properties of curcumin on scopolamine-induced memory impairment in mice. METHODS:The mice of memory impairment were induced by scopolamine. Step down test and Morris water maze test were used to observe the learning and memory ability in curcumin-treated mice. Biochemical assessments of AChE, MDA, and GSH-Px levels in brains were performed. RESULTS:Oral administration of curcumin significantly reduced the numbers of step-down errors (P<0.05) and prolonged the step-down latency induced by scopolamine (P<0.05). The escape latency time in mice treated with curcumin was remarkably reduced compared to that in scopolamine group by Morris water maze test (P<0.05). After the platform was removed, the total time that the mice swam in the target quadrant was also longer in curcumin group than that in model group (P<0.05). The data also indicated that curcumin significantly inhibited AChE activity (P<0.01) and prevented oxidative stress characterized by the significant reduction in MDA content and the significant increase in GSH-Px activities in the brain (P<0.01). CONCLUSION:Curcumin induces cognitive improvement by enhancing the function of cholinergic system and its antioxidant activity.     

Effects of Chinese herbal compound Huannaoyicongfang on inflammatory cytokines and oxidative stress in brain of APP transgenic mice

AIM: To study the effects of Chinese herbal compound Huannaoyicongfang (HNYCF) on inflammatory reaction and oxidative stress in the brain of Alzheimers disease (AD) animal model, and to explore its role in treating AD. METHODS: APP695V717I transgenic mice (3 months old),as an AD model in this study, were randomly divided into model group, donepezil group, HNYCF high-dose group and HNYCF low-dose group. C57BL/6J mice, which were of the same age and genetic background as the transgenic mice, were used as controls. The animals were administered intragastrically with the drug or water from 3 months old to 9 months old. Morris water maze test was performed to measure the spatial learning and memory ability. Step-down test was performed to observe the learning and memory ability of single passive avoidance response. The expression of nuclear factor kappa B (NF-κB) and peroxisome proliferator-activated receptor γ (PPARγ) in hippocampus CA1 region was detected by immunohistochemistry with image analysis. The levels of interleukin-6 (IL-6) and high sensitivity C-reactive protein (hs-CRP) in the brain cortex and hippocampus homogenate were measured by radioimmunoassay. The activity of superoxide dismutase (SOD) in serum was detected by colorimetry. The content of malondialdehyde (MDA) in serum was detected by thibabituric acid method. RESULTS: Morris water maze test showed that the times of crossing platform, and the swimming time and distance in the fourth quadrant in HNYCF groups were much more than those in model group. The step-down test manifested that the escape latency in HNYCF high-dose group was significantly longer than that in model group. Compared with model group, the expression of NF-κB obviously decreased, the expression of PPARγ significantly increased and the content of IL-6 was lower in HNYCF groups. The activity of serum SOD in HNYCF groups was significantly higher than that in model group. CONCLUSION: HNYCF evidently ameliorates the learning and memory ability in APP transgenic mice, which may be related to the anti-inflammatory and anti-oxidation effects of HNYCF.     

金针菇多糖改善小鼠学习记忆功能

研究金针菇多糖对正常小鼠学习记忆的影响。利用三等分辐射式迷宫箱训练小鼠,检测每实验日正确反应率、达标小鼠的比率及达标所需训练次数,训练结束后取脑,用紫外分光光度计检测各项指标的OD值,测得超氧化物歧化酶（SOD）和丙二醛（MDA）含量。结果显示低剂量金针菇多糖可显著提高小鼠的达标率,显著降低小鼠达标的训练次数,金针菇多糖对SOD含量水平均有显著的提高作用（p〈0.05）,低剂量的金针菇多糖明显提高大脑海马组织中蛋白质的含量（p〈0.05）并能显著降低MDA含量（p〈0.05）。这表明金针菇多糖对小鼠的学习记忆有一定的促进作用,并能显著提高大脑海马组织中的蛋白质含量,提高SOD活力,降低MDA含量,表现出明显的抗氧化作用。     

Effect of FSD-C10 on modulation of inflammatory microenvironment in an Alzheimer disease double transgenic mouse model

AIM: To explore the therapeutic effect of a novel Rho kinase inhibitor FSD-C10 on β-amyloid protein precursor (APP)/presenilin-1 (PS1) double transgenic mice. METHODS: The transgenic mice overexpressing human APP with the Swedish mutation (695) and human PS1 with ΔE9 mutation at the age of 8 months were used in this study. The mice were randomly divided into model group and FSD-C10 intervention group, and wild-type mice at the same age served as normal controls. The mice in FSD-C10 intervention group were treated with FSD-C10 (25 mg·kg^-1·d^-1) for 2 months by intraperitoneal injection. The mice in model group and the wild-type mice were injected with saline in the similar manner. Morris water maze (MWM) test was applied to examine the capacity of learning and memory. The Aβ_1-42 deposition, Tau protein phosphorylation, and the expression of β-site APP-cleaving enzyme (BACE) as well as inflammatory molecules, such as TLR-4 and NF-κB, and M1/M2 microglial markers, such as iNOS and Arg-1, were determined by the methods of immunohistochemistry and Western blot. RESULTS: Compared with model group, FSD-C10 significantly improved the learning and memory abilities of APP/PS1 double transgenic mice, accompanied by reduced Aβ_1-42 deposition, Tau protein phosphorylation and BACE expression in the hippocampus. The intervention of FSD-C10 decreased the protein levels of TLR-4 and p-NF-κB, reduced the expression of iNOS and increased the expression of Arg-1 in the brain tissues. CONCLUSION: The novel Rho kinase inhibitor FSD-C10 improves the capacity of spatial learning and memory in APP/PS1 double transgenic mice, which may be related to the inhibition of TLRs/NF-κB signaling pathway, the reduction of the secretion of inflammatory molecules and the polarization of anti-inflammatory M2 microglia, thus improving the inflammatory microenvironment of the brain in APP/PS1 double transgenic mice.     

Effect of curcuma aromatica oil on learning,memory and hippocampal p-CaMKII expression in rats exposed to chronic hypoxia

AIM: To investigate the effects of different concentrations of curcuma aromatica oil on learning and memory in rats exposed to chronic hypoxia. METHODS: The rats were divided randomly into the control, chronic hypoxia and chronic hypoxia with low (LC), middle (MC) and high (HC) concentrations of curcuma aromatica oil groups. After 29 d, all animals were examined to obtain the scores of leaning and memory. The SOD activity and MDA content were determined in the serum and hippocampus, the ［Ca2+］_i in hippocampus was also detected. The staining and expression of p-calcium/calmodulin-dependent protein kinase II (p-CaMKII) in the hippocampus was observed and measured. RESULTS: ① In the chronic hypoxia group, the latency to find the hidden platform remarkably prolonged and the MDA content was obviously higher, but the SOD activity was significantly lower. Meanwhile, hippocampal ［Ca2+］_i was markedly increased. The immunostaining of p-CaMKII was much weaker in hippocampus as well as its expressions (P<0.01). ② The latency to find the hidden platform was remarkably shorter in groups with MC and HC (P<0.05). The MDA content was obviously lower among groups treated with curcuma aromatica, but SOD activity was significantly higher in groups with MC and HC. Meanwhile, hippocampal ［Ca2+］_i was markedly decreased in all groups treated with curcuma aromatica oil (P<0.01). The hippocampal immunostaining of p-CaMKII was much stronger in the MC and HC as well as its expression (P<0.05，P<0.01). Under the electron microscope, synaptic boundaries were not distinct, the edema of dendrite spine and axon was seen, synaptic vesicles and postsynaptic densities (PSD) were disappeared in the chronic hypoxia group. With rising of the concentration of curcuma aromatica oil, the edema of synapse and mitochondria was mitigated and the PSD was increased gradually. CONCLUSION: Curcuma aromatica oil might enhance learning and memory capacities of rats exposed to chronic hypoxia by cleaning up and antagonizing the production of the free radical and increasing the p-CaMKII expression in PSD. The effects are dose-dependent.     

Molecular mechanism of BMSC intracerebral transplantation in improving learning and memory abilities of AD mice

AIM: To investigate the effect of bone marrow mesenchymal stem cell (BMSC) transplantation on learning and memory abilities and pathological changes of Alzheimer disease (AD) mice and the molecular mechanisms. METHODS: C57/BL6 wild-type (WT) and transgenic (Tg) mice were randomly divided into 4 groups:WT/PBS group, WT/BMSCs group, Tg/PBS group and Tg/BMSCs group. The mice were administered with PBS or BMSCs via intracerebroventricular injection. Spatial learning and memory abilities of the mice were evaluated by Morris water maze test on the 3rd day after surgery. Real-time PCR was applied to detect the mRNA expression of CX3C chemokine ligand 1 (CX3CL1), CX3C chemokine receptor 1 (CX3CR1), IL-1β, TNF-α, Nurr1, YM1, insulin-degrading enzyme (IDE) and matrix metalloproteinase 9 (MMP9). The protein levels of CX3CL1 and Aβ42 were measured by ELISA. Western blot was used to detect the protein expression of postsynaptic density protein 95 (PSD95) and synaptophysin (SYP). RESULTS: The transplanted BMSCs were observed near the hippocampus of APP/PS1 mice on the 10th postoperative day. The escape latency of the mice in Tg/PBS group was significantly longer than that in the WT/PBS mice (P<0.05). Compared with Tg/PBS group, the escape latency of Tg/BMSCs group was significantly shorter (P<0.05), and the mRNA and protein levels of CX3CL1 in Tg/BMSCs group were significantly higher than those in Tg/PBS group (P<0.01). The results of immunohistofluorescence staining showed that BMSC transplantation promoted the activation of microglia in the brain of WT and Tg mice. The mRNA expression of YM1 was up-regulated in WT/BMSCs group and Tg/BMSCs group (P<0.05). Compared with WT/PBS mice, the mRNA expression of TNF-α in the cortex and hippocampus of Tg/PBS group was significantly increased (P<0.05), and the mRNA expression of Nurr1 in the cortex was significantly decreased (P<0.01). Meanwhile, the mRNA expression of TNF-α in the cortex of Tg/BMSCs mice was decreased (P<0.01) and the mRNA expression of CX3CR1 and Nurr1 was up-regulated compared with Tg/PBS group (P<0.05). The results of Western blot showed that the protein levels of PSD95, p85, p110 and p-Akt in Tg/BMSCs group were significantly higher than those in Tg/PBS group (P<0.05). Finally, BMSC transplantation reduced the protein level of Aβ42 in APP/PS1 mice (P<0.05), and increased the mRNA expression of IDE and MMP9 in the hippocampus (P<0.05). CONCLUSION: BMSC transplantation modulates neuroinflammatory responses and promotes neuroprotective factor and synaptic protein expression, thus improving the learning and memory abilities in the APP/PS1 mice, which may be achieved by up-regulating the expression of CX3CL1.     

Hyperbaric oxygen therapy ameliorates Aβ-related pathological changes and cognitive function of APP/PS1 transgenic mice by reduction of BACE1

AIM:To explore the neuroprotective effects of hyperbaric oxygen (HBO) therapy on the brain of APP/PS1 transgenic (TG) mice. METHODS:Four-month-old APP/PS1 transgenic mice and the wild-type (WT) littermates were randomly divided into 3 groups:TG+HBO, TG, and WT. All mice were administrated with HBO or control treatment for 6 cycles. The animals were subjected to Morris water maze. The mice were killed and the brains were collec-ted for coronal section and other biochemical analysis. The brain sections were subjected to immunofluorescence staining for observing the amyloid plaques. The levels of Aβ40 and Aβ42 were measured by ELISA. The protein levels of Sirt1, BACE1, APP, α/β-CTF and synaptophysin were determined by Western blot. RESULTS:In TG+HBO group, HBO treatment reduced Aβ generation and plaque formation in the brains as compared with TG group (P<0.01). HBO treatment also increased the protein level of Sirt1, but reduced the protein level of BACE1 and the cleavage of APP by BACE1 (P<0.01). HBO treatment attenuated the loss of spines and synapses, thus rescuing the learning and memory deficits in APP/PS1 mice. CONCLUSION:HBO treatment rescues cognitive deficits of APP/PS1 transgenic mice by increasing the level of Sirt1 and reducing the level of BACE1 protein, thus reducing the generation of Aβ and its neurotoxicity in APP/PS1 transgenic mice.     

Establishment of a mouse model of sepsis associated encephalopathy and preliminary research of cognitive dysfunction in this model

AIM: To establish the mouse model of sepsis-associated encephalopathy (SAE) and the preliminary research of cognitive dysfunction in this model. METHODS: SPF male C57BL/6J mice of 8~10 weeks old were selected. The first part of the experiment divided the mice into 4 groups randomly, namely control group, cecal ligation and puncture (CLP)1 group and CLP2 group (CLP was performed with 7 and 12 syringe needle respectively). The mice in sham operation group were only laparotomy. In the second part of the experiment, the mice were randomly divided into control group, sham operation group and CLP group. The Kaplan-Meier method was used to analyze the postoperative survival rate of the mice in the first part experiment. The neurobehavioral scores were used to evaluate the neurobehavioral changes of the mice. The Morris water maze test and the passive avoidance experiment were used to detect the changes of cognitive memory function in the mice. The pole test and the wire suspension test were used to test the motor coordination of the mice. The serum levels of prostaglandin E2 (PGE₂) were measured by ELISA. RESULTS: In the first part of the experiment, the CLP mice showed obvious symptoms such as lethargy, piloerection, chills and anorexia. The 48 h mortality in CLP1 group and CLP2 group were 20% and 30% respectively. In the 2 parts of the experiments, the neurobehavioral scores of the CLP mice were significantly lower than those in control group and the sham operation group (P<0.01). In CLP mice, the escape latency time of the Morris water maze was significantly prolonged (P<0.01), the target quadrant dwell time and the number of crossing platforms were decreased (P<0.01), the scores in the suspension experiment and the pole test were significantly reduced (P<0.01), the activity of the mice was decreased or even did not enter the darkroom in the step-through test (P<0.05). In the second part of the experiment, the serum level of PGE₂ in the mice after CLP was significantly increased (P<0.01). CONCLUSION: A stable mouse model of sepsis-associated encephalopathy is successfully established by cecal ligation and puncture with 12 syringe needle. The SAE mouse model established by this method is useful for investigating the learning and memory cognitive dysfunction.     

Chrysophanol ameliorates spatial memory ability of rats by inhibiting Aβ1-42-induced oxidative stress

AIM: To investigate whether chrysophanol alleviates amyloid β-protein (Aβ)-induced cognitive dysfunction and the underlying antioxidative mechanism.METHODS:Adult male Wistar rats (230~250 g) were randomly divided into control group, Aβ_1-42 group, chrysophanol group, and Aβ_1-42+chrysophanol (1, 10 and 100 mg/kg) groups. Aβ_1-42 was delivered by intracerebroventricular injection under the guidence of a brain stereotaxic apparatus. Y-maze test, open-field test and Morris water maze test were performed 1 week after Aβ_1-42 injection to evaluate the ability of rat spacial learning and memory. Chrysophanol was intraperitoneally injected once daily for 5 consecutive days. After the behavioral tests, the animals were sacrificed immediately by decapitation, and the hippocampus were collected. The malondialdehyde (MDA) content and the activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) in the hippocampus were measured.RESULTS:Multiple (7 consecutive days, once daily) but not single (once a day) chrysophanol treatment at 1, 10 and 100 mg/kg effectively prevented Aβ_1-42-induced cognitive function deficits in a dose-dependent manner as shown by Y-maze test and Morris water maze test. Moreover, the Aβ_1-42-induced increase in MDA content and decrease in the activity of antioxidant enzymes (SOD, GSH-Px and CAT) in the hippocampus of the rats were also attenuated by multiple chrysophanol treatment.CONCLUSION:Repeated chrysophanol treatment attenuates Aβ_1-42-induced cognitive deficits and synaptic plasticity dysfunction, and the mechanisms underlying the neuroprotective effects are likely due to its antioxidant activity.     

Effects of N-acetylcysteine combined with azithromycin on oxidative stress in rats with chronic obstructive pulmonary disease

AIM: To investigate the effects of N-acetylcysteine (NAC) combined with azithromycin (AZI) on oxidative stress in the rats with chronic obstructive pulmonary disease (COPD). METHODS: Male Wistar rats (n=60) were randomly divided into control group, model group, AZI intervention group,NAC intervention group and AZI+NAC group. The COPD model was established by passive smoking and intratracheal instillation of lipopolysaccharide. Each day 30 min prior to smoking, intragastric administration with AZI, NAC or combination of the 2 drugs was given for AZI, NAC, and AZI+NAC groups, respectively. On the 31st day, all rats were killed following lung function test. Cell counts of bronchoalveolar lavage fluid (BALF) were performed, and the contents of interleukin-8 (IL-8), interleukin-17 (IL-17) and tumor necrosis factor alpha (TNF-α) in BALF were measured by ELISA. The histopathology of the lung tissues was observed under light microscope, and the levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) in the lung homogenate were measured. RESULTS: Compared with control group, the other 4 groups showed decreased pulmonary function, and inflammatory cell infiltration and alveolar destruction in histopathology. Compared with control group, the other groups showed higher white blood cells, monocyte-macrophages, neutrophils and lymphocytes in the BALF (P<0.05). Compared with model group, AZI group and NAC group, lower white blood cells, neutrophils and lymphocytes in the BALF were observed in AZI+NAC group (P<0.05). Compared with model group, IL-8, IL-17, TNF-α and MDA in AZI group, NAC group and AZI+NAC group significantly decreased (P<0.05), while SOD and GSH-Px significantly increased (P<0.05). Compared with AZI or NAC group, IL-8, IL-17, TNF-α and MDA in AZI+NAC group significantly decreased (P<0.05), while SOD and GSH-Px increased significantly (P<0.05). CONCLUSION: Both NAC and AZI attenuate the lung inflammation and oxidative damage in COPD model rats. Combined medication exerts preferable anti-oxidation effects, which might be more suitable for the treatment of COPD.     

Antagonistic effect of bilirulin on acute lung injury induced by LPS in rats

AIM: To investigate the effect of bilirubin on acute lung injury (ALI) and the mechanism. METHODS: 30 male Wistar rats were divided into normal group, ALI group and bilirubin treatment group. Lung specimens were examined by histopathological technique. Lung index (LI) and lung permeability index (LPI) were measured. Moreover, white blood cell (WBC) count, neutrophil percentage (PMN%) and the content of protein (Pr) in the bronchoalveolar lavage fluid (BALF), as well as the contents of superoxide dismutase (SOD), malonaldehyde (MDA) and glutathione peroxidase (GSH-Px) in the lung homogenate were determined. RESULTS: (1) In ALI group: LI, WBC count, PMN%, Pr and LPI increased significantly compared with normal group (P<0.01). In bilirubin treatment group, all the values determined decreased compared with ALI group (P<0.01; P<0.05). No notable discrepancy between bilirubin treatment group and normal group (P>0.05) was observed. (2) In ALI group, the content of MDA was significantly higher (P<0.01), but the contents of SOD and GSH-Px were significantly lower than those in normal group (P<0.01). In bilirubin treatment group, the content of MDA decreased significantly (P<0.01) but the contents of SOD and GSH-Px increased significantly (P<0.01; P<0.05) compared with ALI group. No notable discrepancy between bilirubin treatment group and normal group was observed (P>0.05). CONCLUSION: Bilirubin relieves ALI induced by LPS in rats via antioxidation.     

Apoptosis in mouse pancreatic β cells exposed to intermittent hypoxia

AIM: To investigate the effect of intermittent hypoxia on the apoptosis of mouse pancreatic β cells and its possible mechanism. METHODS: Thirty healthy male C57BL/6J mice were randomly divided into 3 groups: control group, sustained hypoxia (SH)group and intermittent hypoxia (IH)group. Insulin tolerance test was performed immediately after experiment. The level of malondialdehyde (MDA) and superoxide dismutase (SOD) were detected by chemical colorimetry. Real-time PCR was used to measure the mRNA expression of manganese superoxide dismutase(MnSOD) and glutathione peroxidase(GPx1). The apoptosis of pancreatic β cells was determined by the method of TUNEL. RESULTS: The levels of insulin resistance and content of MDA in the pancreatic tissue in IH group were significantly higher than those in control group and SH group (P<0.01). The activity of SOD and the mRNA expression of MnSOD and GPx1 in IH group were significantly lower than those in control group and SH group (P<0.01). The apoptotic rate of IH group was significantly elevated as compared with control group and SH group (P<0.01). No significant difference of all above indexes between control group and SH groups was observed (all P>0.05). CONCLUSION: Apoptosis of pancreatic β cells induced by oxidative stress associated with IH in the pancreatic tissue may be involved in the pathogenesis of obstructive sleep apnea hyponea syndrome with insulin resistance and type 2 diabetes.     

Effects of rolipram on learning and memory and the activity of PDE4 in hippocampus following the focal brain injury induced by ischemia- reperfusion in rats

AIM: To investigate the effects of rolipram on the ability of learning and memory and the activity of PDE4 in hippocampus following the focal brain injury induced by ischemia- reperfusion in rats. METHODS: The cerebral ischemia-reperfusion injury model was made by middle cerebral artery occlusion (MCAO) in rats. The rats were randomly divided into sham-operated group, model group, and rolipram group. Rolipram was administered once a day (1 mg/kg, ip) from 6 h after the onset of the operation for 2 weeks. Then the learning and memory abilities were tested after Morris water maze and step-though training. The activity of PDE4 in hippocampus was evaluated by HPLC. RESULTS: In the Morris water maze test, compared to sham-operated group, the platform-finding time and swimming distance in model group were significantly longer (P<0.05). Compared to model group, the platform-finding time and swimming distance in rolipram group were significantly shorter (P<0.05). In the step-through test, compared to sham-operated group, the lantent period in model group was significantly shorter (P<0.01) and the error times were statistically increased(P<0.05). Compared with model group, the lantent period in rolipram group were significantly longer (P<0.05), and the error times were markedly decreased. The assay of the HPLC demonstrated that the activities of PDE4 in hippocampus in model group were higher than those in the sham-operated group and rolipram group. CONCLUSION: Rolipram reduces the activity of PDE4 in hippocampus and enhances the ability of learning and memory after the injury induced by ischemia-reperfusion.     

Changes of ceramide and apoptosis during myocardial ischemia/reperfusion

AIM: To study the change of myocardial ceramide during myocardial ischemia/reperfusion and the relationship between ceramide and apoptosis and oxidative stress. METHODS: After inducing myocardial ischemia/reperfusion (I/R) injury in mice with pituitrin (Pit), myocardial SOD activity and MDA content were measured. DNA agarose gel electrophoresis and fluorescent staining of DAPI were done to check up apoptosis. The content of myocardial ceramide (μg/kg) was measured through HPTLC and scan of thin plate. RESULTS: The myocardium of I/R model group had the phenomenon of DNA ladder. Apoptosis index and ceramide content in I/R model group were higher than those in normal control group (P<0.01). SOD activity in I/R modal group was lower than that in normal control group (P<0.01). The apoptosis index and ceramide content in I/R model group were positive correlative (r=0.970，P<0.01). The myocardial content of ceramide and MDA were positively correlative too (r=0.974, P<0.01). CONCLUSION: The results indicate that there are apoptosis, oxidative stress and increase in ceramide content in ischemia/reperfusion myocardium.     

Effect of tongxinluo capsule on endothelial function in stable angina pectoris patients

AIM:To investigate clinical effect of tongxinluo capsule in treating stable angina pectoris patients,and its influence on endothelial function,superoxide dismutase (SOD) and malondialdehyde (MDA).METHODS:One hundred and twenty-four stable angina pectoris patients were divided into three groups,isosorbide treatment group (41 cases),tongxinluo capsule treatment group (40 cases),tongxinluo and isosorbide treatment group (combined treatment group,43 cases).The serum concentrations of nitric oxide (NO),endothelin-1 (ET-1),SOD and MDA were determined before and after treatment.The data in traetment groups were compared with that in normal control.RESULTS:The symptoms of 3 groups were significantly improved,and the total effective rate of tongxinluo capsule group and combined treatment groups were better than that in isororbide treatment group (85.00% and 88.37% vs 73.17%,P<0.05).Before treatment,the levels of serum NO and activity of SOD in angina patients were lower than that in control group.The serum MDA and ET-1 levels were higher than those in control.The levels of serum NO and SOD activity were increased remarkably after tongxinluo capsule or tongxinluo combined treatment.However,besides the concentration of NO increased after isosorbide treatment,the levels of serum ET-1 and MDA and SOD activity were not changed.CONCLUSIONS:The results suggest that tongxinluo capsule could effectively improve the symptoms of stable angina pectoris,and it is important for tongxinluo capsule to increase NO level and decrease ET-1 product,scavenge free radical and prevent lipid peroxidation.