ABSTRACT
Objective: To investigate the protective effects of icaritin (ICT), one of the active ingredients in Epimedii Folium, on mouse model of cerebral ischemia-reperfusion (I/R) in vivo. Methods: ICR mice were subjected to an 1 h transient middle cerebral artery occlusion (MCAO) and followed by 24 h of reperfusion. Neurological deficits, infarct volume, brain edema and survive rate were measured, respectively. The levels of brain IL-1β TNF-α ROS and DNA-binding activity of NF-κB p65 were measured by ELISA kits. The levels of malondialdehyde (MDA) and activities of superoxide dismutase (SOD) were detected by spectrophotometry, and the release of nitric oxide (NO) were detected by Griess kit. Results: ICT markedly reduced the neurological deficit scores, brain edema, infarct volume and increased the survival rate of the cerebral I/R mice. The expression of IL-1β TNF-α NO, MDA and DNA-binding activity of NF-κB p65 were significantly inhibited by ICT, while the activity of SOD were up-regulated at the same time. Conclusion: ICT possessed significant neuroprotective effects in cerebral I/R mice, which might be related to prevent neuroinflammatory and oxidative damage.
ABSTRACT
Sublethal ischemic preconditioning (IPC) is a powerful inducer of ischemic brain tolerance. However, its underlying mechanisms are still not well understood. In this study, we chose four different IPC paradigms, namely 5 min (5 min duration), 5×5 min (5 min duration, 2 episodes, 15-min interval), 5×5×5 min (5 min duration, 3 episodes, 15-min intervals), and 15 min (15 min duration), and demonstrated that three episodes of 5 min IPC activated autophagy to the greatest extent 24 h after IPC, as evidenced by Beclin expression and LC3-I/II conversion. Autophagic activation was mediated by the tuberous sclerosis type 1 (TSC1)-mTor signal pathway as IPC increased TSC1 but decreased mTor phosphorylation. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and hematoxylin and eosin staining confirmed that IPC protected against cerebral ischemic/reperfusion (I/R) injury. Critically, 3-methyladenine, an inhibitor of autophagy, abolished the neuroprotection of IPC and, by contrast, rapamycin, an autophagy inducer, potentiated it. Cleaved caspase-3 expression, neurological scores, and infarct volume in different groups further confirmed the protection of IPC against I/R injury. Taken together, our data indicate that autophagy activation might underlie the protection of IPC against ischemic injury by inhibiting apoptosis.
Subject(s)
Animals , Male , Rats , Apoptosis/physiology , Autophagy/physiology , Brain Ischemia/physiopathology , Ischemic Preconditioning/methods , Nerve Degeneration/prevention & control , Reperfusion Injury/metabolism , Adenine/analogs & derivatives , Adenine/pharmacology , Brain Ischemia/prevention & control , /metabolism , Cerebrum/injuries , In Situ Nick-End Labeling , Immunosuppressive Agents/pharmacology , Rats, Sprague-Dawley , Sirolimus/pharmacology , Time Factors , TOR Serine-Threonine Kinases/metabolism , Tumor Suppressor Proteins/metabolismABSTRACT
Objective To observe the influence of electroacupuncure(EA) at different therapeutic time windows on the effects of inosine on neuronal apoptosis and expression of heat-shock-proteins-70 (HSP70)after focal cerebral ischemic reperfusion injury (CIRI) in rats.Methods The model was established by ligation of the artery for 2 hour.EA was delivered to “baihui” and “dazhui” through acupuncture needles 0.5 hr,2 hr,6 hr and 12 hr respectively following MCAO.The expression level of HSP70 and the number of apoptotic cells were examined by immunohistochemical technique and TUNEL,comparing the average optical density of HSP70 and the number of apoptotic positive cells of cortex penumbra and hippocampus CA1 area in rat brain.Results Compared with the model group,the average optical density of HSP70 in every EA group was increased in apoptotic positive cells of cortex penumbra and hippocampus CA1 area 0.5 h (89.98± 6.55),(128.73 ± 8.03),2 h (90.96±6.38),(132.25±8.78),6 h (93.71±6.12),(132.58±7.04),12 (96.19±7.30),(133.57±6.19)and the number of apoptotic positive cells of cortex penumbra in every EA group was decreased 0.5 h (1.80±0.84),2 h (3.40± 1.14),6 h (5.00± 1.00),12 h (5.00±2.45).The number of apoptotic cells of hippocampus CA1 area was decreased just in the EA group of 0.5 h (1.60± 1.89).Conclusion EA could increase the expression level of HSP70 and at the same time decrease the number of apoptotic cells,EA plays an important part in protecting the neuronal cells of brain after focal cerebral ischemic reperfusion injury.The acupuncture treatment should be taken as far as early.
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0.05).The cerebral infarcted area in SHR were significantly greater than that in SD rats [(42.6?5.6)% vs(29.5?6.7)%,P