Neuroprotection of Chrysanthemum indicum Linne against cerebral ischemia/reperfusion injury by anti-inflammatory effect in gerbils

In this study, we tried to verify the neuroprotective effect of Chrysanthemum indicum Linne（CIL） extract, which has been used as a botanical drug in East Asia, against ischemic damage and to explore the underlying mechanism involving the anti-inflammatory approach. A gerbil was given CIL extract for 7 consecutive days followed by bilateral carotid artery occlusion to make a cerebral ischemia/reperfusion model. Then, we found that CIL extracts protected pyramidal neurons in the hippocampal CA1 region（CA1） from ischemic damage using neuronal nucleus immunohistochemistry and Fluoro-Jade B histofluorescence. Accordingly, interleukin-13 immunoreactivities in the CA1 pyramidal neurons of CIL-pretreated animals were maintained or increased after cerebral ischemia/reperfusion. These findings indicate that the pre-treatment of CIL can attenuate neuronal damage/death in the brain after cerebral ischemia/reperfusion via an anti-inflammatory approach.

Pretreated quercetin protects gerbil hippocampal CA1 pyramidal neurons from transient cerebral ischemic injury by increasing the expression of antioxidant enzymes

Quercetin（QE; 3,5,7,3′,4′-pentahydroxyflavone）, a well-known flavonoid, has been shown to prevent against neurodegenerative disorders and ischemic insults. However, few studies are reported regarding the neuroprotective mechanisms of QE after ischemic insults. Therefore, in this study, we investigated the effects of QE on ischemic injury and the expression of antioxidant enzymes in the hippocampal CA1 region of gerbils subjected to 5 minutes of transient cerebral ischemia. QE was pre-treated once daily for 15 days before ischemia. Pretreatment with QE protected hippocampal CA1 pyramidal neurons from ischemic injury, which was confirmed by neuronal nuclear antigen immunohistochemistry and Fluoro-Jade B histofluorescence staining. In addition, pretreatment with QE significantly increased the expression levels of endogenous antioxidant enzymes Cu/Zn superoxide dismutase, Mn superoxide dismutase, catalase and glutathione peroxidase in the hippocampal CA1 pyramidal neurons of animals with ischemic injury. These findings demonstrate that pretreated QE displayed strong neuroprotective effects against transient cerebral ischemia by increasing the expression of antioxidant enzymes.

Neuronal injury and tumor necrosis factor-alpha immunoreactivity in the rat hippocampus in the early period of asphyxia-induced cardiac arrest under normothermia

Low survival rate occurs in patients who initially experience a spontaneous return of circulation after cardiac arrest（CA）. In this study, we induced asphyxial CA in adult male Sprague-Daley rats, maintained their body temperature at 37 ± 0.5°C, and then observed the survival rate during the post-resuscitation phase. We examined neuronal damage in the hippocampus using cresyl violet（CV） and Fluore-Jade B（F-J B） staining, and pro-inflammatory response using ionized calcium-binding adapter molecule 1（Iba-1）, glial fibrillary acidic protein（GFAP）, and tumor necrosis factor-alpha（TNF-α） immunohistochemistry in the hippocampus after asphyxial CA in rats under normothermia. Our results show that the survival rate decreased gradually post-CA（about 63% at 6 hours, 37% at 1 day, and 8% at 2 days post-CA）. Rats were sacrificed at these points in time post-CA, and no neuronal damage was found in the hippocampus until 1 day post-CA. However, some neurons in the stratum pyramidale of the CA region in the hippocampus were dead 2 days post-CA. Iba-1 immunoreactive microglia in the CA1 region did not change until 1 day postCA, and they were activated（enlarged cell bodies with short and thicken processes） in all layers 2 days postCA. Meanwhile, GFAP-immunoreactive astrocytes did not change significantly until 2 days post-CA. TNF-α immunoreactivity decreased significantly in neurons of the stratum pyramidale in the CA1 region 6 hours post-CA, decreased gradually until 1 day post-CA, and increased significantly again 2 days post-CA. These findings suggest that low survival rate of normothermic rats in the early period of asphyxia-induced CA is related to increased TNF-α immunoreactivity, but not to neuronal damage in the hippocampal CA1 region.

Neuroprotection via maintenance or increase of antioxidants and neurotrophic factors in ischemic gerbil hippocampus treated with tanshinone I

Background Danshen （Radix Salvia miltiorrhizae） has been used as a traditional medicine in Asia for treatment of various microcirculatory disturbance related diseases. Tanshinones are mainly hydrophobic active components, which have been isolated from Danshen and show various biological functions. In this study, we observed the neuroprotective effect of tanshinone I （Tsl） against ischemic damage in the gerbil hippocampal CA1 region （CA1） after transient cerebral ischemia and examined its neuroprotective mechanism. Methods The gerbils were divided into vehicle-treated-sham-group, vehicle-treated-ischemia-group, Tsl-treated-sham- group, and Tsl-treated-ischemia-group. Tsl was administrated intraperitoneally three times （once a day for three days） before ischemia-reperfusion. The neuroprotective affect of Tsl was examined using H＆E staining, neuronal nuclei （NeuN） immunohistochemistry and Fluoro-Jade B staining. To investigate the neuroprotective mechanism of Tsl after ischemia- reperfusion, immunohistochemical （IHC） and Western blotting analyses for Cu, Zn-superoxide dismutase （SOD1）, Mn- superoxide dismutase （SOD2）, brain-derived neurotrophic factor （BDNF） and insulin-like growth factor-I （IGF-I） were performed.Results Treatment with Tsl protected pyramidal neurons from ischemia-induced neuronal death in the CA1 after ischemia-reperfusion. In addition, treatment with Tsl maintained the levels of SOD1 and SOD2 as determined by IHC and Western blotting in the CA1 after ischemia- reperfusion compared with the vehicle-ischemia-group. In addition, treatment with Tsl increased the levels of BDNF and IGF-I determined by IHC and Westem blotting in the Tsl-treated-sham-group compared with the vehicle-treated- sham-group, and their levels were maintained in the stratum pyramidale of the ischemic CA1 in the Tsl-treated- ischemia-group. Conclusion Treatment with Tsl protects pyramidal neurons of the CA1 from ischemic damage induced by transient cerebral ischemia via the maintenance of antioxidants and the increase of neurotrophic factors.

Effect of Oenanthe Javanica Extract on Antioxidant Enzyme in the Rat Liver

Background：Oenanthe javanica （O.javanica） has been known to have high antioxidant properties via scavenging reactive oxygen species.We examined the effect of O.javanica extract （OJE） on antioxidant enzymes in the rat liver.Methods：We examined the effect of the OJE on copper,zinc-superoxide dismutase （SOD1）,manganese superoxide dismutase （SOD2）,catalase （CAT）,and glutathione peroxidase （GPx） in the rat liver using immunohistochemistry and western blot analysis.Sprague-Dawley rats were randomly assigned to three groups;（1） normal diet fed group （normal-group）,（2） diet containing ascorbic acid （AA）-fed group （AA-group） as a positive control,（3） diet containing OJE-fed group （OJE-group）.Results：In this study,no histopathological finding in the rat liver was found in all the experimental groups.Numbers of SOD1,SOD2,CAT,and GPx immunoreactive cells and their protein levels were significantly increased in the AA-fed group compared with those in the normal-group.On the other hand,in the OJE-group,numbers of SOD1,SOD2,CAT,and GPx immunoreactive cells in the liver were significantly increased by about 190%,478%,685%,and 346%,respectively,compared with those in the AA-group.In addition,protein levels of SOD 1,SOD2,CAT,and GPx in the OJE-group were also significantly much higher than those in the AA-group.Conclusion：OJE significantly increased expressions of SOD 1 and SOD2,CAT,and GPx in the liver cells of the rat,and these suggests that significant enhancements of endogenous enzymatic antioxidants by OJE might be a legitimate strategy for decreasing oxidative stresses in the liver.

Oenanthe javanica extract increases immunoreactivities of antioxidant enzymes in the rat kidney

Background Oenanthe javanica is an aquatic perennial herb originated from East Asia.Nowadays,the effects of Oenanthe javanica have been proven in various disease models.Studies regarding the antioxidant effect of Oenanthe javanica in the kidney are still unclear.Methods This study was therefore performed to investigate the effect of the Oenanthe javanica extract （OJE） in the rat kidney using immunohistochemistry for antioxidant enzymes,copper,zinc-superoxide dismutase （SOD1）,manganese superoxide dismutase （SOD2）,catalase （CAT） and glutathione peroxidase （GPx）.Sprague-Dawley rats were randomly assigned to three groups：（1） normal diet fed-group （normal-group）,（2） diet containing ascorbic acid （AA）-fed group （AA-group） as a positive control,（3） diet containing OJE-fed group （OJE-group）.AA and OJE were supplied during 28 days.Results The side-effects were not observed in all the groups.Immunoreactivities of SOD1,SOD2,CAT and GPx were easily detected in the distal tubules of the kidney,and their immunoreactivities in the AA-and OJE-groups were increased to about 1.4-1.5 times and 2 times,respectively,compared with those in the normal-group.Conclusion OJE significantly increased expressions of SOD1 ＆ 2,CAT and GPx immunoreactivities in the distal tubules of the rat kidney,and this finding suggests that significant enhancements of endogenous enzymatic antioxidants by OJE treatment may be a legitimate strategy for decreasing oxidative stresses in the kidney.

Oenanthe Javanica Extract Protects Against Experimentally Induced Ischemic Neuronal Damage via its Antioxidant Effects

Background： Water dropwort （Oenanthejavanica） as a popular traditional medicine in Asia shows various biological properties including antioxidant activity. In this study, we firstly examined the neuroprotective effect of Oenanthejavanica extract （OJE） in the hippocampal comus ammonis 1 region （CA 1 region） of the gerbil subjected to transient cerebral ischemia. Methods： Gerbils were established by the occlusion of common carotid arteries for 5 min. The neuroprotective effect of OJE was estimated by cresyl violet staining. In addition, 4 antioxidants （copper, zinc superoxide dismutase [SOD], manganese SOD, catalase, and glutathione peroxidase） immunoreactivities were investigated by immunohistochemistry. Results： Pyramidal neurons in the CA1 region showed neuronal death at 5 days postischemia; at this point in time, all antioxidants immunoreactivities disappeared in CA1 pyramidal neurons and showed 100 mg/kg, OJE protected CA 1 pyramidal neurons from ischemic damage in many nonpyramidal cells. Treatment with 200 mg/kg, not In addition, 200 mg/kg OJE treatment increased or maintained antioxidants immunoreactivities. Especially, among the antioxidants, glutathione peroxidase immunoreactivity was effectively increased in the CA 1 pyramidal neurons of the OJE-treated sham-operated and ischemia-operated groups. Conclusion： Our present results indicate that treatment with OJE can protect neurons from transient ischemic damage and that the neuroprotective effect may be closely associated with increased or maintained intracellular antioxidant enzymes by OJE.