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.

Effect of hyperthermia on calbindin-D 28k immunoreactivity in the hippocampal formation following transient global cerebral ischemia in gerbils

Calbindin D-28K （CB）, a Ca2＋-binding protein, maintains Ca2＋ homeostasis and protects neurons against various insults. Hyperthermia can exacerbate brain damage produced by ischemic insults. However, little is reported about the role of CB in the brain under hyperthermic condition during ischemic insults. We inves- tigated the effects of transient global cerebral ischemia on CB immunoreactivity as well as neuronal damage in the hippocampal formation under hyperthermic condition using immunohistochemistry for neuronal nuclei （NeuN） and CB, and Fluoro-Jade B histofluorescence staining in gerbils. Hyperthermia （39.5 ＋ 0.2~C） was induced for 30 minutes before and during transient ischemia. Hyperthermic ischemia resulted in neu- ronal damage/death in the pyramidal layer of CA1-3 area and in the polymorphic layer of the dentate gyrus at 1, 2, 5 days after ischemia. In addition, hyperthermic ischemia significantly decreaced CB immunoreac- tivity in damaged or dying neurons at 1, 2, 5 days after ischemia. In brief, hyperthermic condition produced more extensive and severer neuronal damage/death, and reduced CB immunoreactivity in the hippocampus following transient global cerebral ischemia. Present findings indicate that the degree of reduced CB immu- noreactivity might be related with various neuronal damage/death overtime and corresponding areas after ischemic insults.

Activation of immediate-early response gene c-Fos protein in the rat paralimbic cortices after myocardial infarction

c-Fos is a good biological marker for detecting the pathogenesis of central nervous system disorders. Few studies are reported on the change in myocardial infarction-induced c-Fos expression in the paralimbic regions. Thus, in this study, we investigated the changes in c-Fos expression in the rat cingulate and piriform cortices after myocardial infarction. Neuronal degeneration in cingulate and piriform cortices after myocardial infarction was detected using cresyl violet staining, Neu N immunohistochemistry and Fluoro-Jade B histofluorescence staining. c-Fos-immunoreactive cells were observed in cingulate and piriform cortices at 3 days after myocardial infarction and peaked at 7 and 14 days after myocardial infarction. But they were hardly observed at 56 days after myocardial infarction. The chronological change of c-Fos expression determined by western blot analysis was basically the same as that of c-Fos immunoreactivity. These results indicate that myocardial infarction can cause the chronological change of immediate-early response gene c-Fos protein expression, which might be associated with the neural activity induced by myocardial infarction.

Long-term administration of scopolamine interferes with nerve cell proliferation, differentiation and migration in adult mouse hippocampal dentate gyrus, but it does not induce cell death

Long-term administration of scopolamine, a muscarinic receptor antagonist, can inhibit the survival of newly generated cells, but its effect on the proliferation, differentiation and migration of nerve cells in the adult mouse hippocampal dentate gyrus remain poorly understood. In this study, we used immunohistochemistry and western blot methods to weekly detect the biological behaviors of nerve cells in the hippocampal dentate gyrus of adult mice that received intraperito- neal administration of scopolamine for 4 weeks. Expression of neuronal nuclear antigen （NeuN; a neuronal marker） and Fluoro-]ade B （a marker for the localization of neuronal degeneration） was also detected. After scopolamine treatment, mouse hippocampal neurons did not die, and Ki-67 （a marker for proliferating cells）-immunoreactive cells were reduced in number and reac hed the lowest level at 4 weeks. Doublecortin （DCX; a marker for newly generated neurons）-im- munoreactive cells were gradually shortened in length and reduced in number with time. After scopolamine treatment for 4 weeks, nearly all of the 5-bromo-2＇-deoxyuridine （BrdU）-labeled newly generated cells were located in the subgranular zone of the dentate gyrus, but they did not migrate into the granule cell layer. Few mature BrdU/NeuN double-labeled cells were seen in the subgranular zone of the dentate gyrus. These findings suggest that long-term administration of scopolamine interferes with the proliferation, differentiation and migration of nerve cells in the adult mouse hippocampal dentate gyrus, but it does not induce cell death.

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.

Hippophae rhamnoides L.leaves extract enhances cell proliferation and neuroblast differentiation through upregulation of intrinsic factors in the dentate gyrus of the aged gerbil

Background Hippophae rhamnoides L.（HL） exerts antioxidant activities against various oxidative stress conditions.In this study,we investigated effects of extract from HL leaves （HLE） on cell proliferation and neuroblast differentiation in the subgranular zone （SGZ） of the dentate gyrus （DG） of aged gerbils.Methods Aged gerbils （24 months） were divided into vehicle （saline）-treated-and HLE-treated-groups.The vehicle and HLE were orally administered with 200 mg/kg once a day for 20 days before sacrifice.Cell proliferation and neurobiast differentiation were examined in the DG using Ki67 and doublecortin （DCX）,respectively.We also observed changes in immunoreactivities of superoxide dismutase 1 （SOD1） and superoxide dismutase 2 （SOD2）,brain-derived neurotrophic factor （BDNF）,and phospho-glycogen synthase kinase-3-beta （p-GSK-3β） to examine their relation with neurogenesis using immunohistochemistry.Results The administration of HLE significantly increased the number of Ki67-positive cells and DCX-positive neuroblasts with well-developed processes in the SGZ of the DG of the HLE-treated-group.In addition,immunoreactivities of SOD1,SOD2,BDNF,and p-GSK-3β were significantly increased in granule and polymorphic cells of the DG in the HLE-treated-group compared with those in the vehicle-treated-group.Conclusions HLE treatment significantly increased cell proliferation and neuroblast differentiation,showing that immunoreactivities of SOD1,SOD2,BDNF,and p-GSK-3β were significantly increased in the DG.These indicate that increased neuroblast differentiation neurogenesis may be closely related to upregulation of SOD1,SOD2,BDNF,and p-GSK-3β in aged gerbils.