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Chunchon, South Korea

Park O.K.,Institute of Neurodegeneration and Neuroregeneration | Yoo K.-Y.,Institute of Neurodegeneration and Neuroregeneration | Lee C.H.,Institute of Neurodegeneration and Neuroregeneration | Choi J.H.,Institute of Neurodegeneration and Neuroregeneration | And 5 more authors.
Journal of the Neurological Sciences

Melatonin is synthesized from serotonin by the action of arylalkylamine N-acetyltransferase (AANAT) and hydroxyindole-O-methyltransferase. In this study, we observed cellular changes of arylalkylamine N-acetyltransferase (EC; AANAT) in the hippocampal CA1 region at various time points after ischemia/reperfusion. In vehicle-treated sham group, AANAT immunoreaction was detected in pyramidal neurons of the CA1 region. AANAT immunoreactivity in the neurons was highest 2 days and disappeared from 4 days after ischemia/reperfusion. From 3 days after ischemia/reperfusion, AANAT immunoreaction was expressed in astrocytes in the strata oriens and radiatum of the CA1 region. AANAT protein and mRNA levels were significantly increased 2 days after ischemia/reperfusion, and markedly decreased from 5 days after ischemia/reperfusion. The repeated administration of melatonin (10 mg/kg, i.p.) 3 times (once a day) to gerbils before ischemia/reperfusion significantly reduced ischemia-induced hyperactivity as well as neuronal death compared to those in the vehicle-treated ischemia group. Melatonin treatment also maintained AANAT immunoreactivity and its protein levels in the CA1 region after ischemia/reperfusion. These results suggest that the reduction of AANAT in ischemic CA1 region is associated with delayed neuronal death following transient ischemia, and melatonin treatment shows neuroprotection with maintenance of AANAT levels in the ischemic CA1 region. © 2010 Elsevier B.V. All rights reserved. Source

Kim I.H.,Kangwon National University | Yan B.C.,Kangwon National University | Park J.H.,Kangwon National University | Yeun G.H.,Hanbat National University | And 9 more authors.
Planta Medica

We investigated effects of caffeic acid, syringic acid, and their synthesis on transient cerebral ischemic damage in the gerbil hippocampal CA1 region. In the 10 mg/kg caffeic acid-, syringic acid-, and 20 mg/kg syringic-treated ischemia groups, we did not find any significant neuroprotection in the ischemic hippocampal CA region. In the 20 mg/kg caffeic acid- and 10 mg/kg caffeic acid-syringic acid-treated ischemia groups, moderate neuroprotection was found in the hippocampal CA1 region. In the 20 mg/kg caffeic acid-syringic acid-treated ischemia group, a strong neuroprotective effect was found in the ischemic hippocampal CA1 region: about 89 % of hippocampal CA1 region pyramidal neurons survived. We also observed changes in glial cells (astrocytes and microglia) in the ischemic hippocampal CA1 region in all the groups. Among them, the distribution pattern of the glial cells was only in the 20 mg/kg caffeic acid-syringic acid-treated ischemia group similar to that in the sham group (control). In brief, 20 mg/kg caffeic acid-syringic acid showed a strong neuroprotective effect with an inhibition of glia activation in the hippocampal CA1 region induced by transient cerebral ischemia. © Georg Thieme Verlag KG Stuttgart. New York. Source

Chung B.-H.,Vascular System Research Center | Chung B.-H.,Kangwon National University | Lee J.J.,Korea Research Institute of Bioscience and Biotechnology | Kim J.-D.,Kangwon National University | And 6 more authors.
Biochemical and Biophysical Research Communications

The natural product sesamin has been known to act as a potent antioxidant and prevent endothelial dysfunction. We here found that sesamin increased in vitro angiogenic processes, such as endothelial cell proliferation, migration, and tube formation, as well as neovascularization in an animal model. This compound elicited the activation of multiple angiogenic signal modulators, such as ERK, Akt, endothelial nitric oxide synthase (eNOS), NO production, FAK, and p38 MAPK, but not Src. The MEK inhibitor PD98059 and the PI3K inhibitor Wortmannin specifically inhibited sesamin-induced activation of the ERK and Akt/eNOS pathways. These inhibitors reduced angiogenic events, with high specificity for MEK/ERK-dependent cell proliferation and migration and PI3K/Akt-mediated tube formation. Moreover, inhibition of p38 MAPK effectively inhibited sesamin-induced cell migration. The angiogenic activity of sesamin was not associated with VEGF expression. Furthermore, this compound did not induce vascular permeability and upregulated ICAM-1 and VCAM-1 expression, which are hallmarks of vascular inflammation. These results suggest that sesamin stimulates angiogenesis in vitro and in vivo through the activation of MEK/ERK-, PI3K/Akt/eNOS-, p125FAK-, and p38 MAPK-dependent pathways, without increasing vascular inflammation, and may be used for treating ischemic diseases and tissue regeneration. © 2009 Elsevier Inc. Source

Cho K.,Yonsei University | Park C.,Amore Pacific | Kim C.,Vascular System Research Center | Jeon H.,Amore Pacific | And 5 more authors.
Asian Journal of Andrology

Several reports have promote. The root-derived Korean red ginseng (KRG; Panax ginseng) as alternative treatment for erectile dysfunction (ED), and ginsenosides are known to b. The principal active ingredients of ginseng. Recent studies showed that ginseng berries produce more ginsenosides than KRG; thus, we investigate. The ability o. The Korean ginseng berry extract GB0710 to rela. The penile corpus cavernosum smooth muscle (CCSM) in this study. As a comparative control. The results were compared to those obtained using KRG. In addition, possible mechanisms of action for GB0710 were investigated. While KRG and GB0710 both displayed dose-dependent relaxation effects on precontracted rabbit CCSM in vitro, GB0710 was shown to be more potent than KRG. The GB0710-induced relaxation could be partially reduced by removin. The endothelium. In addition, pre-treatment with several nitric oxide (NO) inhibitors significantly inhibite. The relaxation of muscle strips. Furthermore, administration of GB0710 increased intracavernosal pressure (ICP) in a rat in vivo model in both a dose- and duration-dependent manner. Intracellular NO production in human microvascular endothelial cells could be induced by GB0710 and inhibited by N G -monomethyl-L-arginine. In conclusion, GB0710 had a greater relaxation effect on rabbit CCSM than did KRG extract, and increased ICP in a rat model in both a dose- and a duration-dependent manner. This relaxing effect might be mediated by NO production. Source

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