• Natural Product Sciences
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• 제10권6호
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• pp.289-295
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• 2004

Myristica fragrans seed from Myristica fragrans Houtt (Myristicaceae) has various pharmacological activities peripherally and centrally. The present study aims to investigate the effect of the methanol extract of Myristica fragrans seed (MF) on N-methyl-D-aspartate (NMDA)-induced neurotoxicity in primary cultured rat cerebellar granule neuron. MF, over a concentration range of 0.05 to $5\;{\mu}g/ml$, inhibited NMDA (1 mM)- induced neuronal cell death, which was measured by trypan blue exclusion test and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay. MF $(0.5\;{\mu}g/ml)$ inhibited glutamate release into medium induced by NMDA (1 mM), which was measured by HPLC. Pretreatrnent of MF $(0.5\;{\mu}g/ml)$ inhibited NMDA (1 mM)-induced elevation of cytosolic calcium concentration $([Ca^{2+}]_c)$, which was measured by a fluorescent dye, Fura 2-AM, and generation of reactive oxygen species (ROS). These results suggest that MF prevents NMDA-induced neuronal cell damage in vitro.

• Natural Product Sciences
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• 제9권4호
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• pp.249-255
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• 2003

Zizypus is one of the herbs widely used in Korea and China due to CNS calming effect. The present study aims to investigate the effect of the methanol extract of Zizyphi Jujube Semen (ZJS) on kainic acid (KA)-induced neurotoxicity in cultured rat cerebellar granule neuron. ZJS, over a concentration range of 0.05 to $5\;{\mu]g/ml$, inhibited KA $(500\;{\mu}M)-induced$ neuronal cell death, which was measured by a trypan blue exclusion test and a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay. Pretreatment of ZJS $(0.5\;{\mu}g/ml)$ inhibited KA$(50\;{\mu}M)$-induced elevation of cytosolic calcium concentration $([Ca^{2+}]_c)$, which was measured by a fluorescent dye, Fura 2-AM, and generation of reactive oxygen species (ROS). ZJS $(0.5\;{\mu}g/ml)$ inhibited glutamate release into medium induced by KA $(500\;{\mu}M)$, which was measured by HPLC. These results suggest that ZJS prevents KA-induced neuronal cell damage in vitro.

• 한국약용작물학회지
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• 제11권4호
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• pp.298-305
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• 2003

Polygalae Radix (PR) from Polygala tenuifolia. (Polygalaceae) is traditionally used in China and Korea, since this herb has a sedative, antiinflammatory, and antibacterial agent. To extend pharmacological actions of PR in the CNS on the basis of its CNS inhibitory effect, the present study examined whether PR has the neuroprotective action against kainic acid (KA) -induced cell death in primarily cultured rat cerebellar granule neurons. PR, over a concentration range of 0.05 to $5{\mu}g/ml$ inhibited KA $(500\;{\mu}M)$-induced neuronal cell death, which was measured by a trypan blue exclusion test and a 3-[4,5-dimethylthiazol-2-y1]-2,5-diphenyl-tetrazolium bromide (MTT) assay. PR $(0.5{\mu}g/ml)$ inhibited glutamate release into medium induced by KA $(500\;{\mu}M)$, which was measured by HPLC. Pretreatment of PR $(0.5{\mu}g/ml)$ inhibited KA $(500\;{\mu}M)$-induced elevation of cytosolic calcium concentration $([Ca^{2+}]_c)$ which was measured by a fluorescent dye, Fura 2-AM, and generation of reactive oxygen species (ROS). These results suggest that PR prevents KA-induced neuronal cell damage in vitro.

• 한국약용작물학회지
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• 제13권2호
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• pp.95-102
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• 2005

Caulis Bambusae in Taenia is widely used in Korea and China due to its various pharmacological activity. The present study aims to investigate the effect of the methanol extract of Caulis Bambusae in Taenia (CB) from Phyllostachys nigra Munro var. henonis Stapf (Gramineae) on amyloid ${\beta}$ protein (25-35) $(A{\beta}\;(25-35))$, a synthetic 25-35 amyloid peptide, -induced neurotoxicity using cultured rat cortical neurons. CB, over a concentration range of $10-50{\mu}g/{\mu}l$, inhibited the $A{\beta}\;(25-35)\;(10\;{\mu}M)$-induced neuronal cell death, as assessed by a 3-[4,5-dimethyIthiazole-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay and the number of apoptotic nuclei, evidenced by Hoechst 33342 staining. CB $(50\;{\mu}g/{\mu}l)$ inhibited glutamate release into medium induced by $10\;{\mu}M\;A{\beta}$, (25-35) which was measured by HPLC. Pretreatment of CB $(50\;{\mu}g/{\mu}l)$ inhibited $10{\mu}M\;A{\beta}$ (25-35)-induced elevation of cytosolic calcium concentration $([Ca^{2+}]_c)$, which was measured by a fluorescent dye, fluo-4 AM, and generation of reactive oxygen species. These results suggest that CB prevents $A{\beta}$ (25-35)-induced neuronal ell damage in vitro.

• 한국약용작물학회지
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• 제13권5호
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• pp.219-226
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• 2005

Sanguisorbae radix (SR) from Sanguisorba officinalis L. (Losaceae) is widely used in Korea and China due to its various pharmacological activity. The present study aims to investigate the effect of the methanol extract of SR on amyloid ${\beta}$ Protein(25-35) $(A{\beta}\;(25-35))$, a synthetic 25-35 amyloid peptide, -induced neurotoxicity using cultured rat cortical neurons. SR, over a concentration range of $10-50\;{\mu}g/ml$, inhibited the $A{\beta}$ (25-35) $(10\;{\mu}M)-induced$ neuronal cell death, as assessed by a 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay and the number of apoptotic nuclei, evidenced by Hoechst 33342 staining. Pretreatment of SR $(50\;{\mu}g/ml)$ inhibited $10\;{\mu}M\;A{\beta}$ (25-35)-induced} elevation of cytosolic calcium concentration $([Ca^{2+}]c)$, which was measured by a fluorescent dye, fluo-4 AM. SR $(10\;and\;50\;{\mu}g/ml)$ inhibited glutamate release into medium induced by $10\;{\mu}M\;A{\beta}(25-35)$, which was measured by HPLC, and generation of reactive oxygen species. These results suggest that SR prevents $A{\beta}$ (25-35)-induced neuronal cell damage in vitro.

• Nutritional Sciences
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• 제3권1호
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• pp.11-17
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• 2000

This study was intended to examine whether dehydroepiandrosterone (DHEA) and dietary fat level or source could modulate glutathione utilizing detoxifying system activity and the cytosolic NADPH generation in rat liver. Male Sprague-Dawley rats were fed semipurifed diet containing either 2%(w/w) corn oil (low level of corn oil diet: 5 ca% of fat) 15% corn oil (high level of corn oil diet: 31 cal% of fat) or 13% sardine oil plus 2% corn oil(high level of fish oil diet: 31 cal% of fat) for 9 weeks. Half of the rats in each diet group were fed a diet supplemented with 0.2% DHEA (w/w). DHEA administration increased plasma total cholesterol level in low corn oil diet-fed rats. The high fish oil diet significantly decreased plasma total cholesterol level compared to the high corn oil diet. Plasma triglyceride level was not significantly changed by DHEA administration and dietary fat level and source. Fasting plasma glucose level was increased by DHEA administration and fish oil diet. Glucose 6-phosphate dehydrogenase activity in liver tissue was significantly increased by DHEA administration and high fat diet, especially fish oil diet. Malic enzyme activity in liver tissue was significantly increased by DHEA administration and high fat diet, especially fish oil diet. Malic enzyme activity in liver tissue was significantly increased by DHEA administration. DHEA suppressed the glutathione peroxidase, glutathione-dependent enzymes compared to the low corn oil diet, while fish oil diet elevated the activity of glutathione peroxidase and glutathione reductase compared to corn oil diet. These results suggest that DHEA administration and high level of corn oil diet may suppress the cellular detoxifying system activity through reduction of glutathione utilization, while the fish oil diet did not show these effects.

• 대한수의학회지
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• 제36권1호
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• pp.83-91
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• 1996

Activation of $K^+$ channels induces relaxation of smooth muscles by reducing electrical excitability and cytosolic free $Ca^{2+}$ level. ${\beta}$-adrenergic agonist isoproterenol is known to induce relaxation of the uterine smooth muscle by membrane hyperpolarization and $K^+$ efflux. Recently it is suggested that the activity of $Ca^{2+}$-activated $K^+$ channel was increased by isoproterenol in the uterine myocytes isolated from myometrium of the pregnant rat. However, the type of $K^+$ channel mediating the relaxant effect of isopreterenol in the tissue level has not yet studied. In this work, we investigated the type of $K^+$ channels involved in the isoproterenol-induced relaxation of uterine smooth muscle by measuring the integrated insometric tension of the estrogen-treated isolated nonpregnant rat uterus. Contraction of uterine tissue was induced by oxytocin (0.2nM, 2~3 contractions/min) or high KCl(20~80mM). The result are as follows : 1. Isoproterenol($10^{-10}{\sim}10^{-4}M$) inhibited oxytocin-induced contraction of isolated rat uterus($EC_{50}=1.17{\times}10^{-10}M$). 2. Isoproterenol($10^{-10}{\sim}10^{-4}M$) effectively inhibited uterine contraction induced by low KCl(20~40mM) but little those induced by high KCl(60~80mM). 3. Relaxant effect of isoproterenol($10^{-10}{\sim}10^{-4}M$) on 0.2nM oxytocin-induced contraction was effectively reduced by 4-aminopyridine(3, 10mM) but little by TEA(10~30mM), $Ba^{2+}$($1{\sim}30{\mu}M$) and glibenclamide($100{\mu}M$). Our data suggest that the relaxant effect of isoproterenol is mediated by the $K^+$ channel(s) which can be blocked by 4-aminopyridine.

• International Journal of Vascular Biomedical Engineering
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• 제3권2호
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• pp.1-9
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• 2005

Flow-induced dilation of blood vessel is the result of a series of bioreaction in vascular endothelial cells(VEC). Shear stress change by blood flow in human artery or vein is sensed by the mechanoreceptor and responsible for such a chain reaction. The inositol(1,4,5)-triphophate($IP_3$) is produced in the first stage to elevate permeability of the intercellular membrane to calcium ions by which the cytosolic calcium concentration is consequently increased. This intracellular calcium transient triggers synthesis of EDRF and prostacyclin. The mathematical model of this VEC calcium dynamics is reproduced from the literature. We then use the Computational Fluid Dynamics(CFD) technique to investigate the blood stream dictating the VEC calcium dynamics. The pulsatile blood flow in a stenosed blood vessel is considered here as a part of study on thrombogenesis. We calculate the pulsating shear stress (thus its temporal change) distributed over the stenosed artery that is implemented to the VEC calcium dynamics model. It has been found that the pulsatile shear stress induces larger intracellular $Ca^{2+}$ transient plus much higher amount of EDRF and prostacyclin release in comparison with the steady shear stress case. It is concluded that pulsatility of the physiological shear stress is important to keep the vasodilation function in the stenosed part of the blood vessel.

• International Journal of Oral Biology
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• 제33권4호
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• pp.125-129
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• 2008

Inositol 1,4,5-trisphosphate ($IP_3$) plays an important role in the release of $Ca^{2+}$ from intracellular stores into the cytoplasm in a variety of cell types. $IP_3$ translocation dynamics have been studied in response to many types of cell signals. However, the dynamics of cytosolic $IP_3$ in salivary acinar cells are unclear. A green fluorescent protein (GFP)-tagged pleckstrin homology domain (PHD) was constructed and introduced into a phospholipase C ${\delta}1$ (PLC ${\delta}1$) transgenic mouse, and then the salivary acinar cells were isolated. GFP-PHD was heterogeneously localized at the plasma membrane and intracellular organelles in submandibular gland and parotid gland cells. Application of trypsin, a G protein-coupled receptor activator, to the two types of cells caused an increase in GFP fluorescence in the cell cytoplasm. The observed time course of trypsin-evoked $IP_3$ movement in acinar cells was independent of cell polarity, and the fluorescent label showed an immediate increase throughout the cells. These results suggest that GFP-PHD in many tissues of transgenic mice, including non-cultured primary cells, can be used as a model for examination of $IP_3$ intracellular dynamics.

• 한국식품위생안전성학회지
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• 제22권3호
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• pp.223-230
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• 2007

저자들은 녹차 카테킨(GTC)이 강한 항 혈전 작용을 나타내며, 이는 항 혈소판 활성에 의한 것임을 보고한 바 있다. 본 연구에서는, 8가지 녹차 카테킨 성분들의 항 혈소판 활성을 비교하였다. 실험결과, 갈레이트(gallate) 구조를 갖는 카테킨들(EGCG, GCG, ECG, CG)은 콜라겐$(5{\mu}g/ml)$으로 유도한 토끼 혈소판 응집능을 강하게 억제하였으며, 50% 억제농도$(IC_{50})$는 각각 79.8, 63.0, 168.2, $67.3{\mu}M$이었다. 또한 EGCG, GCG, CG는 아라키돈산(AA, $100{\mu}M$)으로 유도한 토끼 혈소판 응집능을 억제하였고, 50% 억제농도$(IC_{50})$는 각각 98.9, 200.0, $174.3{\mu}M$이었다. 반면에, 갈레이트 구조를 가지지 않는 카테킨들은 혈소판 응집능 억제 효과가 매우 약했다. 이 결과는 항 혈소판 활성에서 카테킨들의 C-3 위치의 갈레이트 구조의 존재가 매우 중요하다는 것과 카테킨들과 B-ring 갈레이트 구조의 존재 또한 녹차카테킨의 항 혈소판 활성에 중요한 작용한다는 것을 의미한다. 그리고, EGCG는 농도 의존적으로 세포내 칼슘 생성과 아리키돈산의 생성을 억제시켰는데, 이는 혈소판 응집능의 억제와 일치하였다. 반면에, EGC는 세포 내 칼슘 및 다른 혈소판 활성 기전에 아무런 영향이 없었다. 이들 결과는 EGCG의 항 혈소판 활성은 C-ring에서 carbon 3 자리의 에스테르화 된 갈레이트 구조의 존재에 의해서 강화된 항 혈소판 작용으로, 아라키돈산 생성과 세포 내 칼슘 생성을 억제하는 효과에 기인한 것이라 사료된다.