• Title/Summary/Keyword: serotonin receptors

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Effect of Ginseng Saponin on LDL Receptor Biosynthesis (인삼사포닌의 저밀도지질단백질(LDL)수용체에 미치는 영향)

  • Joo Chung No;Lee Hee Bong;Lee Yong Woo;Kang In Chul
    • Proceedings of the Ginseng society Conference
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    • 1988.08a
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    • pp.47-54
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    • 1988
  • Cholesterol a component of all eucaryotic plasma membranes. is essential for the growth and viability of cells in higher organisms. However. too much cholesterol can be lethal because of atherosclerosis resulting from the deposition of cholesterol ester plaques. It was attempted in this study to understand the preventive effect of ginseng saponin. one of the major components of the roots of Panax ginseng C.A. Meyer. against hypercholesterolemia induced by high cholesterol diet. $^{125}I-LDL$ was injected intravenously to rabbits and rats. which were fed a high cholesterol diet with and/or without ginseng saponin for 12 days. The disappearance of the radioactivity occurred faster in the test group than the control. The effect of saponin fraction from Panax ginseng C.A. Meyer and the purified ginsenosilks. $Rb_1,\;Rb_2,\;Re\;and\;Rg_1,$ on LDL receptor biosynthesis in high cholesterol fed rat has been investigated. Analysis of LDL receptors from various organs such as liver. kidney. adrenal cortex and testis showed that the population of LDL receptors of test group significantly higher than that of the control. It was also found that liver homogenate containing ginsenosides $(10^{-3}-10^{-4}\%)$ stimulated the biosynthesis of bile acid form cholesterol. From the above results. it seemed that ginsenosides lower the cholesterol level by stimulating cholesterol metabolism. which result in the suppression of the inhibitory action of cholesterol on LDL receptor biosynthesis.

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Nelumbinis Semen Reverses a Decrease in $5-HT_{1A}$Receptor Binding Induced by Chronic Mild Stress, a Depression-like Symptom

  • Jang, Choon-Gon;Kang, Moon-Kyu;Cho, Jae-Han;Lee, Sun-Bok;Kim, Hyun-Taek;Park, Soon-Kwon;Lee, Jin-Woo;Park, Seong-Kyu;Hong, Moo-Chang;Shin, Min-Kyu;Shim, In-Sup;Bae , Hyun-Su
    • Archives of Pharmacal Research
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    • v.27 no.10
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    • pp.1065-1072
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    • 2004
  • Depression is associated with a dysfunctional serotonin (5-hydroxytryptamine; 5-HT) system. More recently, several lines of evidence suggest that an important factor in the development of depression may be a deficit in the function and expression of $5-HT_{1A}$ receptors. The present study assessed if Nelumbinis Semen (N. s.) had an anti-depression effect through reversing a decrease in $5-HT_{1A}$receptor binding in rats with depression-like symptoms induced by chronic mild stress. Using a $5-HT_{1A}$ receptor binding assay, with a specific $5-HT_{1A}$receptor agonist, 8- OH-DPAT (8-hydroxy-2-(di-n-propylamino) tetralin), the mechanism of the anti-depression effect of N. s. on rats was investigated, and the effects compared with two well-known antidepressants, Hyperium Perforatum (St. Johns Wort) and fluoxetine (Prozac). Animals were divided into five groups: the normal (N) group without chronic mild stress (CMS), the control (C) group under CMS for 8 weeks, the Nelumbinis Semen (N. s.) treatment group under CMS for 8 weeks, the Hyperium Perforatum (H. p.) treatment group under CMS for 8 weeks and finally, the fluoxetine (F) treatment group under CMS for 8 weeks. Each treatment was administered to rats during the last 4 weeks of the 8-week CMS. A sucrose intake test was performed to test the anti-depression effect of N. s. The N. s. treatment significantly reversed the decreased sucrose intake under CMS (P<0.05 compared to control group under CMS). In the CA2 and CA3 regions of the hippocampus, both N. s. and H. p. reversed the CMS-induced decrease in $5-HT_{1A}$receptor binding. In the I to II regions of the frontal cortex, N. s. and H. p. also reversed the CMS-induced decrease in$5-HT_{1A}$receptor binding, and even showed a significant increase in $5-HT_{1A}$receptor binding compared to the F treatment group (N. s. vs. P, p<0.05, H. p. vs. P, p<0.05). However, in the hypothalamus, all treatments reversed the CMSinduced decrease in $5-HT_{1A}$receptor binding. This reversal effect of N. s. on the decrease in $5-HT_{1A}$receptor binding in the frontal cortex, hippocampus and hypothalamus of rat brains was very similar to that of H. p, but different from that of F. It is concluded that N. s. presents an anti-depression effect through enhancing $5-HT_{1A}$receptor binding.