• Asian Pacific Journal of Cancer Prevention
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• v.17 no.sup3
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• pp.293-297
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• 2016

TRAIL, tumor necrosis factor (TNF)-related apoptosis-inducing ligand belongs to one of important cytokine superfamilIES, tumor necrosis factor ($TNF{\alpha}$). TRAIL-2 receptor agonists activate several cell signaling pathways in cells in different manners and could lead to apoptosis or necrosis. Agonistic egg yolk antibodies like IgY which have been developed in a selective manner could activate TRAIL death receptors such as TRAIL-2 (DR5) and thus apoptosis signaling. We here investigated induction of apoptosis in human breast cancer cells (MCF7 cell line) by an IgY produced against an 21 aminoacid epitope of the human TRAIL-2 receptor. As the first step a small peptide of 21 aminoacids choosen from the extracellular domain of DR5 protein was produced with a peptide synthesizer. After control assays and confirmation of the correct amino acid sequence, it was injected to hens immunized to achieve high affinity IgYs. At the next step, the produced IgYs were extracted and examined for specificity against DR5 protein by ELISA assay. Subsequently, the anticancer effect of such IgYs was determined by MTT assay in the MCF7 human breast cancer cell line. The produced peptides successfully immunized hens and the produced antibodies which accumulated in egg yolk specifically recognized the DR5 protein. IgYs exerted significant toxicity and killed MCF7 cells as shown by MTT assay.

• BMB Reports
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• v.29 no.5
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• pp.429-435
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• 1996

To investigate the structure-antagonistic relationship of the cyclohexapeptide L-659,877, a selective NK-2 tachykinin receptor antagonist, seven analogues were chemically synthesized by a solid phase method. The agonistic and antagonistic activities of the analogues were evaluated by contraction assay using the smooth muscle of guinea pig trachea (GPT) containing the NK-2 receptor. It was shown that the aromatic ring of Phe at position 3 and the sulfur group of Met at position 6 in L-659,877 were essential for binding to the NK-2 receptor. Decrease in antagonistic activity of L-659,877 caused by substituting Leu for Nle at position 5 indicates that the ${\gamma}$ methyl group and side chain length of Leu plays an important role in its antagonistic action. Although the activity was slightly lower than L-659,877, cyclo $[{\beta}Ala^{8}]NKA(4-10)$ (analogue 1) showed potential antagonistic activity for the NK-2 receptor. It was confirmed that the expansion of the ring in L-659,877 by substitution of ${\beta}Ala$ for Gly at position 4 stabilized its conformation monitored by CD spectra. The results suggest that analogue 1 can be used as a new leader compound to design a more powerful, selective, and stable NK-2 receptor antagonist.

• Biomolecules & Therapeutics
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• v.5 no.4
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• pp.325-330
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• 1997

Methanol extract of G. elata inhibited the binding of [/sup 3/H]Rol5-1788, a selective benzodiazepine receptor antagonest, to benzodiazepine receptor of rat cortices. Saturation experiments followed by Scatchard analysis of the results showed that the inhibition of [sub 3/H]Ro15-1788 binding by G. dlata. appeared to be com-petitive. These competitive inhibiton of the butanol fraction was observed to be higher than the methanol extract. Methanol extract of G. efara inhibited a [sub 3/H]flunitrazepam, a selective benzodiazepine receptor agonist, binding to benzodiazepine receptor. GABA significantly enhanced the inhibition of [/sub 3/H]flunitrazepam binding by G. elata, and these "positive GABA shift" supported the strong possibility of agonestic activity to benzodiazepine receptor Butanol fraction was observed to be higher than crude extract by methanol in an agonistic activity to benzodiazepine receptor, furthermore enhanced the binding of [sub 3/H]SR95531 to GABA receptor. Butanol fraction of G. elata significantly diminished the pentylenetetrazole-induced lethality of mice. From these results, it can be concluded that substance or substances with neurochemical properties characteri- stic of a benzodiazepine receptor agonist may be important components, and contribute to the anticonvulsant property of G. elata.

• Clinical and Experimental Reproductive Medicine
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• v.20 no.1
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• pp.37-43
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• 1993

In 27 patients with the past history of poor response to the gonadotropin superovulation induction due to poor follicular growth or permature surge of endogenous luteinizing hormone, the effectiveness of pituitary supperssion with the gonadotropin releasing hormone agonist(GnRH-a) in in vitro fertilization(IVF) program was evaluated in 43 cycles using a combination regimen of D-Trp-6 LHRH(Decapeptyl, Ferring)and FSH/hMG from June, 1989 to August, 1990 at Korea University Hospital IVF Clinic. At midluteal phase of menstrual cycle, Decapeptyl-CR was administered by long-term protocol to minimize initial agonistic effect of endogenous gonadotropins. After the confirmation of pituitary suppression, about 2-3 weeks after GNRH-a administration, ovarian follicle growth was stimulated with FSH/hMG and followed by transvaginal ultrasonic measurement of follicle size and by monitoring of serm E2 and LH if necessary. When compared with the control group stimulated with gonadotropin regimen only, the cancellation rate and occurrence rate of premature LH surge during gonadotropin treatment were significantly lower in study group(11.6% and 2.4%, respectively). There is no significant differences in the mean number of aspirated oocytes, fertilization/cleavage rate, embryo transfer(ET) rate, and mean number of embryos transferred between the two groups. The pregnancy rate per treatment cycle, 16.3%, and per ET cycle, 23.3%, were significantly higher in the study group compared with those of control group. These data suggest that GnRH-a therapy is effective for previous poor responder In gonadotropin superovulation induction for IVF.

• Korean Journal of Veterinary Research
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• v.32 no.1
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• pp.41-49
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• 1992

Higenamine is an Aconiti tuber derived compound whose chemical structure is 1-(4'-hydroxybenzyl)-6, 7-dihydroxy-1, 2, 3, 4-tetrahydroisoquinoline containing catechol ring and tetrahydroisoquinoline nucleus in its own structure, both of which are well known to have agonistic effects on adrenergic receptors. Using guinea-pig atria(rich in ${\beta}_1$-receptor) and treachea(rich in ${\beta}_2$-receptor), we studied pharmacological actions of higenamine on these organs with special interest of its relevancy of ${\beta}$-receptor selectivity. In order to further clarify its pharmacological characteristics, the influncences of pretreatment of reserpine or cocaine were also investigated. The results were summarized as follows : 1. Higenamine had remarkable chronotropic, inotropic and bronchodilator effects in guinea-pig spontaneously beating right atria, left atria and trachea, in dose-dependent manners. 2. All of above actions were blocked competitively by propranolol, which shows nonselectivity of higenamine on ${\beta}$-receptor. $pA_2$ values of propranolol against higenamine were 7.93, 7.76 and 8.46 in guinea-pig right atria, left atria and treachea, respectively. 3. Reserpine pretreatment(5mg/kg, ip, 24h) did not show my decrease in pharmacological actions of higenamine, which suggests higenamine has direct action on ${\beta}$-receptor not via catecholamine release. 4. Cocaine pretreatment$(1{\mu}M)$ had no influence on pharmacological actions of higenamine in contrast with nor epinephrine, which suggests there is no neuronal uptake mechanism of higenamine in the studied organ preparations.

• Journal of Ginseng Research
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• v.44 no.5
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• pp.690-696
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• 2020

Background: As the main metabolites of ginsenosides, 20(S, R)-protopanaxadiol [PPD(S, R)] and 20(S, R)-protopanaxatriol [PPT(S, R)] are the structural basis response to a series of pharmacological effects of their parent components. Although the estrogenicity of several ginsenosides has been confirmed, however, the underlying mechanisms of their estrogenic effects are still largely unclear. In this work, PPD(S, R) and PPT(S, R) were assessed for their ability to bind and activate human estrogen receptor α (hERα) by a combination of in vitro and in silico analysis. Methods: The recombinant hERα ligand-binding domain (hERα-LBD) was expressed in E. coli strain. The direct binding interactions of ginsenosides with hERα-LBD and their ERα agonistic potency were investigated by fluorescence polarization and reporter gene assays, respectively. Then, molecular dynamics simulations were carried out to simulate the binding modes between ginsenosides and hERα-LBD to reveal the structural basis for their agonist activities toward receptor. Results: Fluorescence polarization assay revealed that PPD(S, R) and PPT(S, R) could bind to hERα-LBD with moderate affinities. In the dual luciferase reporter assay using transiently transfected MCF-7 cells, PPD(S, R) and PPT(S, R) acted as agonists of hERα. Molecular docking results showed that these ginsenosides adopted an agonist conformation in the flexible hydrophobic ligand-binding pocket. The stereostructure of C-20 hydroxyl group and the presence of C-6 hydroxyl group exerted significant influence on the hydrogen bond network and steric hindrance, respectively. Conclusion: This work may provide insight into the chemical and pharmacological screening of novel therapeutic agents from ginsenosides.

• Archives of Pharmacal Research
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• v.28 no.12
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• pp.1317-1323
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• 2005

In an attempt to examine the ability of benzisothiazole-based drugs to interact with $\beta$-adrenoceptors, a series of 1,2-benzisothiazole derivatives, which were substituted with various propanolamine or oxypropanolamine side chains in the 2 or 3 position, were synthesised and tested. The pharmacological activity of these compounds at the ,$\beta$-adrenoceptors was examined using isolated rat atria and small intestinal segments, which preferentially express the $\beta_{1}$- and $\beta_{3}$-adrenoceptor-mediated responses, respectively. None of these products showed any $\beta$-adrenoceptor agonistic activity. In contrast, the 2- and 3-substituted isopropyl, tert-butyl, benzyl, and piperonyl derivatives 2a-d and 3a-d elicited surmountable inhibition of the isoprena­line-induced chronotropic effects in the atria, suggesting competitive antagonism at the $\beta_{1}$­recognition site. The $pA_{2}$ values revealed tert-butyl 3b and the isopropyl substituted piperonyl derivatives 3a to be the most effective. Remarkably, many of the 2-substituted propanolamines were less active than the corresponding 3-substituted oxypropanolamines. With the exception of compound 3b, none of these drugs antagonised the muscle relaxant activity of isoprenaline in the intestine, suggesting no effect on the $\beta_{3}$-adrenoceptors. These results confirm the ability of the benzisothiazole ring to interact with the $\beta$-adrenoceptors, and demonstrate that 2-substitution with propanolamine or 3-substitution with oxypropanolamine groups yields compounds with preferential antagonistic activity at the cardiac $\beta_{1}$adrenoceptors. The degree of antagonism depends strongly on both the nature of the substituent and its position on the benzisothiazole ring.

• Journal of the Korea Convergence Society
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• v.10 no.1
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• pp.285-290
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• 2019

AHR regulates the expression of xenobiotics metabolizing enzymes (XMEs) as a transcription fact upon binding of ligands that are mainly aryl hydrocarbons. The role of AHR in human physiology has been intensively investigated for the past decades, however our understanding on AHR yet to be elucidated largely due to the lack of proper chemical agents. It has been demonstrated that AHR correlates to pathogenesis for some diseases in recent studies suggesting that the study on the AHR may provide a valid therapeutic target. Classical antagonists in current use are reported to be partially agonistic whereas a pure antagonist is yet to be found. In this study, phenyldiazenylaniline has been designed based on the structure of two known AHR antagonist, Resveratrol and CH223191. The derivatives of phenyldiazenylaniline have been prepared and subjected to assessment as an AHR antagonist in order to optimize the AHR antagonistic activity of the designed structure by means of convergence study of organic synthesis and molecular biology.

• Journal of Digital Convergence
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• v.17 no.1
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• pp.443-447
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• 2019

Aryl hydrocarbon receptor (AhR) is the master regulator of xenobiotics metabolizing enzymes (XMEs). AhR is activated by aryl hydrocarbons upon binding then goes into the cell nucleus and acts as a transcription factor. Despite the role of AhR in human physiology has been investigated for a long while, it is yet to be understood mainly due to the lack of appropriate chemical agents. Furthermore, it has been reported that AhR is related to a wide range of pathogenesis. In addition, recent studies suggest that the study on the development of AhR antagonist may provide a valid therapeutic agent. Some known antagonists in current use are partially agonistic whereas a pure antagonist is still absent. In this study, two phenyl-ring structures of phenyldiazenylphenylpicolinamide has been modified into various structures and evaluated its impact on the AhR antagonistic activity to elucidate the structure-activity relationship.

• Biomolecules & Therapeutics
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• v.31 no.2
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• pp.176-182
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• 2023

Among 14 subtypes of serotonin receptors (5-HTRs), 5-HT_2AR plays important roles in drug addiction and various psychiatric disorders. Agonists for 5-HT_2AR have been classified into three structural groups: phenethylamines, tryptamines, and ergolines. In this study, the structure-activity relationship (SAR) of phenethylamine and tryptamine derivatives for binding 5-HT_2AR was determined. In addition, functional and regulatory evaluation of selected compounds was conducted for extracellular signal-regulated kinases (ERKs) and receptor endocytosis. SAR studies showed that phenethylamines possessed higher affinity to 5-HT_2AR than tryptamines. In phenethylamines, two phenyl groups were attached to the carbon and nitrogen (R³ ) atoms of ethylamine, the backbone of phenethylamines. Alkyl or halogen groups on the phenyl ring attached to the β carbon exerted positive effects on the binding affinity when they were at para positions. Oxygen-containing groups attached to R³ exerted mixed influences depending on the position of their attachment. In tryptamine derivatives, tryptamine group was attached to the β carbon of ethylamine, and ally groups were attached to the nitrogen atom. Oxygen-containing substituents on large ring and alkyl substituents on the small ring of tryptamine groups exerted positive and negative influence on the affinity for 5-HT_2AR, respectively. Ally groups attached to the nitrogen atom of ethylamine exerted negative influences. Functional and regulatory activities of the tested compounds correlated with their affinity for 5-HT_2AR, suggesting their agonistic nature. In conclusion, this study provides information for designing novel ligands for 5-HT_2AR, which can be used to control psychiatric disorders and drug abuse.