• Proceedings of the PSK Conference
• /
• 2003.10b
• /
• pp.177.1-177.1
• /
• 2003

Styrylheterocycles were synthesized as a novel calss of inhibitors on nitric oxide(NO) production. Their inhibitory activities were evaluated using lipopolysaccharid-stimulated RAW264.7 macrophage cells. This series of inhibitors are suggested as lead comounds for the development of potent and selective inhibitors

• Genomics & Informatics
• /
• v.21 no.3
• /
• pp.43.1-43.13
• /
• 2023

Melanin is synthesized by tyrosinase to protect the skin from ultraviolet light. However, overproduction and accumulation of melanin can result in hyperpigmentation and skin melanoma. Tyrosinase inhibitors are commonly used in the treatment of hyperpigmentation. Natural tyrosinase inhibitors are often favoured over synthetic ones due to the potential side effects of the latter, which can include skin irritation, allergies, and other adverse reactions. Nuciferine, an alkaloid derived from Nelumbo nucifera, exhibits potent antioxidant and anti-proliferative properties. This study focused on the in silico screening of nuciferine for anti-tyrosinase activity, using kojic acid, ascorbic acid, and resorcinol as standards. The tyrosinase protein target was selected through homology modeling. The residues of the substrate binding pocket and active site pockets were identified for the purposes of grid box optimization and docking. Therefore, nuciferine is a potent natural tyrosinase inhibitor and shows promising potential for application in the treatment of hyperpigmentation and skin melanoma.

• Development and Reproduction
• /
• v.17 no.4
• /
• pp.379-387
• /
• 2013

Embryonic stem (ES) cells can self-renew and differentiate to various cells depending on the culture condition. Although ES cells are a good model for cell type specification and can be useful for application in clinics in the future, studies on ES cells have many experimental restraints including low transfection efficiency and transgene expression. Here, we observed that transgene expression after transfection was enhanced by treatment with histone deacetylse (HDAC) inhibitors such as trichostatin A, sodium butyrate, and valproic acid. Transfection was performed using conventional transfection reagents with a retroviral vector encoding GFP under the control of CMV promoter as a reporter. Treatment of ES cells with HDAC inhibitors after transfection increased population of GFP positive cells up to 180% compared with untreated control. ES cells showed normal expression of stem cell markers after treatment with HDAC inhibitors. Transgene expression was further enhanced by modifying transfection procedure. GFP positive cells selected after transfection were proved to have the stem cell properties. Our improved protocol for enhanced gene delivery and expression in mouse ES cells without hampering ES cell properties will be useful for study and application of ES cells.

• Korean Journal of Pharmacognosy
• /
• v.30 no.4
• /
• pp.384-396
• /
• 1999

Acyl-CoA: Cholesterol Acyltransferase (ACAT) is a key enzyme responsible for cholesteryl ester formation in atherogenesis and in cholesterol absorption from the intestines. In addition under pathological conditions, formation and accumulation of cholesteryl ester as lipid droplets by ACAT within macrophages constitute a characteristic feature of early lesions of atherosclerotic plaques. ACAT inhibitors are expected to be effective for treatment of atherosclerosis and hypercholesterolemia. ACAT inhibitors of natural origin have been rarely reported. In our screening program for ACAT inhibitors, 303 plants were extracted with methanol or ethanol, and screened for the inhibitory activity against ACAT from the rat liver microsome. Extracts of 13 plants including Quercus aliena, Diospyros kaki, Platycarya strobilacea and Hibiscus syriacus inhibited more than 90% of ACAT activity and 43 samples in alcohol extracts such as Magnolia obovata and Panax ginseng also inhibited more than 70% of ACAT activity at a concentration of $100\;{\mu}g/ml$.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.12
• /
• pp.3092-3094
• /
• 2009

• Journal of Integrative Natural Science
• /
• v.6 no.1
• /
• pp.57-63
• /
• 2013

Histone deacetylase (HDACs) is an enzyme family that deacetylates histones and non-histones protein. Availability of crystal structure of HDAC8 has been a boosting factor to generate target based inhibitors. Hydroxamic class is the most studied one to generate potent inhibitors. HDAC class I and class II enzymes are emerging as a therapeutic target for cancer, diabetes, inflammation and other diseases. DNA methylation and histone modification are epigenetic mechanism, is important for the regulation of cellular functions. HDACs enzymes play essential role in gene transcription to regulate cell proliferation, migration and death. The aim of this article is to provide a comprehensive overview about structure and function of HDACs enzymes, histone deacetylase inhibitors (HDACi) and HDACs enzymes as a therapeutic target for cancer, inflammation and diabetes.

• Natural Product Sciences
• /
• v.1 no.1
• /
• pp.55-60
• /
• 1995

In the course of evaluation of hepatoprotective components against alcohol-induced toxicity from Aloe spp., the methanol extract was found to cause a significant inhibition of rat liver cytosolic alcohol dehydrogenase activity. Systematic fractionation of active tractions monitored by bioassay led to isolation of four compounds; aloe-emodin, aloenin, ethylidene-aloenin and ${\beta}-sitosterol$, which were estimated as active principles for inhibition of c-ADH and c-ALDH activities in vitro.

• Bulletin of the Korean Chemical Society
• /
• v.25 no.12
• /
• pp.1898-1906
• /
• 2004

Nonclassical quinazolinone analogs I, II, and III, in which the glutamic acid moiety of the classical antifolates is substituted by phenylglycine, phenylalanine or aminobenzoic acid and their methyl esters, were synthesized and evaluated as lipophilic inhibitors of thymidylate synthase (TS). The target compounds were generally potent inhibitors of L. casei and human TS with $IC_{50}$ values within the narrow range of 0.2-10 ${\mu}$M and 0.003-0.03 ${\mu}$M, respectively. Further, most of the target compounds showed cytotoxicity against tumor cell lines of murine and human origin with $IC_{50}$ values of as low as 0.050 ${\mu}$M. Substitution of another hydroxyl or carboxylic acid/ester group at the phenyl ring further increased the potency of TS inhibition and cell growth inhibition. Most effective were compounds If and Ic in which extra carboxylic acid/ester was present at the phenyl ring with nanomolar $IC_{50}$ values of 0.0044 and 0.0093 ${\mu}$M against human TS and submicromolar cytotoxic growth inhibition against all four tumor cell lines.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 2002.07a
• /
• pp.247-247
• /
• 2002

• Bulletin of the Korean Chemical Society
• /
• v.33 no.1
• /
• pp.275-277
• /
• 2012