RESUMO
Utilizing the co-transfection assay as a guide to determining structure activity relationships, we have been pursuing the discovery of non-steroidal hPR modulators. Small molecule, non-steroidal lead structures have been identified. Optimization of these structures has yielded more potent hPR modulators. Improved cross-reactivity profiles with other intracellular receptors are a feature of these compounds owing to their non-steroidal nature.
Assuntos
Desenho de Fármacos , Antagonistas de Hormônios/química , Congêneres da Progesterona/efeitos adversos , Receptores de Progesterona/efeitos dos fármacos , Animais , Anisóis/química , Anisóis/farmacocinética , Chlorocebus aethiops , Clorófitas/química , Cicloexanos/química , Cicloexanos/farmacocinética , Terapia de Reposição de Estrogênios , Feminino , Gonanos/química , Gonanos/farmacocinética , Antagonistas de Hormônios/farmacocinética , Humanos , Mifepristona/química , Mifepristona/farmacocinética , Estrutura Molecular , Congêneres da Progesterona/farmacocinética , Receptores de GABA/efeitos dos fármacos , Receptores de GABA/fisiologia , Receptores de Progesterona/metabolismo , Receptores de Esteroides/efeitos dos fármacos , Receptores de Esteroides/metabolismo , Proteínas Recombinantes/efeitos dos fármacos , Fases do Sono/efeitos dos fármacos , Relação Estrutura-Atividade , TransfecçãoRESUMO
The co-transfection assay is a novel functional assay using cells transiently transfected with plasmids encoding intracellular receptors and corresponding reporter genes. Using this assay, natural product extracts were tested to identify compounds that modulate intracellular receptor activity, measured as changes in reporter gene activity. A crude extract of the marine alga Cymopolia barbata was found to inhibit progesterone-stimulated reporter gene expression in cells transfected with the human progesterone receptor (hPR) and an appropriate reporter construct. Purification of the active constituents of the extract, guided by the co-transfection assay, yielded two diastereomers of cyclocymopol monomethyl ether, possessing opposing pharmacological activities with the hPR. The antagonist (3R)-cyclocymopol monomethyl ether (LG100127) blocked 1 nM progesterone-stimulated reporter gene expression with an IC50 value of 549 +/- 55 nM in the co-transfection assay. The agonist (3S)-cyclocymopol monomethyl ether (LG100128) had efficacy similar to that of progesterone and an EC50 value of 35 +/- 2 nM. Stimulation by progesterone of the hPR in the human breast cancer cell line T-47D results in enhanced expression of alkaline phosphatase; LG100127 blocked alkaline phosphatase expression stimulated either by progesterone or by LG100128, and LG100128 mimicked progesterone in this assay. Both diastereomers displaced [3H]progesterone from baculovirus-expressed hPR. LG100127 and LG100128 each interacted with the human androgen receptor but did not interact with the human glucocorticoid receptor, estrogen receptor, vitamin D receptor, or retinoid receptors. In summary, these in vitro studies describe the first nonsteroidal pharmacophores for the hPR and demonstrate the use of the co-transfection assay in their discovery.
Assuntos
Anisóis/farmacologia , Cicloexanos/farmacologia , Eucariotos/metabolismo , Receptores de Progesterona/agonistas , Receptores de Progesterona/antagonistas & inibidores , Animais , Neoplasias da Mama/ultraestrutura , Chlorocebus aethiops , Eucariotos/química , Glucocorticoides/antagonistas & inibidores , Humanos , Progesterona/farmacologia , Estereoisomerismo , Transfecção , Células Tumorais Cultivadas/efeitos dos fármacosRESUMO
Two new compounds, pycnanthuquinone A (1) and pycnanthuquinone B (2), were isolated from leaves and stems of the African plant, Pycnanthus angolensis (Welw.) Warb (Myristicaceae), by bioassay-guided fractionation of an ethanolic extract using a diabetic mouse model. Pycnanthuquinones A and B are the first representatives of a novel terpenoid-type quinone skeleton, and both compounds possess significant antihyperglycemic activity.