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2.
Eur J Pharm Sci ; 131: 177-194, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30776468

RESUMO

Microsomal cytochrome P450 (CYP) enzymes, isolated from recombinant bacterial/insect/yeast cells, are extensively used for drug metabolism studies. However, they may not always portray how a developmental drug would behave in human cells with intact intracellular transport mechanisms. This study emphasizes the usefulness of human HEK293 kidney cells, grown in 'suspension' for expression of CYPs, in finding potent CYP1A1/CYP1B1 inhibitors, as possible anticancer agents. With live cell-based assays, quinazolinones 9i/9b were found to be selective CYP1A1/CYP1B1 inhibitors with IC50 values of 30/21 nM, and > 150-fold selectivity over CYP2/3 enzymes, whereas they were far less active using commercially-available CYP1A1/CYP1B1 microsomal enzymes (IC50, >10/1.3-1.7 µM). Compound 9i prevented CYP1A1-mediated benzo[a]pyrene-toxicity in normal fibroblasts whereas 9b completely reversed cisplatin resistance in PC-3/prostate, COR-L23/lung, MIAPaCa-2/pancreatic and LS174T/colon cancer cells, underlining the human-cell-assays' potential. Our results indicate that the most potent CYP1A1/CYP1B1 inhibitors would not have been identified if one had relied merely on microsomal enzymes.


Assuntos
Citocromo P-450 CYP1A1 , Citocromo P-450 CYP1B1 , Inibidores das Enzimas do Citocromo P-450/química , Inibidores das Enzimas do Citocromo P-450/farmacologia , Quinazolinonas , Antineoplásicos/farmacologia , Benzo(a)pireno/toxicidade , Bioensaio , Linhagem Celular , Cisplatino/farmacologia , Citocromo P-450 CYP1A1/antagonistas & inibidores , Citocromo P-450 CYP1A1/química , Citocromo P-450 CYP1A1/genética , Citocromo P-450 CYP1A1/metabolismo , Citocromo P-450 CYP1B1/antagonistas & inibidores , Citocromo P-450 CYP1B1/química , Citocromo P-450 CYP1B1/genética , Citocromo P-450 CYP1B1/metabolismo , Resistencia a Medicamentos Antineoplásicos , Humanos , Microssomos Hepáticos/enzimologia , Modelos Moleculares , Quinazolinonas/química , Quinazolinonas/farmacologia
3.
Bioorg Med Chem ; 26(23-24): 6076-6086, 2018 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-30448188

RESUMO

Expression of cytochrome P450-1A1 (CYP1A1) is suppressed under physiologic conditions but is induced (a) by polycyclic aromatic hydrocarbons (PAHs) which can be metabolized by CYP1A1 to carcinogens, and (b) in majority of breast cancers. Hence, phytochemicals or dietary flavonoids, if identified as CYP1A1 inhibitors, may help in preventing PAH-mediated carcinogenesis and breast cancer. Herein, we have investigated the cancer chemopreventive potential of a flavonoid-rich Indian medicinal plant, Pongamia pinnata (L.) Pierre. Methanolic extract of its seeds inhibits CYP1A1 in CYP1A1-overexpressing normal human HEK293 cells, with IC50 of 0.6 µg/mL. Its secondary metabolites, the furanoflavonoids pongapin/lanceolatin B, inhibit CYP1A1 with IC50 of 20 nM. Although the furanochalcone pongamol inhibits CYP1A1 with IC50 of only 4.4 µM, a semisynthetic pyrazole-derivative P5b, has ∼10-fold improved potency (IC50, 0.49 µM). Pongapin/lanceolatin B and the methanolic extract of P. pinnata seeds protect CYP1A1-overexpressing HEK293 cells from B[a]P-mediated toxicity. Remarkably, they also block the cell cycle of CYP1A1-overexpressing MCF-7 breast cancer cells, at the G0-G1 phase, repress cyclin D1 levels and induce cellular-senescence. Molecular modeling studies demonstrate the interaction pattern of pongapin/lanceolatin B with CYP1A1. The results strongly indicate the potential of methanolic seed-extract and pongapin/lanceolatin B for further development as cancer chemopreventive agents.


Assuntos
Antineoplásicos/farmacologia , Benzopiranos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Citocromo P-450 CYP1A1/antagonistas & inibidores , Flavonas/farmacologia , Furanos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Benzopiranos/síntese química , Benzopiranos/química , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Citocromo P-450 CYP1A1/biossíntese , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Flavonas/síntese química , Flavonas/química , Citometria de Fluxo , Furanos/síntese química , Furanos/química , Células HEK293 , Humanos , Células MCF-7 , Modelos Moleculares , Estrutura Molecular , Relação Estrutura-Atividade
4.
Medchemcomm ; 9(2): 371-382, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30108931

RESUMO

CYP1A1 is thought to mediate carcinogenesis in oral, lung and epithelial cancers. In order to identify a CYP1A1 inhibitor from an edible plant, 394 natural products in the IIIM's natural product repository were screened, at 10 µM concentration, using CYP1A1-Sacchrosomes™ (i.e. microsomal enzyme isolated from recombinant baker's yeast). Twenty-seven natural products were identified that inhibited 40-97% of CYP1A1's 7-ethoxyresorufin-O-deethylase activity. The IC50 values of the 'hits', belonging to different chemical scaffolds, were determined. Their selectivity was studied against a panel of 8 CYP-Sacchrosomes™. In order to assess cellular efficacy, the 'hits' were screened for their capability to inhibit CYP enzymes expressed within live recombinant human embryonic kidney (HEK293) cells from plasmids encoding specific CYP genes (1A2, 1B1, 2C9, 2C19, 2D6, 3A4). Isopimpinellin (IN-475; IC50, 20 nM) and karanjin (IN-195; IC50, 30 nM) showed the most potent inhibition of CYP1A1 in human cells. Isopimpinellin is found in celery, parsnip, fruits and in the rind and pulp of limes whereas different parts of the Indian beech tree, which contain karanjin, have been used in traditional medicine. Both isopimpinellin and karanjin negate the cellular toxicity of CYP1A1-mediated benzo[a]pyrene. Molecular docking and molecular dynamic simulations with CYP isoforms rationalize the observed trends in the potency and selectivity of isopimpinellin and karanjin.

5.
ACS Omega ; 3(8): 8553-8566, 2018 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-31458985

RESUMO

Cytochrome P450 family 1 (CYP1) enzymes catalyze the metabolic activation of environmental procarcinogens such as benzo[a]pyrene, B[a]P, into carcinogens, which initiates the process of carcinogenesis. Thus, stopping the metabolic activation of procarcinogens can possibly prevent the onset of cancer. Several natural products have been reported to show unique ability in inhibiting CYP1 enzymes. We found that khellin, a naturally occurring furanochromone from Ammi visnaga, inhibits CYP1A1 enzyme with an IC50 value of 4.02 µM in CYP1A1-overexpressing human HEK293 suspension cells. To further explore this natural product for discovery of more potent and selective CYP1A1 inhibitors, two sets of semisynthetic derivatives were prepared. Treatment of khellin with alkali results in opening of a pyrone ring, yielding khellinone (2). Claisen-Schmidt condensation of khellinone (2) with various aldehydes in presence of potassium hydroxide, at room temperature, provides a series of furanochalcones 3a-v (khellinochalcones). Treatment of khellinone (2) with aryl aldehydes in the presence of piperidine, under reflux, affords the flavanone series of compounds 4a-p (khellinoflavanones). The khellinoflavanone 4l potently inhibited CYP1A1 with an IC50 value of 140 nM in live cells, with 170-fold selectivity over CYP1B1 (IC50 for CYP1B1 = 23.8 µM). Compound 4l at 3× IC50 concentration for inhibition of CYP1A1 completely protected HEK293 cells from CYP1A1-mediated B[a]P toxicity. Lung cancer cells, A549 (p53+) and Calu-1 (p53-null), blocked in growth at the S-phase by B[a]P were restored into the cell cycle by compound 4l. The results presented herein strongly indicate the potential of these khellin derivatives for further development as cancer chemopreventive agents.

6.
Bioorg Med Chem Lett ; 27(24): 5409-5414, 2017 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-29138024

RESUMO

The overexpression of CYP1 family of enzymes is reported to be associated with development of human carcinomas. It has been well reported that CYP1A1 specific inhibitors prevents carcinogenesis. Herein, thirteen pyridine-4-yl series of chalcones were synthesized and screened for inhibition of CYP1 isoforms 1A1, 1B1 and 1A2 in Sacchrosomes™ and live human HEK293 cells. The structure-activity relationship analysis indicated that chalcones bearing tri-alkoxy groups (8a and 8k) on non-heterocyclic ring displayed selective inhibition of CYP1A1 enzyme, with IC50 values of 58 and 65 nM, respectively. The 3,4,5-trimethoxy substituted derivative 8a have shown >10-fold selectivity towards CYP1A1 with respect to other enzymes of the CYP1 sub-family and >100-fold selectivity with respect to CYP2 and CYP3 family of enzymes. The potent and selective CYP1A1 inhibitor 8a displayed antagonism of B[a]P mediated activation of aromatic hydrocarbon receptor (AhR) in yeast cells, and also protected human cells from CYP1A1-mediated B[a]P toxicity in human cells. This potent and selective inhibitor of CYP1A1 enzyme have a potential for development as cancer chemopreventive agent.


Assuntos
Chalconas/química , Citocromo P-450 CYP1A1/antagonistas & inibidores , Propano/análogos & derivados , Sítios de Ligação , Chalconas/farmacologia , Cisplatino/farmacologia , Citocromo P-450 CYP1A1/genética , Citocromo P-450 CYP1A1/metabolismo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Células HEK293 , Humanos , Concentração Inibidora 50 , Simulação de Acoplamento Molecular , Propano/química , Propano/farmacologia , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/metabolismo , Estrutura Terciária de Proteína , Receptores de Hidrocarboneto Arílico/antagonistas & inibidores , Receptores de Hidrocarboneto Arílico/metabolismo , Transdução de Sinais/efeitos dos fármacos , Relação Estrutura-Atividade , Leveduras/efeitos dos fármacos , Leveduras/metabolismo
7.
J Chem Inf Model ; 57(6): 1309-1320, 2017 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-28489395

RESUMO

Target structure-guided virtual screening (VS) is a versatile, powerful, and inexpensive alternative to experimental high-throughput screening (HTS). To discover potent CYP1A1 enzyme inhibitors for cancer chemoprevention, a commercial library of 50 000 small molecules was utilized for VS guided by both ligand and structure-based strategies. For experimental validation, 300 ligands were proposed based on combined analysis of fitness scores from ligand based e-pharmacophore screening and docking score, prime MMGB/SA binding affinity and interaction pattern analysis from structure-based VS. These 300 compounds were screened, at 10 µM concentration, for in vitro inhibition of CYP1A1-Sacchrosomes (yeast-derived microsomal enzyme) in the ethoxyresorufin-O-de-ethylase assay. Thirty-two compounds displayed >50% inhibition of CYP1A1 enzyme activity at 10 µM. 2-Phenylimidazo-[1,2-a]quinoline (5121780, 119) was found to be the most potent with 97% inhibition. It also inhibited ∼95% activity of CYP1B1 and CYP1A2, the other two CYP1 enzymes. The compound 5121780 (119) showed high selectivity toward inhibition of CYP1 enzymes with respect to CYP2 and CYP3 enzymes (i.e., there was no detectable inhibition of CYP2D6/CYP2C9/CYP2C19 and CYP3A4 at 10 µM). It was further investigated in live CYP-expressing human cell system, which confirmed that compound 5121780 (119) potently inhibited CYP1A1, CYP1A2, CYP1B1 enzymes with IC50 values of 269, 30, and 56 nM, respectively. Like in Sacchrosomes, inhibition of CYP2D6/CYP2C9/CYP2C19 and CYP3A4 enzymes, expressed within live human cells, could hardly be detected at 10 µM. The compound 119 rescued CYP1A1 overexpressing HEK293 cells from CYP1A1 mediated benzo[a]pyrene (B[a]P) toxicity and also overcame cisplatin resistance in CYP1B1 overexpressing HEK293 cells. Molecular dynamics simulations of 5121780 (119) with CYP1 enzymes was performed to understand the interaction pattern to CYP isoforms. Results indicate that VS can successfully be used to identify promising CYP1A1 inhibitors, which may have potential in the development of novel cancer chemo-preventive agents.


Assuntos
Citocromo P-450 CYP1A1/antagonistas & inibidores , Inibidores das Enzimas do Citocromo P-450/farmacologia , Avaliação Pré-Clínica de Medicamentos/métodos , Microssomos/efeitos dos fármacos , Interface Usuário-Computador , Leveduras/genética , Sobrevivência Celular , Citocromo P-450 CYP1A1/química , Citocromo P-450 CYP1A1/metabolismo , Células HEK293 , Humanos , Ligantes , Microssomos/metabolismo , Simulação de Dinâmica Molecular , Conformação Proteica
8.
Eur J Med Chem ; 130: 320-327, 2017 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-28259840

RESUMO

CYP1B1 is implicated to have a role in the development of breast, ovarian, renal, skin and lung carcinomas. It has been suggested that identification of potent and specific CYP1B1 inhibitors can lead to a novel treatment of cancer. Flavonoids have a compact rigid skeleton which fit precisely within the binding cavity of CYP1B1. Systematic isosteric replacement of flavonoid 'O' atom with 'N' atom led to the prediction that a 'quinazoline' scaffold could be the basis for designing potential CYP1B1 inhibitors. A total of 20 quinazoline analogs were synthesized and screened for CYP1B1 and CYP1A1 inhibition in Sacchrosomes™. IC50 determinations of six compounds with capability of inhibiting CYP1B1 identified quinazolines 5c and 5h as the best candidates for CYP1B1 inhibition, with IC50 values in the nM range. Further selectivity studies with homologous CYPs, belonging to the CYP1, CYP2 and CYP3 family of enzymes, showed that the compounds are likely to be free from critical drug-drug interaction liability. Molecular modelling studies were performed to rationalize the observed enzymatic inhibitions. Further biological studies in live yeast and human cells, harboring CYP1A1 and CYP1B1 enzymes, have illustrated the most potent compounds' cellular permeability and capability of potently inhibiting CYP1B1 enzyme expressed within live cells.


Assuntos
Antineoplásicos/química , Citocromo P-450 CYP1B1/antagonistas & inibidores , Quinazolinas/farmacologia , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Permeabilidade da Membrana Celular , Células Cultivadas , Citocromo P-450 CYP1A1 , Família 2 do Citocromo P450/efeitos dos fármacos , Família 3 do Citocromo P450/efeitos dos fármacos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacocinética , Humanos , Modelos Moleculares , Quinazolinas/química , Quinazolinas/farmacocinética , Leveduras/citologia
9.
Eur J Med Chem ; 129: 159-174, 2017 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-28222316

RESUMO

The structure of alpha-napthoflavone (ANF), a potent inhibitor of CYP1A1 and CYP1B1, mimics the structure of chalcones. Two potent CYP1B1 inhibitors 7k (DMU2105) and 6j (DMU2139) have been identified from two series of synthetic pyridylchalcones. They inhibit human CYP1B1 enzyme bound to yeast-derived microsomes (Sacchrosomes™) with IC50 values of 10 and 9 nM, respectively, and show a very high level of selectivity towards CYP1B1 with respect to the IC50 values obtained with CYP1A1, CYP1A2, CYP3A4, CYP2D6, CYP2C9 and CYP2C19 Sacchrosomes™. Both compounds also potently inhibit CYP1B1 expressed within 'live' recombinant yeast and human HEK293 kidney cells with IC50 values of 63, 65, and 4, 4 nM, respectively. Furthermore, the synthesized pyridylchalcones possess better solubility and lipophilicity values than ANF. Both compounds overcome cisplatin-resistance in HEK293 and A2780 cells which results from CYP1B1 overexpression. These potent cell-permeable and water-soluble CYP1B1 inhibitors are likely to have useful roles in the treatment of cancer, glaucoma, ischemia and obesity.


Assuntos
Chalconas/farmacologia , Inibidores Enzimáticos/farmacocinética , Linhagem Celular Tumoral , Permeabilidade da Membrana Celular , Chalconas/síntese química , Chalconas/farmacocinética , Cisplatino , Citocromo P-450 CYP1B1/antagonistas & inibidores , Descoberta de Drogas , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Células HEK293 , Compostos Heterocíclicos , Humanos
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