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1.
J Pharm Biomed Anal ; 181: 113094, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-31927167

RESUMO

Saffron is one of the most expensive and valuable spice having tremendous commercial value in food industry and thus its quality check is of utmost importance. Crocins are unique group of extremely hydrophilic apocarotenoids which are main components of saffron. Crocetin is an aglycone of crocins which do occur naturally in saffron, and is produced in biological system as a bioactive metabolite via hydrolytic cleavage of crocins. Crocins are unstable and tend to undergo isomerisation/ inter-conversions, and therefore their quantitative estimation is difficult. Herein, we have established for the first time, a crocetin-based HPLC method to evaluate the total crocin content of saffron, and thereby analyze the quality of saffron. The present approach comprises alkali-mediated conversion of crocins to crocetin in raw material followed by quantitative estimation of in-situ formed crocetin by HPLC analysis. The unique and efficient protocol for preparation of high purity analytical grade 'crocetin' directly from saffron has also been established. It is simple and efficient way to check the quality of saffron/ saffron-containing products.

2.
Bioorg Chem ; 95: 103500, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31869665

RESUMO

The structure-guided virtual screening (VS) has proved to be successful strategy in identification of new scaffolds for biological targets. The overactivity of NLRP3 inflammasome has been implicated in variety of inflammatory diseases including Alzheimer's disease. The up-regulation of estrogen-receptor ß (ER-ß) activity has been directly linked with inhibition of NLRP3 inflammasome activity. In the present study, we report discovery of new NLRP3 inflammasome inhibitors via ER-ß crystal structure (PDB: 5TOA) guided virtual screening of 20,000 compound library. For experimental validation, top 10 ligands were selected based on structure novelty, docking score, prime MMGB/SA binding affinity and interaction pattern analysis. Amongst the tested compounds, three thiazolidin-4-ones IIIM-1268, IIIM-1269 and IIIM-1270 and benzo[cd]indol-2-one IIIM-1266 have shown 73, 69, 75 and 77% suppression of IL-1ß release in mouse macrophages (J774A.1 cells) at 10 µM. Benzylidene-thiazolidine-2,4-diones IIIM-1268 and IIIM-1270 inhibited IL-1ß release with IC50 of 2.3 and 3.5 µM and also significantly decreased the protein expression level of mature form of IL-1ß in western-blot analysis. IIIM-1266 and IIIM-1270 displayed bidentate H-bonding with Arg 346 and Glu 305 residues in the active site of ER-ß; and they also strongly occupied the ADP-binding site of NLRP3 protein. The results presented herein, indicate that ER-ß guided VS can be successfully used to identify new NLRP3 inflammasome inhibitors, which may have potential in the development of novel anti-Alzheimer agents.

3.
Int J Pharm ; 570: 118683, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31513869

RESUMO

The objective of this study was to formulate an anticancer preclinical lead, IIIM-290, loaded in solid dispersions to enhance its solubility, dissolution, and oral pharmacokinetics. IIIM-290 is an in-house preclinical anticancer lead prepared by semisynthetic modification of the natural product rohitukine. It is an orally bioavailable Cdk inhibitor showing efficacy in xenograft models of pancreatic, colon and leukemia cancer. It demonstrated in vivo efficacy at a relatively higher dose owing to its poor aqueous solubility (~8.6 µg/mL). Binary and ternary solid dispersions containing PVP K-30, xanthan gum, and PEG-PPG-PEG were selected after solubility screening of various hydrophilic polymers. Several formulations with varying ratios of polymers, alone and in combination, were prepared and investigated for their effects on the solubility enhancement of IIIM-290. The binary solid dispersion VKB-SD75, prepared with PVP K-30 at the ratio of 1:4 w/w, was identified as the optimized composition that displayed 17-fold improvement in the aqueous solubility of IIIM-290. VKB-SD75 was scaled up to a 100-g scale. IIIM-290 and VKB-SD75 were evaluated for DSC, p-XRD, FTIR, 1H NMR, SEM, in vitro dissolution, and oral pharmacokinetics, as well as for in vivo anticancer activity in the Ehrlich solid tumor model. The oral administration of VKB-SD75 in BALB/c mice resulted in a 1.9-fold improvement in plasma exposure. These findings also correlated well when the formulation was administered to mice in the Ehrlich solid tumor model. The newly developed solid dispersion is expected to reduce the dose of IIIM-290 by ~40-50% in preclinical and clinical studies.

4.
Environ Toxicol Pharmacol ; 71: 103218, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31302432

RESUMO

A novel panel of oximes were synthesized, which have displayed varying degree of reactivation ability towards different organophosphorus (OP) modified cholinesterases. In the present article, we report a comparative reactivation profile of a series of quaternary pyridinium-oximes for electric eel acetylcholinesterase (EEAChE) inhibited by the organophosphorus (OP) inhibitors methyl paraoxon (MePOX), ethyl paraoxon (POX; paraoxon) and diisopropyl fluorophosphate (DFP) that are distinguishable as dimethoxyphosphoryl, diethoxyphosphoryl and diisopropoxyphosphoryl AChE-OP-adducts. Most of the 59-oximes tested led to faster and more extensive reactivation of MePOX- and POX-inhibited EEAChE as compared to DFP-modified EEAChE. All were effective reactivators of three OP-modified EEAChE conjugates showing 18-21% reactivation for DFP-inhibited AChE and ≥45% reactivation for MePOX- and POX-inhibited EEAChE. Oximes 7 and 8 showed kr values better than pralidoxime (1) for DFP-inhibited EEAChE. Reactivation rates determined at different inhibition times showed no significant change in kr values during 0-90 min incubation with three OPs. However, a 34-72% decrease in kr for MePOX and POX and > 95% decrease in kr for DFP-inhibited EEAChE was observed after 24 h of OP-exposure (aging).


Assuntos
Acetilcolinesterase/metabolismo , Inibidores da Colinesterase/química , Reativadores da Colinesterase/farmacologia , Compostos Organofosforados/química , Oximas/farmacologia , Compostos de Piridínio/farmacologia , Animais , Reativadores da Colinesterase/síntese química , Reativadores da Colinesterase/química , Desenho de Drogas , Electrophorus , Simulação de Acoplamento Molecular , Estrutura Molecular , Agentes Neurotóxicos/química , Intoxicação por Organofosfatos/enzimologia , Intoxicação por Organofosfatos/prevenção & controle , Oximas/síntese química , Oximas/química , Compostos de Piridínio/síntese química , Compostos de Piridínio/química
7.
Bioorg Chem ; 90: 103062, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31220673

RESUMO

Alkaloids have always been a great source of cholinesterase inhibitors. Numerous studies have shown that inhibiting acetylcholinesterase as well as butyrylcholinetserase is advantageous, and have better chances of success in preclinical/ clinical settings. With the objective to discover dual cholinesterase inhibitors, herein we report synthesis and biological evaluation of indoloquinoline alkaloid cryptolepine (1) and its bromo-derivative 2. Our study has shown that cryptolepine (1) and its 2-bromo-derivative 2 are dual inhibitors of acetylcholinesterase and butyrylcholinesterase, the enzymes which are involved in blocking the process of neurotransmission. Cryptolepine inhibits Electrophorus electricus acetylcholinesterase, recombinant human acetylcholinesterase and equine serum butyrylcholinesterase with IC50 values of 267, 485 and 699 nM, respectively. The 2-bromo-derivative of cryptolepine also showed inhibition of these enzymes, with IC50 values of 415, 868 and 770 nM, respectively. The kinetic studies revealed that cryptolepine inhibits human acetylcholinesterase in a non-competitive manner, with ki value of 0.88 µM. Additionally, these alkaloids were also tested against two other important pathological events of Alzheimer's disease viz. stopping the formation of toxic amyloid-ß oligomers (via inhibition of BACE-1), and increasing the amyloid-ß clearance (via P-gp induction). Cryptolepine displayed potent P-gp induction activity at 100 nM, in P-gp overexpressing adenocarcinoma LS-180 cells and excellent toxicity window in LS-180 as well as in human neuroblastoma SH-SY5Y cell line. The molecular modeling studies with AChE and BChE have shown that both alkaloids were tightly packed inside the active site gorge (site 1) via multiple π-π and cation-π interactions. Both inhibitors have shown interaction with the allosteric "peripheral anionic site" via hydrophobic interactions. The ADME properties including the BBB permeability were computed for these alkaloids, and were found within the acceptable range.

8.
Drug Dev Res ; 80(5): 655-665, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31050027

RESUMO

Beta-secreatse (BACE-1) and cholinesterases are clinically validated targets of Alzheimer's disease (AD), for which natural products have provided immense contribution. The multifaceted nature of AD signifies the need of multitargeted agents to tackle this disease. In the search of new natural products as dual BACE-1/cholinesterase inhibitors, a library of pure natural products was screened for inhibition of acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and BACE-1. The screening efforts have identified 1,4-benzoquinone "embelin," a natural product derived from Embelia ribes displaying inhibition of all three enzymes, with IC50 values of 2.5, 5.4, and 2.1 µM, respectively. This screen has also identified isoquinoline alkaloids papaverine and L-tetrahydropalmatine as AChE inhibitors. Kinetic study has shown that embelin inhibits EeAChE and EqBChE with ki values of 4.59 and 0.57 µM, in an uncompetitive and noncompetitive manner, respectively. The interactions of embelin with allosteric peripheral anionic site of cholinesterases, has further supported the results of kinetic study. Embelin has also enhanced the activity of P-gp in LS-180 cells, the efflux pump which is involved in the clearance of amyloid-ß from AD brain. Further, the cell viability study in neuronal cell line has indicated the excellent therapeutic window of embelin. These results are indicative of the fact that embelin is a multitargeted agent playing role in stopping the formation of amyloid-ß oligomers (via inhibition of BACE-1), improves cholinergic-transmission (via inhibition of AChE/BChE) and increases amyloid-ß clearance (via P-gp induction).


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/química , Acetilcolinesterase/química , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/química , Ácido Aspártico Endopeptidases/química , Benzoquinonas/farmacologia , Butirilcolinesterase/química , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Doença de Alzheimer/tratamento farmacológico , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Benzoquinonas/química , Butirilcolinesterase/metabolismo , Linhagem Celular , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Embelia/química , Proteínas Ligadas por GPI/antagonistas & inibidores , Proteínas Ligadas por GPI/química , Humanos , Modelos Moleculares , Simulação de Acoplamento Molecular , Estrutura Molecular
9.
Autophagy ; 15(10): 1810-1828, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30894052

RESUMO

Imbalance in production and clearance of amyloid beta (Aß) is the primary reason for its deposition in Alzheimer disease. Macroautophagy/autophagy is one of the important mechanisms for clearance of both intracellular and extracellular Aß. Here, through screening, we identified alborixin, an ionophore, as a potent inducer of autophagy. We found that autophagy induced by alborixin substantially cleared Aß in microglia and primary neuronal cells. Induction of autophagy was accompanied by up regulation of autophagy proteins BECN1/Beclin 1, ATG5, ATG7 and increased lysosomal activities. Autophagy induced by alborixin was associated with inhibition of the phosphoinositide 3-kinase (PI3K)-AKT pathway. A knock down of PTEN and consistent, constitutive activation of AKT inhibited alborixin-induced autophagy and consequent clearance of Aß. Furthermore, clearance of Aß by alborixin led to significant reduction of Aß-mediated cytotoxicity in primary neurons and differentiated N2a cells. Thus, our findings put forward alborixin as a potential anti-Alzheimer therapeutic lead. Abbreviations: Aß: amyloid beta; ALB: alborixin; ATG: autophagy-related; BECN1: beclin 1; DAPI: 4, 6-diamidino-2-phenylindole; DCFH-DA: 2,7-dichlorodihydrofluorescein diacetate; fAß: fibrillary form of amyloid beta; GFAP: glial fibrillary acidic protein; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; MAP2: microtubule-associated protein 2; MTOR: mechanistic target of rapamycin kinase; PTEN: phosphatase and tensin homolog; ROS: reactive oxygen species; SQSTM1: sequestosome 1; TMRE: tetramethylrhodamine, ethyl ester.

10.
J Org Chem ; 84(9): 5129-5140, 2019 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-30896160

RESUMO

NLRP3 inflammasome is an important therapeutic target for a number of human diseases. Herein, computationally designed series of quinazolin-4(3 H)-ones were synthesized using iodine-catalyzed coupling of arylalkynes (or styrenes) with O-aminobenzamides. The key event in this transformation involves the oxidative cleavage of the C-C triple/double bond and the release of formaldehyde. The reaction relies on the C-N bond formation along with the C-C bond cleavage under metal-free conditions. The nitro-substituted quinazolin-4(3 H)-one 2k inhibited NLRP3 inflammasome (IC50 5 µM) via the suppression of IL-1ß release from ATP-stimulated J774A.1 cells.

11.
J Integr Med ; 17(3): 192-204, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30898582

RESUMO

OBJECTIVE: Bergenia ciliata (Haw.) Sternb. is used in the Indian traditional system of medicine to treat various ailments including rheumatism and to heal wounds. The objective of the present study was to perform a preclinical characterization of the B. ciliata-based botanical extract IIIM-160. METHODS: IIIM-160 was chemically standardized and analyzed for heavy metal content, aflatoxins, pesticides and microbial load. The in vitro and in vivo efficacies were determined in suitable models of inflammation, arthritis and nociception. An acute oral toxicity study was performed in Swiss albino mice. A suitable oral formulation was developed and characterized. RESULTS: Bergenin was found to be the major component (9.1% w/w) of IIIM-160. The botanical lead displayed inhibition of lipopolysaccharide-induced production of proinflammatory cytokines in THP-1 cells, with selectivity toward interleukin-6 (IL-6) and had an excellent safety-window. It showed anti-inflammatory, anti-arthritic and antinociceptive activity in animal models and was not toxic at oral doses up to 2 g/kg in Swiss-albino mice. The gastroretentive, sustained-release capsule formulation showed sustained-release of the bergenin over the period of 24 h, resulting in improved plasma-exposure of bergenin in Sprague-Dawley rats. CONCLUSION: The dual-activity of IL-6 inhibition and antinociception marks the suitability of IIIM-160 for treating rheumatoid arthritis. This study will serve as the benchmark for further research on this botanical formulation.

12.
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
13.
Bioorg Chem ; 85: 152-158, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30612081

RESUMO

Aggregation/misfolding of α-synuclein and ßA4 proteins cause neuronal cell death (NCD) associated with Parkinson's and Alzheimer's disease. It has been suggested that a heat shock protein-90 (Hsp90) inhibitor can prevent NCD by activating the heat shock transcription factor-1 which, in turn, upregulates molecular chaperones such as Hsp70 that targets aggregated/misfolded proteins for refolding/degradation. We have isolated radicicol, an Hsp90 inhibitor, from a fungus occurring in the crevices of marble rocks of Central India. Radicicol, which was found to be a strong antioxidant, was tested for its ability to rescue yeast cells from death induced by expression of wild-type α-synuclein, its more toxic A53T mutant, and ßA4. It effectively overcomes wild-type/mutant α-synuclein mediated yeast cell death, concomitantly diminishes ROS levels, reverses mitochondrial dysfunction and prevents nuclear DNA-fragmentation, a hallmark of apoptosis. Surprisingly however, radicicol is unable to rescue yeast cells from death triggered by expression of secreted ßA4. Moreover, although radicicol acts as an antioxidant it fails to prevent yeast cell death inflicted by the proapoptotic protein, Bax. Our results indicate that radicicol specifically targets aggregated/misfolded α-synuclein's toxicity and opens up the possibility of using multiple yeast assays to screen natural product libraries for compounds that would unambiguously target α-synuclein aggregation/misfolding.

14.
Eur J Pharm Sci ; 128: 118-127, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30502452

RESUMO

Aggregated Aß peptides which cause amyloid deposits, a characteristic of Alzheimer's disease (AD), activate a stress response in the endoplasmic reticulum (ER), known as the unfolded protein response, UPRER. Nascent UPRER induction helps in reducing ER stress by eliminating accumulated misfolded/aggregated secretory proteins. However, prolonged UPRER induction may trigger apoptosis. Here we show that, when expressed in yeast with an NH2-terminal secretory signal sequence (ss), the 42-amino acid human Aß42 (h_Aß42), but not the mouse/ratAß42 (m_Aß42) which reportedly does not misfold/aggregate, induces UPRER as monitored via an eGFP reporter. We also show that expression of ss-h_Aß42, not ss-m_Aß42, blocks yeast cell growth, with cells expressing ss-h_Aß42 manifesting distinctive features of apoptosis such as loss of mitochondrial membrane potential, increase in ROS levels and DNA fragmentation. Screening for suppressors of ss-h_Aß42-activated UPRER-eGFP induction, in a computationally-designed 29-compound methoxy-stilbene library, revealed three compounds that reduce >95% of UPRER-eGFP induction at 5 µM concentration, with EC50 values of 40-50 nM. Surprisingly, the compounds also rescue yeast cells from ss-h_Aß42-mediated apoptosis, with EC50-s of 50-60 nM. These results provide direct evidence, probably for the first time, that there is a direct correlation between deactivation of UPRER and attenuation of apoptosis.


Assuntos
Peptídeos beta-Amiloides/antagonistas & inibidores , Apoptose/fisiologia , Fragmentos de Peptídeos/antagonistas & inibidores , Saccharomyces cerevisiae/efeitos dos fármacos , Estilbenos/farmacologia , Peptídeos beta-Amiloides/metabolismo , Animais , Retículo Endoplasmático , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Camundongos , Estrutura Molecular , Fragmentos de Peptídeos/metabolismo , Ratos , Espécies Reativas de Oxigênio , Saccharomyces cerevisiae/metabolismo , Estilbenos/síntese química , Estilbenos/química , Relação Estrutura-Atividade , Resposta a Proteínas não Dobradas
15.
J Pharm Biomed Anal ; 166: 1-5, 2019 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-30590350

RESUMO

IIIM-290, an orally bioavailable preclinical candidate is effective in human xenograft models of leukemia, colon and pancreatic cancer. The promising preclinical data of this lead candidate has shown its potential for clinical development. As a part of its preclinical development, impurity profiling of pilot scale batches is one of the most important component of the CMC documentation. Herein, we report impurity profiling, its quantification in different scale-up batches and analytical method validation. Three impurities ranging from 0.09 to 1.25% in preclinical anticancer candidate, IIIM-290 were detected by validated HPLC method. The impurities (Imp-A, Imp-B and Imp-F) were isolated from the partially purified batch of IIIM-290 using semi-preparative HPLC. Isolated impurities were characterized by 1H, 13C NMR, FTIR and ESI-MS spectral data. Based on the characterization data, the sources of these impurities were identified as unreacted starting material (Imp-A), impurity from botanical raw material (Imp-B; impurity carried from starting material) and the chemically transformed product (Imp-F) of Imp-B, respectively.


Assuntos
Contaminação de Medicamentos , Benzopiranos/química , Cromatografia Líquida de Alta Pressão
16.
Bioorg Med Chem Lett ; 29(3): 454-460, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30579794

RESUMO

Herein, we have identified yeast Sec22p (ySec22p), a SNARE protein essential for endoplasmic reticulum to Golgi trafficking, as a suppressor of Bax-induced yeast apoptosis and corroborated published observations that ySec22p suppresses α-synuclein's toxicity in yeast. It has been suggested that compounds which enhance expression, in neurons, of human homologues of ySec22p (Sec22Bp/Sec22p/Sec22A) would prevent synucleinopathies, such as Parkinson's disease. With the aim of finding a small molecule that would mimic ySec22p, a library of natural products consisting of 394-compounds was screened using yeast cells that express either human α-synuclein or human Bax. The antioxidant aegeline, an alkaloid-amide occurring in the leaves of the plant Aegle marmelos Correa, was the only molecule that overcame apoptosis induced by both α-synuclein and Bax in yeast. Besides, aegeline also prevented growth block in cells expressing the more toxic A53T α-synuclein mutant. Restoration of cell growth occurred through inhibition of increased ROS levels, mitochondrial membrane potential loss and nuclear DNA fragmentation, characteristics of apoptosis manifested in α-synuclein or Bax-expressing cells. These results highlight the importance of yeast systems to identify rapidly molecules that may prevent the onset of apoptosis that occurs in Parkinson's disease.


Assuntos
Aegle/química , Amidas/farmacologia , Antioxidantes/farmacologia , Produtos Biológicos/farmacologia , Proteínas R-SNARE/antagonistas & inibidores , Proteínas de Saccharomyces cerevisiae/antagonistas & inibidores , Saccharomyces cerevisiae/efeitos dos fármacos , Amidas/química , Amidas/isolamento & purificação , Antioxidantes/química , Antioxidantes/isolamento & purificação , Apoptose/efeitos dos fármacos , Produtos Biológicos/química , Produtos Biológicos/isolamento & purificação , Relação Dose-Resposta a Droga , Estrutura Molecular , Proteínas R-SNARE/metabolismo , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/citologia , Proteínas de Saccharomyces cerevisiae/metabolismo , Relação Estrutura-Atividade , alfa-Sinucleína/metabolismo , Proteína X Associada a bcl-2/metabolismo
17.
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
18.
ChemMedChem ; 13(23): 2581-2598, 2018 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-30358112

RESUMO

A series of indolo[3,2-b]quinoline-C11-carboxamides were synthesized by incorporation of aminoalkyl side chains into the core of indolo[3,2-b]quinoline-C11-carboxylic acid. Their in vitro antiplasmodial evaluation against Plasmodium falciparum led to the identification of a 2-(piperidin-1-yl)ethanamine-linked analogue {2-bromo-N-[2-(piperidin-1-yl)ethyl]-10H-indolo[3,2-b]quinoline-11-carboxamide (3 g)} (IC50 =1.3 µm) as the most promising compound exhibiting good selectivity indices against mammalian cell lines. The kill kinetics on erythrocytic-stage parasites revealed that 3 g caused complete killing of only the trophozoite-stage parasites. Mechanistic studies showed that 3 g targets the food vacuole of the parasite and inhibits hemoglobin uptake, ß-hematin formation, and the basic endocytic processes of the parasite. Analogue 3 g was found to be orally bioavailable, and its curative antimalarial studies at 50 mg per kg p.o. against a Plasmodium berghei (ANKA)-infected mouse model revealed that mice treated with 3 g showed 27-35 % suppression of parasitemia with an increase in life span relative to untreated, control mice. Thus, the present work demonstrated a proof of concept for the oral efficacy of indolo[3,2-b]quinoline-C11-carboxamides.


Assuntos
Antimaláricos/uso terapêutico , Hemoglobinas/metabolismo , Interações Hospedeiro-Parasita/efeitos dos fármacos , Alcaloides Indólicos/uso terapêutico , Malária/tratamento farmacológico , Plasmodium berghei/efeitos dos fármacos , Plasmodium falciparum/efeitos dos fármacos , Quinolinas/uso terapêutico , Animais , Antimaláricos/química , Antimaláricos/farmacologia , Linhagem Celular , Humanos , Alcaloides Indólicos/química , Alcaloides Indólicos/farmacologia , Malária/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Plasmodium berghei/metabolismo , Plasmodium falciparum/metabolismo , Quinolinas/química , Quinolinas/farmacologia
19.
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.

20.
ACS Omega ; 3(7): 8365-8377, 2018 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-30087943

RESUMO

IIIM-290, a semisynthetic derivative of natural product rohitukine, is an orally bioavailable Cdk inhibitor, efficacious in the xenograft models of colon, pancreatic, and leukemia cancer. Its low aqueous solubility (∼8.6 µg/mL) could be one of the reasons for achieving optimal in vivo efficacy relatively at a higher dose. Being a nitrogenous compound, salt formation was envisaged as one of the ideal approaches to enhance its solubility and dissolution profile. Thus, herein, a solubility-guided miniaturized 96-well plate salt screening protocol was devised for identification of the suitable salt form of this preclinical candidate. The solubility-guided strategy has resulted in the identification of hydrochloride as the most favorable counterion, resulting in 45-fold improvement in aqueous solubility. The HCl salt was then scaled up at a gram size and characterized using 1H and 13C NMR, scanning electron microscopy, powder X-ray diffraction, Fourier-transform infrared, and differential scanning calorimetry studies. The HCl salt displayed enhancement in the in vitro dissolution profile as well as improved plasma exposure in the pharmacokinetic study. The oral administration of the IIIM-290·HCl salt in BALB/c mice resulted in >1.5-fold improvement in areas under the curve, Cmax, and half-life. The prepared salt also did not alter its cyclin-dependent kinase (Cdk)-2 and Cdk-9 inhibition activity. This biopharmaceutically improved lead has a potential to investigate further in preclinical studies. The solubility-guided salt screening strategy implemented herein could be utilized for other preclinical leads.

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