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1.
Molecules ; 26(7)2021 Apr 03.
Article in English | MEDLINE | ID: mdl-33916785

ABSTRACT

Nordihydroguaiaretic acid (NDGA) is a major lignan metabolite found in Larrea spp., which are widely used in South America to treat various diseases. In breast tissue, estradiol is metabolized to the catechol estrogens such as 4-hydroxyestradiol (4-OHE2), which have been proposed to be cancer initiators potentially involved in mammary carcinogenesis. Catechol-O-methyltransferase (COMT) catalyzes the O-methylation of catechol estrogens to their less toxic methoxy derivatives, such as 4-O-methylestradiol (4-MeOE2). The present study investigated the novel biological activities of NDGA in relation to COMT and the effects of COMT inhibition by NDGA on 4-OHE2-induced cyto- and genotoxicity in MCF-7 human breast cancer cells. Two methoxylated metabolites of NDGA, 3-O-methylNDGA (3-MNDGA) and 4-O-methyl NDGA (4-MNDGA), were identified in the reaction mixture containing human recombinant COMT, NDGA, and cofactors. Km values for the COMT-catalyzed metabolism of NDGA were 2.6 µM and 2.2 µM for 3-MNDGA and 4-MNDGA, respectively. The COMT-catalyzed methylation of 4-OHE2 was inhibited by NDGA at an IC50 of 22.4 µM in a mixed-type mode of inhibition by double reciprocal plot analysis. Molecular docking studies predicted that NDGA would adopt a stable conformation at the COMT active site, mainly owing to the hydrogen bond network. NDGA is likely both a substrate for and an inhibitor of COMT. Comet and apurinic/apyrimidinic site quantitation assays, cell death, and apoptosis in MCF-7 cells showed that NDGA decreased COMT-mediated formation of 4-MeOE2 and increased 4-OHE2-induced DNA damage and cytotoxicity. Thus, NDGA has the potential to reduce COMT activity in mammary tissues and prevent the inactivation of mutagenic estradiol metabolites, thereby increasing catechol estrogen-induced genotoxicities.


Subject(s)
Catechol O-Methyltransferase Inhibitors/chemistry , Catechol O-Methyltransferase Inhibitors/pharmacology , Catechol O-Methyltransferase/metabolism , Estrogens, Catechol/metabolism , Masoprocol/metabolism , Masoprocol/pharmacology , Mutagens/toxicity , Binding Sites , Cell Death/drug effects , DNA Damage , Estrogens, Catechol/chemistry , Estrogens, Catechol/pharmacology , Humans , MCF-7 Cells , Masoprocol/chemistry , Methylation , Molecular Docking Simulation , Recombinant Proteins/metabolism , Substrate Specificity/drug effects
2.
Phytother Res ; 34(6): 1347-1357, 2020 Jun.
Article in English | MEDLINE | ID: mdl-31908073

ABSTRACT

Prunus cerasoides (PC) products contain relatively high levels of flavones and isoflavones and may be potential sources of phytoestrogens for postmenopausal symptom relief. We assessed the PC extract (PCE) and its representative constituents in vitro with assays for estrogen receptor alpha binding, estrogen response element transcriptional activity, cell proliferation, and gene expression changes for pS2 in MCF-7 cells. PCE and its compounds showed strong estrogen receptor binding affinities and estrogen response element induction. A previously undescribed compound (designated as compound 18), now identified as being gentisic acid, 5-O-ß-D-(6'-O-trans-4-coumaroyl)-glucopyranoside, also showed potent estrogenic properties and induced proliferation of MCF-7 cells. PCE was evaluated for its in vivo uterotrophic effects in immature female rats as well as for its lipid lowering effects in estrogen-deprived animals. For ovariectomized rats and aged female mice, PCE-treated groups had lower plasma triglyceride levels compared with control and, for the same comparison, had reduced serum levels of liver stress/damage markers. Our results point to strong estrogenic activities and beneficial metabolic effects for PCE, with properties that put PC and its extracts as promising sources of phytoestrogens for symptom relief in menopausal and postmenopausal cases.


Subject(s)
Estrogens/therapeutic use , Plant Extracts/chemistry , Prunus/chemistry , Animals , Disease Models, Animal , Estrogens/pharmacology , Female , Humans , MCF-7 Cells/metabolism , Mice , Rodentia
4.
Int J Mol Sci ; 19(11)2018 Oct 30.
Article in English | MEDLINE | ID: mdl-30380747

ABSTRACT

Opuntia ficus indica (OFI) is grown abundantly in arid areas and its fruits are regarded as an important food and nutrient source owing to the presence of flavonoids, minerals, and proteins. The previous report that OFI exerts phytoestrogenic activity makes it plausible for OFI-containing supplements to be used as alternative estrogen replacement therapy. In the case of polypharmacy with the consumption of OFI-containing botanicals in post- or peri-menopausal women, it is critical to determine the potential drug-OFI interaction due to the modulation of drug metabolism. In the present study, the modulating effects on the hepatic drug metabolizing enzymes (DMEs) by OFI and its flavonoid constituents (kaempferol, quercetin, isorhamnetin, and their glycosidic forms) were investigated using the liver microsomal fractions prepared from ovariectomized (OVX) rats, human liver microsomes, and human hepatocarcinoma cell line (HepG2). As a result, the oral administration of extracts of OFI (OFIE) in OVX rats induced hepatic CYP2B1, CYP3A1, and UGT2B1. OFIE, hydrolyzed (hdl) OFIE, and several flavonols induced the transcriptional activities of both CYP2B6 and CYP3A4 genes in HepG2 cells. Finally, OFIE did not inhibit activities of cytochrome P450 (CYPs) or uridine diphosphate (UDP)-glucuronosyltransferases (UGTs), whereas hdl OFIE or flavonol treatment inhibited CYP1A2 and CYP3A1/3A4 in rat and human liver microsomes. Our data demonstrate that OFIE may induce or inhibit certain types of DMEs and indicate that drug-OFI interaction may occur when the substrate or inhibitor drugs of specific CYPs or UGTs are taken concomitantly with OFI-containing products.


Subject(s)
Cytochrome P-450 Enzyme Inducers/pharmacology , Cytochrome P-450 Enzyme Inhibitors/pharmacology , Cytochrome P-450 Enzyme System/metabolism , Flavonoids/pharmacology , Glucuronosyltransferase , Opuntia/chemistry , Plant Extracts/pharmacology , Animals , Cytochrome P-450 Enzyme Inducers/chemistry , Cytochrome P-450 Enzyme Inhibitors/chemistry , Female , Flavonoids/chemistry , Glucuronosyltransferase/antagonists & inhibitors , Glucuronosyltransferase/metabolism , Hep G2 Cells , Humans , Microsomes, Liver/enzymology , Plant Extracts/chemistry , Rats , Rats, Sprague-Dawley
5.
Molecules ; 23(7)2018 Jun 26.
Article in English | MEDLINE | ID: mdl-29949932

ABSTRACT

Sakuranetin (SKN), found in cherry trees and rice, is a flavanone with various pharmacological activities. It is biosynthesized from naringenin in rice or cherry trees, and the metabolism of SKN has been studied in non-human species. The present study aimed to investigate the metabolic pathways of SKN in human liver microsomes and identify the phase I and phase II metabolites, as well as evaluate the potential for drug⁻herb interactions through the modulation of drug metabolizing enzymes (DMEs). HPLC-DAD and HPLC-electrospray mass spectrometry were used to study the metabolic stability and identify the metabolites from human liver microsomes incubated with SKN. The potential of SKN to inhibit the DMEs was evaluated by monitoring the formation of a DME-specific product. The cytochrome P450 2B6 and 3A4-inductive effects were studied using promoter reporter assays in human hepatocarcinoma cells. The major pathways for SKN metabolism include B-ring hydroxylation, 5-O-demethylation, and conjugation with glutathione or glucuronic acid. The phase I metabolites were identified as naringenin and eriodictyol. SKN was found to be a UDP-glucuronosyltransferases (UGT) 1A9 inhibitor, whereas it induced transactivation of the human pregnane X receptor-mediated cytochrome P450 (CYP) 3A4 gene.


Subject(s)
Cytochrome P-450 Enzyme System/metabolism , Flavonoids/metabolism , Glucuronosyltransferase/metabolism , Liver/metabolism , Animals , Chromatography, High Pressure Liquid , Cytochrome P-450 Enzyme Inhibitors/pharmacology , Cytochrome P-450 Enzyme System/genetics , Hep G2 Cells , Humans , Liver/drug effects , Metabolic Detoxication, Phase I , Metabolic Detoxication, Phase II , Metabolome , Microsomes, Liver/drug effects , Microsomes, Liver/metabolism , NADP/metabolism , Pregnane X Receptor , Promoter Regions, Genetic/genetics , Receptors, Steroid/metabolism , Transcriptional Activation/genetics , Uridine Diphosphate Glucuronic Acid/metabolism
6.
Molecules ; 23(2)2018 Jan 31.
Article in English | MEDLINE | ID: mdl-29385086

ABSTRACT

Bioactivity-guided fractionation for the stems of leaves of Larrea nitida Cav., using interleukin-6 (IL-6) inhibitory assay in human mast cells (HMC-1), led to the isolation of three new compounds with an unprecedented skeleton in nature (1-3) and three known compounds (4-6). Their structures were elucidated through extensive spectroscopic analysis. The three new compounds were elucidated as two new spiroketones, nitidaones A (1), and B (2) and one new biphenyl analog, nitidaol (3). The known compounds were identified as nordihydroguaiaretic acid (4), 7,3',4'-tri-O-methylquercetin (5) and ayanin (6). All the isolates were tested for their inhibitory activity against IL-6 production in HMC-1 cells. Of them, compounds 1, 3-6 showed potent anti-inflammatory activity, with IC50 values of 12.8, 17.5, 14.9, 22.9, and 17.8 µM, respectively.


Subject(s)
Anti-Inflammatory Agents , Biphenyl Compounds , Interleukin-6/biosynthesis , Larrea/chemistry , Mast Cells/metabolism , Plant Leaves/chemistry , Plant Stems/chemistry , Spironolactone , Anti-Inflammatory Agents/chemistry , Anti-Inflammatory Agents/pharmacology , Biphenyl Compounds/chemistry , Biphenyl Compounds/pharmacology , Cell Line , Humans , Mast Cells/cytology , Spironolactone/chemistry , Spironolactone/pharmacology
7.
Phytother Res ; 31(1): 140-151, 2017 Jan.
Article in English | MEDLINE | ID: mdl-28058783

ABSTRACT

Larrea nitida Cav. (LNC), which belongs to the family Zygophyllaceae, is widely indigenous and used in South America to treat various pathological conditions. It contains the antioxidant and antiinflammatory but toxic nordihydroguaiaretic acid (NDGA) as well as O-methylated metabolite of NDGA (MNDGA) as bioactive compounds. The hepatic metabolism-based toxicological potential of extracts of LNC (LNE), NDGA, and MNDGA has not previously been reported. The present study aimed to characterize the phase I and phase II hepatic metabolism and reactive intermediates of LNE, NDGA, and MNDGA and their effects on the major drug-metabolizing enzymes in vitro and ex vivo. A methanol extract of LNC collected from Chile as well as NDGA and MNDGA isolated from LNE were subjected to metabolic stability assays in liver microsomes in the presence of the cofactors reduced nicotinamide dinucleotide phosphate (NADPH) and/or uridine 5'-diphosphoglucuronic acid (UDPGA). Cytochrome P450 (CYP) inhibition assays were performed using CYP isozyme-specific model substrates to examine the inhibitory activities of LNE, NDGA, and MNDGA, which were expressed as % inhibition and IC50 values. Ex vivo CYP induction potential was investigated in the liver microsomes prepared from the rats intraperitoneally administered with LNE. Glutathione (GSH) adduct formation was monitored by LC-MS3 analysis of the microsomal incubation samples with either NDGA or MNDGA and an excess of GSH to determine the formation of electrophilic reactive intermediates. Both NDGA and MNDGA were stable to NADPH-dependent phase I metabolism, but labile to glucuronide conjugation. LNE, NDGA, and MNDGA showed significant inhibitory effects on CYP1A2, 2C9, 2D6, and/or 3A4, with IC50 values in the micromolar range. LNE was found to be a CYP1A2 inducer in ex vivo rat experiments, and mono- and di-GSH adducts of both NDGA and MNDGA were identified by LC-MS3 analysis. Our study suggests that hepatic clearance is the major elimination route for the lignans NDGA and MNDGA present in LNE. These lignans may possess the ability to modify biomacromolecules via producing reactive intermediates. In addition, LNE, NDGA, and MNDGA are found to be inhibitors for various CYP isozymes such as CYP2C9 and 3A4. Thus, the consumption of LNC as an herbal preparation or NDGA may cause metabolism-driven herb-drug interactions. Copyright © 2016 John Wiley & Sons, Ltd.


Subject(s)
Larrea/chemistry , Lignans/chemistry , Liver/metabolism , Microsomes, Liver/drug effects , Animals , Female , Herb-Drug Interactions , Humans , Lignans/pharmacology , Rats
8.
Phytother Res ; 30(6): 971-80, 2016 Jun.
Article in English | MEDLINE | ID: mdl-26989859

ABSTRACT

Phytoestrogens are selective estrogen receptor modulators (SERMs) with potential for use in hormone replacement therapy (HRT) to relieve peri/postmenopausal symptoms. This study was aimed at elucidating the molecular mechanisms underlying the SERM properties of the extract of Korean-grown Opuntia ficus-indica (KOFI). The KOFI extract induced estrogen response element (ERE)-driven transcription in breast and endometrial cancer cell lines and the expression of endogenous estrogen-responsive genes in breast cancer cells. The flavonoid content of different KOFI preparations affected ERE-luciferase activities, implying that the flavonoid composition likely mediated the estrogenic activities in cells. Oral administration of KOFI decreased the weight gain and levels of both serum glucose and triglyceride in ovariectomized (OVX) rats. Finally, KOFI had an inhibitory effect on the 17ß-estradiol-induced proliferation of the endometrial epithelium in OVX rats. Our data demonstrate that KOFI exhibited SERM activity with no uterotrophic side effects. Therefore, KOFI alone or in combination with other botanical supplements, vitamins, or minerals may be an effective and safe alternative active ingredient to HRTs, for the management of postmenopausal symptoms. Copyright © 2016 John Wiley & Sons, Ltd.


Subject(s)
Chromatography, High Pressure Liquid/methods , Opuntia/chemistry , Receptors, Estrogen/chemistry , Animals , Female , Humans , Plant Extracts/pharmacology , Rats , Rats, Sprague-Dawley , Transfection
9.
Biochem Biophys Res Commun ; 452(3): 840-4, 2014 Sep 26.
Article in English | MEDLINE | ID: mdl-25218501

ABSTRACT

Estrogen receptor α (ERα) plays a crucial role in estrogen-mediated signaling pathways and exerts its action as a nuclear transcription factor. Binding of the ligand-activated ERα to the estrogen response element (ERE) is a central part of ERα-associated signal transduction pathways and its aberrant modulation is associated with many disease conditions. Human glutathione S-transferase P1-1 (GSTP) functions as an enzyme in conjugation reactions in drug metabolism and as a regulator of kinase signaling pathways. It is overexpressed in tumors following chemotherapy and has been associated with a poor prognosis in breast cancer. In this study, a novel regulatory function of GSTP has been proposed in which GSTP modulates ERE-mediated ERα signaling events. Ectopic expression of GSTP was able to induce the ERα and ERE-mediated transcriptional activities in ERα-positive but GSTP-negative MCF7 human breast cancer cells. This inductive effect of GSTP on the ERE-transcription activity was diminished when the cells express a mutated form of the enzyme or are treated with a GSTP-specific chemical inhibitor. It was found that GSTP inhibited the expression of the receptor interacting protein 140 (RIP140), a negative regulator of ERα transcription, at both mRNA and protein levels. Our study suggests a novel non-enzymatic role of GSTP which plays a significant role in regulating the classical ERα signaling pathways via modification of transcription cofactors such as RIP140.


Subject(s)
Adaptor Proteins, Signal Transducing/genetics , Breast Neoplasms/genetics , Estrogen Receptor alpha/genetics , Gene Expression Regulation, Neoplastic , Glutathione S-Transferase pi/genetics , Nuclear Proteins/genetics , RNA, Messenger/genetics , Adaptor Proteins, Signal Transducing/metabolism , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Cell Line, Tumor , Estradiol/pharmacology , Estrogen Receptor Modulators/metabolism , Estrogen Receptor alpha/metabolism , Female , Genes, Reporter , Glutathione S-Transferase pi/metabolism , Humans , Luciferases/genetics , Luciferases/metabolism , Mutation , Nuclear Proteins/metabolism , Nuclear Receptor Interacting Protein 1 , RNA, Messenger/metabolism , Response Elements , Signal Transduction , Transcription, Genetic
10.
Bioorg Med Chem Lett ; 24(5): 1403-6, 2014 Mar 01.
Article in English | MEDLINE | ID: mdl-24507928

ABSTRACT

A novel biological activity of psoralidin as an agonist for both estrogen receptor (ER)α and ERß agonist has been demonstrated in our study. Psoralidin has been characterized as a full ER agonist, which activates the classical ER-signaling pathway in both ER-positive human breast and endometrial cell lines as well as non-human cultured cells transiently expressing either ERα or ERß. The estrogenic activity was determined using the relative expression levels of either reporter or the endogenous genes dependent on the agonist-bound ER to the estrogen response element (ERE). Psoralidin at 10 µM was able to induce the maximum reporter gene expression corresponding to that of E2-treated cells and such activation of the ERE-reporter gene by psoralidin was completely abolished by the cotreatment of a pure ER antagonist, implying that the biological activities of psoralidin are mediated by ER. Psoralidin was also able to induce the endogenous estrogen-responsive gene, pS2, in human breast cancer cells MCF-7. It was observed that activation of the classical ER-signaling pathway by psoralidin is mediated via induction of ER conformation by psoralidin and direct binding of the psoralidin-ER complex to the EREs present in the promoter region of estrogen-responsive genes, as shown by chromatin immunoprecipitation assay results. Finally, molecular docking of psoralidin to the ligand binding pocket of the ERα showed that psoralidin is able to mimic the binding interactions of E2, and thus, it could act as an ER agonist in the cellular environment.


Subject(s)
Benzofurans/chemistry , Coumarins/chemistry , Psoralea/chemistry , Receptors, Estrogen/metabolism , Benzofurans/isolation & purification , Benzofurans/pharmacology , Binding Sites , Cell Line , Cell Proliferation/drug effects , Coumarins/isolation & purification , Coumarins/pharmacology , Estrogen Receptor alpha/agonists , Estrogen Receptor alpha/metabolism , Estrogen Receptor beta/agonists , Estrogen Receptor beta/metabolism , Female , Humans , Molecular Docking Simulation , Protein Binding , Protein Structure, Tertiary , Psoralea/metabolism , Receptors, Estrogen/agonists , Signal Transduction/drug effects
11.
Regul Toxicol Pharmacol ; 69(2): 207-16, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24747398

ABSTRACT

CKD-501 is a peroxisome proliferator-activated receptor (PPAR) agonist. The current study was conducted in Sprague Dawley (SD) rats for 94-101 weeks to investigate the carcinogenic potential of CKD-501. 60 males received 0, 0.03, 0.12, or 1.0mg/kg/day, which was changed after 66 weeks to 0.24 mg/kg/day due to increased mortality, while 60 females received 0, 0.03, 0.06, or 0.12 mg/kg/day throughout the study period. After switching the dosage, no significant changes in the survival rates were observed. Non-neoplastic lesions such as bladder transitional cell hyperplasia and a diminished corpus luteum were observed in females administered 0.12 mg/kg/day and the right chamber dilation and left ventricular hypertrophy were increased dose dependently in both males and females. Non-neoplastic lesions such as bone marrow hypoplasia and fat cell proliferation and neoplastic lesions such as lipomas and liposarcomas observed in males and/or females were considered expected pharmacological effects for this compound. Compared to rosiglitazone, CKD-501 had a 4.4-fold higher margin of safety for tumor induction and did not cause bladder carcinoma as was observed with pioglitazone.


Subject(s)
Carcinogens/toxicity , Lipoma/chemically induced , Liposarcoma/chemically induced , PPAR alpha/agonists , PPAR gamma/agonists , Pyrimidines/administration & dosage , Pyrimidines/toxicity , Thiazolidinediones/administration & dosage , Thiazolidinediones/toxicity , Administration, Oral , Animals , Body Weight/drug effects , Carcinogenicity Tests , Carcinogens/administration & dosage , Dose-Response Relationship, Drug , Female , Lipoma/pathology , Liposarcoma/pathology , Male , Platelet Count , Rats , Rats, Sprague-Dawley , Time Factors
12.
J Neurochem ; 124(4): 523-35, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23199288

ABSTRACT

Oxidative stress after stroke is associated with the inflammatory system activation in the brain. The complement cascade, especially the degradation products of complement component 3, is a key inflammatory mediator of cerebral ischemia. We have shown that pro-inflammatory complement component 3 is increased by oxidative stress after ischemic stroke in mice using DNA array. In this study, we investigated whether up-regulation of complement component 3 is directly related to oxidative stress after transient focal cerebral ischemia in mice and oxygen-glucose deprivation in brain cells. Persistent up-regulation of complement component 3 expression was reduced in copper/zinc-superoxide dismutase transgenic mice, and manganese-superoxide dismutase knock-out mice showed highly increased complement component 3 levels after transient focal cerebral ischemia. Antioxidant N-tert-butyl-α-phenylnitrone treatment suppressed complement component 3 expression after transient focal cerebral ischemia. Accumulation of complement component 3 in neurons and microglia was decreased by N-tert-butyl-α-phenylnitrone, which reduced infarct volume and impaired neurological deficiency after cerebral ischemia and reperfusion in mice. Small interfering RNA specific for complement component 3 transfection showed a significant increase in brain cells viability after oxygen-glucose deprivation. Our study suggests that the neuroprotective effect of antioxidants through complement component 3 suppression is a new strategy for potential therapeutic approaches in stroke.


Subject(s)
Brain Ischemia/drug therapy , Complement C3/metabolism , Cyclic N-Oxides/therapeutic use , Neurons/drug effects , Neuroprotective Agents/therapeutic use , Reperfusion Injury/prevention & control , Up-Regulation/physiology , Animals , Brain/drug effects , Brain/metabolism , Brain/pathology , Brain Ischemia/blood , Brain Ischemia/complications , Brain Ischemia/pathology , Cell Survival/drug effects , Cell Survival/genetics , Cells, Cultured , Cerebral Cortex/cytology , Complement C3/genetics , Cyclooxygenase 2/metabolism , Disease Models, Animal , Down-Regulation/drug effects , Down-Regulation/genetics , Enzyme-Linked Immunosorbent Assay , Glucose/deficiency , Hypoxia , L-Lactate Dehydrogenase/metabolism , Male , Mice , Mice, Transgenic , Nervous System Diseases/etiology , Nervous System Diseases/prevention & control , Neuroglia/drug effects , Neuroglia/metabolism , Neurons/metabolism , Oxidative Stress/drug effects , Oxidative Stress/genetics , RNA, Messenger/metabolism , Reactive Oxygen Species/metabolism , Superoxide Dismutase/deficiency , Superoxide Dismutase/genetics , Superoxide Dismutase-1 , Time Factors , Up-Regulation/drug effects
13.
Foods ; 12(22)2023 Nov 10.
Article in English | MEDLINE | ID: mdl-38002146

ABSTRACT

Greasiness in apple skin reduces its quality, and its level varies depending on the variety. In this study, low-temperature (1 ± 0.5 °C) stored 'Hongro' and 'Fuji', which had differences in the occurrence of greasiness, were moved to room temperature (20 °C) and untargeted metabolite and fatty acids for skin and flesh along with quality changes due to greasiness occurrence were compared. Ethylene production differed noticeably between the two varieties and increased rapidly in 'Hongro' until 9 d of room-temperature storage. The ethylene production did not differ significantly between the two varieties on day 20 when greasiness occurred. According to the PLS-DA score plot, while 'Hongro' had similar amounts of unsaturated and saturated fatty acids, 'Fuji' had approximately twice as much unsaturated-fatty-acid content. 'Hongro', after 50 d of low-temperature (1 ± 0.5 °C) storage, produced excessive ethylene during room-temperature storage, which was directly related to greasiness development. As a result, the primary wax components of greasy 'Hongro' were nonacosane and nonacosan-10-ol. As the room-temperature storage period elapsed, pentyl linoleate and α-farnesene contents increased significantly. Furthermore, these greasiness-triggering characteristics of 'Hongro' may have been genetically influenced by the paternal parent used during breeding.

14.
Bioorg Med Chem Lett ; 22(9): 3067-71, 2012 May 01.
Article in English | MEDLINE | ID: mdl-22497764

ABSTRACT

Metabolism of LB42908, a novel farnesyl transferase inhibitor, was investigated for preclinical development. In vitro hepatic metabolism of LB42908 gave rise to at least 9 metabolites via phase I biotransformation pathways, which were characterized by HPLC-UV, LC-MS, and LC-MS/MS analyses. N-Dealkylation was shown to be a major phase I metabolic pathway. Species-specific in vitro metabolism of LB42908 was studied in liver fractions of rat, dog, monkey, and human. Order of metabolic stability is human≈dog>rat≈monkey in both S9 and microsomal fractions. Tissue-specific metabolism of LB42908 in various tissue homogenates of rats demonstrated that the liver was the major organ responsible for phase I metabolism of LB42908. The results from both qualitative and quantitative metabolism studies such as metabolic profiling and metabolic clearance indicated that dog would be the animal model of choice for preclinical toxicology studies. In addition, LB42908 was a potent CYP3A4 inhibitor in human liver microsomes and induced the activities of several CYP isozymes, implying that it has the potential for drug-drug interactions. Repeated dosing of LB42908 in rats did not significantly affect its own metabolism, indicating that long-term administration of LB42908 would not alter its pharmacokinetic profiles.


Subject(s)
Alkyl and Aryl Transferases/antagonists & inhibitors , Cytochrome P-450 Enzyme System/metabolism , Imidazoles/metabolism , Piperazines/metabolism , Animals , Biotransformation , Cytochrome P-450 CYP3A , Cytochrome P-450 CYP3A Inhibitors , Enzyme Inhibitors/metabolism , Enzyme Inhibitors/pharmacology , Humans , Isoenzymes , Microsomes, Liver
15.
Food Sci Biotechnol ; 31(13): 1667-1678, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36312999

ABSTRACT

A Box-Behnken Design (BBD) was employed to optimize the extraction of antioxidants from Ruby S apple peel by ultrasound-assisted extraction (UAE). The effect of extraction temperature (20-40 °C), extraction time (15-45 min), and ethanol concentration (50-90%) in water on extraction yield, total phenol content (TPC), total flavonoid content (TFC), and DPPH radical scavenging activity of Ruby S peel extracts (RPEs) were investigated. The optimized extraction conditions that maximized extraction yield, TPC, TFC, and DPPH radical scavenging ability, were temperature 20 °C, extraction time 25.30 min, and ethanol concentration 50%. The validity of designed model was verified, and experimental values obtained under optimum conditions concurred with predicted values. Hyperoside, isoquercitrin, and phloridzin, were among the major flavonoids extracted. Our findings demonstrate the suitability of UAE and RSM for the optimization of Ruby S peel extraction and suggest the potential use of RPEs as bioactive functional materials.

16.
Metabolites ; 11(8)2021 Jul 26.
Article in English | MEDLINE | ID: mdl-34436421

ABSTRACT

The biguanide drug metformin has been widely used for the treatment of type 2 diabetes, and there is evidence supporting the anticancer effect of metformin despite some controversy. Here, we report the growth inhibitory activity of metformin in the breast cancer (MCF-7) cells, both in vitro and in vivo, and the associated metabolic changes. In particular, a decrease in a well-known oncometabolite 2-hydroxyglutarate (2-HG) was discovered by a metabolomics approach. The decrease in 2-HG by metformin was accompanied by the reduction in histone methylation, consistent with the known tumorigenic mechanism of 2-HG. The relevance of 2-HG inhibition in breast cancer was also supported by a higher level of 2-HG in human breast cancer tissues. Genetic knockdown of PHGDH identified the PHGDH pathway as the producer of 2-HG in the MCF-7 cells that do not carry isocitrate dehydrogenase 1 and 2 (IDH1/IDH2) mutations, the conventional producer of 2-HG. We also showed that metformin's inhibitory effect on the PHGDH-2HG axis may occur through the regulation of the AMPK-MYC pathway. Overall, our results provide an explanation for the coherent pathway from complex I inhibition to epigenetic changes for metformin's anticancer effect.

17.
Chem Res Toxicol ; 23(8): 1374-83, 2010 Aug 16.
Article in English | MEDLINE | ID: mdl-20540524

ABSTRACT

4-Hydroxyequilenin (4-OHEN) is a major phase I metabolite of the equine estrogens present in widely prescribed hormone replacement formulations. 4-OHEN is autoxidized to an electrophilic o-quinone that has been shown to redox cycle, generating ROS, and to covalently modify proteins and DNA and thus potentially to act as a chemical carcinogen. To establish the ability of 4-OHEN to act as a hormonal carcinogen at the estrogen receptor (ER), estrogen responsive gene expression and proliferation were studied in ER(+) breast cancer cells. Recruitment by 4-OHEN of ER to estrogen responsive elements (ERE) of DNA in MCF-7 cells was also studied and observed. 4-OHEN was a potent estrogen, with additional weak activity associated with binding to the arylhydrocarbon receptor (AhR). The potency of 4-OHEN toward classical ERalpha mediated activity was unexpected given the reported rapid autoxidation and trapping of the resultant quinone by GSH. Addition of thiols to cell cultures did not attenuate the estrogenic activity of 4-OHEN, and preformed thiol conjugates added to cell incubations only marginally reduced ERE-luciferase induction. On reaction of the 4OHEN-GSH conjugate with NADPH, 4-OHEN was observed to be regenerated at a rate dependent upon NADPH concentration, indicating that intracellular nonenzymatic and enzymatic regeneration of 4-OHEN accounts for the observed estrogenic activity of 4-OHEN. 4-OHEN is therefore capable of inducing chemical and hormonal pathways that may contribute to estrogen-dependent carcinogenesis, and trapping by cellular thiols does not provide a mechanism of termination of these pathways.


Subject(s)
Equilenin/analogs & derivatives , Glutathione/metabolism , Animals , Cell Proliferation/drug effects , DNA, Neoplasm/drug effects , Equilenin/chemistry , Equilenin/metabolism , Equilenin/pharmacology , Glutathione/chemistry , Horses , Humans , Ligands , NADP/chemistry , NADP/metabolism , Receptors, Estrogen/agonists , Receptors, Estrogen/metabolism , Sulfhydryl Compounds/chemistry , Sulfhydryl Compounds/metabolism , Tumor Cells, Cultured
18.
Bioorg Med Chem ; 18(1): 111-6, 2010 Jan 01.
Article in English | MEDLINE | ID: mdl-19931463

ABSTRACT

In searching for opportunities to exploit the benefits of silicon in TRPV1 research, we tried to investigate the pharmacological effects of sila-substitution (C/Si exchange) of tert-butyl group in the MK-056 series. Compound 13a, with a 4-positioned trimethylsilanyl group on the B ring in place of tert-butyl group, exhibited the most potent antagonist activity with IC(50) values of 0.15 microM, which is almost equipotent with that of MK-056. This is the first example that tert-butyl group on MK-056 series can be replaced to the other substituent without loss of activity.


Subject(s)
Phenylthiourea/analogs & derivatives , Silicon/chemistry , TRPV Cation Channels/antagonists & inhibitors , TRPV Cation Channels/metabolism , Animals , Calcium/metabolism , Cells, Cultured , Molecular Structure , Neurons/drug effects , Neurons/metabolism , Phenylthiourea/chemistry , Phenylthiourea/pharmacology , Rats , Rats, Sprague-Dawley
19.
Foods ; 9(9)2020 Sep 21.
Article in English | MEDLINE | ID: mdl-32967309

ABSTRACT

Oriental melons have a relatively short shelf life as they are harvested during the summer season and susceptible to cold-induced injuries. Typical chilling injury when stored at 4 °C is expressed as browning of the fruit suture. To prolong the shelf life and reduce browning of the fruit, the effects of modified atmosphere packaging (MAP), X-tend modified atmosphere (MA)/modified humidity (MH) bulk packaging (XF), and polyethylene (PE) packaging, on oriental melons were investigated during storage at 4 °C and 10 °C for 14 days and under retail display conditions at 20 °C. The O2 concentrations in PE packages stored at 4 °C and 10 °C ranged from 17.4 to 18.5%, whereas those in XF packages were reduced to 16.3-16.6%. The CO2 content of XF package (4.2-4.6%) was higher than that of PE package (1.4-1.9%) stored at 4 °C or 10 °C. Relative humidity (RH) saturated in the PE packages but not in the XF packages after seven days of storage. Furthermore, PE packages performed better at maintaining melon weight and firmness than XF packages during storage at 10 °C for 14 days and under retail display conditions at 20 °C. PE and XF packages effectively reduced the browning index of the peel and white linear sutures of oriental melons compared with the unpackaged control during cold storage at 4 °C, and this observation was maintained at the retail display condition at 20 °C. The enhanced CO2 levels, reduced O2 levels, and optimal RH values that were provided by the MAP, prevented the browning symptoms, and improved the marketability and shelf life of oriental melons.

20.
J Agric Food Chem ; 67(31): 8649-8659, 2019 Aug 07.
Article in English | MEDLINE | ID: mdl-31283213

ABSTRACT

Spent coffee grounds (SCG) are the most abundant coffee byproduct and are generally discarded as waste. The horticultural use of SCG and SCG compost (SCGC) has become popular due to a growing interest in environmentally friendly measures for waste disposal. Estrogen-like endocrine disrupting chemicals in the soil can be absorbed by plants and subsequently by humans who consume these plants. The objectives of this study are to determine the phytochemical profiles of extracts of SCG and SCGC and to evaluate the estrogen-like activities of SCG, SCGC, and the major coffee phenolic acids, specifically, 5-O-caffeoylquinic acid (CQA), caffeic acid, and ferulic acid. Their inductive effects on estrogen receptor (ER)-mediated gene transcription have been examined in cultured cell lines. CQA was the most abundant phenolic acid in SCG and SCGC and was further examined for its ER-mediated estrogen-like activity using various assays. This is the first study to report the estrogen-like signaling activities of coffee byproducts and their major constituents.


Subject(s)
Coffea/chemistry , Hydroxybenzoates/metabolism , Phytoestrogens/metabolism , Plant Extracts/metabolism , Receptors, Estrogen/genetics , Transcriptional Activation , Waste Products/analysis , Animals , Caffeic Acids/analysis , Caffeic Acids/metabolism , Cell Line , Composting , Female , Genes, Reporter , Humans , Hydroxybenzoates/chemistry , Phytoestrogens/chemistry , Plant Extracts/chemistry , Rats , Rats, Sprague-Dawley , Receptors, Estrogen/metabolism , Seeds/chemistry
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