Toxicokinetic and metabolism data in humans and experimental animals indicate that genistein is absorbed into the systemic circulation of infants and adults. Genistein ... circulates as its glucuronide conjugate, and a much smaller percentage circulates as the aglycone. Genistein can be glucuronidated in the intestine or liver, but the intestine appears to play the major role in glucuronidation. Genistein glucuronides undergo enterhepatic cycling, and in the process can be deconjugated by intestinal bacteria. The role of gut bacteria in the metabolism of genistein has been clearly established. Genistein can be metabolized through a pathway that ultimately leads to the formation of 6'-hydroxy-O-demethylangolensin. Once absorbed, genistein glucuronide, and to a smaller extent genistien aglycone, are widely distributed to organ systems and the conceptus. The majority of a genistein dose is excreted in urine within 24 hours.
Prior to entering the systemic circulation, most genistein is conjugated with glucuronic acid by uridine diphosphate (UDP)-glucuronosyltransferase (UDPGT); a much smaller amount is conjugated to sulfate by sulfotransferase enzymes. Conjugation of genistein occurs in the intestine, although it also has been reported to occur in liver. One study demonstrated that the ability to catalyze glucuronidation of genistein was greatest with microsomes from kidney > colon > liver. UDPGT isoenzymes including 1A1, 1A4, 1A6, 1A7, 1A9, and 1A10 were observed to catalyze the glucuronidation of genistein. The UGT 1A10 isoform, which is present in colon, gastric, and biliary epithelium but not in liver, was observed to have the highest activity and specificity for genistein. Based on those observations, the study authors concluded that the intestine plays a major role in the glucuronidation of genistein. The glucuronide and sulfate conjugates can enter the systemic circulation, and the majority of isoflavone compounds in the circulation are present in conjugated form. In studies where humans were exposed to genistein alone or in combination with other isoflavone aglycones (calculated as genistein doses of 1-16 mg/kg bw), most of the genistein was present in plasma in conjugated form; free genistein represented 1-3% of total plasma genistein levels. The conjugated isoflavones undergo enterohepatic circulation, and upon return to the intestine, they are deconjugated by bacteria possessing beta-glucuronidase or arylsulfatase activity. The metabolites may be reabsorbed or further metabolized by gut microflora. One review reported that about 10% of isoflavonoids are circulated in plasma unconjugated.
Biotransformations by gut microflora play a pivotal role in determining the biological activity of isoflavones that occur in soya-based foods predominantly as betaglycosyl conjugates. Microflora prepared from rat caeca and human feces were used to investigate the metabolic fate of genistein beta-glycosides extracted from soya flour. The end-products of such metabolism were determined by parallel incubations of microflora with [2',3,5',6'-3H] and [4-14C]-labelled genistein. ... Quantitative analysis by LC-MS/IS indicated very rapid and complete degradation of genistin, which was associated with a transient increase in genistein. Qualitative studies indicated that the malonyl and acetyl glycosides of genistein were also degraded by the microflora. ... Incubation of caecal and fecal microflora with (3)H and (14)C genistein yielded similar radiolabelled metabolites, which were identified by radio-LC-MS(n) as the intermediates dihydrogenistein and 6'-hydroxy-O-desmethylangolensin and end-product 4-hydroxyphenyl-2-propionic acid. This profile of genistein metabolites indicated selective hydrolysis of 6'-hydroxy-O-desmethylangolensin between carbon atoms 1' and 1 to yield the end-products 4-hydroxyphenyl-2-propionic acid and 1,3,5-trihydroxybenzene. ... The biological significance of the products of genistein metabolism warrant further investigation since they may play an important role in mediating the beneficial antioxidant health effects associated with the consumption of isoflavones in food.
Biotransformation of the phytoestrogen (14-C)genistein was investigated in male and female rats by application of narrow-bore radio-HPLC-MSn (LCQ, Finnigan) to determine intermediates in metabolism. Urine contained five metabolites, Gm1-Gm5, 24 hr after dosing by gavage with [14C]genistein (4 mg kg(-1)). Structural analysis following ESI revealed molecular ions (M+H)+ of m/z 447, 449, 273, and 271 for metabolites Gm2, Gm3, Gm5 and genistein, respectively and an [M-H]- of m/z 349 for Gm4. Metabolite structure was deduced by evaluation of product ion spectra derived from unlabelled and (14)C-labelled ions and sensitivity to treatment with beta-glucuronidase. These studies indicated identity of metabolites with genistein glucuronide (Gm2), dihydrogenistein glucuronide (Gm3), genistein sulphate (Gm4) and dihydrogenistein (Gm5). Detection of the beta-glucuronidase resistant major metabolite Gm1 by ESI was poor and so was analysed by negative ion APCI; this revealed a deprotonated molecular ion of m/z 165 which had chromatographic and mass spectral properties consistent with authentic 4-hydroxyphenyl-2-propionic acid, a novel metabolite of genistein. In vitro metabolism studies with anaerobic caecal cultures derived from male and female rats revealed metabolism of genistein to Gm1 via Gm5 and an additional metabolite (Gm6) which was identified from product ion spectra as 6'-hydroxy-O-desmethylangolensin. Biotransformation of genistein by both isolated hepatocytes and precision-cut liver slices was limited to glucuronidation of parent compound. Commonality of genistein metabolites found in rats with those reported in man suggest similar pathways of biotransformation, primarily involving gut micro-flora.
Genistein has known human metabolites that include Orobol, Dihydrogenistein, and (2S,3S,4S,5R)-3,4,5-Trihydroxy-6-[5-hydroxy-3-(4-hydroxyphenyl)-4-oxochromen-7-yl]oxyoxane-2-carboxylic acid.
Genistein may inhibit cancer cell growth by blocking enzymes required for cell growth.
Genistein may decrease cardiovascular risk in postmenopausal women by interacting with the nuclear estrogen receptors to alter the transcription of cell specific genes. In randomized clinical trials, genistein was seen to increase the ratio of nitric oxide to endothelin and improved flow-mediated endothelium dependent vasodilation in healthy postmenopausal women. [1] In addition, genistein may have beneficial effects on glucose metabolism by inhibiting islet tyrosine kinase activity as well as insulin release dependent on glucose and sulfonylurea. [1]
来源:Toxin and Toxin Target Database (T3DB)
毒理性
致癌物分类
对人类不具有致癌性（未被国际癌症研究机构IARC列名）。
No indication of carcinogenicity to humans (not listed by IARC).
Humans and wildlife are frequently exposed to mixtures of endocrine active-compounds (EAC). The objective of the present study was to investigate the potential of the phytoestrogen genistein to influence the reproductive developmental toxicity of the endocrine-active pesticide methoxychlor. Three levels of genistein (0, 300, or 800 ppm) and two levels of methoxychlor (0 or 800 ppm) were used in this study. Sprague-Dawley rats were exposed to the two compounds, either alone or in combinations, through dietary administration to dams during pregnancy and lactation and to the offspring directly after weaning. Both compounds, methoxychlor in particular, were associated with reduced body growth at 800 ppm, but pregnancy outcome was not affected by either treatment. An acceleration of vaginal opening (VO) in the exposed female offspring was the only observed effect of genistein at 300 ppm. Exposure to 800 ppm genistein or 800 ppm methoxychlor caused accelerated VO and also altered estrous cyclicity toward persistent estrus in the female offspring. The estrogenic responses to genistein and methoxychlor administered together were apparently accumulative of the effects associated with each compound alone. Methoxychlor, but not genistein, delayed preputial separation (PPS) in the male rats. When administered with methoxychlor, genistein at 800 ppm enhanced the effect of methoxychlor on delaying PPS. Genistein and methoxychlor treatment did not change gender-specific motor activity patterns in either sex. To explore possible mechanisms for interaction between the two compounds on development, we performed estrogen receptor (ER)- and androgen receptor (AR)-based in vitro transcriptional activation assays using genistein and the primary methoxychlor metabolite 2,2-bis-(p-hydroxyphenyl)-1,1,1-trichloroethane (HPTE). While the in vitro assays supported the estrogenic effects of genistein and methoxychlor and the antiandrogenic effects of methoxychlor, the reactivity of these compounds with ERs alpha and beta could not predict the greater in vivo estrogenic potency of methoxychlor over genistein; nor could the potentiation of the methoxychlor effect on PPS by genistein be predicted based on in vitro HPTE and genistein reactions with the AR. Data from this study indicate that phytoestrogens are capable of altering the toxicological behaviors of other EACs, and the interactions of these compounds may involve complexities that are difficult to predict based on their in vitro steroid receptor reactivities.
... Interactions between the soy isoflavone, genistein, and an antiestrogen, tamoxifen (TAM), on the growth of estrogen (E)-dependent breast cancer (MCF-7) cells implanted in ovariectomized athymic mice /were investigated/. ... Six treatment groups were used: control (C); 0.25 mg estradiol (E2) implant (E); E2 implant + 2.5 mg TAM implant (2.5 TE); E2 implant + 2.5 mg TAM implant + 1000 ppm genistein (2.5 TEG); E2 implant + 5 mg TAM implant (5 TE), and E2 implant +5 mg TAM implant +1000 ppm genistein (5 TEG). Treatment with TAM (2.5 TE and 5 TE) suppressed E2-stimulated MCF-7 tumor growth in ovariectomized athymic mice. Dietary genistein negated/overwhelmed the inhibitory effect of TAM on MCF-7 tumor growth, lowered E2 level in plasma, and increased expression of E-responsive genes (e.g., pS2, PR, and cyclin D1). ... Caution is warranted for postmenopausal women consuming dietary genistein while on TAM therapy for E-responsive breast cancer.
The anticancer agent genistein inhibits cell growth of tumor cell lines from various malignancies. ... /The authors/ investigated the effectiveness of combined treatment of ionizing radiation (IR) with genistein on cervical HeLa cells and its possible mechanism. It was found that the inhibitory rate in cells with combined treatment was significantly higher than that of the cells treated with IR or genistein alone. After treatments of IR (4 Gy) combined with genistein (40 micromol/L), the apoptotic index of the cells was significantly increased and the cells were arrested in the G2/M phase. Survivin mRNA expression increased after IR (4 Gy), while it significantly decreased after combined treatment. These findings indicated that genistein enhanced the radiosensitivity of cervical cancer HeLa cells, and the mechanisms for this action might include increase of apoptosis, decrease of survivin expression, and prolongation of cell cycle arrest.
... Genistein is rapidly absorbed in humans following oral intake. Before absorption into the systemic circulation, most genistein is conjugated with glucuronic acid and excreted in the bile to undergo enterohepatic circulation ... . Therefore, genistein bioavailability is very limited. Times to obtain maximum plasma concentrations were reported at 1 to 6 hours for free genistein ... and 3 to 8 hours for total genistein (aglycone + conjugates ...). In one of the studies, the lowest dose used (2 mg/kg bw) was stated to provide more than twice the level of isoflavones ingested in a Japanese daily diet. A study in which menopausal women were given a 50 mg commercial isoflavone extract incorporated into fruit juice, chocolate, or a cookie showed no significant effect of the food matrix on genistein absorption or urinary excretion parameters. In a study in which 8 women were dosed with 0.4 or 0.8 mg/kg bw 13C-labeled genistein, the area under the curve (AUC) at the higher dose was less than double the AUC at the lower dose, suggesting a decrease in fractional absorption with increasing dose.
There is considerable individual variation in the absorption and metabolism of ingested genistin and genistein. There are some data suggesting that genistein may be more bioavailable than genistin. However, other data suggest that the extent of absorption of genistein is similar for the aglycone and the glucoside forms. There are little data available on the tissue distribution of genistein.
A recently completed study has also shown inter-individual variation in the urinary excretion of isoflavones and their metabolites following soy challenge in adults. In this study, 76 volunteers were fed either a high (104+/-24 mg total isoflavones/day) or low (0.5+/-0.5 mg total isoflavones/day) soya diet for 10 weeks. Volunteers on the high soya diet showed extensive urinary excretion of daidzein, genistein and their metabolites. Of the volunteers on the high soya diet 34% were identified as good equol excretors ( 1000 nmol/24 hours). Comparative analysis of the fecal flora between equol and non-equol producers was investigated, however, the microflora (bacteria) responsible for equol production could not be isolated and therefore, were not be identified
The pharmacokinetics of isoflavones in 10 healthy women were determined from serum appearance/disappearance concentration profiles and urinary excretions after single-bolus ingestion of 10, 20 or 40 g of soy nuts delivering increasing amounts of the conjugated forms of daidzein (6.6, 13.2 and 26.4 mg) and genistein (9.8, 19.6 and 39.2 mg). Peak serum daidzein and genistein concentrations were attained after 4-8 hr, and elimination half-lives were 8.0 and 10.1 hr, respectively. There were no differences in the pharmacokinetics of daidzein and genistein between pre- and postmenopausal women, indicating absorption and disposition of isoflavones to be independent of age or menopausal status. A curvilinear relationship was observed between the bioavailability of daidzein and genistein, apparent from the area under the curve to infinity (AUC(inf)) of the serum concentration-time profiles and the amount of isoflavones ingested. The mean fraction of the isoflavones excreted in urine decreased with increasing intake when expressed as a percentage of the administered dose (63.2 + or - 8.0, 54.4 + or - 8.1 and 44.0 + or - 4.3%, respectively, for daidzein, and correspondingly, 25.2 + or - 5.3, 13.4 + or - 2.1 and 15.8 + or - 2.7% for genistein), underscoring the trend toward nonlinear pharmacokinetics. Equol was identified as a metabolite in 30% of women; it was present consistently in urine and blood from the same subjects. Its delayed appearance was consistent with colonic synthesis. On the basis of the pharmacokinetics, optimum steady-state serum isoflavone concentrations would be expected from modest intakes of soy foods consumed regularly throughout the day rather than from a single highly enriched product.
Compositions for Treatment of Cystic Fibrosis and Other Chronic Diseases
申请人：Vertex Pharmaceuticals Incorporated
公开号：US20150231142A1
公开（公告）日：2015-08-20
The present invention relates to pharmaceutical compositions comprising an inhibitor of epithelial sodium channel activity in combination with at least one ABC Transporter modulator compound of Formula A, Formula B, Formula C, or Formula D. The invention also relates to pharmaceutical formulations thereof, and to methods of using such compositions in the treatment of CFTR mediated diseases, particularly cystic fibrosis using the pharmaceutical combination compositions.
[EN] COMPOUNDS AS MODULATORS OF TIGIT SIGNALLING PATHWAY<br/>[FR] COMPOSÉS MODULATEURS DE LA VOIE DE SIGNALISATION DE TIGIT
申请人：AURIGENE DISCOVERY TECH LTD
公开号：WO2018047139A1
公开（公告）日：2018-03-15
The present invention relates to compound of formula (I) as therapeutic agents to modulate the TIGIT signalling pathway. The invention also encompasses the use of the compound of formula (I) or a stereoisomer thereof or a pharmaceutically acceptable salt thereof for the treatment of diseases or disorders mediated by TIGIT.
Substituted 1-benzoyl-3-cyano-pyrrolo [1,2-a] quinolines and analogs as activators of caspases and inducers of apoptosis
申请人：Cai Xiong Sui
公开号：US20050014759A1
公开（公告）日：2005-01-20
The present invention is directed to substituted 1-benzoyl-3-cyano-pyrrolo[1,2-a]quinolines and analogs thereof, represented by the general Formula I:
wherein R
1
—R
8
, L, Q, dash line and Ar are defined herein. The present invention also relates to the discovery that compounds having Formula I are activators of caspases and inducers of apoptosis. Therefore, the activators of caspases and inducers of apoptosis of this invention can be used to induce cell death in a variety of clinical conditions in which uncontrolled growth and spread of abnormal cells occurs.
[EN] alpha7 NICOTINIC ACETYLCHOLINE RECEPTOR MODULATORS AND USES THEREOF-I<br/>[FR] MODULATEURS DU RÉCEPTEUR Alpha7 NICOTINIQUE D'ACÉTYLCHOLINE ET LEURS UTILISATIONS
申请人：BIONOMICS LTD
公开号：WO2014019023A1
公开（公告）日：2014-02-06
The present invention relates to chemical compounds of formula (I), with the substituents as described in the specification, useful in the positive modulation of the alpha 7 nicotinic acetylcholine receptor (α7 nAChR). The invention also relates to the use of these compounds in the treatment or prevention of a broad range of diseases in which the positive modulation of α7 nAChR is advantageous, including neurodegenerative and neuropsychiatric diseases and also neuropathic pain and inflammatory diseases.
SYNTHETIC SUBSTRATES FOR ENZYMES THAT CATALYZE REACTIONS OF MODIFIED CYSTEINES AND RELATED METHODS
申请人：The University of Chicago
公开号：US20180147250A1
公开（公告）日：2018-05-31
Synthetic probes for detecting the activity of enzymes that catalyze reactions of post-translationally modified cysteine residues are described. The probes include “turn-on” probes that include a carbamate linkage that is cleaved via an intramolecular reaction with a free thiol produced by an enzyme catalyzed activity. The probes also include ratiometric, Michael addition-based probes that respond to enzymatic activity by a change in structure that results in a change in fluorescence properties. Methods of using the probes to detect enzymatic activity and disease are described. For example, the probes can be used to detect enzymatic activity in a variety of samples, including live cells and heterogeneous tissues. In addition, prodrugs that can be activated by enzymes that catalyze reactions of post-translationally modified cysteine residues and methods of using the prodrugs to treat disease are described.
