Dietary polyphenols have been associated with many beneficial cardiovascular effects. However, these effects are rather attributed to small phenolic metabolites formed by the gut microbiota, which reach sufficient concentrations in systemic circulation. 4-Methylcatechol (4-MC) is one such metabolite. As it is shown to possess considerable vasorelaxant effects, this study aimed to unravel its mechanism of action. To this end, experimental in vitro and in silico approaches were employed. In the first step, isometric tension recordings were performed on rat aortic rings. 4-MC potentiated the effect of cyclic nucleotides, but the effect was not mediated by either soluble guanylyl cyclase (sGC), modification of cyclic adenosine monophosphate levels, or protein kinase G. Hence, downstream targets such as calcium or potassium channels were considered. Inhibition of voltage-gated K+ channels (KV) markedly decreased the effect of 4-MC, and vasodilation was partly decreased by inhibition of the KV7 isoform. Contrarily, other types of K+ channels or L-type Ca2+ channels were not involved. In silico reverse docking confirmed that 4-MC binds to KV7.4 through hydrogen bonding and hydrophobic interactions. In particular, it interacts with two crucial residues for KV7.4 activation: Trp242 and Phe246. In summary, our findings suggested that 4-MC exerts vasorelaxation by opening KV channels with the involvement of KV7.4.

• MeSH
• aorta účinky léků   metabolismus   MeSH
• draslíkové kanály řízené napětím * metabolismus   MeSH
• katecholy * farmakologie   MeSH
• krysa rodu rattus MeSH
• potkani Wistar MeSH
• quercetin * farmakologie   MeSH
• simulace molekulového dockingu MeSH
• vazodilatace * účinky léků   MeSH
• vazodilatancia farmakologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The human body is regularly exposed to simple catechols and small phenols originating from our diet or as a consequence of exposure to various industrial products. Several biological properties have been associated with these compounds such as antioxidant, anti-inflammatory, or antiplatelet activity. Less explored is their potential impact on the endocrine system, in particular through interaction with the alpha isoform of the estrogen receptor (ERα). In this study, human breast cancer cell line MCF-7/S0.5 was employed to investigate the effects on ERα of 22 closely chemically related compounds (15 catechols and 7 phenols and their methoxy derivatives), to which humans are widely exposed. ERα targets genes ESR1 (ERα) and TFF1, both on mRNA and protein level, were chosen to study the effect of the tested compounds on the mentioned receptor. A total of 7 compounds seemed to impact mRNA and protein expression similarly to estradiol (E2). The direct interaction of the most active compounds with the ERα ligand binding domain (LBD) was further tested in cell-free experiments using the recombinant form of the LBD, and 4-chloropyrocatechol was shown to behave like E2 with about 1/3 of the potency of E2. Our results provide evidence that some of these compounds can be considered potential endocrine disruptors interacting with ERα.

• MeSH
• alfa receptor estrogenů * metabolismus   genetika   MeSH
• endokrinní disruptory * farmakologie   toxicita   MeSH
• faktor TFF1 metabolismus   genetika   MeSH
• fenoly * farmakologie   chemie   MeSH
• lidé MeSH
• MFC-7 buňky MeSH
• nádory prsu metabolismus   MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

The purpose of the present study was to purify and characterize the catechol 1,2-dioxygenase (EC 1.13.11.1; catechol-oxygen 1,2-oxidoreductase; C12O) enzyme from the local isolate of Pseudomonas putida. This enzyme catalyzes the initial reaction in the ortho-pathway for phenol degradation in various gram-negative bacteria, including the genus of Pseudomonas. Pseudomonads are commonly used in the biodegradation of xenobiotics due to their versatility in degrading a wide range of chemical compounds. Eighty-nine soil samples were taken from the contaminated soil of the Midland Refineries Company (MRC) of Al-Daura refinery area at Baghdad from April to August 2021. The samples were grown in a mineral salt medium containing 250 mg per L of phenol to test their ability to biodegrade phenol. The pH was adjusted to 8.0 at 30 °C using a shaking incubator for 24-48 h. A number of 62 (69.6%) isolates of the total number were able to degrade phenol efficiently. The findings of the VITEK system and the housekeeping gene 16S rDNA confirmed that out of the positive isolates for phenol degradation, 36 from 62 (58.06%) were identified as Pseudomonas spp. isolates. Those isolates were distributed as P. aeruginosa 30 (83.3%) and P. putida 6 (16.6%). The enzyme production capabilities of the isolates were evaluated, and the highest activity was 2.39 U per mg for the isolate No. 15 which it was identified as P. putida. The previous isolate was selected for enzyme production, purification, and characterization. The enzyme was purified using ion exchange and gel filtration chromatography, with a combined yield of 36.12% and purification fold of 15.42 folds. Using a gel filtration column, the enzyme's molar mass was calculated to be 69 kDa after purification. The purified enzyme was stable at 35 °C and a pH of 6.0.

• MeSH
• bakteriální proteiny metabolismus   genetika   chemie   izolace a purifikace   MeSH
• biodegradace * MeSH
• fenol * metabolismus   MeSH
• fylogeneze MeSH
• katechol-1,2-dioxygenasa * metabolismus   genetika   MeSH
• koncentrace vodíkových iontů MeSH
• Pseudomonas putida * enzymologie   genetika   metabolismus   MeSH
• půdní mikrobiologie * MeSH
• RNA ribozomální 16S genetika   MeSH
• teplota MeSH
• Publikační typ
• časopisecké články MeSH

Substituted catechols include both natural and synthetic compounds found in the environment and foods. Some of them are flavonoid metabolites formed by the gut microbiota which are absorbed afterwards. Our previous findings showed that one of these metabolites, 4-methylcatechol, exerts potent vasorelaxant effects in rats. In the current study, we aimed at testing of its 22 structural congeners in order to find the most potent structure and to investigate the mechanism of action. 3-methoxycatechol (3-MOC), 4-ethylcatechol, 3,5-dichlorocatechol, 4-tert-butylcatechol, 4,5-dichlorocatechol, 3-fluorocatechol, 3-isopropylcatechol, 3-methylcatechol and the parent 4-methylcatechol exhibited high vasodilatory activities on isolated rat aortic rings with EC50s ranging from ∼10 to 24 μM. Some significant sex-differences were found. The most potent compound, 3-MOC, relaxed also resistant mesenteric artery but not porcine coronary artery, and decreased arterial blood pressure in both male and female spontaneously hypertensive rats in vivo without affecting heart rate. It potentiated the vasodilation mediated by cAMP and cGMP, but did not impact L-type Ca2+-channels. By using two inhibitors, activation of voltage-gated potassium channels (KV) was found to be involved in the mechanism of action. This was corroborated by docking analysis of 3-MOC with the KV7.4 channel. None of the most active catechols decreased the viability of the A-10 rat embryonic thoracic aorta smooth muscle cell line. Our findings showed that various catechols can relax vascular smooth muscles and hence could provide templates for developing new antihypertensive vasodilator agents without affecting coronary circulation.

• MeSH
• aorta thoracica účinky léků   metabolismus   MeSH
• arteriae mesentericae * účinky léků   metabolismus   MeSH
• arteriální tlak účinky léků   MeSH
• draslíkové kanály řízené napětím metabolismus   antagonisté a inhibitory   účinky léků   MeSH
• guanosinmonofosfát cyklický metabolismus   MeSH
• hypertenze farmakoterapie   patofyziologie   metabolismus   MeSH
• katecholy * farmakologie   chemie   MeSH
• koronární cévy účinky léků   metabolismus   MeSH
• krysa rodu rattus MeSH
• modely nemocí na zvířatech MeSH
• myocyty hladké svaloviny účinky léků   metabolismus   MeSH
• potkani inbrední SHR * MeSH
• prasata MeSH
• sexuální faktory MeSH
• simulace molekulového dockingu * MeSH
• svaly hladké cévní účinky léků   metabolismus   MeSH
• vazodilatace * účinky léků   MeSH
• vazodilatancia * farmakologie   chemie   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• vztahy mezi strukturou a aktivitou MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Insect prophenoloxidases (PPOs) are important immunity proteins for defending against the invading pathogens and parasites. As a Type-III copper-containing proteins, unlike Homo sapiens tyrosinases, the insect PPOs and most bacterial tyrosinases contain no signal peptides for unknown reason, however they can still be released. To this end, we fused different signal peptides to Drosophila melanogaster PPOs for in vitro and in vivo expression, respectively. We demonstrate that an artificial signal peptide can help PPO secretion in vitro. The secreted PPO appeared larger than wild-type PPO on molecular weight sizes due to glycosylation when expressed in S2 cells. Two asparagine residues for potential glycosylation in PPO1 were identified when a signal peptide was fused. After purification, the glycosylated PPO1 lost zymogen activity. When PPO1 containing a signal peptide was over-expressed in Drosophila larvae, the glycosylation and secretion of PPO1 was detected in vivo. Unlike insect PPO, human tyrosinase needs a signal peptide for protein expression and maintaining enzyme activity. An artificial signal peptide fused to bacterial tyrosinase had no influence on the protein expression and enzyme activity. These Type-III copper-containing proteins from different organisms may evolve to perform their specific functions. Intriguingly, our study revealed that the addition of calcium inhibits PPO secretion from the transiently cultured larval hindguts in vitro, indicating that the calcium concentration may regulate PPO secretion. Taken together, insect PPOs can maintain enzyme activities without any signal peptide.

• MeSH
• buněčné linie MeSH
• Drosophila melanogaster * imunologie   metabolismus   MeSH
• glykosylace MeSH
• hmyzí proteiny metabolismus   genetika   MeSH
• katecholoxidasa * metabolismus   MeSH
• larva metabolismus   MeSH
• lidé MeSH
• prekurzory enzymů * metabolismus   MeSH
• proteinové prekurzory metabolismus   MeSH
• proteiny - lokalizační signály * MeSH
• proteiny Drosophily metabolismus   genetika   MeSH
• tyrosinasa metabolismus   MeSH
• vápník metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Léčba Parkinsonovy nemoci je v současnosti stále léčbou symptomatickou a její management je primárně zaměřen na kontrolu motorických projevů. Hlavním pilířem současné terapie zůstávají dopaminergní preparáty nahrazující působení chybějícího dopaminu. Významného pokroku bylo v posledních desetiletích dosaženo v možnostech terapie pokročilého stadia onemocnění pomocí intervenčních metod, jako je léčba pumpovými systémy a hluboká mozková stimulace. Důležitou součástí léčby je ovlivnění non-motorických symptomů, které významně ovlivňují kvalitu života pacientů. Nové léčebné strategie schopné ovlivnit rozvoj a progresi onemocnění, které jsou stále ve fázi preklinického a klinického výzkumu, zahrnují nejrůznější léčebné postupy s cílem ovlivnit tvorbu a agregaci patologických forem alfa-synukleinu a modifikovat šíření patologického procesu v mozku.

Despite intensive research, the current treatment of Parkinson's disease is still symptomatic treatment and its management is primarily aimed at controlling motor symptoms. Dopaminergic agents that replace the action of the missing dopamine remain the mainstay of current therapy. In recent decades, significant progress has been made in the treatment of advanced stage of disease using interventional methods such as treatment with pump systems and deep brain stimulation. An important part of the treatment is the influence of non-motor symptoms, which significantly affect the quality of life of patients. New treatment strategies capable to affect the development and progression of the disease, which are still in the preclinical and clinical research phase, include various treatment procedures with the aim to influence the formation and aggregation of pathological forms of alpha-synuclein and modify the spread of the pathological process in the brain.

• MeSH
• agonisté dopaminu farmakologie   klasifikace   terapeutické užití   MeSH
• amantadin farmakologie   terapeutické užití   MeSH
• cholinergní antagonisté farmakologie   klasifikace   terapeutické užití   MeSH
• hluboká mozková stimulace metody   MeSH
• inhibitory katechol-O-methyltransferasy farmakologie   klasifikace   terapeutické užití   MeSH
• inhibitory MAO farmakologie   klasifikace   terapeutické užití   MeSH
• levodopa farmakologie   terapeutické užití   MeSH
• lidé MeSH
• motorické poruchy diagnóza   farmakoterapie   MeSH
• Parkinsonova nemoc * diagnóza   farmakoterapie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• přehledy MeSH

A polyphenol-rich diet has beneficial effects on cardiovascular health. However, dietary polyphenols generally have low bioavailability and reach low plasma concentrations. Small phenolic metabolites of these compounds formed by human microbiota are much more easily absorbable and could be responsible for this effect. One of these metabolites, 4-methylcatechol (4-MC), was suggested to be a potent anti-platelet compound. The effect of 4-MC was tested ex vivo in a group of 53 generally healthy donors using impedance blood aggregometry. The mechanism of action of this compound was also investigated by employing various aggregation inducers/inhibitors and a combination of aggregometry and enzyme linked immunosorbent assay (ELISA) methods. 4-MC was confirmed to be more potent than acetylsalicylic acid on both arachidonic acid and collagen-triggered platelet aggregation. Its clinically relevant effect was found even at a concentration of 10 μM. Mechanistic studies showed that 4-MC is able to block platelet aggregation caused by the stimulation of different pathways (receptors for the von Willebrand factor and platelet-activating factor, glycoprotein IIb/IIIa, protein kinase C, intracellular calcium elevation). The major mechanism was defined as interference with cyclooxygenase-thromboxane synthase coupling. This study confirmed the strong antiplatelet potential of 4-MC in a group of healthy donors and defined its mechanism of action.

• MeSH
• fenoly MeSH
• imunologické testy * MeSH
• katecholy * farmakologie   MeSH
• lidé MeSH
• polyfenoly MeSH
• vyšetření funkce trombocytů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Sulfation is an important reaction in nature, and sulfated phenolic compounds are of interest as standards of mammalian phase II metabolites or pro-drugs. Such standards can be prepared using chemoenzymatic methods with aryl sulfotransferases. The aim of the present work was to obtain a large library of sulfated phenols, phenolic acids, flavonoids, and flavonolignans and optimize their HPLC (high performance liquid chromatography) analysis. Four new sulfates of 2,3,4-trihydroxybenzoic acid, catechol, 4-methylcatechol, and phloroglucinol were prepared and fully characterized using MS (mass spectrometry), 1H, and 13C NMR. The separation was investigated using HPLC with PDA (photodiode-array) detection and a total of 38 standards of phenolics and their sulfates. Different stationary (monolithic C18, C18 Polar, pentafluorophenyl, ZICpHILIC) and mobile phases with or without ammonium acetate buffer were compared. The separation results were strongly dependent on the pH and buffer capacity of the mobile phase. The developed robust HPLC method is suitable for the separation of enzymatic sulfation reaction mixtures of flavonoids, flavonolignans, 2,3-dehydroflavonolignans, phenolic acids, and phenols with PDA detection. Moreover, the method is directly applicable in conjunction with mass detection due to the low flow rate and the absence of phosphate buffer and/or ion-pairing reagents in the mobile phase.

• MeSH
• fenoly analýza   MeSH
• flavonoidy analýza   MeSH
• flavonolignany * MeSH
• sírany * MeSH
• vysokoúčinná kapalinová chromatografie metody   MeSH
• Publikační typ
• časopisecké články MeSH

• Klíčová slova
• LECIGIMON,
• MeSH
• antiparkinsonika terapeutické užití   MeSH
• gastrointestinální intubace metody   MeSH
• gely MeSH
• karbidopa aplikace a dávkování   farmakokinetika   MeSH
• katecholy aplikace a dávkování   farmakokinetika   MeSH
• kombinovaná farmakoterapie MeSH
• levodopa aplikace a dávkování   farmakokinetika   MeSH
• lidé MeSH
• nitrily aplikace a dávkování   farmakokinetika   MeSH
• Parkinsonova nemoc farmakoterapie   patofyziologie   MeSH
• stupeň závažnosti nemoci MeSH
• Check Tag
• lidé MeSH

Tyrosinase, exquisitely catalyzes the phenolic compounds into brown or black pigment, inhibition is used as a treatment for dermatological or neurodegenerative disorders. Natural products, such as cyanidin-3-O-glucoside and (-/+)-catechin, are considered safe and non-toxic food additives in tyrosinase inhibition but their ambiguous inhibitory mechanism against tyrosinase is still elusive. Thus, we presented the mechanistic insights into tyrosinase with cyanidin-3-O-glucoside and (-/+)-catechin using computational simulations and in vitro assessment. Initial molecular docking results predicted ideal docked poses (- 9.346 to - 5.795 kcal/mol) for tyrosinase with selected flavonoids. Furthermore, 100 ns molecular dynamics simulations and post-simulation analysis of docked poses established their stability and oxidation of flavonoids as substrate by tyrosinase. Particularly, metal chelation via catechol group linked with the free 3-OH group on the unconjugated dihydropyran heterocycle chain was elucidated to contribute to tyrosinase inhibition by (-/+)-catechin against cyanidin-3-O-glucoside. Also, predicted binding free energy using molecular mechanics/generalized Born surface area for each docked pose was consistent with in vitro enzyme inhibition for both mushroom and murine tyrosinases. Conclusively, (-/+)-catechin was observed for substantial tyrosinase inhibition and advocated for further investigation for drug development against tyrosinase-associated diseases.

• MeSH
• Agaricus enzymologie   MeSH
• anthokyaniny farmakologie   MeSH
• inhibitory enzymů farmakologie   MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• simulace molekulární dynamiky MeSH
• simulace molekulového dockingu MeSH
• termodynamika MeSH
• tyrosinasa antagonisté a inhibitory   chemie   metabolismus   MeSH
• vazba proteinů MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH