The polymerase acidic (PA) subunit of the influenza virus, an endonuclease of the RNA-dependent RNA polymerase, represents a viable target for anti-influenza therapies, as evidenced by the efficacy of the FDA-approved drug Xofluza. A characteristic feature of endonuclease inhibitors is their ability to chelate Mg2+ or Mn2+ ions within the enzyme's catalytic site. Previously, our studies identified luteolin and its C-8-glucoside orientin as potent endonuclease inhibitors. This report details our subsequent investigation into the structural modifications of the phenyl moiety attached to the C-8 position of luteolin. The inhibitory potencies (IC50 values) quantified with AlphaScreen technology indicated that substituting the C-8 glucose moiety of orientin resulted in compounds with comparable inhibitory potency. From a series of eighteen compounds, acid 12 with 3-carboxylphenyl moiety at the C-8 position was the most potent inhibitor with nanomolar potency.
- MeSH
- antivirové látky * farmakologie chemická syntéza chemie MeSH
- endonukleasy * antagonisté a inhibitory metabolismus MeSH
- inhibitory enzymů * farmakologie chemická syntéza chemie MeSH
- luteolin * farmakologie chemická syntéza chemie MeSH
- molekulární struktura MeSH
- racionální návrh léčiv * MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Publikační typ
- časopisecké články MeSH
PURPOSE: The aim of this study was to investigate whether luteoloside, a flavonoid, could protect human dental pulp cells (HDPCs) against inflammation and oxidative stress induced by methylglyoxal (MGO), one of the advanced glycated end products (AGE) substances. METHODS: HDPCs were stimulated with MGO and treated with luteoloside. MTT assay was used to determine cell viability. Protein expression was measured via western blotting. Reactive oxygen species (ROS) were measured with a Muse Cell Analyzer. Alkaline phosphatase activity (ALP) and Alizarin red staining were used for mineralization assay. RESULTS: Luteoloside down-regulated the expression of inflammatory molecules such as ICAM-1, VCAM-1, TNF-α, IL-1β, MMP-2, MMP-9, and COX-2 in MGO-induced HDPCs without showing any cytotoxicity. It attenuated ROS formation and enhanced osteogenic differentiation such as ALP activity and Alizarin red staining in MGO-induced HDPCs. Overall, luteoloside showed protective actions against inflammation and oxidative stress in HDPCs induced by MGO through its anti-inflammatory, anti-oxidative, and osteogenic activities by down-regulating p-JNK in the MAPK pathway. CONCLUSION: These results suggest that luteoloside might be a potential adjunctive therapeutic agent for treating pulpal pathological conditions in patients with diabetes mellitus.
- MeSH
- anthrachinony * MeSH
- antiflogistika farmakologie MeSH
- glukosidy * MeSH
- kultivované buňky MeSH
- lidé MeSH
- luteolin * MeSH
- osteogeneze * fyziologie MeSH
- oxid hořečnatý MeSH
- pyruvaldehyd * toxicita MeSH
- reaktivní formy kyslíku MeSH
- zánět chemicky indukované farmakoterapie MeSH
- zubní dřeň MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Luteolin and naringenin are flavonoids found in various foods/beverages and present in certain dietary supplements. After a high intake of these flavonoids, their sulfate and glucuronide conjugates reach micromolar concentrations in the bloodstream. Some pharmacokinetic interactions of luteolin and naringenin have been investigated in previous studies; however, only limited data are available in regard to their metabolites. In this study, we aimed to investigate the interactions of the sulfate and glucuronic acid conjugates of luteolin and naringenin with human serum albumin, cytochrome P450 (CYP2C9, 2C19, and 3A4) enzymes, and organic anion transporting polypeptide (OATP1B1 and OATP2B1) transporters. Our main findings are as follows: (1) Sulfate conjugates formed more stable complexes with albumin than the parent flavonoids. (2) Luteolin and naringenin conjugates showed no or only weak inhibitory action on the CYP enzymes examined. (3) Certain conjugates of luteolin and naringenin are potent inhibitors of OATP1B1 and/or OATP2B1 enzymes. (4) Conjugated metabolites of luteolin and naringenin may play an important role in the pharmacokinetic interactions of these flavonoids.
- MeSH
- cytochrom P-450 CYP3A * metabolismus MeSH
- cytochrom P450 CYP2C19 metabolismus MeSH
- cytochrom P450 CYP2C9 metabolismus MeSH
- flavonoidy farmakologie MeSH
- glukuronidy MeSH
- lidé MeSH
- lidský sérový albumin metabolismus MeSH
- luteolin farmakologie MeSH
- přenašeče organických aniontů * metabolismus MeSH
- sírany metabolismus MeSH
- systém (enzymů) cytochromů P-450 metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Herein, we report the use of the Suzuki-Miyaura cross-coupling reaction for the preparation of a library of synthetic derivatives of flavonoids for biological activity assays. We have investigated the reactivity of halogenated flavonoids with aryl boronates and with boronyl flavonoids. This reaction was used to prepare new synthetic derivatives of flavonoids substituted at C-8 with aryl, heteroaryl, alkyl, and boronate substituents. The formation of flavonoid boronate enabled a cross-coupling reaction with halogenated flavones yielding biflavonoids connected at C-8. This method was used for the preparation of natural compounds including C-8 prenylated compounds, such as sinoflavonoid NB. Flavonoid boronates were used for the preparation of rare C-8 hydroxyflavonoids (natural flavonoids gossypetin and hypolaetin). A series of previously unknown derivatives of quercetin and luteolin were prepared and fully characterized.
The part of the influenza polymerase PA subunit featuring endonuclease activity is a target for anti-influenza therapies, including the FDA-approved drug Xofluza. A general feature of endonuclease inhibitors is their ability to chelate Mg2+ or Mn2+ ions located in the enzyme's catalytic site. Previously, we screened a panel of flavonoids for PA inhibition and found luteolin and its C-glucoside orientin to be potent inhibitors. Through structural analysis, we identified the presence of a 3',4'-dihydroxyphenyl moiety as a crucial feature for sub-micromolar inhibitory activity. Here, we report results from a subsequent investigation exploring structural changes at the C-7 and C-8 positions of luteolin. Experimental IC50 values were determined by AlphaScreen technology. The most potent inhibitors were C-8 derivatives with inhibitory potencies comparable to that of luteolin. Bio-isosteric replacement of the C-7 hydroxyl moiety of luteolin led to a series of compounds with one-order-of-magnitude-lower inhibitory potencies. Using X-ray crystallography, we solved structures of the wild-type PA-N-terminal domain and its I38T mutant in complex with orientin at 1.9 Å and 2.2 Å resolution, respectively.
Luteoloside (Lute), a bioactive natural ingredient, widely exists in nature and possesses hepatoprotective and hepatocyte proliferation-promoting properties. This study aimed to investigate whether Lute could counteract non-alcoholic fatty liver disease (NAFLD)-caused hepatocyte damage via its stimulation of hepatocyte regeneration efficacy and to explore the involved mechanism. LO2 cells and primary hepatocytes were used to examine the hepatocyte proliferation effects of Lute under physiological conditions and in the palmitic acid (PA)- induced in vitro model of NAFLD. STAT3 and cell cycle-related proteins (cyclin D1, c-myc and p21) were evaluated by Western blot. Under physiological conditions, LO2 cells and primary hepatocytes treated with various concentration of Lute for 12 and 24 h showed increased hepatocyte proliferation, especially with 20 μM treatment for 24 h. More notably, under the model conditions, co-incubation with 20 μM of Lute also markedly reversed PA-induced inhibition of cell proliferation and viability in primary hepatocytes. Mechanistically, Lute could activate STAT3 and subsequently increase cyclin D1 and cmyc expression, which positively regulates cell cycle progression, and decrease expression of p21, an inhibitor of cell cycle progression. Furthermore, Luteinduced hepatocyte proliferation-promoting efficacy was abolished by STAT3 inhibitor stattic. Collectively, Lute can alleviate PA-induced hepatocyte damage via activating STAT3-mediated hepatocyte regeneration.
- MeSH
- glukosidy MeSH
- hepatocyty MeSH
- játra MeSH
- kyselina palmitová MeSH
- lidé MeSH
- luteolin MeSH
- nealkoholová steatóza jater * farmakoterapie MeSH
- transkripční faktor STAT3 MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Authentic standards of food flavonoids are important for human metabolic studies. Their isolation from biological materials is impracticable; however, they can be prepared in vitro. Twelve sulfated metabolites of luteolin, myricetin, and ampelopsin were obtained with arylsulfotransferase from Desulfitobacterium hafniense and fully characterized by high-performance liquid chromatography, MS, and NMR. The compounds were tested for their ability to scavenge 1,1-diphenyl-2-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid), and N,N-dimethyl-p-phenylenediamine radicals, to reduce ferric ions and Folin-Ciocalteu reagent, and to inhibit tert-butyl hydroperoxide-induced lipid peroxidation of rat liver microsomes. The activity differed considerably even between monosulfate isomers. The parent compounds and myricetin-3'-O-sulfate were the most active while other compounds displayed significantly lower activity, particularly luteolin sulfates. No mutagenic activity of the parent compounds and their main metabolites was observed; only myricetin showed minor pro-mutagenicity. The prepared sulfated metabolites are now available as authentic standards for future in vitro and in vivo metabolic studies.
- MeSH
- antioxidancia chemie farmakologie MeSH
- arylsulfotransferasa chemie MeSH
- bakteriální proteiny chemie MeSH
- biofyzikální jevy MeSH
- biokatalýza MeSH
- Desulfitobacterium enzymologie MeSH
- flavonoidy chemie metabolismus farmakologie MeSH
- isomerie MeSH
- jaterní mikrozomy účinky léků metabolismus MeSH
- krysa rodu rattus MeSH
- luteolin chemie metabolismus farmakologie MeSH
- molekulární struktura MeSH
- peroxidace lipidů účinky léků MeSH
- sírany chemie metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Aqueous extracts of aerial flowering parts of five Agrimonia species (Rosaceae): Agrimonia coreana Nakai, Agrimonia japonica (Miq.) Koidz, Agrimonia procera Wallr., Agrimonia eupatoria L. and Agrimonia leucantha Kunze were investigated on their antioxidant activity, measured using five different methods; the best was the extract from A. procera with IC50 values from 6 to 29 μg/mL. All the extracts displayed inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) at the tested concentration of 100 μg/mL. We found the highest inhibition of cholinesterase in the extract of A. japonica with inhibition 70.4% for AChE and 79.8% for BuChE. These findings are statistically significant in comparison with those of other extracts (p < 0.001). The phytochemical analyses showed that the antioxidant activity of Agrimonia extracts can be affected especially by hexahydroxydiphenoyl (HHDP)-glucose and quercetin glycosides, and inhibition of cholinesterases by apigenin, luteolin and quercetin glycosides.
- MeSH
- acetylcholinesterasa metabolismus MeSH
- Agrimonia chemie klasifikace MeSH
- antioxidancia izolace a purifikace farmakologie MeSH
- apigenin izolace a purifikace farmakologie MeSH
- butyrylcholinesterasa metabolismus MeSH
- cholinesterasové inhibitory izolace a purifikace farmakologie MeSH
- fytonutrienty chemie MeSH
- luteolin izolace a purifikace farmakologie MeSH
- quercetin izolace a purifikace farmakologie MeSH
- rostlinné extrakty chemie farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
AKR1B10 is an NADPH-dependent reductase that plays an important function in several physiological reactions such as the conversion of retinal to retinol, reduction of isoprenyl aldehydes, and biotransformation of procarcinogens and drugs. A growing body of evidence points to the important role of the enzyme in the development of several types of cancer (e.g., breast, hepatocellular), in which it is highly overexpressed. AKR1B10 is regarded as a therapeutic target for the treatment of these diseases, and potent and specific inhibitors may be promising therapeutic agents. Several inhibitors of AKR1B10 have been described, but the area of natural plant products has been investigated sparingly. In the present study almost 40 diverse phenolic compounds and alkaloids were examined for their ability to inhibit the recombinant AKR1B10 enzyme. The most potent inhibitors-apigenin, luteolin, and 7-hydroxyflavone-were further characterized in terms of IC50, selectivity, and mode of action. Molecular docking studies were also conducted, which identified putative binding residues important for the interaction. In addition, cellular studies demonstrated a significant inhibition of the AKR1B10-mediated reduction of daunorubicin in intact cells by these inhibitors without a considerable cytotoxic effect. Although these compounds are moderately potent and selective inhibitors of AKR1B10, they constitute a new structural type of AKR1B10 inhibitor and may serve as a template for the development of better inhibitors.
- MeSH
- aldehydreduktasa antagonisté a inhibitory účinky léků MeSH
- apigenin farmakologie MeSH
- daunomycin farmakologie MeSH
- flavonoidy farmakologie MeSH
- flavony chemie farmakologie MeSH
- HCT116 buňky MeSH
- inhibitory enzymů chemie MeSH
- lidé MeSH
- luteolin farmakologie MeSH
- molekulární konformace MeSH
- molekulární struktura MeSH
- nádory farmakoterapie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
x
x
- Klíčová slova
- biofarmakum, medicína,
- MeSH
- antioxidancia MeSH
- farmakologie MeSH
- flavonoidy chemie MeSH
- fytoterapie metody využití MeSH
- klinické zkoušky jako téma MeSH
- lidé MeSH
- luteolin * analýza aplikace a dávkování biosyntéza terapeutické užití toxicita MeSH
- protinádorové látky MeSH
- rostliny MeSH
- toxikologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
