RESUMO
Artemisia is one of the largest genera in the plant family Asteraceae and has long been used in traditional medicine for its antitussive, analgesic, antihypertensive, antitoxic, antiviral, antimalarial, and anti-inflammatory properties. However, the anti-diabetic activity of Artemisia montana has not been broadly studied. The goal of this study was to determine whether extracts of the aerial parts of A. montana and its main constituents inhibit protein tyrosine phosphatase 1B (PTP1B) and α-glucosidase activities. We isolated nine compounds from A. montana including ursonic acid (UNA) and ursolic acid (ULA), which significantly inhibited PTP1B with IC50 values of 11.68 and 8.73 µM, respectively. In addition, UNA showed potent inhibitory activity against α-glucosidase (IC50 = 61.85 µM). Kinetic analysis of PTP1B and α-glucosidase inhibition revealed that UNA was a non-competitive inhibitor of both enzymes. Docking simulations of UNA demonstrated negative binding energies and close proximity to residues in the binding pockets of PTP1B and α-glucosidase. Molecular docking simulations between UNA and human serum albumin (HSA) revealed that UNA binds tightly to all three domains of HSA. Furthermore, UNA significantly inhibited fluorescent AGE formation (IC50 = 4.16 µM) in a glucose-fructose-induced HSA glycation model over the course of four weeks. Additionally, we investigated the molecular mechanisms underlying the anti-diabetic effects of UNA in insulin-resistant C2C12 skeletal muscle cells and discovered that UNA significantly increased glucose uptake and decreased PTP1B expression. Further, UNA increased GLUT-4 expression level by activating the IRS-1/PI3K/Akt/GSK-3 signaling pathway. These findings clearly demonstrate that UNA from A. montana shows great potential for treatment of diabetes and its complications.
Assuntos
Artemisia , Diabetes Mellitus , Insulinas , Humanos , Lactente , Hipoglicemiantes/farmacologia , alfa-Glucosidases/metabolismo , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Monoéster Fosfórico Hidrolases/metabolismo , Cinética , Artemisia/química , Artemisia/metabolismo , Simulação de Acoplamento Molecular , Quinase 3 da Glicogênio Sintase/metabolismo , Montana , Diabetes Mellitus/tratamento farmacológico , Transdução de Sinais , Proteína Tirosina Fosfatase não Receptora Tipo 1RESUMO
Aglycone- and glycoside-derived forms of flavonoids exist broadly in plants and foods such as fruits, vegetables, and peanuts. However, most studies focus on the bioavailability of flavonoid aglycone rather than its glycosylated form. Kaempferol-3-O-ß-d-glucuronate (K3G) is a natural flavonoid glycoside obtained from various plants that have several biological activities, including antioxidant and anti-inflammatory effects. However, the molecular mechanism related to the antioxidant and antineuroinflammatory activity of K3G has not yet been demonstrated. The present study was designed to demonstrate the antioxidant and antineuroinflammatory effect of K3G against lipopolysaccharide (LPS)-stimulated BV2 microglial cells and to evaluate the underlying mechanism. Cell viability was determined by MTT assay. The inhibition rate of reactive oxygen species (ROS) and the production of pro-inflammatory mediators and cytokines were measured by DCF-DA assay, Griess assay, enzyme-linked immunosorbent assay (ELISA), and western blotting. K3G inhibited the LPS-induced release of nitric oxide, interleukin (IL)-6, and tumor necrosis factor-α (TNF-α) as well as the expression of prostaglandin E synthase 2. Additionally, K3G reduced the expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and nuclear factor-kappa B (NF-κB) related proteins. Mechanistic studies found that K3G downregulated phosphorylated mitogen-activated protein kinases (MAPKs) and upregulated the Nrf2/HO-1 signaling cascade. In this study, we demonstrated the effects of K3G on antineuroinflammation by inactivating phosphorylation of MPAKs and on antioxidants by upregulating the Nrf2/HO-1 signaling pathway through decreasing ROS in LPS-stimulated BV2 cells.
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By various chromatographic methods, 30 phloroglucinols (1-30) were isolated from a methanol extract of Dryopteris crassirhizoma, including two new dimeric phloroglucinols (13 and 25). The structures of the isolates were confirmed by HR-MS, 1D, and 2D NMR as well as by comparison with the literature. The protein tyrosine phosphatase 1B (PTP1B) effects of the isolated compounds (1-30) were evaluated using sodium orthovanadate and ursolic acid as a positive control. Among them, trimeric phloroglucinols 26-28 significantly exhibited the PTP1B inhibitory effects with the IC50 values of 1.19 ± 0.13, 1.00 ± 0.04, 1.23 ± 0.05 µM, respectively. In addition, the kinetic analysis revealed compounds 26-28 acted as competitive inhibitors against PTP1B enzyme with Ki values of 0.63, 0.61, 1.57 µM, respectively. Molecular docking simulations were performed to demonstrate that these active compounds can bind with the catalytic sites of PTP1B with negative binding energies and the results are in accordance with that of the kinetic studies. In vitro and in silico results suggest that D. crassirhizoma rhizomes together with compounds 26-28 are potential candidates for treating type 2 diabetes.
Assuntos
Dryopteris/química , Simulação de Acoplamento Molecular , Floroglucinol/farmacologia , Proteína Tirosina Fosfatase não Receptora Tipo 1/antagonistas & inibidores , Rizoma/química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Domínio Catalítico , Cinética , Floroglucinol/química , Floroglucinol/isolamento & purificação , Proteína Tirosina Fosfatase não Receptora Tipo 1/metabolismo , Espectroscopia de Prótons por Ressonância MagnéticaRESUMO
Phlorotannins are polyphenolic compounds in marine alga, especially the brown algae. Among numerous phlorotannins, dieckol and phlorofucofuroeckol-A (PFF-A) are the major ones and despite a wider biological activity profile, knowledge of the G protein-coupled receptor (GPCR) targets of these phlorotannins is lacking. This study explores prime GPCR targets of the two phlorotannins. In silico proteocheminformatics modeling predicted twenty major protein targets and in vitro functional assays showed a good agonist effect at the α2C adrenergic receptor (α2CAR) and an antagonist effect at the adenosine 2A receptor (A2AR), δ-opioid receptor (δ-OPR), glucagon-like peptide-1 receptor (GLP-1R), and 5-hydroxytryptamine 1A receptor (5-TH1AR) of both phlorotannins. Besides, dieckol showed an antagonist effect at the vasopressin 1A receptor (V1AR) and PFF-A showed a promising agonist effect at the cannabinoid 1 receptor and an antagonist effect at V1AR. In silico molecular docking simulation enabled us to investigate and identify distinct binding features of these phlorotannins to the target proteins. The docking results suggested that dieckol and PFF-A bind to the crystal structures of the proteins with good affinity involving key interacting amino acid residues comparable to reference ligands. Overall, the present study suggests α2CAR, A2AR, δ-OPR, GLP-1R, 5-TH1AR, CB1R, and V1AR as prime receptor targets of dieckol and PFF-A.
Assuntos
Benzofuranos/química , Dioxinas/química , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Animais , Células CHO , Linhagem Celular , Simulação por Computador , Cricetulus , Células HeLa , Humanos , Camundongos , Simulação de Acoplamento Molecular , Phaeophyceae/química , RatosRESUMO
The onion, known as the bulb onion or common onion, is not only a key ingredient in many tasty and healthy vegetarian meals but also many traditional medicines. Nine new flavonoids [cepaflavas A, B (5, 6), cepadials A-D (7-9 and 14), and cepabiflas A-C (10-12)] and six known compounds (1-4, 13, 15) were obtained from the outer skins of Allium cepa L. Among them, compounds 5, 6, and 9 might be artificial products formed during extraction and isolation. New compounds were structurally elucidated using various spectroscopy/spectrometry techniques, including NMR and HRMS, and computational methods. Their absolute configurations were determined using time-dependent density functional theory calculations, combined with ECD spectroscopy, optical rotation calculation, and statistical procedures (CP3 and DP4 analysis). The free radical scavenging assays revealed that the new compounds 10-12 possessed considerable antioxidant activities with IC50 values of 4.25-8.88 and 7.12-8.14 µM against DPPH and ABTSâ¢+, respectively. Compounds 13-15 showed substantial inhibitory activities against both α-glucosidase and protein tyrosine phosphatase 1B (PTP1B), with IC50 values of 0.89-6.80 and 1.13-6.82 µM, respectively. On the basis of molecular docking studies, 13 and 15 were predicted to have high binding capacity and strong affinity toward the active site of PTP1B.
Assuntos
Antioxidantes/química , Flavonoides/química , Hipoglicemiantes/química , Cebolas/química , Extratos Vegetais/química , Inibidores Enzimáticos/química , Flavonoides/farmacologia , Simulação de Acoplamento Molecular , Estrutura Molecular , Proteína Tirosina Fosfatase não Receptora Tipo 1/química , alfa-Glucosidases/químicaRESUMO
Oxidation and enzymatic browning of food can affect nutritional quality, physical and chemical properties, and food safety, emphasizing the utmost importance of discovering new natural antioxidants and anti-browning agents. The present study aimed to characterize the antioxidant and anti-browning potential of 2-arylbenzofuran derivatives from the root bark of Morus alba Linn. All test compounds showed good antioxidant effects on non-enzymatic antioxidant assays. Only mulberrofuran H demonstrated potent inhibition against substrates l-tyrosine (IC50; 4.45 ± 0.55 µM) and l-DOPA (IC50; 19.70 ± 0.54 µM), indicating negative effects of the prenyl and geranyl groups in the other compounds. Molecular docking simulation predicted the involvement of an -OH group in the bulky substituent in C-11 in van der Waals interactions with copper ions (Cu400, Cu401) and peroxide ions (Per404) in the active site. Overall results characterize MH as an antioxidant and anti-browning agent, highlighting its potential role in food preservation.
Assuntos
Antioxidantes/química , Benzofuranos/química , Morus/química , Extratos Vegetais/química , Cor , Simulação de Acoplamento Molecular , Oxirredução , Casca de Planta/química , Raízes de Plantas/químicaRESUMO
Compounds were isolated from Ecklonia stolonifera Okamura, a marine brown alga widely consumed as food. Among the isolated compounds, 974-A was demonstrated for the first time to be a potent competitive inhibitor of mushroom tyrosinase activity towards l-tyrosine and l-DOPA (IC50 values = 1.57 ± 0.08 and 3.56 ± 0.22 µM, respectively). Molecular docking simulations clarified that the hydroxyl residues of the isolated compounds formed hydrogen bonds with residues at the catalytic and allosteric sites of tyrosinase, while other residues participated in hydrophobic interactions. Moreover, 974-A, phlorofucofuroeckol-A and eckol reduced the cellular melanin content and tyrosinase activity, and downregulated the expression of melanogenesis enzymes including tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2 in B16F10 melanoma cells. These compounds also effectively scavenged radicals at the cellular level. Thus, our results revealed that compounds isolated from E. stolonifera are potent tyrosinase inhibitors with potential applications in the cosmetic industry for treatment of hyperpigmentation and for the anti-browning effect in the agricultural field.
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A marine red alga, Symphyocladia latiuscula (Harvey) Yamada (Rhodomelaceae), is a rich source of bromophenols with a wide array of biological activities. This study investigates the anti-tyrosinase activity of the alga. Moderate activity was demonstrated by the methanol extract of S. latiuscula, and subsequent column chromatography identified three bromophenols: 2,3,6-tribromo-4,5-dihydroxybenzyl methyl alcohol (1), 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether (2), and bis-(2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether) (3). Bromophenols 1 and 3 exhibited potent competitive tyrosinase inhibitory activity against l-tyrosine substrates, with IC50 values of 10.78 ± 0.19 and 2.92 ± 0.04 µM, respectively. Against substrate l-3,4-dihydroxyphenylalanine (l-DOPA), compounds 1 and 3 demonstrated moderate activity, while 2 showed no observable effect. The experimental data were verified by a molecular docking study that found catalytic hydrogen and halogen interactions were responsible for the activity. In addition, compounds 1 and 3 exhibited dose-dependent inhibitory effects in melanin and intracellular tyrosinase levels in α-melanocyte-stimulating hormone (α-MSH)-induced B16F10 melanoma cells. Compounds 3 and 1 were the most effective tyrosinase inhibitors. In addition, increasing the bromine group number increased the mushroom tyrosinase inhibitory activity.
Assuntos
Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Rodófitas/química , Tirosina/antagonistas & inibidores , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Humanos , Concentração Inibidora 50 , Metanol/química , Simulação de Acoplamento MolecularRESUMO
The marine alga, Symphyocladia latiuscula (Harvey) Yamada, is a good source of bromophenols with numerous biological activities. This study aims to characterize the anti-diabetic potential of 2,3,6-tribromo-4,5-dihydroxybenzyl derivatives isolated from S. latiuscula via their inhibition of tyrosine phosphatase 1B (PTP1B) and α-glucosidase. Additionally, this study uses in silico modeling and glucose uptake potential analysis in insulin-resistant (IR) HepG2 cells to reveal the mechanism of anti-diabetic activity. This bioassay-guided isolation led to the discovery of three potent bromophenols that act against PTP1B and α-glucosidase: 2,3,6-tribromo-4,5-dihydroxybenzyl alcohol (1), 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether (2), and bis-(2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether) (3). All compounds inhibited the target enzymes by 50% at concentrations below 10 µM. The activity of 1 and 2 was comparable to ursolic acid (IC50; 8.66 ± 0.82 µM); however, 3 was more potent (IC50; 5.29 ± 0.08 µM) against PTP1B. Interestingly, the activity of 1â»3 against α-glucosidase was 30â»110 times higher than acarbose (IC50; 212.66 ± 0.35 µM). Again, 3 was the most potent α-glucosidase inhibitor (IC50; 1.92 ± 0.02 µM). Similarly, 1â»3 showed concentration-dependent glucose uptake in insulin-resistant HepG2 cells and downregulated PTP1B expression. Enzyme kinetics revealed different modes of inhibition. In silico molecular docking simulations demonstrated the importance of the 7â»OH group for H-bond formation and bromine/phenyl ring number for halogen-bond interactions. These results suggest that bromophenols from S. latiuscula, especially highly brominated 3, are inhibitors of PTP1B and α-glucosidase, enhance insulin sensitivity and glucose uptake, and may represent a novel class of anti-diabetic drugs.
Assuntos
Compostos de Benzil/farmacologia , Diabetes Mellitus/tratamento farmacológico , Éteres/farmacologia , Proteína Tirosina Fosfatase não Receptora Tipo 1/antagonistas & inibidores , Rodófitas/química , alfa-Glucosidases/metabolismo , Compostos de Benzil/química , Compostos de Benzil/isolamento & purificação , Sobrevivência Celular/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Éteres/isolamento & purificação , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/isolamento & purificação , Inibidores de Glicosídeo Hidrolases/farmacologia , Células Hep G2 , Humanos , Hipoglicemiantes/química , Hipoglicemiantes/isolamento & purificação , Hipoglicemiantes/farmacologia , Resistência à Insulina , Simulação de Acoplamento MolecularRESUMO
This study examined whether serotonin and two of its derivatives, N -feruloylserotonin and N -( p -coumaroyl) serotonin, have a renoprotective effect in a mouse model of cisplatin-induced acute renal failure. Cisplatin (20 mg/kg body weight) was administered by intraperitoneal injection to male BALB/c mice that had received oral serotonin, N -feruloylserotonin or N -( p -coumaroyl) serotonin (7.5 mg/kg body weight per day) during the preceding 2 days. At 3 days after the cisplatin injection, serum and renal biochemical factors, oxidative stress, inflammation and apoptosis-related protein expression were evaluated, and histological examinations were performed. Cisplatin caused reduction in body weight and an increase in kidney weight; however, N -( p -coumaroyl) serotonin and N -feruloylserotonin attenuated these effects. Moreover, the serotonin derivatives significantly decreased serum urea nitrogen and creatinine levels. They also significantly reduced the level of reactive oxygen species and upregulated the expression of glutathione peroxidase in the kidney. Furthermore, the serotonin derivatives improved the abnormal expression of mitogen-activated protein kinases activation-dependent inflammation- and apoptosis-related protein and caused less renal damage. These results provide important evidence that N -( p -coumaroyl) serotonin and N -feruloylserotonin exert a pleiotropic effect on several parameters related to oxidative stress, inflammation and apoptosis. The derivatives also have a renoprotective effect in cisplatin-treated mice; however, this effect is higher with N -( p -coumaroyl) serotonin.
Assuntos
Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/prevenção & controle , Antineoplásicos/efeitos adversos , Cisplatino/efeitos adversos , Fitoterapia , Serotonina/análogos & derivados , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Nitrogênio da Ureia Sanguínea , Carthamus tinctorius/química , Creatinina/sangue , Modelos Animais de Doenças , Expressão Gênica , Glutationa Peroxidase/genética , Glutationa Peroxidase/metabolismo , Inflamação/genética , Injeções Intraperitoneais , Rim/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Serotonina/administração & dosagem , Serotonina/farmacologiaRESUMO
Inhibition of overactivated inflammation has been demonstrated as one of the most efficient strategies for treating inflammatory diseases. In the present study, 6formyl umbelliferone (6FU) was used to evaluate its antiinflammatory effects on lipopolysaccharide (LPS)stimulated RAW 264.7 macrophages. 6FU inhibited chronic inflammatory processes, including increasing nitric oxide levels, and the expression of proinflammatory genes and producing cytokines was investigated by a nitrite assay and reverse transcriptionpolymerase chain reaction, respectively. Nitric oxide and proinflammatory cytokines, including tumor necrosis factorα, interleukin (IL)1ß and IL6 were decreased by treatment with 6FU, without cell cytotoxicity in LPSstimulated RAW 264.7 cells, which was measured by a WST1 assay. In the western blot analysis, the expression levels of phosphorylated extracellular signalregulated kinase (ERK)1/2 was downregulated in 6FUtreated cells. Furthermore, in the western blotting and immunofluorescence staining results, translocation activities of ERK1/2 and NFκB from the cytoplasm to the nucleus were suppressed, which may inhibit translation of numerous proteins associated with proinflammation, including inducible nitric oxide synthase and cyclooxygenase2. Therefore, based on these results, it was suggested that 6FU may be a potential candidate for the development of agents against chronic inflammation.
Assuntos
Anti-Inflamatórios/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , NF-kappa B/metabolismo , Umbeliferonas/farmacologia , Animais , Sobrevivência Celular/efeitos dos fármacos , Ciclo-Oxigenase 2/metabolismo , Citocinas/genética , Citocinas/metabolismo , Ativação Enzimática/efeitos dos fármacos , Lipopolissacarídeos , Camundongos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Óxido Nítrico/biossíntese , Óxido Nítrico Sintase Tipo II/metabolismo , Fosforilação/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Células RAW 264.7 , RNA Mensageiro/genética , RNA Mensageiro/metabolismoRESUMO
In the search for natural products having a dual inhibitory action on diabetes and Alzheimer's disease, this study investigated the activity of different parts of Korean thistle (Cirsium japonicum var. maackii (Maxim.) Matsum), and its fractional constituents by in vitro enzymatic and in silico molecular docking studies. Cirsium maackii has been used as a traditional medicine for the treatment of several diseases. The ethyl acetate and dichloromethane fractions of a leaf extract showed α-glucosidase and BACE1 inhibitory activity, respectively. Furthermore, the isolated compound, luteolin, exhibited concentration-dependent non-competitive inhibition against both α-glucosidase and BACE1 (IC50 = 51.27 ± 1.23 and 13.75 ± 0.26 µM; Ki value = 52.04 and 14.76 µM, respectively). Moreover, docking studies showed that luteolin formed a strong hydrogen bond with the peripheral binding amino acid residues, and hydrophobic interactions with the α-glucosidase and BACE1 enzymes. Therefore, Korean thistle may act as an important dietary supplement against diabetes and Alzheimer's disease, especially the leaves, because of the preponderance of the active component, luteolin, making Korean thistle a promising candidate for more detailed in vitro and in vivo studies.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Cirsium/química , Diabetes Mellitus/tratamento farmacológico , Extratos Vegetais/farmacologia , Animais , Produtos Biológicos/farmacologia , Células CACO-2 , Linhagem Celular , Linhagem Celular Tumoral , Suplementos Nutricionais , Cães , Flavonas/farmacologia , Humanos , Interações Hidrofóbicas e Hidrofílicas , Luteolina/farmacologia , Células Madin Darby de Rim Canino , Simulação de Acoplamento Molecular/métodos , República da CoreiaRESUMO
The G protein-coupled receptor (GPCR) family of proteins comprises signaling proteins that mediate cellular responses to various hormones and neurotransmitters, and serves as a prime target for drug discovery. Towards our goal of discovering secondary metabolites from natural sources that can function as neuronal drugs, we evaluated the modulatory effect of eckol on various GPCRs via cell-based functional assays. In addition, we conducted in silico predictions to obtain molecular insights into the functional effects of eckol. Functional assays revealed that eckol had a concentration-dependent agonist effect on dopamine D3 and D4 receptors. The half maximal effective concentration (EC50) of eckol for the dopamine D3 and D4 receptors was 48.62 ± 3.21 and 42.55 ± 2.54 µM, respectively, while the EC50 values of dopamine as a reference agonist for these two receptors were 2.9 and 3.3 nM, respectively. In silico studies revealed that a low binding energy in addition to hydrophilic, hydrophobic, πâ»alkyl, and πâ»π T-shaped interactions are potential mechanisms by which eckol binds to the dopamine receptors to exert its agonist effects. Molecular dynamics (MD) simulation revealed that Phe346 of the dopamine receptors is important for binding of eckol, similar to eticlopride and dopamine. Our results collectively suggest that eckol is a potential D3/D4 agonist for the management of neurodegenerative diseases, such as Parkinson's disease.
Assuntos
Dioxinas/química , Dioxinas/farmacologia , Receptores de Dopamina D3/agonistas , Receptores de Dopamina D4/agonistas , Animais , Linhagem Celular , Cricetinae , Dopamina , Humanos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Ratos , Receptores de Dopamina D3/metabolismo , Receptores de Dopamina D4/metabolismo , Receptores de Estrogênio/metabolismo , Receptores Acoplados a Proteínas G/metabolismoRESUMO
The aim of the present study was a comparative investigation of water and 70% ethanol extracts derived from yellow and red onion (Allium cepa L.) peels against diabetes and diabetic complications. The total phenolic contents (TPCs) and total flavonoid contents (TFCs) of each cultivar, measured to assess phytochemical characteristics, showed a direct correlation with the in vitro antioxidant effects. Among the two captives, the yellow onion peel extract showed higher antioxidant activity than red one. However, all extracts exhibited significant protein tyrosine phosphatase 1B (PTP1B) inhibitory activity (IC50; 0.30-0.86 µg/ml), showing water extracts more potent (IC50; approximately 0.3 µg/mL), than the 70% ethanol extracts (IC50; approximately 0.8 µg/ml). Similarly, in insulin-resistant HepG2 cells, all extracts enhanced the glucose uptake and reduced the expression of PTP1B in a concentration-dependent manner, water extract displaying better activity. Our results overall suggest that in vitro antioxidant and antidiabetic potentials vary among red and yellow cultivars and extracting solvents, which could therefore be a promising strategy to prevent diabetes and associated complications.
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We investigated whether obtusin, obtusifolin, and cassiaside isolated from the seeds of Cassia obtusifolia inhibit the gene expression and production of airway mucin 5AC (MUC5AC). Confluent NCI-H292 cells were pretreated with obtusin, obtusifolin, or cassiaside for 30 min and then stimulated with epidermal growth factor (EGF), phorbol 12-myristate 13-acetate (PMA), or tumor necrosis factor-α (TNF-α) for 24 hr. The MUC5AC mucin gene expression was measured by reverse transcription-polymerase chain reaction. Production of MUC5AC mucin protein was measured by enzyme-linked immunosorbent assay. To elucidate the action mechanism of obtusifolin, effect of obtusifolin on PMA-induced nuclear factor kappa B (NF-κB) signaling pathway was investigated by western blot analysis. Obtusin, obtusifolin, or cassiaside inhibited the expression of MUC5AC mucin gene and the production of MUC5AC mucin protein, induced by EGF, PMA, or TNF-α. Obtusifolin inhibited PMA-induced activation (phosphorylation) of inhibitory kappa B kinase, and thus phosphorylation and degradation of inhibitory kappa B alpha. Obtusifolin inhibited PMA-induced nuclear translocation of NF-κB p65. These results suggest that obtusifolin can regulate the production and gene expression of mucin by acting on airway epithelial cells through regulation of NF-κB signaling pathway.
Assuntos
Antraquinonas/farmacologia , Mucina-5AC/genética , NF-kappa B/fisiologia , Linhagem Celular Tumoral , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Mucina-5AC/biossíntese , Sementes/química , Transdução de Sinais/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
Inhibition of glycogen synthase kinase 3ß (GSK-3ß) is considered to be the central therapeutic approach against Alzheimer's disease (AD). In the present study, boiled water extracts of the Kangen-karyu (KK) herbal mixture and its constituents were screened for GSK-3ß inhibitory activity. KK is used in traditional Kampo and Chinese medicines for improving cognitive function. The GSK-3ß inhibition potential was evaluated by using the Kinase-Glo luminescent kinase assay platform. Furthermore, enzyme kinetics and in silico modeling were performed by using AutoDockTools to demonstrate the mechanism of enzyme inhibition. KK extract significantly inhibited GSK-3ß in a concentration-dependent manner (IC50: 17.05 ± 1.14 µg/mL) when compared with the reference drug luteolin (IC50: 2.18 ± 0.13 µM). Among the six components of KK, extracts of Cyperi Rhizoma and Salviae Miltiorrhizae Radix significantly inhibited GSK-3ß with IC50 values of 20.68 ± 2.50 and 7.77 ± 1.38 µg/mL, respectively. Among the constituents of the roots of S. miltiorrhiza water extract, rosmarinic acid, magnesium lithospermate B, salvianolic acid A, salvianolic acid B, and salvianolic acid C inhibited GSK-3ß with IC50 values ranging from 6.97 to 135.5 µM. Salvianolic acid B was found to be an ATP-competitive inhibitor of GSK-3ß and showed the lowest IC50 value (6.97 ± 0.96 µM). In silico modeling suggested a mechanism of action by which the hydrophobic, πâ»cation, and hydrophilic interactions of salvianolic acid B at ATP and substrate sites are critical for the observed GSK-3ß inhibition. Therefore, one of the mechanisms of action of KK against AD may be the inhibition of GSK-3ß and one of the active components of KK is the root of S. miltiorrhiza and its constituents: rosmarinic acid, magnesium lithospermate B, and salvianolic acids A, B, and C. Our results demonstrate the pharmacological basis for the use of KK against AD.
Assuntos
Doença de Alzheimer/enzimologia , Medicamentos de Ervas Chinesas/farmacologia , Glicogênio Sintase Quinase 3 beta/antagonistas & inibidores , Alcenos/química , Alcenos/farmacologia , Doença de Alzheimer/tratamento farmacológico , Benzofuranos/química , Benzofuranos/farmacologia , Ácidos Cafeicos/química , Ácidos Cafeicos/farmacologia , Cinamatos/química , Cinamatos/farmacologia , Simulação por Computador , Depsídeos/química , Depsídeos/farmacologia , Relação Dose-Resposta a Droga , Medicamentos de Ervas Chinesas/química , Glicogênio Sintase Quinase 3 beta/química , Humanos , Lactatos/química , Lactatos/farmacologia , Simulação de Acoplamento Molecular , Estrutura Molecular , Raízes de Plantas/química , Polifenóis/química , Polifenóis/farmacologia , Ácido RosmarínicoRESUMO
Sargassum species have been reported to be a source of phytochemicals, with a wide range of biological activities. In this study, we evaluated the hepatoprotective effect of a meroterpenoid-rich fraction of the ethanolic extract from Sargassum serratifolium (MES) against tert-butyl hydroperoxide (t-BHP)-treated HepG2 cells. Treatment with MES recovered the cell viability from the t-BHP-induced oxidative damage in a dose-dependent manner. It suppressed the reactive oxygen species production, lipid peroxidation, and glutathione depletion in the t-BHP-treated HepG2 cells. The activity of the antioxidants induced by t-BHP, including superoxide dismutase (SOD) and catalase, was reduced by the MES treatment. Moreover, it increased the nuclear translocation of nuclear factor erythroid 2-related factor 2, leading to the enhanced activity of glutathione S transferase, and the increased production of heme oxygenase-1 and NAD(P)H:quinine oxidoreductase 1 in t-BHP-treated HepG2 cells. These results demonstrate that the antioxidant activity of MES substituted the activity of the SOD and catalase, and induced the production of detoxifying enzymes, indicating that MES might be used as a hepatoprotectant against t-BHP-induced oxidative stress.
Assuntos
Etanol/química , Estresse Oxidativo/efeitos dos fármacos , Sargassum/química , Terpenos/química , Terpenos/farmacologia , terc-Butil Hidroperóxido/farmacologia , Antioxidantes/metabolismo , Catalase/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Glutationa/metabolismo , Heme Oxigenase-1/metabolismo , Células Hep G2 , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , NADP/metabolismo , Oxirredução/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismoRESUMO
Four undescribed 23,24-O-isopropylidene-19(18â¯ââ¯17)-abeo-28-noroleanane-derived spirocyclic triterpenoids and an undescribed 28-noroleanane-derived spirocyclic triterpenoid, together with five known 28-noroleanane-derived spirocyclic triterpenoids, were isolated and identified. In addition, three undescribed iridoid glucosides and four known ones were also identified. All the isolates were identified using spectroscopic techniques, and the absolute configurations of 28-noroleanane-derived spirocyclic triterpenoids were determined by CD method for the first time. Additionally, the alkaline hydrolysis method and HPLC analysis were applied to confirm the moieties of the iridoid glucosides. The fraction and isolates were evaluated for cytotoxic activity on cervical cancer (Hela), human promyelocytic leukemia (HL-60), and breast cancer (MCF-7) cell lines. Among them, phlomisu E possessed an aldehyde group showed the most potent cytotoxic effect with IC50 value less than 10⯵M.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Glucosídeos Iridoides/farmacologia , Lamiaceae/química , Raízes de Plantas/química , Compostos de Espiro/farmacologia , Triterpenos/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Células HL-60 , Células HeLa , Humanos , Glucosídeos Iridoides/química , Glucosídeos Iridoides/isolamento & purificação , Células MCF-7 , Conformação Molecular , Compostos de Espiro/química , Compostos de Espiro/isolamento & purificação , Relação Estrutura-Atividade , Triterpenos/química , Triterpenos/isolamento & purificaçãoRESUMO
Kuwanon G (KG) and benzofuran flavonoids such as mulberrofuran G (MG) and albanol B (AB) isolated from Morus sp. are reported to exhibit anti-Alzheimer's disease, anti-inflammatory, fungicidal, anti-cancer, anti-bacterial, and anti-tyrosinase properties. We investigated the inhibition of mono- and diphenolase activity of mushroom tyrosinase by KG, MG, and AB. KG and MG displayed acceptable inhibition activity compared to kojic acid. AB did not show any activity up to 350 µM. MG displayed six-fold higher inhibition of l-tyrosine oxidation (IC50 = 6.35 ± 0.45 µM) compared to kojic acid (IC50 = 36.0 µM). Kinetic studies revealed that KG and MG inhibited monophenolase activity of tyrosinase in a competitive manner. Docking simulations of KG and MG demonstrated favorable binding energies with amino acid residues of the active sites of tyrosinase. Our investigation of the structure-activity relationship of the fused benzofuran flavonoids (MG vs. AB) implicated the methyl cyclohexene ring moiety in tyrosinase inhibition. The enzyme substrate and relative structural analyses demonstrated that KG and MG from Morus sp. could be useful natural tyrosinase inhibitors in foods or cosmetics.
Assuntos
Benzofuranos/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Flavonoides/farmacologia , Monofenol Mono-Oxigenase/antagonistas & inibidores , Terpenos/farmacologia , Benzofuranos/química , Flavonoides/química , Cinética , Simulação de Acoplamento Molecular , Relação Estrutura-Atividade , Terpenos/químicaRESUMO
Cassia obtusifolia L. seed is one of the most popular traditional Chinese medicine for mutagenicity, genotoxicity, hepatotoxicity, and acute inflammatory diseases. We evaluated the hepatoprotective activity of anthraquinone and naphthopyrone glycosides isolated from the butanol fraction of C. obtusifolia seeds and explored their effects on cell signaling pathways. Continuous chromatographic separation led to the isolation of 1-desmethylaurantio-obtusin 2-O-ß-D-glucopyranoside (1), rubrofusarin 6-O-ß-D-apiofuranosyl-(1 â 6)-O-ß-D-glucopyranoside (2) and rubrofusarin 6-O-ß-gentiobioside (3). All glycosides were non-toxic at concentrations up to 80 µM. The increased intracellular reactive oxygen species (ROS) and decreased glutathione levels observed after tert-butylhydroperoxide (t-BHP) intoxication were ameliorated by all three glycosides, with compound 3 being the most active. Pretreatment with the three glycosides increased nuclear factor erythroid-2-related factor 2 (Nrf2)-mediated heme oxidase-1 (HO-1) expression. All the glycosides enhanced the phosphorylation of c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK), and the dephosphorylation of p38. The protective effects of the anthraquinone and naphthopyrone glycosides against t-BHP-induced oxidative damage in human liver-derived HepG2 cells were due to the prevention of ROS generation and up-regulated activity of HO-1 via Nrf2 activation and modulation of the JNK/ERK/MAPK signaling pathway. The data indicate the potential of these compounds as hepatoprotective agents in pharmaceuticals and/or nutraceuticals.