RESUMO
Affinity-based ultrafiltration-mass spectrometry coupled with ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry was utilised for the structural identification of direct tyrosinase ligands from a crude Pseudolysimachion rotundum var. subintegrum extract. False positives were recognised by introducing time-dependent inhibition in the control for comparison. The P. rotundum extract contained nine main metabolites in the UPLC-QTOF-MS chromatogram. However, four metabolites were reduced after incubation with tyrosinase, indicating that these metabolites were bound to tyrosinase. The IC50 values of verproside (1) were 31.2 µM and 197.3 µM for mTyr and hTyr, respectively. Verproside showed 5.6-fold higher efficacy than that of its positive control (kojic acid in hTyr). The most potent tyrosinase inhibitor, verproside, features a 3,4-dihydroxybenzoic acid moiety on the iridoid glycoside and inhibits tyrosinase in a time-dependent and competitive manner. Among these three compounds, verproside is bound to the active site pocket with a docking energy of -6.9 kcal/mol and four hydrogen bonding interactions with HIS61 and HIS85.
Assuntos
Glucosídeos Iridoides , Monofenol Mono-Oxigenase , Humanos , Cromatografia Líquida , GlicosídeosRESUMO
Asthma is a chronic inflammatory lung disease that causes respiratory difficulties. Black ginseng extract (BGE) has preventative effects on respiratory inflammatory diseases such as asthma. However, the pharmacological mechanisms behind the anti-asthmatic activity of BGE remain unknown. To investigate the anti-asthmatic mechanism of BGE, phorbol 12-myristate 13-acetate plus ionomycin (PMA/Iono)-stimulated mouse EL4 cells and ovalbumin (OVA)-induced mice with allergic airway inflammation were used. Immune cells (eosinophils/macrophages), interleukin (IL)-4, -5, -13, and serum immunoglobulin E (IgE) levels were measured using an enzyme-linked immunosorbent assay. Inflammatory cell recruitment and mucus secretion in the lung tissue were estimated. Protein expression was analyzed via Western blotting, including that of inducible nitric oxide synthase (iNOS) and the activation of protein kinase C theta (PKCθ) and its downstream signaling molecules. BGE decreased T helper (Th)2 cytokines, serum IgE, mucus secretion, and iNOS expression in mice with allergic airway inflammation, thereby providing a protective effect. Moreover, BGE and its major ginsenosides inhibited the production of Th2 cytokines in PMA/Iono-stimulated EL4 cells. In EL4 cells, these outcomes were accompanied by the inactivation of PKCθ and its downstream transcription factors, such as nuclear factor of activated T cells (NFAT), nuclear factor kappa B (NF-κB), activator of transcription 6 (STAT6), and GATA binding protein 3 (GATA3), which are involved in allergic airway inflammation. BGE also inhibited the activation of PKCθ and the abovementioned transcriptional factors in the lung tissue of mice with allergic airway inflammation. These results highlight the potential of BGE as a useful therapeutic and preventative agent for allergic airway inflammatory diseases such as allergic asthma.
Assuntos
Antiasmáticos , Asma , Hipersensibilidade , Panax , Animais , Camundongos , Antiasmáticos/farmacologia , Antiasmáticos/uso terapêutico , Interleucina-4/metabolismo , Asma/metabolismo , Pulmão/metabolismo , Citocinas/metabolismo , Hipersensibilidade/metabolismo , Transdução de Sinais , Inflamação/metabolismo , Imunoglobulina E , Panax/metabolismo , Ovalbumina , Camundongos Endogâmicos BALB C , Modelos Animais de DoençasRESUMO
The recently defined type of cell death ferroptosis has garnered significant attention as a potential new approach to cancer treatment owing to its more immunogenic nature when compared with apoptosis. Ferroptosis is characterized by the depletion of glutathione (GSH)/glutathione peroxidase-4 (GPx4) and iron-dependent lipid peroxidation. Diplacone (DP), a geranylated flavonoid compound found in Paulownia tomentosa fruit, has been identified to have anti-inflammatory and anti-radical activity. In this study, the potential anticancer activity of DP was explored against A549 human lung cancer cells. It was found that DP induced a form of cytotoxicity distinct from apoptosis, which was accompanied by extensive mitochondrial-derived cytoplasmic vacuoles. DP was also shown to increase mitochondrial Ca2+ influx, reactive oxygen species (ROS) production, and mitochondrial permeability transition (MPT) pore-opening. These changes led to decreases in mitochondrial membrane potential and DP-induced cell death. DP also induced lipid peroxidation and ATF3 expression, which are hallmarks of ferroptosis. The ferroptosis inhibitors ferrostatin-1 and liproxstatin-1 were effective in counteracting the DP-mediated ferroptosis-related features. Our results could contribute to the use of DP as a ferroptosis-inducing agent, enabling studies focusing on the relationship between ferroptosis and the immunogenic cell death of cancer cells.
Assuntos
Ferroptose , Humanos , Necrose Dirigida por Permeabilidade Transmembrânica da Mitocôndria , Frutas/metabolismo , Morte Celular/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Glutationa/metabolismo , Peroxidação de Lipídeos , Poro de Transição de Permeabilidade Mitocondrial/metabolismoRESUMO
Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease which causes breathing problems. YPL-001, consisting of six iridoids, has potent inhibitory efficacy against COPD. Although YPL-001 has completed clinical trial phase 2a as a natural drug for COPD treatment, the most effective iridoid in YPL-001 and its mechanism for reducing airway inflammation remain unclear. To find an iridoid most effectively reducing airway inflammation, we examined the inhibitory effects of the six iridoids in YPL-001 on TNF or PMA-stimulated inflammation (IL-6, IL-8, or MUC5AC) in NCI-H292 cells. Here, we show that verproside among the six iridoids most strongly suppresses inflammation. Both TNF/NF-κB-induced MUC5AC expression and PMA/PKCδ/EGR-1-induced IL-6/-8 expression are successfully reduced by verproside. Verproside also shows anti-inflammatory effects on a broad range of airway stimulants in NCI-H292 cells. The inhibitory effect of verproside on the phosphorylation of PKC enzymes is specific to PKCδ. Finally, in vivo assay using the COPD-mouse model shows that verproside effectively reduces lung inflammation by suppressing PKCδ activation and mucus overproduction. Altogether, we propose YPL-001 and verproside as candidate drugs for treating inflammatory lung diseases that act by inhibiting PKCδ activation and its downstream pathways.
Assuntos
Interleucina-6 , Doença Pulmonar Obstrutiva Crônica , Animais , Humanos , Camundongos , Células Epiteliais/metabolismo , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Interleucina-6/metabolismo , Iridoides/farmacologia , Iridoides/uso terapêutico , Iridoides/metabolismo , Pulmão/metabolismo , NF-kappa B/metabolismo , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Doença Pulmonar Obstrutiva Crônica/metabolismo , Proteína Quinase C-delta/metabolismoRESUMO
Pulmonary fibrosis is a devastating lung disease with few therapeutic options. CHIT1 (chitinase 1), an 18 glycosyl hydrolase family member, contributes to the pathogenesis of pulmonary fibrosis through the regulation of TGF-ß (transforming growth factor-ß) signaling and effector function. Therefore, CHIT1 is a potential therapeutic target for pulmonary fibrosis. This study aimed to identify and characterize a druggable CHIT1 inhibitor with strong antifibrotic activity and minimal toxicity for therapeutic application to pulmonary fibrosis. Extensive screening of small molecule libraries identified the aminoglycoside antibiotic kasugamycin (KSM) as a potent CHIT1 inhibitor. Elevated concentrations of CHIT1 were detected in the lungs of patients with pulmonary fibrosis. In in vivo bleomycin- and TGF-ß-stimulated murine models of pulmonary fibrosis, KSM showed impressive antifibrotic effects in both preventive and therapeutic conditions. In vitro studies also demonstrated that KSM inhibits fibrotic macrophage activation, fibroblast proliferation, and myofibroblast transformation. Null mutation of TGFBRAP1 (TGF-ß-associated protein 1), a recently identified CHIT1 interacting signaling molecule, phenocopied antifibrotic effects of KSM in in vivo lungs and in vitro fibroblasts responses. KSM inhibits the physical association between CHIT1 and TGFBRAP1, suggesting that the antifibrotic effect of KSM is mediated through regulation of TGFBRAP1, at least in part. These studies demonstrate that KSM is a novel CHIT1 inhibitor with a strong antifibrotic effect that can be further developed as an effective and safe therapeutic drug for pulmonary fibrosis.
Assuntos
Aminoglicosídeos , Antifibróticos , Quitinases , Fibrose Pulmonar , Aminoglicosídeos/farmacologia , Aminoglicosídeos/uso terapêutico , Animais , Antifibróticos/farmacologia , Antifibróticos/uso terapêutico , Bleomicina/farmacologia , Quitinases/antagonistas & inibidores , Fibroblastos/metabolismo , Humanos , Pulmão/efeitos dos fármacos , Pulmão/patologia , Camundongos , Camundongos Endogâmicos C57BL , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/tratamento farmacológico , Fator de Crescimento Transformador beta/metabolismoRESUMO
Longifolioside A is an iridoid glucoside compound isolated from Pseudolysimachion rotundum var. subintegrum, which has been used in traditional herbal medicines to treat respiratory inflammatory diseases. Logifolioside A is a potent antioxidant; however, its underlying pharmacological mechanisms of action in inflammatory diseases are unknown. Here, we investigated the inhibitory effects of longifolioside A in lipopolysaccharide (LPS)-stimulated toll-like receptor 4 (TLR4) signal transduction systems using human THP-1 macrophages and HEK293 cells stably expressing human TLR4 protein (293/HA-hTLR4). Longifolioside A significantly reduced the release of inflammatory cytokines such as interleukin (IL)-6, -8, and tumor necrosis factor (TNF)-α in LPS-stimulated THP-1 macrophages. Furthermore, longifolioside A inhibited the expression of inflammatory mediator genes such as inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 that produce nitric oxide (NO) and prostaglandin E2 (PGE2), respectively. Longifolioside A suppressed the phosphorylation of PKCδ, IRAK4, IKKα/ß, IκBα, and mitogen-activated protein (MAP) kinases (ERK 1/2 and JNK, but not p38), thereby inactivating the nuclear localization of NF-κB and AP-1, and thus decreasing the expression of inflammatory response genes. Notably, longifolioside A disrupted the interaction between human TLR4 and the TIR domain-containing adaptor protein (TIRAP), an early step during TLR4 activation, thereby reducing IL-8 secretion in 293/HA-hTLR4 cells. This inhibitory effect was comparable to that of TAK-242 (a TLR4 inhibitor, or resatorvid). Our results indicate that longifolioside A prevents inflammatory response by suppressing TLR4 activation required for NF-κB and AP-1 activation.
Assuntos
Mediadores da Inflamação/metabolismo , Macrófagos/efeitos dos fármacos , Proteína Quinase C-delta/antagonistas & inibidores , Receptor 4 Toll-Like/antagonistas & inibidores , Citocinas/metabolismo , Ativação Enzimática/efeitos dos fármacos , Células HEK293 , Humanos , Interleucina-8/metabolismo , Lipopolissacarídeos/farmacologia , Macrófagos/enzimologia , Macrófagos/metabolismo , Glicoproteínas de Membrana/antagonistas & inibidores , NF-kappa B/metabolismo , Proteína Quinase C-delta/metabolismo , Receptores de Interleucina-1/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Células THP-1 , Fator de Transcrição AP-1/metabolismoRESUMO
Nine new xanthones, cudracuspixanthones I - Q (12-14, 25, 32-36), and 30 known xanthones (1-11, 15-24, 26-31, 37-39) were isolated from the stems of Cudrania tricuspidata (Moraceae). The structures of isolated compounds were established by using 1D and 2D NMR in combination with HR-TOF-MS. Xanthones from the stems of C. tricuspidata exerted pancreatic lipase inhibitory activity. In addition, cudracuspixanthone P (35), a new xanthone, reduced the fat accumulation in liver cells stimulated with fatty acids. Therefore, these compounds might be beneficial in the treatment of metabolic diseases.
Assuntos
Lipase/antagonistas & inibidores , Metabolismo dos Lipídeos/efeitos dos fármacos , Moraceae/química , Pâncreas/efeitos dos fármacos , Caules de Planta/química , Xantonas/farmacologia , Células Hep G2 , Humanos , Estrutura Molecular , Pâncreas/embriologia , Extratos Vegetais/química , Triglicerídeos/metabolismo , Xantonas/química , Xantonas/isolamento & purificaçãoRESUMO
Fisetin (3,7,3',4'-tetrahydroxyflavone), a natural flavonoid, is a therapeutic agent for respiratory inflammatory diseases such as chronic obstructive pulmonary disease (COPD). However, detailed molecular mechanisms regarding the target protein of fisetin remain unknown. Fisetin significantly reduces tumour necrosis factor alpha (TNF-α)-induced interleukin (IL)-8 levels by inhibiting both nuclear factor kappa B (NF-κB) transcriptional activity and the phosphorylation of its upstream effectors. We show that fisetin prevents interactions between protein kinase C (PKC)δ and TNF receptor-associated factor 2 (TRAF2), thereby inhibiting the inhibitor of kappa B kinase (IKK)/NF-κB downstream signalling cascade. Furthermore, we found that fisetin directly binds to PKCδ in vitro. Our findings provide evidence that fisetin inhibits the TNF-α-activated IKK/NF-κB cascade by targeting PKCδ, thereby mediating inflammatory diseases such as COPD. These data suggest that fisetin is a good therapeutic drug for the treatment of inflammatory lung diseases, such as COPD, by inhibiting the TNF-α/NF-κB signalling pathway.
Assuntos
Células Epiteliais/efeitos dos fármacos , Flavonoides/farmacologia , Interleucina-8/metabolismo , NF-kappa B/antagonistas & inibidores , Proteína Quinase C-delta/metabolismo , Transdução de Sinais , Fator de Necrose Tumoral alfa/metabolismo , Células Epiteliais/enzimologia , Flavonóis , Células HEK293 , Humanos , Simulação de Acoplamento Molecular , NF-kappa B/metabolismo , Fosforilação , Ligação Proteica , Fator 2 Associado a Receptor de TNF/metabolismoRESUMO
In the course of screening to find a plant material decreasing the activity of triacylglycerol and cholesterol, we identified Tripterygium regelii (TR). The methanol extract of TR leaves (TR-LM) was shown to reduce the intracellular lipid contents consisting of triacylglycerol (TG) and cholesterol in HepG2 cells. TR-LM also downregulated the mRNA and protein expression of the lipogenic genes such as SREBP-1 and its target enzymes. Consequently, TR-LM reduced the TG biosynthesis in HepG2 cells. In addition, TR-LM decreased SREBP2 and its target enzyme HMG-CoA reductase, which is involved in cholesterol synthesis. In this study, we evaluated that TR-LM attenuated cellular lipid contents through the suppression of de novo TG and cholesterol biosynthesis in HepG2 cells. All these taken together, TR-LM could be beneficial in regulating lipid metabolism and useful preventing the hyperlipidemia and its complications, in that liver is a crucial tissue for the secretion of serum lipids.
Assuntos
Colesterol/biossíntese , Extratos Vegetais/farmacologia , Triglicerídeos/biossíntese , Tripterygium/química , Regulação da Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Humanos , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/metabolismo , Metanol/química , Folhas de Planta/químicaRESUMO
Six known triterpenoid compounds, 3-oxoolean-12-en-27-oic acid (1), gypsogenic acid (2), 3α-hydroxyolean-12-en-27-oic acid (3), 3ß-hydroxyolean-12-en-27-oic acid (4), aceriphyllic acid A (5), and oleanolic acid (6), were isolated from the roots of Aceriphyllum rossii. Their chemical structures were determined by comparison with available (1)H-NMR and (13)C-NMR data on known compounds. All the isolated compounds were evaluated for inhibitory activity against human diacylglycerol acyltransferases 1 and 2. Most of the isolates exhibited a better inhibitory activity against diacylglycerol acyltransferase 2 (IC50: 11.6-44.2 µM) than against diacylglycerol acyltransferase 1 (IC50: 22.7-119.5 µM). In particular, compounds 1 and 5 showed strong inhibition efficacy towards diacylglycerol acyltransferases 1 and 2, and appeared to act competitively against oleoyl-CoA in vitro. The results also indicated that both compounds reduced newly synthesized triacylglycerol in HuTu80 and HepG2 cells. Oral administration of compound 1 significantly reduced postprandial triacylglycerol in mice following an oral lipid challenge. In conclusion, the current study indicates that compound 1 suppresses both de novo triacylglycerol biosynthesis and resynthesis through the inhibition of diacylglycerol acyltransferase activity, and therefore may be a useful agent for treating diseases associated with a high triacylglycerol level.
Assuntos
Diacilglicerol O-Aciltransferase/sangue , Inibidores Enzimáticos/farmacologia , Ácido Oleanólico/farmacologia , Extratos Vegetais/farmacologia , Saxifragaceae/química , Triglicerídeos/sangue , Acil Coenzima A/metabolismo , Animais , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Células Hep G2 , Humanos , Camundongos , Estrutura Molecular , Ácido Oleanólico/análogos & derivados , Ácido Oleanólico/química , Ácido Oleanólico/isolamento & purificação , Extratos Vegetais/química , Raízes de PlantasRESUMO
Diacylglycerol acyltransferase 2 (DGAT2), which catalyzes the final step in triacylglycerol (TG) synthesis, is a key enzyme associated with hepatic steatosis and insulin resistance. Here, using an in vitro screen of 20000 molecules, we identified a class of compounds with a substituted 1H-pyrrolo[2,3-b]pyridine core which proved to be potent and selective inhibitors of human DGAT2. Of these compounds, H2-003 and -005 exhibited a considerable reduction in TG biosynthesis in HepG2 hepatic cells and 3T3-L1 preadipose cells. These compounds exert DGAT2-specific-inhibitory activity, which was further confirmed in DGAT2- or DGAT1-overexpressing HEK293 cells. In addition, these compounds almost completely abolished lipid droplet formation in 3T3-L1 cells when co-treated with a DGAT1 inhibitor, which was not attained using either a DGAT2 or DGAT1 inhibitor alone. Collectively, we identified two DGAT2 inhibitors, H2-003 and -005. These compounds will aid in DGAT2-related lipid metabolism research as well as in therapeutic development for the treatment of metabolic diseases associated with excessive TG.
Assuntos
Acetatos/química , Acetatos/farmacologia , Diacilglicerol O-Aciltransferase/antagonistas & inibidores , Descoberta de Drogas/métodos , Piridinas/química , Piridinas/farmacologia , Células 3T3-L1 , Animais , Diacilglicerol O-Aciltransferase/metabolismo , Células HEK293 , Células Hep G2 , Humanos , CamundongosRESUMO
Rotundifuran (RF), a potent anti-inflammatory and anti-cancer compound, is a natural compound predominantly present in Vitex Rotundifolia. Herein, we investigated the effects of RF on the growth of lung cancer cells. Our findings suggested that RF inhibits cell growth, highlighting its potential as a therapeutic agent for cancer treatment. Interestingly, we observed that cell growth inhibition was not due to apoptosis, as caspases were not activated and DNA fragmentation did not occur. Furthermore, we found that intracellular vacuoles and autophagy were induced, but RF-induced cell death was not affected when autophagy was inhibited. This prompted us to investigate other possible mechanisms underlying cell growth inhibition. Through a cDNA chip analysis, we confirmed changes in the expression of ferroptosis-related genes and observed lipid peroxidation. We further examined the effect of ferroptosis inhibitors and found that they alleviated cell growth inhibition induced by RF. We also observed the involvement of calcium signaling, ROS accumulation, and JNK signaling in the induction of ferroptosis. Our findings suggested that RF is a potent anti-cancer drug and further studies are needed to validate its clinal use.
RESUMO
Allergic asthma is a major health burden on society as a chronic respiratory disease characterized by inflammation and muscle tightening around the airways in response to inhaled allergens. Daphne kiusiana Miquel is a medicinal plant that can suppress allergic airway inflammation; however, its specific molecular mechanisms of action are unclear. In this study, we aimed to elucidate the mechanisms by which D. kiusiana inhibits allergic airway inflammation. We evaluated the anti-inflammatory effects of the ethyl acetate (EA) fraction of D. kiusiana and its major compound, daphnetin, on murine T lymphocyte EL4 cells stimulated with phorbol 12-myristate 13-acetate and ionomycin in vitro and on asthmatic mice stimulated with ovalbumin in vivo. The EA fraction and daphnetin inhibited T-helper type 2 (Th2) cytokine secretion, serum immunoglobulin E production, mucus secretion, and inflammatory cell recruitment in vivo. In vitro, daphnetin suppressed intracellular Ca2+ mobilization (a critical regulator of nuclear factor of activated T cells) and functions of the activator protein 1 transcription factor to reduce interleukin (IL)-4 and IL-13 expression. Daphnetin effectively suppressed the IL-4/-13-induced activation of Janus kinase (JAK)/signal transducer and activator of transcription 6 (STAT6) signaling in vitro and in vivo, thereby inhibiting the expression of GATA3 and PDEF, two STAT6-target genes responsible for producing Th2 cytokines and mucins. These findings indicate that daphnetin suppresses allergic airway inflammation by stabilizing intracellular Ca2+ levels and subsequently inactivating the JAK/STAT6/GATA3/PDEF pathway, suggesting that daphnetin is a promising alternative to existing asthma treatments.
Assuntos
Asma , Janus Quinases , Fator de Transcrição STAT6 , Transdução de Sinais , Umbeliferonas , Animais , Umbeliferonas/farmacologia , Umbeliferonas/uso terapêutico , Fator de Transcrição STAT6/metabolismo , Transdução de Sinais/efeitos dos fármacos , Camundongos , Asma/tratamento farmacológico , Asma/imunologia , Asma/metabolismo , Janus Quinases/metabolismo , Ativação Linfocitária/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Feminino , Citocinas/metabolismo , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T/metabolismo , Células Th2/efeitos dos fármacos , Células Th2/imunologia , Linhagem Celular , Daphne/química , Fator de Transcrição GATA3/metabolismo , Fator de Transcrição GATA3/genética , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Cálcio/metabolismoRESUMO
A series of indolyl acrylamide derivatives was synthesized as potential diacylglycerol acyltransferase (DGAT) inhibitors. Furfurylamine containing indolyl acrylamide derivative 5h exhibited the most potent DGAT inhibitory activity using microsomes prepared from rat liver. Further evaluation against human DGAT-1 and DGAT-2 identified indolyl acrylamide analogues as selective inhibitors against human DGAT-2. In addition, the most potent compound 5h inhibited triglyceride synthesis dose-dependently in HepG2 cell lines.
Assuntos
Acrilamida/química , Acrilamida/farmacologia , Diacilglicerol O-Aciltransferase/antagonistas & inibidores , Animais , Diacilglicerol O-Aciltransferase/metabolismo , Células Hep G2 , Humanos , Microssomos/efeitos dos fármacos , Microssomos/metabolismo , Ratos , Triglicerídeos/antagonistas & inibidores , Triglicerídeos/metabolismoRESUMO
G-protein coupled receptor 43 (GPR43) serves as a receptor for short-chain fatty acids (SCFAs), implicated in neutrophil migration and inflammatory cytokine production. However, the intracellular signaling pathway mediating GPR43 signaling remains unclear. Here, we show that ß-arrestin 2 mediates the internalization of GPR43 by agonist. Agonism of GPR43 reduced the phosphorylation and nuclear translocation of nuclear factor-κB (NF-κB), which was relieved by short interfering RNA (siRNA) of ß-arrestin 2. Subsequently, mRNA expression of proinflammatory cytokines, interleukin (IL)-6 and IL-1ß, was downregulated by activation of GPR43 and knockdown of ß-arrestin 2 recovered the expression of the cytokines. Taken together, these results suggest that GPR43 may be a plausible target for a variety of inflammatory diseases.
Assuntos
Arrestinas/metabolismo , NF-kappa B/metabolismo , Receptores de Superfície Celular/metabolismo , Células HEK293 , Células HeLa , Humanos , beta-Arrestina 2 , beta-ArrestinasRESUMO
Diacylglycerol acyltransferase 2 (DGAT2) is one of two distinct DGAT enzymes that catalyze the last step in triacylglycerol (TG) synthesis. Findings from previous studies suggest that inhibition of DGAT2 is a promising strategy for the treatment of hepatic steatosis and insulin resistance. Here, we identified compound 122 as a potent and selective inhibitor of human DGAT2, which appeared to act competitively against oleoyl-CoA in vitro. The selective inhibition of DGAT2 was also confirmed by the reductions in enzymatic activity and de novo TG synthesis in DGAT2-overexpressing HEK293 cells and hepatic cells HepG2. Compound 122, as a newly identified inhibitor of DGAT2, will be useful for the research on DGAT2-related lipid metabolism as well as the development of therapeutic drug for several metabolic diseases.
Assuntos
Diacilglicerol O-Aciltransferase/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Bibliotecas de Moléculas Pequenas/farmacologia , Animais , Diacilglicerol O-Aciltransferase/genética , Inibidores Enzimáticos/química , Células HEK293 , Ensaios de Triagem em Larga Escala , Humanos , Estrutura Molecular , Células Sf9 , Bibliotecas de Moléculas Pequenas/química , Spodoptera , Relação Estrutura-Atividade , TransfecçãoRESUMO
Centella asiatica (L.) Urban is an herbaceous perennial plant of the Apiaceae family that has diverse medicinal uses. Its active components are saponin, phenolics, and polyacetylenes. Plant cell cultures have been exploited for the efficient production of metabolites with pharmacological activity. In this work, we prepared adventitious root cultures of C. asiatica and analyzed their content and biological activity. Adventitious root extracts were found to increase glucose uptake by differentiated L6 skeletal muscle cells and to be more efficient than the extract of whole plants. Chromatographic fractionation of the extracts from adventitious roots of C. asiatica led to the isolation of two known polyacetylenes, araliadiol (1) and 8-acetoxy-1,9-pentadecadiene-4,6-diyn-3-ol (2), in addition to a new polyacetylene, which we have named centellidiol (3). All the three polyacetylenes stimulated glucose uptake in a dose-dependent manner. The methanol extract of adventitious roots contained 0.53% and 0.82% of compounds 1 and 2, respectively, which are values that were 15 and 21 times higher that are found in mother plants. We therefore suggest that the high content of these polyacetylenes contributes to the high efficacy of C. asiatica adventitious root cultures. Overall, adventitious root cultures of C. asiatica can be part of a secure supply of effective ingredients including polyacetylenes.
Assuntos
Centella , Triterpenos , Centella/química , Centella/metabolismo , Polímero Poliacetilênico/metabolismo , Polímero Poliacetilênico/farmacologia , Extratos Vegetais/química , Triterpenos/farmacologia , Glucose/metabolismoRESUMO
Regulation of diacylglycerol acyltransferase (DGAT) and pancreatic lipase (PL) activities is important in the treatment of triacylglycerol (TG)-related metabolic diseases. Garcinia mangostana, also known as mangosteen, is a traditional medicine ingredient used in the treatment of inflammation in Southeast Asia. In this study, The ethanolic extract of G. mangostana peel inhibited human recombinant DGAT1 and DGAT2, and PL enzyme activities in vitro. The inhibitory activity of DGAT1 and DGAT2 enzymes of four representative bioactive substances in mangosteen was confirmed. In addition, G. mangostana was confirmed to suppress the serum TG levels in C57 mice by inhibiting the absorption and synthesis of TG in the gastrointestinal tract. Through this study, it was revealed that G. mangostana extract could be useful for the prevention and amelioration of TG-related metabolic diseases such as obesity and fatty liver.
RESUMO
Background: Methyl lucidone (ML), a methyl derivative of lucidone, has anti-inflammatory properties. However, the molecular mechanisms that reduce the inflammatory effect of ML in human lung epithelial cells remain unkown. This study aimed to elucidate the molecular mechanisms underlying the anti-inflammatory effect of ML. Methods: Four compounds (ML, methyl linderone, kanakugiol, and linderone) from Lindera erythrocarpa Makino were evaluated for their ability to reduce MUC5AC secretion levels in phorbol-12-myristate-13-acetate (PMA)-stimulated NCI-H292 cells using ELISA. The expression and secretion levels of inflammatory response-related proteins were analyzed using quantitative reverse transcription-PCR, ELISA, and western blotting. To determine whether ML directly regulates TGF-ß-activated kinase 1 (TAK1), we performed an in vitro kinase assay. Results: ML treatment effectively reduced the levels of inflammatory cytokines, including interleukin-1ß and TNF-α, increased by stimulation. Furthermore, ML downregulated the pathway cascade of both IκB kinase (IKK)/NF-κB and p38 mitogen-activated protein (MAP) kinase/CREB by inhibiting the upstream kinase TAK1. An in vitro kinase analysis confirmed that ML treatment significantly reduced the kinase activity of TAK1. Conclusion: ML pretreatment repressed the PMA-stimulated inflammation reaction by reducing the TAK1-mediated IKK/NF-κB and p38 MAP kinase/CREB signaling. These findings suggest that ML may improve respiratory health and can be used as a dietary supplement or functional food to prevent inflammatory lung diseases.
RESUMO
A novel series of benzimidazole derivatives was prepared and evaluated for their diacylglycerol acyltransferase (DGAT) inhibitory activity using microsome from rat liver. Among the newly synthesized compounds, furfurylamine containing benzimidazole carboxamide 10j showed the most potent DGAT inhibitory effect (IC(50)=4.4 µM) and inhibited triglyceride formation in HepG2 cells. Furthermore, compound 10j reduced body weight gain of Institute of Cancer Research mice on a high-fat diet and decreased levels of total triglyceride, total cholesterol, and LDL-cholesterol in the blood accompanied with a significant increase in HDL-cholesterol level.