RESUMO
Halitosis is referred to as an unpleasant odor coming from the mouth. Recently, probiotics have been studied as an alternative prevention for halitosis. The aim of this study was to evaluate the effects of probiotic bacterium Weissella cibaria Chonnam Medical University (CMU)-containing tablets (1 × 108 colony forming units [CFU]/g) on oral malodor. The randomized, double-blind, placebo-controlled trial was conducted in 92 healthy adults (20-39 years of age) with bad breath. All subjects were randomly assigned to a test (probiotic, n = 49) or control (placebo, n = 43) group after dental scaling and root planing. The tablets were taken once daily for 8 weeks. Measurements included an organoleptic test (OLT), volatile sulfur compounds (VSC), bad breath improvement (BBI) scores, and the oral colonization of W. cibaria CMU. This study also assessed safety variables of adverse reactions, vital signs, and the findings of hematology and blood chemistry. Most of the variables were measured at baseline, 4, and 8 weeks. Safety-related variables were measured at baseline and 8 weeks. At week 4, a significant decrease in OLT and VSC results was observed in the test group while BBI scores were significantly reduced at week 8 (P < .05). Statistically significant intergroup differences were observed for changes in W. cibaria number at weeks 4 and 8. No safety issues were encountered in either group. These results indicate that W. cibaria CMU tablets could be a safe and useful oral care product for controlling bad breath.
Assuntos
Halitose/terapia , Probióticos/uso terapêutico , Weissella , Adulto , Método Duplo-Cego , Humanos , Compostos de Enxofre/análise , Comprimidos , Compostos Orgânicos Voláteis/análise , Adulto JovemRESUMO
BACKGROUND: Gold nanoparticles (AuNPs) have potential applications in the treatment and diagnosis process, which are attributed to their biocompatibility and high efficiency of drug delivery. In the current study, we utilized an extract of Euphrasia officinalis, a traditional folk medicine, to synthesize gold nanoparticles (EO-AuNPs), and investigated their anti-inflammatory effects on lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. MATERIALS AND METHODS: The AuNPs were synthesized from an ethanol extract of E. officinalis leaves and characterized using several analytical techniques. Anti-inflammatory activities of EO-AuNPs were detected by a model of LPS-induced upregulation of inflammatory mediators and cytokines including nitric oxide (NO), inducible nitric oxide synthase (iNOS), tumor necrosis factor-α (TNF-α), IL-1ß, and IL-6 in RAW 264.7 cells. The activation of nuclear factor (NF)-κB and Janus kinase/signal transducer and activators of transcription (JAK/STAT) signaling pathways was investigated by Western blot. RESULTS: The results confirmed the successful synthesis of AuNPs by E. officinalis. Transmission electron microscopy images showed obvious uptake of EO-AuNPs and internalization into intracellular membrane-bound compartments, resembling endosomes and lysosomes by RAW 264.7 cells. Cell viability assays showed that EO-AuNPs exhibited little cytotoxicity in RAW 264.7 cells at 100 µg/mL concentration after 24 hours. EO-AuNPs significantly suppressed the LPS-induced release of NO, TNF-α, IL-1ß, and IL-6 as well as the expression of the iNOS gene and protein in RAW 264.7 cells. Further experiments demonstrated that pretreatment with EO-AuNPs significantly reduced the phosphorylation and degradation of inhibitor kappa B-alpha and inhibited the nuclear translocation of NF-κB p65. In addition, EO-AuNPs suppressed LPS-stimulated inflammation by blocking the activation of JAK/STAT pathway. CONCLUSION: The synthesized EO-AuNPs showed anti-inflammatory activity in LPS-induced RAW 264.7 cells, suggesting they may be potential candidates for treating inflammatory-mediated diseases.
Assuntos
Euphrasia/química , Ouro/química , Química Verde/métodos , Macrófagos/patologia , Nanopartículas Metálicas/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Transdução de Sinais , Animais , Anti-Inflamatórios/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Citocinas/metabolismo , Inflamação/metabolismo , Inflamação/patologia , Mediadores da Inflamação/metabolismo , Janus Quinases/metabolismo , Lipopolissacarídeos , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Macrófagos/ultraestrutura , Nanopartículas Metálicas/ultraestrutura , Camundongos , NF-kappa B/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Células RAW 264.7 , Fatores de Transcrição STAT/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
We report a non-covalent loading of ginsenoside compound K (CK) onto our previously reported gold nanoparticles (DCY51T-AuCKNps) through one-pot biosynthesis using a probiotic Lactobacillus kimchicus DCY51T isolated from Korean kimchi. The ginsenoside-loaded gold nanoparticles were characterized by various analytical and spectroscopic techniques such as field emission transmission electron microscopy (FE-TEM), energy-dispersive X-ray (EDX) spectroscopy, elemental mapping, X-ray powder diffraction (XRD), selected area electron diffraction (SAED), Fourier-transform infrared (FTIR) spectroscopy and dynamic light scattering (DLS). Furthermore, drug loading was also determined by liquid chromatography-mass spectrometry (LC-MS). In addition, DCY51T-AuNps and DCY51T-AuCKNps were resistant to aggregation caused by pH variation or a high ionic strength environment. Cell-based study confirmed that DCY51T-AuCKNps exhibited slightly higher cytotoxicity compared to ginsenoside CK treatment in A549 cells (human lung adenocarcinoma cell line) and HT29 (human colorectal adenocarcinoma cell line). Upon laser treatment, DCY51T-AuCKNps showed enhanced cell apoptosis in A549, HT29 and AGS cells (human stomach gastric adenocarcinoma cell line) compared with only DCY51T-AuCKNps treated cells. In conclusion, this preliminary study identified that DCY51T-AuCKNps act as a potent photothermal therapy agents with synergistic chemotherapeutic effects for the treatment of cancer.
Assuntos
Apoptose/efeitos dos fármacos , Ginsenosídeos/farmacologia , Ouro/metabolismo , Lactobacillus/metabolismo , Nanopartículas Metálicas , Fototerapia , Temperatura , Animais , Linhagem Celular Tumoral , Portadores de Fármacos/química , Portadores de Fármacos/metabolismo , Ginsenosídeos/química , Ouro/química , Humanos , Medições Luminescentes , Camundongos , Tamanho da PartículaRESUMO
Chronic stress induces neuronal cell death, which can cause nervous system disorders including Parkinson's disease and Alzheimer's disease. In this study, we evaluated the neuroprotective effects of Clematis terniflora extract (CTE) against corticosterone-induced apoptosis in rat pheochromocytoma (PC12) cells, and also investigated the underlying molecular mechanisms. At concentrations of 300 and 500 µg/ml, CTE significantly decreased apoptotic cell death and mitochondrial damage induced by 200 µM corticosterone. CTE decreased the expression levels of endoplasmic reticulum (ER) stress proteins GRP78, GADD153, and mitochondrial damage-related protein BAD, suggesting that it downregulates ER stress evoked by corticosterone. Furthermore, our results suggested that these protective effects were mediated by the upregulation of p-AKT and p-ERK1/2, which are involved in cell survival signaling. Collectively, our results indicate that CTE can lessen neural damage caused by chronic stress. [BMB Reports 2018; 51(8): 400-405].
Assuntos
Clematis/química , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Extratos Vegetais/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Apoptose/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Corticosterona/farmacologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/patologia , Células PC12 , Ratos , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
Many natural substances were screened to develop nutraceuticals that reduce menopausal symptoms. A complex of Cirsium japonicum var. maackii and Thymus vulgaris extracts, named MS-10, had significant positive effects. Under a low concentration of estrogen, which represents postmenopausal physiological conditions, MS-10 had beneficial effects on estrogen receptor-expressing MCF-7 cells by reversibly enhancing estrogen activity. In addition, in the ovariectomized rat model, changes in bone-specific alkaline phosphatase activity and osteocalcin, as well as low-density lipoprotein cholesterol and triglyceride levels were significantly decreased by MS-10. These results show that MS-10 protected bone health and reduced metabolic disturbances. Furthermore, in a clinical study, all menopausal symptoms, including hot flushes, parenthesis, insomnia, nervousness, melancholia, vertigo, fatigue, rheumatic pain, palpitations, formication, and headache, as well as colpoxerosis, were significantly improved by taking MS-10 for 90 days. Therefore, the evidence supports that MS-10 is an effective natural substance that can safely improve menopausal symptoms, including colpoxerosis.
Assuntos
Cirsium/química , Menopausa/efeitos dos fármacos , Extratos Vegetais/administração & dosagem , Thymus (Planta)/química , Doenças Vaginais/prevenção & controle , Animais , Feminino , Fogachos/tratamento farmacológico , Fogachos/metabolismo , Fogachos/prevenção & controle , Humanos , Lipoproteínas LDL/metabolismo , Menopausa/metabolismo , Pessoa de Meia-Idade , Osteocalcina/metabolismo , Ratos , Ratos Sprague-Dawley , Doenças Vaginais/tratamento farmacológico , Doenças Vaginais/metabolismoRESUMO
ß-Apo-carotenoids, including ß-apo-13-carotenone and ß-apo-14'-carotenal, are potent retinoic acid receptor (RAR) antagonists in transactivation assays. We asked how these influence RAR-dependent processes in living cells. Initially, we explored the effects of ß-apo-13-carotenone and ß-apo-14'-carotenal on P19 cells, a mouse embryonal carcinoma cell line that differentiates into neurons when treated with all-trans-retinoic acid. Treatment of P19 cells with either compound failed to block all-trans-retinoic acid induced differentiation. Liquid chromatography tandem mass spectrometry studies, however, established that neither of these ß-apo-carotenoids accumulates in P19 cells. All-trans-retinoic acid accumulated to high levels in P19 cells. This suggests that the uptake and metabolism of ß-apo-carotenoids by some cells does not involve the same processes used for retinoids and that these may be cell type specific. We also investigated the effects of two ß-apo-carotenoids on 3T3-L1 adipocyte marker gene expression during adipocyte differentiation. Treatment of 3T3-L1 adipocytes with either ß-apo-13-carotenone or ß-apo-10'-carotenoic acid, which lacks RAR antagonist activity, stimulated adipocyte marker gene expression. Neither blocked the inhibitory effects of a relatively large dose of exogenous all-trans-retinoic acid on adipocyte differentiation. Our data suggest that in addition to acting as transcriptional antagonists, some ß-apo-carotenoids act through other mechanisms to influence 3T3-L1 adipocyte differentiation.
Assuntos
Adipócitos/citologia , Adipócitos/efeitos dos fármacos , Carotenoides/farmacologia , Diferenciação Celular/efeitos dos fármacos , Células 3T3-L1 , Animais , Camundongos , Receptores do Ácido Retinoico/antagonistas & inibidores , Tretinoína/farmacologiaRESUMO
Rice (Oryza sativa L.) has been a major dietary staple worldwide for centuries. Growing interest in the beneficial effects of antioxidants has inspired investigation of rice hulls as an attractive source of chemopreventive compounds for breast cancer intervention. We prepared methanol extracts from rice hulls of three Korean bred cultivars (japonica), Ilpum, Heugjinju, and Jeogjinju, and one japonica weedy rice, WD-3. We examined the antiproliferative potential of the hull extracts on MCF-7 human breast cancer cells and the related mechanisms thereof. Hull extracts inhibited proliferation of the cells and mediated G0/G1 phase arrest by suppressing cyclins and cyclin-dependent kinases, where WD-3 extract showed the most potent. Blockage of p21 expression by small interfering RNA transfection attenuated G1 phase arrest induced by WD-3 extract. The WD-3 extract exhibited greater antioxidant potential and total phenolic compounds, compared with other rice hulls. Gas chromatography-mass spectrometry analysis for the F4 fractioned from WD-3 extract revealed that cinnamic acid derivatives were the major active constituents. The F4 fraction most potently inhibited proliferation of MCF-7 cells than WD-3 extract through the suppression of cell cycle regulatory factors. Collectively, our results suggest that the pigmented rice hulls possess greater antioxidant and chemopreventive activity against breast cancer than the other rice cultivars tested, demonstrating that WD-3 rice hulls are an attractive source of chemopreventive bioactive compounds.
Assuntos
Antioxidantes/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Oryza/química , Fitoterapia , Extratos Vegetais/uso terapêutico , Sementes/química , Antineoplásicos Fitogênicos/farmacologia , Antineoplásicos Fitogênicos/uso terapêutico , Antioxidantes/análise , Antioxidantes/farmacologia , Proliferação de Células/efeitos dos fármacos , Quinases Ciclina-Dependentes/metabolismo , Ciclinas/metabolismo , Feminino , Fase G1/efeitos dos fármacos , Humanos , Células MCF-7 , Oryza/classificação , Fenóis/análise , Fenóis/farmacologia , Fenóis/uso terapêutico , Extratos Vegetais/farmacologia , Especificidade da EspécieRESUMO
CONTEXT: Recently, there has been renewed interest in barley (Hordeum vulgare L. Poaceae) as a functional food and for its medicinal properties. OBJECTIVE: This study examines the anti-inflammatory potential of the active fractions of barley and the mechanisms involved. MATERIALS AND METHODS: The macrophages were exposed to 100 µg/mL of each of the barley extracts in the presence of 1 µg/mL lipopolysaccharide (LPS) and after 24 or 48 h of incubation, cells or culture supernatants were analyzed by various assays. The anti-inflammatory potential of barley fractions was also investigated using the LPS-injected septic mouse model. The active constituents in the fractions were identified using gas chromatography-mass spectrometry (GC-MS). RESULTS: The active fractions, named F4, F7, F9 and F12, inhibited almost completely the LPS-induced production of nitric oxide (NO) and inducible NO synthase. Pre-treatment with these fractions at 100 µg/mL diminished the tumor necrosis factor-α (TNF-α) levels to 19.8, 3.5, 1.2 and 1.7 ng/mL, respectively, compared to LPS treatment alone (41.5 ng/mL). These fractions at 100 µg/mL also suppressed apparently the secretion of interleukin (IL)-6 and IL-1ß and the DNA-binding activity of nuclear factor-κB in LPS-stimulated cells. Mice injected intraperitoneally with LPS (30 mg/kg BW) showed 20% survival at 48 h after injection, whereas oral administration of the fractions improved the survival rates to 80%. GC-MS analysis revealed the presence of the derivatives of benzoic and cinnamic acids and fatty acids in the fractions. DISCUSSION AND CONCLUSION: The aerial parts of barley are useful as functional food to prevent acute inflammatory responses.
Assuntos
Anti-Inflamatórios/farmacologia , Hordeum/química , Inflamação/tratamento farmacológico , Extratos Vegetais/farmacologia , Animais , Anti-Inflamatórios/isolamento & purificação , Modelos Animais de Doenças , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Inflamação/fisiopatologia , Lipopolissacarídeos , Metanol/química , Camundongos , Camundongos Endogâmicos BALB C , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/efeitos dos fármacos , Óxido Nítrico Sintase Tipo II/metabolismo , Componentes Aéreos da Planta , Extratos Vegetais/química , Sepse/tratamento farmacológico , Sepse/fisiopatologia , Taxa de Sobrevida , Fatores de TempoRESUMO
Alfalfa (Medicago sativa L.) is commonly used as a traditional medicine and functional food. This study investigated the anti-inflammatory potential of alfalfa and the mechanisms involved. The chloroform extract of alfalfa aerial parts inhibited lipopolysaccharide (LPS)-stimulated immune responses more than ether, butanol, or water soluble extracts. Treatment with 1 µg/mL LPS increased nitrite concentrations to 44.3 µM in RAW267.4 macrophages, but it was reduced to 10.6 µM by adding 100 µg/mL chloroform extract. LPS treatment also increased the concentrations of tumor necrosis factor-α, interleukin (IL)-6, and IL-1ß to 41.3, 11.6, and 0.78 ng/mL in culture supernatants of the cells, but these cytokine levels decreased to 12.5, 3.1, and 0.19 ng/mL, respectively, by pretreating with 100 µg/mL of the extract. ICR mice injected with LPS (30 mg/kg body weight) alone showed a 0% survival rate after 48 h of the injection, but 48-h survival of the mice increased to 60% after oral administration of the extract. Subfractions of the chloroform extract markedly suppressed LPS-mediated activation of the extracellular signal-regulated kinase and nuclear factor kappa-B. Cinnamic acid derivatives and fatty acids were found to be active constituents of the extract. This research demonstrated that alfalfa aerial parts exert anti-inflammatory activity and may be useful as a functional food for the prevention of inflammatory disorders.
Assuntos
Anti-Inflamatórios/administração & dosagem , Regulação para Baixo/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/genética , Inflamação/tratamento farmacológico , Lipopolissacarídeos/efeitos adversos , Medicago sativa/química , NF-kappa B/genética , Extratos Vegetais/administração & dosagem , Animais , Anti-Inflamatórios/isolamento & purificação , Linhagem Celular , Citocinas/genética , Citocinas/imunologia , MAP Quinases Reguladas por Sinal Extracelular/imunologia , Feminino , Humanos , Inflamação/genética , Inflamação/imunologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos ICR , NF-kappa B/imunologia , Extratos Vegetais/isolamento & purificação , Transdução de Sinais/efeitos dos fármacosRESUMO
OBJECTIVES: Acteoside is a phenylpropanoid glycoside extracted from the leaves of Rehmannia glutinosa that displays various biological activities. In this study, we tested the effects of acteoside on tyrosinase activity and melanin biosynthesis in B16F10 melanoma cells. We also explored molecular mechanisms for the inhibition of melanogenesis observed, focusing on the signalling pathway of extracellular signal-regulated kinase (ERK). METHODS: The effects of acteoside were determined using several cell-free assay systems and B16F10 melanoma cells for melanin content and tyrosinase activity. To investigate effects on melanogenic regulatory factors we performed reverse transcription polymerase chain reaction, cAMP assay and Western blot analyses. KEY FINDINGS: Acteoside showed an inhibitory effect on tyrosinase activity and melanin synthesis in both cell-free assay systems and cultured B16F10 melanoma cells. Acteoside decreased levels of tyrosinase, tyrosinase-related protein-1 (TRP-1) and microphthalmia-associated transcription factor (MITF) proteins, whereas it increased ERK phosphorylation. A specific ERK inhibitor, PD98059, abolished the acteoside-induced down-regulation of MITF, tyrosinase and TRP-1 proteins. The ERK inhibitor increased tyrosinase activity and melanin production and reversed the acteoside-induced decrease in tyrosinase activity and melanin content. In addition, acteoside suppressed melanogenesis induced by α-melanocyte-stimulating hormone and showed UV-absorbing effects. CONCLUSIONS: Acteoside decreased tyrosinase activity and melanin biosynthesis in B16F10 cells by activating ERK signalling, which down-regulated MITF, tyrosinase and TRP-1 production.
Assuntos
Inibidores Enzimáticos/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Glucosídeos/farmacologia , Melaninas/biossíntese , Monofenol Mono-Oxigenase/antagonistas & inibidores , Fenóis/farmacologia , Extratos Vegetais/farmacologia , Rehmannia/química , Linhagem Celular Tumoral , Regulação para Baixo , Ativação Enzimática/efeitos dos fármacos , Flavonoides/farmacologia , Humanos , Melanoma Experimental , Fator de Transcrição Associado à Microftalmia/metabolismo , Oxirredutases/metabolismo , Fosforilação , Folhas de Planta , Transdução de Sinais , alfa-MSH/metabolismoRESUMO
The real-time digestion of entrapped single-DNA molecules by λ-exonuclease in nanoporous alumina membranes was observed using an epifluorescence microscope. The alumina membrane provides pL (â¼ 10(-12)L) containers for confining single-DNA molecules without immobilization. When one end of the DNA molecule was inserted into a nanopore, it was possible to monitor the digestion process outside, near and inside the pore, where the individual DNA molecules exhibited different characteristic digestion modes. The digestion rates calculated from the decrease in fluorescence intensity showed different values according to the location of the individual molecules. Entrapment rather than immobilization allows the DNA strand to be fully exposed to the enzyme and the reaction buffer. These results confirm that the enzymatic digestion of DNA molecules is affected by their three-dimensional (3D) environment.
Assuntos
DNA/química , DNA/metabolismo , Exodesoxirribonucleases/metabolismo , Nanoporos , Óxido de Alumínio/química , Eletroquímica , Interações Hidrofóbicas e Hidrofílicas , Cinética , Membranas Artificiais , Fenômenos Ópticos , Eletricidade Estática , Propriedades de SuperfícieRESUMO
Quercetin is known to inhibit tyrosinase activity and melanin production in melanocytes. However, several reports suggest that quercetin has different and opposite effects on melanogenesis. This study examined the precise effects of quercetin on melanogenesis using cell-free assay systems and melanocytes. Quercetin inhibited the monophenolase and diphenolase activities of tyrosinase, and melanin synthesis in cell-free assay systems. Quercetin induced mild stimulation of the tyrosinase activity and dihydroxyphenylalaminechrome tautomerase (TRP-2) expression but only at low concentrations (<20 µm) in B16F10 melanoma cells. In contrast, the addition of 50 µm quercetin to the cells led to a significant decrease in the activity and synthesis of tyrosinase, as well as a decrease in the expression of tyrosinase-related protein-1 and TRP-2 proteins, regardless of the presence or absence of α-melanocyte stimulating hormone (α-MSH). Quercetin also reduced the intracellular cAMP and the phosphorylated protein kinase A levels in α-MSH-stimulated B16F10 cells. Moreover, quercetin (20 µm) diminished the expression and activity of tyrosinase, and melanin content in cultured normal human epidermal melanocytes. These effects were not related to its cytotoxic action. Although the in vivo effects of quercetin are still unclear, these results suggest that quercetin could play important roles in controlling melanogenesis.
Assuntos
Melaninas/biossíntese , Melanoma Experimental/metabolismo , Quercetina/farmacologia , alfa-MSH/antagonistas & inibidores , Animais , Diferenciação Celular/efeitos dos fármacos , Processos de Crescimento Celular/efeitos dos fármacos , Células Cultivadas , AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Humanos , Oxirredutases Intramoleculares/biossíntese , Melaninas/antagonistas & inibidores , Melanócitos/efeitos dos fármacos , Melanócitos/metabolismo , Melanoma Experimental/patologia , Camundongos , Monofenol Mono-Oxigenase/antagonistas & inibidores , Monofenol Mono-Oxigenase/metabolismo , Oxirredutases/biossíntese , Fosforilação , Pigmentação/efeitos dos fármacos , Células Tumorais Cultivadas , alfa-MSH/farmacologiaRESUMO
Reduction of susceptibility to apoptosis signals is a crucial step in carcinogenesis. Therefore, sensitization of tumor cells to apoptosis is a promising therapeutic strategy. c-Jun NH2-terminal kinase (JNK) has been implicated in stress-induced apoptosis. However, many studies also emphasize the role of JNK on cell survival, although its mechanisms are not completely understood. Previously, we found that inhibition of JNK activity promotes flavonoid-mediated apoptosis of human osteosarcoma cells. We thus determined whether inhibition of JNK sensitizes tumor cells to a bioflavonoid-induced apoptosis, and whether this effect of JNK is a general effect. As the results, quercetin and genistein as well as a flavonoid fraction induced apoptosis of tumor cells, which was further accelerated by specific JNK inhibitor, SP600125 or by small interfering RNA specific to JNK1/2. This effect was specific to types of cells because it was further apparent in tumorigenic cell lines. Inhibition of JNK by SP600125 also reduced flavonoid-stimulated nuclear induction of JunD which was known to have protective role in apoptosis, whereas JNK inhibition alone had little effect on apoptosis. The flavonoid-induced apoptosis of tumor cells was significantly enhanced by transfecting them with antisense JunD oligonucleotides. These results suggest that inhibition of JNK facilitates flavonoid-induced apoptosis through down-regulation of JunD, which is further sensitive to tumor cells. Therefore, combination with a specific JNK inhibitor further enhances the anti-cancer and chemopreventive potential of bio-flavonoids.
Assuntos
Antineoplásicos/farmacologia , Apoptose , Flavonoides/farmacologia , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Neoplasias/enzimologia , Proteínas Proto-Oncogênicas c-jun/antagonistas & inibidores , Animais , Antracenos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , DNA/metabolismo , Flavonoides/química , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Fosforilação , Extratos Vegetais/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-jun/metabolismo , RNA Interferente Pequeno/farmacologia , Rhus/química , Fator de Transcrição AP-1/metabolismo , TransfecçãoRESUMO
Flavonoids have antioxidant and antitumor promoting effects. Rhus verniciflua Stokes (RVS) is a flavonoid-rich herbal medicine that has long been used in Korea as both a food additive and antitumor agent. It was previous reported that a purified flavonoid fraction prepared from RVS, herein named RCMF (the RVS chloroform-methanol fraction), inhibited the proliferation and induced apoptosis in human osteosarcoma (HOS) cells. This study examined the mechanisms involved in the RCMF-mediated apoptosis in HOS cells. RCMF was shown to be capable of inducing apoptosis in HOS cells by inducing p53 in the cells resulting in the decrease in Bcl-2 level, activation of Bax, and cytoplasmic release of cytochrome c, which led to the translocation of apoptosis-inducing factor (AIF) and endonuclease G (EndoG) into the nucleus. However, the RCMF-induced apoptosis was suppressed by transfecting the cells with antisense p53 oligonucleotides but not by treating them with a MAPK or caspase inhibitor. This suppression occurred through the regulation of Bcl-2 members as well as by preventing the nuclear translocation of the mitochondrial apoptogenic factors. Overall, it appears that p53-mediated mitochondrial stress and the nuclear translocation of AIF and EndoG are mainly required for the apoptosis induced by RCMF.