RESUMO
BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver diseases and is caused by obesity, diabetes, high blood pressure, and insulin resistance. Many studies have explored novel candidates to treat NAFLD using herbal medicines owing to their fewer side effects. In this study, we examined the effect of MIT, an herbal formula comprising Ephedra sinica, Panax ginseng, and Alisma orientale, on the murine model of NAFLD. METHODS: To evaluate the effect of MIT on NAFLD, we used the high-fat diet (HFD)-induced NAFLD mice model. The mice were divided into four groups: control, HFD, HFD with metformin administration, and HFD with MIT administration. Freeze-dried MIT was dissolved in phosphate buffered saline and orally administered for 8 weeks to MIT-treated mice (60â¯mg/kg) after feeding them with HFD for 16 weeks. RESULTS: MIT treatment significantly attenuated fat accumulation, serum glucose levels, and excessive cholesterol. It also reduced the activation of NF-κB, JNK, ERK, mammalian target of rapamycin, and peroxisome proliferator-activated receptor γ in the HFD-induced NAFLD mice. The expression level of enzymes involved in the synthesis and oxidation of fatty acids, acetyl-coA carboxylase and CYP2E1, were clearly reduced by MIT treatment. Reactive oxygen species (ROS) production and subsequent liver damage were effectively reduced by MIT treatment. CONCLUSION: We suggest that MIT is a potent herbal formula that can be used for the prevention and treatment of obesity-related NAFLD via regulating the levels of serum glucose and free fatty acids, inflammation, lipid accumulation, and ROS-mediated liver damage.
RESUMO
BACKGROUND: There is increasing evidence that peripheral glutamate signaling mechanism is involved in the nociceptive transmission during pathological conditions. However, little is known about the glutamate signaling mechanism and related specific type of vesicular glutamate transporter (VGLUT) in the dental pulp following inflammation. To address this issue, we investigated expression and protein levels of VGLUT1 and VGLUT2 in the dental pulp and trigeminal ganglion (TG) following complete Freund's adjuvant (CFA) application to the rat dental pulp by light microscopic immunohistochemistry and Western blot analysis. RESULTS: The density of VGLUT2- immunopositive (+) axons in the dental pulp and the number of VGLUT2+ soma in the TG increased significantly in the CFA-treated group, compared to control group. The protein levels of VGLUT2 in the dental pulp and TG were also significantly higher in the CFA-treated group than control group by Western blot analysis. The density of VGLUT1+ axons in the dental pulp and soma in the TG remained unchanged in the CFA-treated group. CONCLUSIONS: These findings suggest that glutamate signaling that is mediated by VGLUT2 in the pulpal axons may be enhanced in the inflamed dental pulp, which may contribute to pulpal axon sensitization leading to hyperalgesia following inflammation.
Assuntos
Axônios/efeitos dos fármacos , Ácido Glutâmico/metabolismo , Hiperalgesia/genética , Inflamação/genética , Proteína Vesicular 1 de Transporte de Glutamato/genética , Proteína Vesicular 2 de Transporte de Glutamato/genética , Animais , Axônios/metabolismo , Axônios/patologia , Polpa Dentária/efeitos dos fármacos , Polpa Dentária/metabolismo , Polpa Dentária/fisiopatologia , Adjuvante de Freund/administração & dosagem , Regulação da Expressão Gênica , Hiperalgesia/etiologia , Hiperalgesia/fisiopatologia , Inflamação/induzido quimicamente , Inflamação/complicações , Inflamação/fisiopatologia , Masculino , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , Gânglio Trigeminal/efeitos dos fármacos , Gânglio Trigeminal/metabolismo , Gânglio Trigeminal/fisiopatologia , Proteína Vesicular 1 de Transporte de Glutamato/metabolismo , Proteína Vesicular 2 de Transporte de Glutamato/metabolismoRESUMO
Combined treatment with radiation has improved the outcome in various cancers and many radiosensitizers are used to enhance the therapeutic efficiency of radiotherapy. Withaferin A (Wit A), a natural compound derived from the medicinal plant Withania somnifera, has been reported for its anti-inflammatory and anti-tumor effects. In this study, we show that Wit A enhances the ionizing radiation (IR)-induced apoptosis in human lymphoma U937 cells. Wit A-enhanced IR-induced apoptosis is associated with the PARP cleavage, caspase-3 activation, as well as specifically down-regulation of anti-apoptotic protein Bcl-2, suggesting that Wit A may be useful as a potential radiosensitizer. In addition, pretreatment of U937 cells with SP600125 (JNK inhibitor) or SB203589 (p38 MAPK inhibitor) dose-dependently inhibited the proteolytic cleavage of PARP. We provide the evidence here that generation of reactive oxygen species (ROS), Bcl-2 down-regulation and activation of MAPKs pathway are critically involved in the apoptosis induced by Wit A and radiation.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/radioterapia , Vitanolídeos/farmacologia , Terapia por Raios X , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Terapia Combinada , Regulação para Baixo , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Linfoma Difuso de Grandes Células B/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Células U937 , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
Withaferin A (Wit A), a natural compound derived from the medicinal plant Withania somnifera, has been reported for the anti-tumor effects, including the inhibition of tumor cell growth, metastasis and angiogenesis. In this study, we investigated the effect of Wit A on radiation-induced apoptosis in human renal cancer cells (Caki cells). Our results showed that, compared with Wit A or radiation alone, the combination of both resulted in a significant enhancement of apoptosis, showing the increase in the cleavage of caspase-3 and PARP as well as sub-G1 cell population. In addition, reactive oxygen species (ROS) generation was correlated with the enhancement of radiation-induced apoptosis by Wit A. Wit A downregulated Bcl-2 protein levels and ectopic expression of Bcl-2 in Caki cells attenuated the apoptosis induced by Wit A plus radiation. Taken together, these results indicate that Wit A enhanced radiation-induced apoptosis in Caki cells through ROS generation, down-regulation of Bcl-2 and Akt dephosphorylation. Thus, our study shows that Wit A may be used as an effective radiosensitizer in cancer therapy.
Assuntos
Antineoplásicos/farmacologia , Apoptose , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Radiação Ionizante , Espécies Reativas de Oxigênio/metabolismo , Vitanolídeos/farmacologia , Antineoplásicos/química , Caspase 3/metabolismo , Linhagem Celular Tumoral , Fase G1 , Humanos , Plantas Medicinais/química , Poli(ADP-Ribose) Polimerases/metabolismo , Withania/química , Vitanolídeos/químicaRESUMO
Chronic alcohol administration has been known to increase peroxynitrite hepatotoxicity by enhancing concomitant production of nitric oxide and superoxide. We previously reported that control of the mitochondrial redox balance and the cellular defense against oxidative damage are primary functions of mitochondrial NADP(+)-dependent isocitrate dehydrogenase (IDPm) through to supply NADPH for antioxidant systems. In the present study, we demonstrate that modulation of IDPm expression in HepG2 cells regulates ethanol-induced toxicity. We observed the significantly enhanced protection to cell killing, lipid peroxidation, protein oxidation, oxidative DNA damage, and decrease in generation of intracellular reactive oxygen species and reactive nitrogen species in IDPm-overexpressed cells compared to control cells upon exposure to ethanol. In contrast, transfection of HepG2 cells with IDPm short interfering RNA markedly decreased the expression of IDPm, modulating cellular redox status and subsequently enhancing the susceptibility of ethanol-induced toxicity. These studies support the hypothesis that IDPm plays an important role in regulating the toxicity induced by ethanol presumably through maintaining the cellular redox status.
Assuntos
Etanol/toxicidade , Isocitrato Desidrogenase/metabolismo , Mitocôndrias/enzimologia , Sequência de Aminoácidos , Antioxidantes/metabolismo , Linhagem Celular Tumoral , Citocromo P-450 CYP2E1/metabolismo , DNA Complementar/genética , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Humanos , Isocitrato Desidrogenase/genética , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Dados de Sequência Molecular , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Ácido Peroxinitroso/metabolismo , RNA Interferente Pequeno/genética , TransfecçãoRESUMO
A high concentration of glucose has been implicated as a causal factor in initiation and progression of diabetic complications, and there is evidence to suggest that hyperglycemia increases the production of free radicals and oxidative stress. Therefore, compounds that scavenge reactive oxygen species may confer regulatory effects on high glucose-induced apoptosis. Epigallocatechin gallate (EGCG), the major polyphenolic of green tea, is reported to have an antioxidant activity. We investigated the effect of EGCG on high glucose-induced apoptosis in U937 cells. Upon exposure to 35 mM glucose for 2 days, there was a distinct difference between untreated cells and cells pre-treated with 1 microM EGCG for 2 h in regard to cellular redox status and oxidative DNA damage to cells. EGCG pre-treated cells showed significant suppression of apoptotic features such as DNA fragmentation, damage to mitochondrial function, and modulation of apoptotic marker proteins upon exposure to high glucose. This study indicates that EGCG may play an important role in regulating the apoptosis induced by high glucose presumably through scavenging of reactive oxygen species.
Assuntos
Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Catequina/análogos & derivados , Glucose/toxicidade , Chá/química , Western Blotting , Catequina/farmacologia , Dano ao DNA/efeitos dos fármacos , Fragmentação do DNA/efeitos dos fármacos , Citometria de Fluxo , Corantes Fluorescentes , Produtos Finais de Glicação Avançada/metabolismo , Humanos , Indóis , Potenciais da Membrana/efeitos dos fármacos , Membranas Mitocondriais/efeitos dos fármacos , Oxirredução , Células U937RESUMO
Sensitive to apoptosis gene (SAG) protein, a novel zinc RING finger protein that protects mammalian cells from apoptosis by redox reagents, is a metal chelator and a potential reactive oxygen species (ROS) scavenger, but its antioxidant properties have not been completely defined. Nitric oxide (NO), a radical species produced by many types of cells, is known to play a critical role in many regulatory processes, yet it may also participate in collateral reactions at higher concentrations, leading to cellular oxidative stress. In this report, we demonstrate that modulation of SAG expression in U937 cells regulates NO-induced apoptosis. When we examined the protective role of SAG against NO-induced apoptosis with U937 cells transfected with the cDNA for SAG, a clear inverse relationship was observed between the amount of SAG expressed in target cells and their susceptibility to apoptosis. We also observed the significant decrease in the endogenous production of ROS and oxidative DNA damage in SAG-overexpressed cells compared to control cells upon exposure to NO. These results suggest that SAG plays an important protective role in NO-induced apoptosis, presumably, through regulating the cellular redox status.