RESUMO
Excessive glucose concentrations in blood and cells promote the intensification of auto-oxidation. This is one of the mechanisms through which free radicals form in hyperglycemia. As a result of hyperglycemia, oxidative stress develops and lipid peroxidation (LPO) is enhanced. Erythrocytes are particularly susceptible to reactive oxygen species and LPO, which can violate cell functions. This article describes the analysis of the influence of mycelia from the medicinal mushrooms Agaricus brasiliensis and Ganoderma lucidum on the enzymatic link of the antioxidant system in rat erythrocytes under streptozotocin-induced diabetes mellitus. Oxidative stress was strengthened in red blood cells of diabetic rats, as evidenced by decreased activity of antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase, and by increased amounts of thiobarbituric acid-positive products, which are markers of LPO. Administration of A. brasiliensis and G. lucidum submerged cultivated mycelial powder to animals with streptozotocin-induced diabetes restored superoxide dismutase, catalase, and glutathione peroxidase activity and reduced the amounts of thiobarbituric acid-positive products to control values, but did not affect the activity of glutathione reductase.
Assuntos
Agaricus , Antioxidantes/uso terapêutico , Diabetes Mellitus Experimental/tratamento farmacológico , Eritrócitos/efeitos dos fármacos , Hipoglicemiantes/uso terapêutico , Reishi , Animais , Produtos Biológicos/uso terapêutico , Catalase/metabolismo , Eritrócitos/enzimologia , Eritrócitos/metabolismo , Glutationa Peroxidase/metabolismo , Masculino , Micélio , Estresse Oxidativo/efeitos dos fármacos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Superóxidos/metabolismo , Tiobarbitúricos/metabolismoRESUMO
BACKGROUND: Cold stress is regarded as a key factor limiting widespread use for bermudagrass (Cynodon dactylon). Therefore, to improve cold tolerance for bermudagrass, it is urgent to understand molecular mechanisms of bermudagrass response to cold stress. However, our knowledge about the molecular responses of this species to cold stress is largely unknown. The objective of this study was to characterize the transcriptomic response to low temperature in bermudagrass by using RNA-Seq platform. RESULTS: Ten cDNA libraries were generated from RNA samples of leaves from five different treatments in the cold-resistant (R) and the cold-sensitive (S) genotypes, including 4 °C cold acclimation (CA) for 24 h and 48 h, freezing (-5 °C) treatments for 4 h with or without prior CA, and controls. When subjected to cold acclimation, global gene expressions were initiated more quickly in the R genotype than those in the S genotype. The R genotype activated gene expression more effectively in response to freezing temperature after 48 h CA than the S genotype. The differentially expressed genes were identified as low temperature sensing and signaling-related genes, functional proteins and transcription factors, many of which were specifically or predominantly expressed in the R genotype under cold treatments, implying that these genes play important roles in the enhanced cold hardiness of bermudagrass. KEGG pathway enrichment analysis for DEGs revealed that photosynthesis, nitrogen metabolism and carbon fixation pathways play key roles in bermudagrass response to cold stress. CONCLUSIONS: The results of this study may contribute to our understanding the molecular mechanism underlying the responses of bermudagrass to cold stress, and also provide important clues for further study and in-depth characterization of cold-resistance breeding candidate genes in bermudagrass.
Assuntos
Temperatura Baixa , Cynodon/fisiologia , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Adaptação Fisiológica , Cynodon/genética , Genótipo , Folhas de Planta/fisiologia , Proteínas de Plantas/metabolismo , TranscriptomaRESUMO
Diabetes mellitus (DM) is accompanied by the development of hypoxia, which disturbs the physicochemical properties of the erythrocyte membrane and further leads to the occurrence of anemia and a reduction of the lifespan. In response, the body activates compensatory reactions directed at a renewal of the red blood cell pool and an increase in tissue oxygenation. In this study the influence of Agaricus brasiliensis and Ganoderma lucidum medicinal mushroom mycelia on the erythron system of control and streptozotocin (STZ)-induced diabetic rats were investigated. Wistar outbred white male rats were intraperitoneally injected with saline (control rats) or STZ (50 mg/kg, DM rats) and orally treated with placebo or submerged culture mycelium powder (1 g/kg/day) for 2 weeks. Peripheral blood erythrocytes were collected. Hypoglycemic effects of A. brasiliensis and G. lucidum occurred in the diabetic rats, as evidenced by decreased blood glucose and glycosylated hemoglobin concentrations. In STZ-diabetic animals treated with submerged culture mycelium powder, an increase in the number of erythrocytes in the bloodstream (an antianemic effect), erythrocyte resistance to acid hemolysis, and the normalization of fetal hemoglobin concentrations, along with the intensification of erythropoiesis were observed. In conclusion, our results suggest that in diabetic animals A. brasiliensis and G. lucidum have therapeutic effects that manifest in hypoglycemic and antianemic action.
Assuntos
Agaricus/química , Diabetes Mellitus Experimental/tratamento farmacológico , Eritrócitos/efeitos dos fármacos , Hipoglicemiantes/administração & dosagem , Preparações de Plantas/administração & dosagem , Reishi/química , Agaricus/crescimento & desenvolvimento , Animais , Glicemia/metabolismo , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/metabolismo , Hemoglobinas Glicadas/metabolismo , Humanos , Masculino , Micélio/química , Micélio/crescimento & desenvolvimento , Pós/administração & dosagem , Ratos , Ratos Wistar , Reishi/crescimento & desenvolvimento , Estreptozocina/efeitos adversosRESUMO
Oxidative-nitrative stress develops as a result of hyperglycemia under diabetes mellitus. Formation of excessive reactive oxygen species and reactive nitrogen species leads to different cytotoxic effects and ultimately to increased cell death by apoptosis of immune-competent blood cells. This study showed the influence of medicinal mushroom (MM) administration on the L-arginine/nitric oxide (NO) system and rat leukocyte apoptosis under normal and experimental diabetic conditions. Animals were divided into 6 groups: (1) control, (2) control animals treated with Agaricus brasiliensis, (3) control animals treated with Ganoderma lucidum, (4) animals with experimental diabetes (EDM), (5) diabetic animals treated with A. brasiliensis, and (6) diabetic animals treated with G. lucidum. Control and diabetic animals were fed powdered mushrooms at a dose of 1 g/kg body weight. Administration of MMs to animals with diabetes caused a decrease in the activity of the NO synthase enzyme, as well as in the content of stable end products of NO metabolism-nitrates and nitrites-at the control level. The normalizing effect of mushrooms on the percentage of leukocytes that contain pro- (p53) and antiapoptotic (Bcl-2) proteins compared with the EDM group was shown by immunocytochemical analysis. Thus the administration of MMs under EDM showed a positive corrective action on the L-arginine/NO system and the ratio between p53 and Bcl-2 proteins in white blood cells, as well as on apoptotic index reduction.
Assuntos
Agaricus/metabolismo , Apoptose , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Tipo 1/patologia , Dieta/métodos , Leucócitos/fisiologia , Reishi/metabolismo , Animais , Arginina/metabolismo , Leucócitos/metabolismo , Masculino , Óxido Nítrico/metabolismo , RatosRESUMO
With diabetes mellitus and increased glucose concentrations, the mitochondria electron transport chain is disrupted, superoxide anions are overproduced, and oxidative stress develops in cells. Thus, preventing oxidative stress can produce a decrease in the antioxidant system activity and an increase in apoptosis in immune cells. The application of medicinal mushrooms is a new possible approach to diabetes mellitus treatment. Therefore, the aim of this work was to investigate the influence of administration of the medicinal mushrooms Agaricus brasiliensis and Ganoderma lucidum on antioxidant enzyme activity in rat leukocytes. Wistar outbred white rats were used in the study. Streptozotocin was intraperitoneally injected once at a dose of 50 mg/kg body weight. Mushroom preparations were orally administered at a dose of 1 g/kg/day for 2 weeks. This revealed that in diabetes mellitus, the level of antioxidant enzyme activity is significantly decreased compared with control values, whereas the levels of lipid peroxidation is increased; this manifested in an increase in the amount of thiobarbituric acid reactive substances (TBARS). The medicinal mushrooms' administration is accompanied by an increase in antioxidant enzyme activity to control values and is even higher in the case of A. brasiliensis administration when compared with the diabetic group. As for the indicators of lipid peroxidation under mushroom administration of A. brasiliensis and G. lucidum, we observed a significant decrease of TBARS levels compared with the diabetic group. Increased activity of antioxidant enzymes and reduction of TBARS level indicate pronounced antioxidant properties of studied mushrooms.
Assuntos
Agaricus , Antioxidantes/farmacologia , Reishi , Animais , Catalase/metabolismo , Diabetes Mellitus Experimental/terapia , Glutationa Redutase/metabolismo , Glicoproteínas/metabolismo , Leucócitos/enzimologia , Peroxidação de Lipídeos , Masculino , Estresse Oxidativo , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismoRESUMO
Under conditions of chronic hyperglycemia there is dysregulation of ion homeostasis, violation of redox metabolism and functioning of membrane enzymes, as well as changes in the structural and functional states of erythrocyte membranes. As a result, the aggregation ability of erythrocytes increased and their deformability decreased. These changes lead to complications to microcirculation blood flow and provoke the development of vascular complications caused by diabetes mellitus. This study investigated the effect of the medicinal mushrooms Agaricus brasiliensis and Ganoderma lucidum on the structure of carbohydrate determinants of surface membrane glycoconjugates of rat peripheral blood erythrocytes under both normal conditions and streptozotocin-induced diabetes mellitus. The research was carried out using Wistar outbred white rats. Diabetes was induced by streptozotocin intraperitoneally injected once at a dose of 50 mg/kg body weight. The mushroom preparations were orally administered at a dose of 1 g/kg for 14 days. The treatment of diabetic rats by submerged culture mycelium powder restored the physiological balance between sialylation and desialylation processes, renewed the membrane surface charge of red blood cells, normalized aggregation properties, and caused the structural recovery of oligosaccharide chains of erythrocyte membrane surface glycoconjugates. The discovered changes show an improvement in the erythrocyte functional state and rejuvenation of their population caused by biologically active compounds of the studied medicinal mushrooms.
Assuntos
Agaricus/química , Produtos Biológicos/uso terapêutico , Diabetes Mellitus Experimental/tratamento farmacológico , Eritrócitos/efeitos dos fármacos , Glicoconjugados/sangue , Reishi/química , Animais , Produtos Biológicos/farmacologia , Glicemia/metabolismo , Complicações do Diabetes/sangue , Complicações do Diabetes/prevenção & controle , Diabetes Mellitus Experimental/sangue , Eritrócitos/metabolismo , Masculino , Micélio , Ratos WistarRESUMO
Vitamin E is an essential human nutrient that was first isolated from wheat. Emmer wheat, the cereal of Old World agriculture and a precursor to durum wheat, grows wild in the Fertile Crescent. Evolution Canyon, Israel, provides a microsite that models effects of contrasting environments. The north-facing and south-facing slopes exhibit low and high stress environments, respectively. Wild emmer wheat seeds were collected from both slopes and seed tocochromanol contents measured to test the hypothesis that high stress alters emmer wheat seed tocol-omics. Seeds from high stress areas contained more total vitamin E (108±15 nmol/g) than seeds from low stress environments (80±17 nmol/g, P=.0004). Vitamin E profiles within samples from these different environments revealed significant differences in isoform concentrations. Within each region, ß- plus γ-tocotrienols represented the highest concentration of wheat tocotrienols (high stress, P<.0001; low stress, P<.0001), while α-tocopherol represented the highest concentration of the tocopherols (high stress, P=.0002; low stress, P<.0001). Percentages of both δ-tocotrienol and δ-tocopherol increased in high stress conditions. Changes under higher stress apparently are due to increased pathway flux toward more tocotrienol production. The production of more δ-isoforms suggests increased flow through a divergent path controlled by the VTE1 gene. Hence, stress conditions alter plant responses such that vitamin E profiles are changed, likely an attempt to provide additional antioxidant activity to promote seed viability and longevity.
Assuntos
Meio Ambiente , Sementes/química , Estresse Fisiológico , Tocotrienóis/análise , Triticum/química , Vitamina E/química , Cromanos/análise , Transferases Intramoleculares , Israel , Vitamina E/análogos & derivados , Vitamina E/análise , Vitamina E/isolamento & purificação , alfa-Tocoferol/análise , gama-Tocoferol/análiseRESUMO
The ever-increasing occurrence of cancer and the severe side effects and limited efficacy of current cancer chemotherapy based on chemical drugs shift the attention toward drugs of plant origin. The Cactaceae family comprises more than 1500 species, but until recently only a few of them have been tested for their chemopreventive and anticancer attributes, leaving a wide unexplored area still waiting for researchers to investigate. Considering this fact, and also the promising results obtained with the relatively few plants of this family already tested, it should justly be expected that some plants of the Cactaceae family yet unexplored might possess outstanding anticancer attributes, exceeding those displayed by the plants already tested. This review presents in vitro and in vivo experimental evidence on cancer chemopreventive and therapeutic potential of bioactive phytoconstituents and extracts derived from cactus plants. It also examines the underlying biochemical and molecular mechanisms involved in the antineoplastic effects of plants of the Cactaceae family. Current limitation and future directions of research towards effective use of cacti to develop efficient and side effect-free future cancer-preventive and anticancer drugs are also discussed.
Assuntos
Anticarcinógenos/farmacologia , Cactaceae/química , Neoplasias/prevenção & controle , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Animais , Antineoplásicos Fitogênicos/farmacologia , Cactaceae/fisiologia , Ensaios de Seleção de Medicamentos Antitumorais , HumanosRESUMO
The rapidly increasing incidence of diabetes mellitus is becoming a serious threat to mankind's health in all parts of the world. In fact, known cases reflect only part of the problem, as many diabetics, especially with type 2 diabetes, are unaware of their disease, which initially shows no definitive symptoms. Despite the great efforts invested in diabetes research, its prevalence continues to grow, while current medications do not cover all of the symptoms and complications of the disease. The present review highlights a plethora of studies focusing on the antidiabetic properties of desert and semidesert (steppic) plants, many of them being used for centuries in traditional medicine by Bedouins living in the arid zones of the Middle East and also by ethnic groups in other arid and semiarid parts of the world. The review concludes in summarizing the work done on the subject and also in pointing to the yet existing gaps in diabetes research of desert and steppic plants, and suggests directions for future exploration.
Assuntos
Antioxidantes/uso terapêutico , Clima Desértico , Diabetes Mellitus/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Fenóis/uso terapêutico , Fitoterapia , Extratos Vegetais/uso terapêutico , Antioxidantes/química , Diabetes Mellitus/prevenção & controle , Humanos , Hipoglicemiantes/química , Hipoglicemiantes/isolamento & purificação , Medicina Tradicional , Fenóis/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Plantas/químicaRESUMO
CONTEXT: Phytochemicals are produced by desert plants to protect themselves against stressful environments. They have been shown to be useful in preventing and fighting adverse pathophysiological conditions and complex diseases, including cancer. Although many desert plants have been investigated for their antitumor properties, a large number of them still remain to be explored for possible therapeutic applications in oncologic diseases. OBJECTIVE: To screen the antitumor effects of selected desert plants, namely Achillea fragrantissima (Forssk.) Sch. Bip. (Compositae), Ochradenus baccatus Delile (Resedaceae), Origanum dayi Post (Lamiaceae), Phlomis platystegia Post (Lamiaceae) and Varthemia iphionoides Boiss (Compositae), against an in vitro tumor model utilizing HepG2 human hepatocellular carcinoma cells. MATERIALS AND METHODS: The aqueous extracts of aerial parts of the aforementioned plants were prepared and used for the in vitro experiments. The HepG2 cells were exposed to varying concentrations (0-4 mg/mL) of each plant extract for 24 or 48 h and the cytotoxicity was measured by the MTT assay. RESULTS: Following 24 h exposure, O. dayi extract exhibited a substantial antiproliferative effect in HepG2 cells (IC50 = 1.0 mg/mL) followed by O. baccatus (IC50 = 1.5 mg/mL). All plant extracts displayed cytotoxicity following 48 h exposure. Nevertheless, a substantial effect was observed with O. dayi (IC50 = 0.35 mg/mL) or O. baccatus (IC50 = 0.83 mg/mL). CONCLUSION: The aqueous extracts from aerial parts of O. dayi and O. baccatus possess antitumor effects against human liver cancer cells. These desert plants represent valuable resources for the development of potential anticancer agents.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Extratos Vegetais/farmacologia , Antineoplásicos Fitogênicos/administração & dosagem , Carcinoma Hepatocelular/patologia , Clima Desértico , Relação Dose-Resposta a Droga , Células Hep G2 , Humanos , Concentração Inibidora 50 , Neoplasias Hepáticas/patologia , Componentes Aéreos da Planta , Extratos Vegetais/administração & dosagem , Plantas Medicinais/química , Sais de Tetrazólio/química , Tiazóis/química , Fatores de TempoRESUMO
Aloe is a genus of medicinal plants with a notable history of medical use. Basic research over the past couple of decades has begun to reveal the extent of Aloe's pharmaceutical potential, particularly against neoplastic disease. This review looks at Aloe, both the genus and the folk medicine, often being called informally "aloes", and delineates their chemistry and anticancer pharmacognosy. Structures of key compounds are provided, and their pharmacological activities reviewed. Particular attention is given to their free radical scavenging, antiproliferative, and immunostimulatory properties. This review highlights major research directions on aloes, reflecting the enormous potential of natural sources, and of the genus Aloe in particular, in preventing and treating cancer.
Assuntos
Adjuvantes Imunológicos/farmacologia , Aloe , Antineoplásicos Fitogênicos/farmacologia , Antioxidantes/farmacologia , Plantas Medicinais/química , Aloe/química , Animais , Antraquinonas/farmacologia , Antioxidantes/uso terapêutico , Emodina/análogos & derivados , Emodina/química , Emodina/farmacologia , Emodina/uso terapêutico , Humanos , Mananas/química , Mananas/farmacologia , Mananas/uso terapêutico , Medicina Tradicional , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Lectinas de Plantas/farmacologiaRESUMO
The ever-increasing emergence of the resistance of mammalian tumor cells to chemotherapy and its severe side effects reduces the clinical efficacy of a large variety of anticancer agents that are currently in use. Thus, despite the significant progress in cancer therapeutics in the last decades, the need to discover and to develop new, alternative, or synergistic anticancer agents remains. Cancer prevention or chemotherapy based on bioactive fractions or pure components derived from desert plants with known cancer-inhibiting properties suggests promising alternatives to current cancer therapy. Plants growing on low nutrient soils and/or under harsh climatic conditions, such as extreme temperatures, intense solar radiation, and water scarcity, are particularly susceptible to attack from reactive oxygen species and have evolved efficient antioxidation defense systems. The many examples of desert plants displaying anticancer effects as presented here indicates that the same defensive secondary metabolites protecting them against the harsh environment may also play a protective or a curative role against cancer, as they also do against diabetes, neurodegenerative, and other acute and chronic diseases. The present review highlights a plethora of studies focused on the antineoplastic properties of desert plants and their prinicipal phytochemicals, such as saponins, flavonoids, tannins, and terpenes. Although many desert plants have been investigated for their antitumor properties, there are many that still remain to be explored - a challenge for the prospective cancer therapy of the future.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Plantas Medicinais/química , Plantas Medicinais/metabolismo , Animais , Antineoplásicos Fitogênicos/química , Clima Desértico , Humanos , Fenóis/química , Fenóis/farmacologia , Saponinas/química , Saponinas/farmacologiaRESUMO
Breast cancer is the most commonly diagnosed cancer among women. Currently, there is no effective therapy for malignant estrogen-independent breast cancer. In our study, we used hydrogen peroxide, a well-known strong oxidative reagent capable of activating the nuclear factor kappa B (NF-kappaB) transcription factor. The IC50 value of the culinary-medicinal Shaggy Inc Cap mushroom Coprinus comatus culture liquid crude extract on MCF7 cell viability was found to be as low as 76 microg/mL, and the IC50 value of C. comatus ethyl acetate extract was only 32 microg/ mL. Our results also showed that both extracts significantly affected IkappaBalpha phosphorylation in a dose-dependent manner. The effect of ethyl acetate extract was comparable to the effect of curcumin, a known NF-kappaB pathway inhibitor, and seemed to be the most active inhibitor of H2O2-dependent IkappaBalpha phosphorylation. In addition, the data obtained showed that only ethyl acetate extract inhibited the activity of IKK complex, at close to 90% as compared to the control of the untreated sample. These results suggest that C. comatus contains potent compounds capable of inhibiting NF-kappaB function and also possibly acts as an antitumor agent.
Assuntos
Misturas Complexas/farmacologia , Coprinus/química , Peróxido de Hidrogênio/farmacologia , Quinase I-kappa B/efeitos dos fármacos , Proteínas I-kappa B/efeitos dos fármacos , NF-kappa B/efeitos dos fármacos , Acetatos/química , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular , Misturas Complexas/isolamento & purificação , Relação Dose-Resposta a Droga , Feminino , Humanos , Quinase I-kappa B/antagonistas & inibidores , Quinase I-kappa B/metabolismo , Proteínas I-kappa B/metabolismo , Concentração Inibidora 50 , Inibidor de NF-kappaB alfa , NF-kappa B/antagonistas & inibidores , NF-kappa B/metabolismo , Fosforilação/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Fatores de TempoRESUMO
Hordeum spontaneum, wild barley, is the direct progenitor of domestic barley, Hordeum vulgare, an economically important ingredient of animal feed, beer, soy sauce, and more recently, of nutraceuticals. Domestic barley has also been used in the past as a medicine. Barley is a rich source of tocotrienols, with α-tocotrienol being the most prevalent. Wild barley seeds were harvested from ecogeographically diverse areas across the Fertile Crescent, and the tocopherol (α-δ) and tocotrienol (α-δ) contents were determined. Diversity differences in individual and total 'tocol' values were significant between and within specific countries, and were significantly correlated with temperature. Wild barley may be used in the future to improve functional qualities of domestic barley. 'Tocolome' and 'tocolomics' are proposed to encompass all tocols and potentially synergy-enhancing 'entourage' compounds that may occur in tocols' 'metabolomic neighborhoods', aiding the standardized manufacture of complex barley derivatives for nutraceutical and pharmaceutical functions.
Assuntos
Produtos Agrícolas/química , Hordeum/química , Hordeum/crescimento & desenvolvimento , Plantas Medicinais/química , Tocoferóis/isolamento & purificação , Tocotrienóis/isolamento & purificação , Biodiversidade , Cromatografia Líquida de Alta Pressão , Produtos Agrícolas/crescimento & desenvolvimento , Geografia , Irã (Geográfico) , Israel , Jordânia , Estrutura Molecular , Plantas Medicinais/crescimento & desenvolvimento , Análise de Regressão , Sementes/química , Sementes/crescimento & desenvolvimento , Especificidade da Espécie , Tocoferóis/química , Tocotrienóis/química , TurquiaRESUMO
Hepatocellular carcinoma (HCC), one of the most prevalent and lethal cancers, has shown an alarming rise in the USA. Without effective therapy for HCC, novel chemopreventive strategies may effectively circumvent the current morbidity and mortality. Oxidative stress predisposes to hepatocarcinogenesis and is the major driving force of HCC. Pomegranate, an ancient fruit, is gaining tremendous attention due to its powerful antioxidant properties. Here, we examined mechanism-based chemopreventive potential of a pomegranate emulsion (PE) against dietary carcinogen diethylnitrosamine (DENA)-induced rat hepatocarcinogenesis that mimics human HCC. PE treatment (1 or 10 g/kg), started 4 weeks prior to the DENA challenge and continued for 18 weeks thereafter, showed striking chemopreventive activity demonstrated by reduced incidence, number, multiplicity, size and volume of hepatic nodules, precursors of HCC. Both doses of PE significantly attenuated the number and area of γ-glutamyl transpeptidase-positive hepatic foci compared with the DENA control. PE also attenuated DENA-induced hepatic lipid peroxidation and protein oxidation. Mechanistic studies revealed that PE elevated gene expression of an array of hepatic antioxidant and carcinogen detoxifying enzymes in DENA-exposed animals. PE elevated protein and messenger RNA expression of the hepatic nuclear factor E2-related factor 2 (Nrf2). Our results provide substantial evidence, for the first time, that pomegranate constituents afford chemoprevention of hepatocarcinogenesis possibly through potent antioxidant activity achieved by upregulation of several housekeeping genes under the control of Nrf2 without toxicity. The outcome of this study strongly supports the development of pomegranate-derived products in the prevention and treatment of human HCC, which remains a devastating disease.
Assuntos
Antioxidantes , Carcinoma Hepatocelular , Neoplasias Hepáticas Experimentais , Lythraceae , Fator 2 Relacionado a NF-E2 , Fitoterapia , Extratos Vegetais , Animais , Masculino , Ratos , Alquilantes/toxicidade , Antioxidantes/uso terapêutico , Western Blotting , Carcinoma Hepatocelular/induzido quimicamente , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/metabolismo , Dietilnitrosamina/toxicidade , gama-Glutamiltransferase/metabolismo , Técnicas Imunoenzimáticas , Peroxidação de Lipídeos/efeitos dos fármacos , Neoplasias Hepáticas Experimentais/induzido quimicamente , Neoplasias Hepáticas Experimentais/tratamento farmacológico , Neoplasias Hepáticas Experimentais/metabolismo , Lythraceae/química , Estresse Oxidativo , Extratos Vegetais/uso terapêutico , Ratos Sprague-Dawley , Fator 2 Relacionado a NF-E2/metabolismoRESUMO
Ganoderma lucidum (Curt.:Fr.) P. Karst, a medicinal fungus, has been widely used in Asian countries for centuries to prevent or treat a variety of diseases, including cancer. However, the mechanisms responsible for the effects of G. lucidum on cancer cells remain to be elucidated. We have previously shown that ethyl acetate extract of G. lucidum inhibits LNCaP prostate cancer cell viability and proliferation. We also demonstrated that G. lucidum extract decreased androgen receptor transcriptional activity, suppressed levels of secreted prostate-specific antigen, and suppressed androgen receptor protein level. In this study we investigated the mechanisms that underlie the activities of G. lucidum crude extract and its active fraction GLF4 in LNCaP prostate cancer cells. Our data demonstrate that G. lucidum inhibits cell viability by induction of apoptosis through the extrinsic pathway that include activation of caspase-8 and caspase-3 and inhibits cell proliferation by the down-regulation of cyclin D1 expression. Furthermore, G. lucidum crude extract and fraction GLF4 interfere with androgen receptor function via competition with the natural ligand dihydrotestosterone and suppression of androgen receptor/androgen response element complex formation. These results indicate that G. lucidum extracts have profound activity against LNCaP cells that merits further investigation as a potential therapeutic agent for the treatment of prostate cancer.
Assuntos
Apoptose/efeitos dos fármacos , Neoplasias Hormônio-Dependentes/tratamento farmacológico , Extratos Vegetais/farmacologia , Neoplasias da Próstata/tratamento farmacológico , Receptores Androgênicos/metabolismo , Reishi/química , Anexina A5/metabolismo , Caspase 3/metabolismo , Caspase 8/metabolismo , Proliferação de Células/efeitos dos fármacos , Ciclina D , Ciclinas/antagonistas & inibidores , Ciclinas/genética , Ciclinas/metabolismo , Di-Hidrotestosterona/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Neoplasias Hormônio-Dependentes/metabolismo , Neoplasias Hormônio-Dependentes/patologia , Poli(ADP-Ribose) Polimerases/metabolismo , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Receptores Androgênicos/genética , Células Tumorais CultivadasRESUMO
MCF7 breast cancer cell line, carrying a luciferase reporter gene under the control of nuclear factor kappa B (NF-kappaB)-responsive promoter, was established and used for the screening of fungal organic extracts for their ability to interfere with the NF-kappaB activation pathway. Twenty-eight crude fungal extracts, out of 242, were found to inhibit NF-kappaB reporter activity by more than 40%. Furthermore, positive extracts were used to evaluate their antiproliferative activity as well as their ability to influence the phosphorylation and degradation levels of IkappaBa. Fungal extracts prepared from Marasmius oreades and Cyathus striatus showed significant inhibitory effects on the NF-kappaB activation pathway. Taken together, our results support the notion of the presence of novel activities that might be utilized as cancer therapeutics.
Assuntos
Proteínas Fúngicas/farmacologia , NF-kappa B/antagonistas & inibidores , NF-kappa B/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Citotoxinas/farmacologia , Avaliação Pré-Clínica de Medicamentos , Fungos/química , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Proteínas I-kappa B/metabolismo , Inibidor de NF-kappaB alfa , Transdução de Sinais/efeitos dos fármacos , Células Tumorais CultivadasRESUMO
Erythropoietin (Epo) is the primary regulator of erythropoiesis, controlling the proliferation, maturation, and survival of erythroid progenitor cells. The functions of Epo are mediated through its specific receptor (EpoR) expressed mainly on the surface of erythroid progenitor cells, and the expression of both responds to hypoxia. The subterranean mole rat (Spalax) is a unique model system to study the molecular mechanisms for adaptation to hypoxia. Here, we cloned two forms of Spalax EpoR: a complete EpoR cDNA as well as a novel truncated bone marrow specific EpoR form. In the full-length Spalax EpoR (sEpoR), two out of the eight conserved tyrosine- phosphorylation sites were substituted (Y481F and Y499G), suggesting that Spalax Epo signaling pathways may be modulated. The level of the sEpoR mRNA in the spleen and in bone marrow was relatively low and similar in Spalax newborns and adults, with no significant response to hypoxia. The truncated sEpoR was not detected in the spleen and comprised only approximately 1% of the sEpoR expressed in the bone marrow. In Rattus, the truncated EpoR form was approximately 15% of the total expressed receptor. The level of Rattus EpoR in newborn spleens was three- to fourfold higher than in Spalax newborns and decreased toward adulthood. Severe hypoxia induces a significant increase in adult Rattus EpoR. Our data provide further insight into the adaptive mechanisms of Spalax to the extreme conditions of hypoxia in its subterranean environment.