RESUMO
Hydroxyurea (HU), or hydroxycarbamide, is used for the treatment of some myeloproliferative and neoplastic diseases, and is currently the only drug approved by the FDA for use in sickle cell disease (SCD). Despite the relative success of HU therapy for SCD, a genetic disorder of the hemoglobin ß chain that results in red-cell sickling, hemolysis, vascular inflammation and recurrent vasoocclusion, the exact mechanisms by which HU actuates remain unclear. We hypothesized that HU may modulate endothelial angiogenic processes, with important consequences for vascular inflammation. The effects of HU (50-200 µM; 17-24 h) on endothelial cell functions associated with key steps of angiogenesis were evaluated using human umbilical vein endothelial cell (HUVEC) cultures. Expression profiles of the HIF1A gene and the miRNAs 221 and 222, involved in endothelial function, were also determined in HUVECs following HU administration and the direct in vivo antiangiogenic effects of HU were assessed using a mouse Matrigel-plug neovascularization assay. Following incubation with HU, HUVECs exhibited high cell viability, but displayed a significant 75% inhibition in the rate of capillary-like-structure formation, and significant decreases in proliferative and invasive capacities. Furthermore, HU significantly decreased HIF1A expression, and induced the expression of miRNA 221, while downregulating miRNA 222. In vivo, HU reduced vascular endothelial growth factor (VEGF)-induced vascular development in Matrigel implants over 7 days. Findings indicate that HU is able to inhibit vessel assembly, a crucial angiogenic process, both in vitro and in vivo, and suggest that some of HU's therapeutic effects may occur through novel vascular mechanisms.
Assuntos
Anemia Falciforme/tratamento farmacológico , Inibidores da Angiogênese/química , Hidroxiureia/química , Animais , Movimento Celular , Proliferação de Células , Células Endoteliais da Veia Umbilical Humana , Humanos , Hipóxia/tratamento farmacológico , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Marcação In Situ das Extremidades Cortadas , Inflamação/tratamento farmacológico , Úlcera da Perna/patologia , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/metabolismo , Transtornos Mieloproliferativos/tratamento farmacológico , Neovascularização Patológica , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
Alchornea glandulosa has traditionally been used in Brazilian folk medicine for the treatment of immune-inflammatory diseases and as an antiulcer agent to heal gastric ulcer and gastritis. Angiogenesis is a complex multistep process that consists of proliferation, migration, and anastomosis of endothelial cells and has a major role in the development of pathologic conditions, such as inflammatory diseases. To investigate a possible link between the anti-inflammatory activities and antiangiogenic effects of A. glandulosa ethyl acetate fraction (AGF), this study examined which features of the angiogenic process could be disturbed by this fraction. The antiangiogenic activity of AGF was determined in vitro by using human umbilical vein endothelial cells (HUVEC), and cell viability, proliferation, apoptosis, invasion, and capillary-like structures formation were addressed. To elucidate the mechanism of action, nuclear factor κB (NFκB), a transcription factor implicated in these processes, was also evaluated in HUVEC incubated with AGF. A significant decrease in proliferation, a relevant increase in apoptosis, and a strong reduction in invasion capacity (as assessed by bromodeoxyuridine, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling, and double-chamber assays, respectively) were observed. AGF also led to a drastic reduction in the number of capillary-like structures formed when HUVEC were cultured on growth factor-reduced Matrigel-coated plates. In addition, incubation of HUVEC with AGF resulted in reduced NFκB activity. These findings emphasize the antiangiogenic potential of AGF and support its therapeutic use for disorders that involve excessive angiogenesis, such as chronic inflammation and tumor growth.
Assuntos
Inibidores da Angiogênese/farmacologia , Euphorbiaceae/química , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Extratos Vegetais/farmacologia , Acetatos , Apoptose/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/citologia , Humanos , Marcação In Situ das Extremidades Cortadas , NF-kappa B/genética , NF-kappa B/metabolismo , Invasividade Neoplásica , Neovascularização Patológica , Transdução de Sinais , Fatores de Transcrição , Veias UmbilicaisRESUMO
CONTEXT: Alchornea triplinervia (Spreng.) Müll. Arg. (Euphorbiaceae) is a tree widespread in many Brazilian states. This plant naturally occurs in different ecosystems including tropical Atlantic forest, Amazon rain forest, moist tropical mixed forest, savanna forest, among others. Local populations traditionally use it in tea form to treat gastric disturbances. OBJECTIVE: The objective of this research was to evaluate the plant A. triplinervia as a potential inhibitor of some macrophage functions involved in the inflammatory process. MATERIALS AND METHODS: The effects of Alchornea triplinervia ethyl acetate fraction (AtF) on hydrogen peroxide (H2O2), nitric oxide (NO) and tumor necrosis factor-α (TNF-α) production in peritoneal macrophages were investigated using phenol red, Griess reagent and a sandwich immunoassay, respectively. RESULTS: AtF chromatographic analyses indicate the presence of flavonoids as majority compounds. The fraction also showed an intense inhibition of H2O2 and NO production. The inhibitory effects of the fraction in H2O2 and NO production ranged from 72.25 ± 4.68 to 69.64 ± 4.21 and from 47.8 ± 8.96 to 76.77 ± 8.11%, respectively in the two tested concentrations, 15.62 and 62.5 µg/mL. TNF-α production was partially inhibited in the tested concentrations and the inhibitory rate was around 18%. DISCUSSION AND CONCLUSION: It is supposed that the elevated biological potential of A. triplinervia is related to the presence of phenolic compounds in the plant leaves. According to the results observed in this study, it is suggested that AtF presents anti-inflammatory activity, supporting the traditional use of A. triplinervia in Brazilian folk medicine.
Assuntos
Anti-Inflamatórios/farmacologia , Euphorbiaceae/química , Inflamação/tratamento farmacológico , Extratos Vegetais/farmacologia , Animais , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/isolamento & purificação , Brasil , Relação Dose-Resposta a Droga , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Peróxido de Hidrogênio/metabolismo , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/metabolismo , Masculino , Medicina Tradicional , Camundongos , Óxido Nítrico/metabolismo , Fenóis/isolamento & purificação , Fenóis/farmacologia , Extratos Vegetais/administração & dosagem , Folhas de Planta , Fator de Necrose Tumoral alfa/metabolismoRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Mouriri elliptica Martius (Melastomataceae) is species reputed in folk medicine to heal gastric ulcer and gastritis. AIM OF THE STUDY: Methanolic extract (ME) and ethyl acetate fraction (EAF) from leaves of Mouriri elliptica were evaluated for their gastroprotective, healing, immunological, toxicological and anti-Helicobacter pylori activities. MATERIAL AND METHODS: The gastroprotective action of ME and EAF was evaluated in rodent experimental models and to elucidate mechanisms of action, the antisecretory action, involvements of NO, SH, PGE(2), anti-Helicobacter pylori action of ME was evaluated. We also used immunohistochemical (PCNA and COX-2) and immunomodulatory (murine peritoneal macrophages) assays to evaluate Mouriri elliptica effects. RESULTS: ME present gastroprotective action without antisecretory effect. Otherwise, ME showed anti-Helicobacter pylori action (MIC=0.025mug/mL) and was able to inhibit NO production by macrophages. This species also accelerate the healing of ulcerated gastric mucosa by stimulating proliferation factors (PCNA), COX-2 and maintained basal PGE(2) level independent action of NSAID in gastric mucosa. The phytochemical investigation showed that this species possesses phenolic acid derivatives, acylglycoflavonoids and condensed tannins which probably influenced their pharmacological action. CONCLUSION: All these results suggest the efficacy and safety of Mouriri elliptica in combating and healing gastric ulcer.
Assuntos
Antiulcerosos/uso terapêutico , Mucosa Gástrica/efeitos dos fármacos , Infecções por Helicobacter/tratamento farmacológico , Helicobacter pylori/efeitos dos fármacos , Melastomataceae , Fitoterapia , Extratos Vegetais/uso terapêutico , Úlcera Gástrica/tratamento farmacológico , Animais , Antibacterianos/efeitos adversos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Anti-Inflamatórios não Esteroides , Antiulcerosos/efeitos adversos , Antiulcerosos/farmacologia , Ciclo-Oxigenase 2/metabolismo , Dinoprostona/metabolismo , Modelos Animais de Doenças , Etanol , Feminino , Flavonoides/efeitos adversos , Flavonoides/farmacologia , Flavonoides/uso terapêutico , Mucosa Gástrica/metabolismo , Infecções por Helicobacter/induzido quimicamente , Macrófagos/efeitos dos fármacos , Masculino , Melastomataceae/química , Camundongos , Óxido Nítrico/antagonistas & inibidores , Fenóis/efeitos adversos , Fenóis/farmacologia , Fenóis/uso terapêutico , Extratos Vegetais/efeitos adversos , Extratos Vegetais/farmacologia , Folhas de Planta , Antígeno Nuclear de Célula em Proliferação/metabolismo , Ratos , Úlcera Gástrica/induzido quimicamente , Úlcera Gástrica/microbiologia , Taninos/efeitos adversos , Taninos/farmacologia , Taninos/uso terapêuticoRESUMO
Mycobacterium tuberculosis is responsible for over 8 million cases of tuberculosis (TB) annually. Natural products may play important roles in the chemotherapy of TB. The immunological activity of Davilla elliptica chloroform extract (DECE) was evaluated in vitro by the determination of hydrogen peroxide (H2O2), nitric oxide (NO), and tumor necrosis factor-alpha (TNF-alpha) release in peritoneal macrophages cultures. DECE was also tested for its antimycobacterial activity against M. tuberculosis using the microplate alamar blue assay. DECE (50, 150, 250 mug/ml) stimulated the production of H2O2 (from 1,79 ± 0,23 to 7,27 ± 2,54; 15,02 ± 2,86; 20,5 ± 2,1 nmols) (means ± SD), NO (from 2,64 ± 1,02 to 25,59 ± 2,29; 26,68 ± 2,41; 29,45 ± 5,87 mumols) (means ± SD) and TNF-alpha (from 2,44 ± 1,46 to 30,37 ± 8,13; 38,68 ± 1,59; 41,6 ± 0,90 units/ml) (means ± SD) in a dose-dependent manner and also showed a promising antimycobacterial activity with a minimum inhibitory concentration of 62,5 mug/ml. This plant may have therapeutic potential in the immunological and microbiological control of TB.
Assuntos
Animais , Camundongos , Antibióticos Antituberculose/farmacologia , Dilleniaceae/química , Macrófagos/microbiologia , Mycobacterium tuberculosis/efeitos dos fármacos , Antibióticos Antituberculose/isolamento & purificação , Peróxido de Hidrogênio/metabolismo , Testes de Sensibilidade Microbiana , Macrófagos/metabolismo , Óxido Nítrico/biossíntese , Extratos Vegetais/farmacologia , Fator de Necrose Tumoral alfa/biossínteseRESUMO
The effects of Alchornea glandulosa ethyl acetate fraction (AGF) on hydrogen peroxide (H2O2), nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha) production in peritoneal macrophages activated with lipopolysaccharide (LPS) or phorbol myristate acetate (PMA) were investigated. Analysis by thin layer chromatography (TLC) of AGF showed several constituents, including flavonoids, which may have anti-inflammatory activity. Inhibitory effects of the fraction in H2O2 and NO production ranged from 8.59+/-7.84% to 70.56+/-4.16% and from 16.06+/-3.65% to 38.73+/-3.90%, respectively. The TNF-alpha production was only partially inhibited in the tested concentrations (12.21+/-6.23% - 15.16+/-0.96%). According to these results, it is suggested that AGF has anti-inflammatory activity. This medicinal plant may have therapeutic potential in the control of inflammatory disorders.
Assuntos
Euphorbiaceae/química , Peróxido de Hidrogênio/metabolismo , Macrófagos Peritoneais/metabolismo , Óxido Nítrico/biossíntese , Fator de Necrose Tumoral alfa/biossíntese , Acetatos , Animais , Sobrevivência Celular/efeitos dos fármacos , Cromatografia em Camada Fina , Peróxido de Hidrogênio/antagonistas & inibidores , Fatores Imunológicos/farmacologia , Camundongos , Extratos Vegetais , Folhas de Planta/química , SolventesRESUMO
Macrophages release more than one hundred compounds into the extracellular environment. Among these, there are cytokines and intermediate oxigen compounds, such as TNF-"ALPHA" and 'H POT. 2''O POT. 2'. We evaluated the effect of the crude essential oil of Achillea millefolium L. (Asteraceae) by determining hydrogen peroxide ('H POT. 2''O POT. 2') and tumor necrosis factor-a (TNF-"ALPHA") release in cultures of peritoneal macrophages cells from Swiss mice. Commercial azulene was also tested for comparison with the essential oil. The macrophages viability in the presence of the oil was analyzed and dilutions of 1:100 and 1:200 showed the best results. A mild production of 'H POT. 2''O POT. 2' and a moderate liberation of TNF-"ALPHA" were observed...