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1.
Iran J Pharm Res ; 17(4): 1306-1317, 2018.
Article in English | MEDLINE | ID: mdl-30568689

ABSTRACT

Annona muricata Linnaeus (Annonaceae), popularly known as graviola, is used in folk medicine as both sedative and anticonvulsant. This study correlates the neurochemical profile with the behavioral effects of the hydroalcoholic extract from the leaves of Annona muricata (HLEAM) in mice, proposing to elucidate their mechanism of action on the central nervous system. Flavonoids and phenolic compounds were identified and quantified by High Performance Liquid Chromatography (HPLC) method. The acute toxicity (median lethal dose - LD50) was determined by probitos method using the percentage of mortality based on the Hippocratic screen. HLEAM (25, 50 and 100 mg/kg) was tested, intraperitoneally (i.p.), in models of sedation, anxiety, motor coordination, and seizures. The endogenous levels of dopamine, norepinephrine and DOPAC were assayed by reverse-phase HPLC with electrochemical detection. The HPLC analysis of the extract revealed the presence of flavonoids (quercetin, isoquercitrin, quercitrin, rutin, and kaempferol) and phenolics acids (gallic, chlorogenic, ellagic and caffeic acids). The LD50 was 1091.7 mg/kg and Hippocratic screening indicated central nervous system depressant effect. HLEAM presented sedative effects at doses of 25, 50, and 100 mg/kg, as well as anxiolytic and anticonvulsant effects at a dose of 100 mg/kg. In addition, these effects were partially reversed by flumazenil. The monoamines analysis by HPLC showed that HLEAM decreased the level of norepinefrine and dopamine in the mouse brain striatum. Thus, the results indicate a possible interaction of HLEAM with the GABAergic and monoaminergic systems, adding medicinal value to the popular use of the plant for the treatment of behavioral and neurological disorders.

2.
Iran J Pharm Res ; 17(1): 268-275, 2018.
Article in English | MEDLINE | ID: mdl-29755558

ABSTRACT

With the increase of neglected diseases such as leishmaniasis and Chagas disease, there was a need for the search for new therapeutic alternatives that reduce the harm caused by medicine available for treatment. Thus, this study was performed to investigate the antiparasitic activity of the essential oil from the fruits of Piper tuberculatum Jacq, against lines of Leishmania braziliensis (MHOM/CO/88/UA301), Leishmania infantum (MHOM/ES/92/BCN83) and Trypanosoma cruzi (LC-B5 clone). Before running protocols, an analysis of the chemical composition of essential oil was conducted, which presented monoterpenes and sesquiterpenes. As major constituents, ß-pinene and α-pinene were identified. Regarding to antiparasitic activity, the essential oil had an EC50 values of 133.97 µg/mL and 143.59 µg/mL against variations promastigotes of L. infantum and L. braziliensis, respectively. As for trypanocidal activity, the oil showed EC50 value of 140.31 µg/mL against epimastigote form of T. cruzi. Moreover, it showed moderate cytotoxicity in fibroblasts with LC50 value of 204.71 µg/mL. The observed effect may be related to the presence of terpenes contained in the essential oil, since it has its antiparasitic activity proven in the literature.

3.
Saudi J Biol Sci ; 25(4): 609-621, 2018 May.
Article in English | MEDLINE | ID: mdl-29736140

ABSTRACT

Annona muricata Linnaeus, popularly known as "graviola" and also called soursop, is a species typical of countries with a tropical climate, and it is used in folk medicine as an anticancer, analgesic and antispasmodic agent. The aim of the present study was to validate the gastroprotective activity of the hydroalcoholic extract of the leaves of A. muricata (HEAM) and to investigate the underlying mechanisms of action for this effect. Gastric lesions were induced in mice by absolute ethanol, acidified ethanol or indomethacin. Before, the animals were pretreated with saline, omeprazole or HEAM orally at doses of 50-400 mg/kg. To determine the mechanism of action of the extract, we investigated, using specific inhibitors, the involvement of nitric oxide (NO), prostaglandins (PGEs), ATP-dependent K+ channels and α2-noradrenergic receptors. HEAM showed significant antiulcer activity against lesions induced by absolute ethanol, acidified ethanol or indomethacin, which was mediated by endogenous gastric prostaglandins.

4.
Rev Assoc Med Bras (1992) ; 64(3): 214-216, 2018 Mar.
Article in English | MEDLINE | ID: mdl-29641782

ABSTRACT

An 82-year-old man sought our service with dysphagia and was referred for upper endoscopy with biopsies, which evidenced multiple ulcers of the esophagus and oropharinx. Histopathology confirmed the unusual diagnosis of esophageal lichen planus. The correct clinical suspicion of this disease can facilitate the diagnosis and guide specific treatment, which can drastically change the natural course of the disease.


Subject(s)
Deglutition Disorders/diagnostic imaging , Deglutition Disorders/etiology , Esophageal Diseases/complications , Lichen Planus/complications , Aged, 80 and over , Biopsy , Epithelial Cells/pathology , Esophageal Diseases/diagnostic imaging , Esophageal Diseases/pathology , Esophagoscopy , Humans , Lichen Planus/diagnostic imaging , Lichen Planus/pathology , Male , T-Lymphocytes/pathology
5.
Rev. cienc. salud (Bogotá) ; 16(1): 49-58, ene.-abr. 2018. tab, graf
Article in Portuguese | LILACS, COLNAL | ID: biblio-959682

ABSTRACT

Resumo Introdução: a espécie Hyptis martiusii Benth, comumente chamada de "cidrera del campo", têm múltiplas propriedades biológicas, como ser inseticida, antifúngica e anti-inflamatória. O objetivo deste estudo foi investigar a atividade moduladora do óleo essencial das folhas frescas de Hyptis martiusii em associação com diferentes antibióticos contra as bactérias Staphylococcus aureus, Escherichia coli e Pseudomonas aeruginosa, e avaliar a atividade citotóxica da espécie. Materiais e métodos: o estudo utilizou a concentração inibitória mínima (CIM) como uma forma de avaliar a modulação com uma inoculação de 100 microlitros de cada estirpe bacteriana. As provas de citotoxicidade se realizaram mediante cultivo in vitro de células do tecido conectivo de camundongo (fibroblastos de mamíferos). Resultados: a pesquisa demonstrou que o óleo essencial das folhas de Hyptis martiusii Benth (OEHM) apresenta sinergismo só em associação com os antibióticos gentamicina e imipenem contra as bactérias Pseudomonas aeruginosa e Escherichia coli. No entanto, apresenta antagonismo em associação com amicacina, gentamicina e imipenem contra as três bactérias estudadas. Para além da ciprofloxacina não demonstrou resultados relevantes. Em relação com a atividade citotóxica, a concentração letal média (LC50) expôs um valor de 263,12 [ig/ml. Conclusão: finalmente, revelou-se que a H. martiusii apresenta atividade citotóxica sinérgica contra as bactérias avaliadas.


Resumen Introducción: la especie Hyptis martiusii Benth, comúnmente llamada "cidreira do campo", tiene múltiples propiedades biológicas, como ser insecticida, antifúngica y antiinflamatoria. El objetivo de este estudio fue investigar la actividad moduladora del aceite esencial de las hojas frescas de Hyptis martiusii en asociación con diferentes antibióticos contra las bacterias Staphylococcus aureus, Escherichia coli y Pseudomonas aeruginosa, y evaluar la actividad citotóxica de la especie. Materiales y métodos: el estudio utilizó la concentración mínima inhibitoria (CMI) como una forma de evaluar la modulación con una inoculación de 100 microlitros de cada cepa bacteriana. Las pruebas de citotoxicidad se realizaron mediante cultivo in vitro de células de tejido conectivo de ratón (fibroblastos de mamíferos). Resultados: la investigación demostró que el aceite esencial de las hojas de Hyptis martiusii Benth (OEHM) presenta sinergismo solo en asociación con los antibióticos gentamicina e imipenem contra las bacterias Pseudomonas aeruginosa y Escherichia coli. Sin embargo, presenta antagonismo en asociación con amikacina, gentamicina e imipenem contra las tres bacterias estudiadas. Además de la ciprofloxacina, no demostró resultados relevantes. En relación con la actividad citotóxica, la concentración letal media (CL50) exhibió un valor de 263,12 [ig/ml. Conclusión: finalmente, se reveló que la H. martiusii presenta actividad citotóxica sinérgica contra las bacterias evaluadas.


Abstract Introduction: The species Hyptis martiusii Benth. commonly called "cidreira do campo" has multiple biological properties, such as antifungal, anti-inflammatory, and insecticide. The aim of this study was to investigate the modulating activity of the essential oil of the fresh leaves of Hyptis martiusii in association with different antibiotics against the bacteria Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, as also the cytotoxic activity of this species. Materials and methods: The study used the MIC (minimum inhibitory concentration) as a way of assessing the modulation using an inoculation of 100 microliters of each bacterial strain. The cytotoxicity tests were conducted using in vitro culture of mouse connective tissue cells (fibroblasts of mammals). Results: The research demonstrated that the essential oil from leaves of Hyptis martiusii Benth (OEHM) presented synergism only when associated with the antibiotics gentamicin and imipenem against the bacteria Pseudomonas aeruginosa and Escherichia coli. However, it presented antagonism in association with amikacin, gentamicin and imipenem against the three studied bacteria. In addition to the ciprofloxacin showed no relevant results. In relation to the cytotoxic activity the lethal concentration (LC50) exhibited a value of 263.12 [ig/ml. Conclusion: Ultimately it was established, that H. Martiusii presents a synergistic cytotoxic activity against the evaluated bacteria.


Subject(s)
Humans , Hyptis , Biological Products , Oils, Volatile , Ciprofloxacin , Anti-Bacterial Agents
6.
Rev. Assoc. Med. Bras. (1992, Impr.) ; 64(3): 214-216, Mar. 2018. graf
Article in English | LILACS | ID: biblio-896451

ABSTRACT

Summary An 82-year-old man sought our service with dysphagia and was referred for upper endoscopy with biopsies, which evidenced multiple ulcers of the esophagus and oropharinx. Histopathology confirmed the unusual diagnosis of esophageal lichen planus. The correct clinical suspicion of this disease can facilitate the diagnosis and guide specific treatment, which can drastically change the natural course of the disease.


Resumo Paciente do sexo masculino, de 82 anos, com disfagia, foi encaminhado para realização de endoscopia digestiva alta com biópsias, na qual foram evidenciadas múltiplas úlceras de esôfago e orofaringe. O estudo histopatológico confirmou o diagnóstico raro de líquen plano esofágico. A correta suspeita clínica dessa doença pode facilitar o diagnóstico e direcionar para um tratamento específico, o que pode drasticamente alterar o curso natural dessa comorbidade.


Subject(s)
Humans , Male , Aged, 80 and over , Deglutition Disorders/etiology , Deglutition Disorders/diagnostic imaging , Esophageal Diseases/complications , Lichen Planus/complications , Biopsy , T-Lymphocytes/pathology , Esophagoscopy , Epithelial Cells/pathology , Esophageal Diseases/pathology , Esophageal Diseases/diagnostic imaging , Lichen Planus/pathology , Lichen Planus/diagnostic imaging
7.
Rev. cuba. plantas med ; 22(1)ene.-mar. 2017. tab
Article in Portuguese | CUMED | ID: cum-73020

ABSTRACT

Introdução: Piper tuberculatum Jacq., popularmente conhecida como pimenta-longa ou pimenta-d'Arda, é utilizada empiricamente no tratamento de doenças respiratórias (asma, bronquite e tosse) e digestivas (dores abdominais e diarreias). Na literatura é descrita com importantes atividades anti-inflamatória, antimicrobiana, antileucêmico e anti-helmíntica. Objetivos: avaliar a atividade moduladora do óleo essencial dos frutos de P. tuberculatum (OEPT) em associação com diferentes antibióticos frente à Staphylococcus aureus, Escherichia coli e Pseudomona aeruginosa. Metodos: Os frutos (frescos) de P. tuberculatum foram coletados em Barbalha/CE e submetidos à hidrodestilação em aparelho tipo Clevenger para ser extraído o óleo essencial, após a extração o óleo essencial foi tratado com sulfato de sódio anidro para eliminação da umidade residual. A avaliação da atividade antibacteriana e modulação (em resistência bacteriana) frente às cepas de S. aureus (SA358), E. coli (EC27) e P. aeruginosa (PA03) foram determinadas pelo método de microdiluição para identificar a concentração inibitória mínima (CIM), realizada em triplicata. CIM de ≤ 256 µg/mL foi considerado clinicamente relevante. Resultados: a atividade antibacteriana do OEPT exibiu um CIM de ≥ 1024 µg/mL contra as cepas de bactérias de padrão resistente...(AU)


Introducción: Piper tuberculatum Jacq. popularmente conocida como pimenta-longa o pimenta-d'Arda, se utiliza empíricamente en el tratamiento de enfermedades respiratorias (asma, bronquitis y tos) y digestivas (dolor abdominal y diarrea). En la literatura es describe con importantes actividades antiinflamatorias, antimicrobianas, antileucémicas y antihelmínticas. Objetivo: evaluar la actividad moduladora de los aceites esenciales de frutos de P. tuberculatum (AEPT) en asociación con diferentes antibióticos contra Staphylococcus aureus, Escherichia coli y Pseudomona aeruginosa. Metodología: los frutos (frescos) de P. tuberculatum fueron recolectados en Barbalha/CE y sometidos a hidrodestilación en un equipo Clevenger, para extraer el aceite essencial (AEPT), el cual, una vez extraído, fue tratado con sulfato de sodio anhidro para eliminar la humedad residual. Se evaluó su actividad antibacteriana contra las cepas de S. aureus (SA358), E. coli (EC27) y P. aeruginosas (PA03). Empleando el método de microdilución se determinó la concentración inhibitoria mínima (CIM), con tres réplicas por cada tratamiento. Un valor de CIM ≤ 256 µg/mL se considera clínicamente...(AU)


Introduction: Piper tuberculatum Jacq., commonly known as pimenta-longa or pimenta-d'Arda, is empirically used to treat respiratory conditions (asthma, bronchitis and coughing) and digestive disorders (abdominal pain and diarrhea). Reference may be found in the literature to outstanding antiinflammatory, antimicrobial, antileukemic and antihelmintic activity. Objective: Evaluate the modulatory activity of essential oils from fruits of P. tuberculatum (AEPT) combined with various antibiotics againstStaphylococcus aureus, Escherichia coli and Pseudomona aeruginosa. Methods: Fresh fruits of P. tuberculatum were collected in Barbalha, CE, and subjected to hydrodistillation in a Clevenger set to extract the essential oil (AEPT). The oil extracted was then treated with anhydrous sodium sulfate to eliminate residual humidity. Antibacterial activity was evaluated against strains of S. aureus (SA358), E. coli (EC27) and P. aeruginosas (PA03). Minimum inhibitory concentration (MIC) was determined by the microdilution method, with three replications for each treatment. A MIC ≤ 256 µg/mL was considered to be clinically relevant. Results: Antibacterial activity of AEPT displayed a MIC of ≥1024 µg/mL against standard strains of multi-drug resistant bacteria. In fact, activity of AEPT antagonized the effect of amikacin against...(AU)


Subject(s)
Humans , Anti-Infective Agents/therapeutic use , Imipenem/therapeutic use , Oils, Volatile/therapeutic use , Piper nigrum
8.
Rev. cuba. plantas med ; 22(1)ene.-mar. 2017. tab
Article in Portuguese | LILACS, CUMED | ID: biblio-901507

ABSTRACT

Introdução: Piper tuberculatum Jacq., popularmente conhecida como pimenta-longaou pimenta-d'Arda, é utilizada empiricamente no tratamento de doenças respiratórias (asma, bronquite e tosse) e digestivas (dores abdominais e diarreias). Na literatura é descrita com importantes atividades anti-inflamatória, antimicrobiana, antileucêmico e anti-helmíntica. Objetivos: avaliar a atividade moduladora do óleo essencial dos frutos de P. tuberculatum (OEPT) em associação com diferentes antibióticos frente à Staphylococcus aureus, Escherichia coli e Pseudomona aeruginosa. Metodos: Os frutos (frescos) de P. tuberculatum foram coletados em Barbalha/CE e submetidos à hidrodestilação em aparelho tipo Clevenger para ser extraído o óleo essencial, após a extração o óleo essencial foi tratado com sulfato de sódio anidro para eliminação da umidade residual. A avaliação da atividade antibacteriana e modulação (em resistência bacteriana) frente às cepas de S. aureus (SA358), E. coli (EC27) e P. aeruginosa (PA03) foram determinadas pelo método de microdiluição para identificar a concentração inibitória mínima (CIM), realizada em triplicata. CIM de ≤ 256 µg/mL foi considerado clinicamente relevante. Resultados: a atividade antibacteriana do OEPT exibiu um CIM de ≥ 1024 µg/mL contra as cepas de bactérias de padrão resistente a múltiplas drogas. Na avaliação da atividade moduladora, o OEPT antagonizou o efeito da amicacina contra E. coli e S. aureus, mas teve efeito sinérgico contra P. aeruginosa. Combinado com a getamicina o óleo exibiu antagonismo frente a E. coli, no entanto não apresentou resultado relevante contra S. aureas e P. aeruginosa. A associação do OEPT com o antibiótico imipenem resultou efeito mais relevante, apresentando sinergismo para todas as bactérias avaliadas, por outro lado, em associação com ciprofloxacino não apresentou efeito significante em relação ao controle. Conclusão: O OEPT apresentou uma melhor atividade quando associado ao imipenem frente todas as bactérias avaliadas, mostrando ser uma possível alternativa no desenvolvimento de novos fármacos com atividade antibacteriana advindos de produtos fitoterápicos(AU)


Introducción: Piper tuberculatum Jacq. popularmente conocida como pimenta-longa o pimenta-d'Arda, se utiliza empíricamente en el tratamiento de enfermedades respiratorias (asma, bronquitis y tos) y digestivas (dolor abdominal y diarrea). En la literatura es describe con importantes actividades antiinflamatorias, antimicrobianas, antileucémicas y antihelmínticas. Objetivo: evaluar la actividad moduladora de los aceites esenciales de frutos de P. tuberculatum (AEPT) en asociación con diferentes antibióticos contra Staphylococcus aureus, Escherichia coli y Pseudomona aeruginosa. Metodología: los frutos (frescos) de P. tuberculatum fueron recolectados en Barbalha/CE y sometidos a hidrodestilación en un equipo Clevenger, para extraer el aceite essencial (AEPT), el cual, una vez extraído, fue tratado con sulfato de sodio anhidro para eliminar la humedad residual. Se evaluó su actividad antibacteriana contra las cepas de S. aureus (SA358), E. coli (EC27) y P. aeruginosas (PA03). Empleando el método de microdilución se determinó la concentración inhibitoria mínima (CIM), con tres réplicas por cada tratamiento. Un valor de CIM ≤ 256 µg/mL se considera clínicamente relevante. Resultados: la actividad antibacteriana del AEPT exhibió una CIM ≥ 1024 µg/mL contra las cepas estándar de bacterias resistentes a múltiples fármacos. En efecto, la actividad AEPT antagoniza el efecto de amikacina contra E. coli y S. aureus, pero tenía un efecto sinérgico contra P. aeruginosa. Combinado con la getamicina el aceite exhibió antagonismo contra E. coli, sin embargo no presentó resultado relevante ante S. aureus y P. aeruginosa. La asociación de AEPT con el antibiótico imipenem resultó el efecto más relevante, mostrando sinergismo frente a todas las bacterias evaluadas. Por el contrario, en asociación con ciprofloxacina no mostró ningún efecto significativo con respecto al control. Conclusión: el AEPT presentó una mejor actividad cuando se asoció a imipenem, frente todas las bacterias evaluadas, demostrando ser una posible alternativa en el desarrollo de nuevos fármacos con actividad antimicrobiana, a partir de productos herbarios(AU)


Introduction: Piper tuberculatum Jacq., commonly known as pimenta-longa or pimenta-d'Arda, is empirically used to treat respiratory conditions (asthma, bronchitis and coughing) and digestive disorders (abdominal pain and diarrhea). Reference may be found in the literature to outstanding antiinflammatory, antimicrobial, antileukemic and antihelmintic activity. Objective: Evaluate the modulatory activity of essential oils from fruits of P. tuberculatum (AEPT) combined with various antibiotics againstStaphylococcus aureus, Escherichia coli and Pseudomona aeruginosa. Methods: Fresh fruits of P. tuberculatum were collected in Barbalha, CE, and subjected to hydrodistillation in a Clevenger set to extract the essential oil (AEPT). The oil extracted was then treated with anhydrous sodium sulfate to eliminate residual humidity. Antibacterial activity was evaluated against strains of S. aureus (SA358), E. coli (EC27) and P. aeruginosas (PA03). Minimum inhibitory concentration (MIC) was determined by the microdilution method, with three replications for each treatment. A MIC ≤ 256 µg/mL was considered to be clinically relevant. Results: Antibacterial activity of AEPT displayed a MIC of ≥1024 µg/mL against standard strains of multi-drug resistant bacteria. In fact, activity of AEPT antagonized the effect of amikacin against E. coli and S. aureus, but had a synergic effect against P. aeruginosa. Combined with gentamicin, the oil exhibited antagonism against E. coli, but no relevant result was obtained against S. aureus and P. aeruginosa. Combination of AEPT with the antibiotic imipenem had the most relevant effect, displaying synergism against all the bacteria evaluated. However, in combination with ciprofloxacin it did not show any significant effect with respect to the control. Conclusion: AEPT displayed better activity against all the bacteria evaluated when combined with imipenem, proving to be a possible alternative for the development of new herbal drugs with antimicrobial activity(AU)


Subject(s)
Humans , Oils, Volatile/therapeutic use , Imipenem/therapeutic use , Piper nigrum/drug effects , Anti-Infective Agents/therapeutic use
9.
FASEB J ; 19(7): 819-21, 2005 May.
Article in English | MEDLINE | ID: mdl-15857892

ABSTRACT

Angiogenesis is critical for many physiological and pathological processes. We show here that the lipid sphingosylphosphorylcholine (SPC) induces angiogenesis in vivo and GPR4 is required for the biological effects of SPC on endothelial cells (EC). In human umbilical vein EC, down-regulation of GPR4 specifically inhibits SPC-, but not sphingosine-1-phosphate-, or vascular endothelial growth factor (VEGF)-induced tube formation. Re-introduction of GPR4 fully restores the activity of SPC. In microvascular EC, GPR4 plays a pivotal role in cell survival, growth, migration, and tube formation through both SPC-dependent and -independent pathways. The biological effects resulting from SPC/GPR4 interactions involve the activation of both phosphatidylinositol-3 kinase and Akt. Moreover, the effects of SPC on EC require SPC induced trans-phosphorylation and activation of the VEGF receptor 2. These results identify SPC and its receptor, GPR4, as critical regulators of the angiogenic potential of EC.


Subject(s)
Endothelial Cells/physiology , Neovascularization, Physiologic/physiology , Phosphorylcholine/analogs & derivatives , Receptors, G-Protein-Coupled/physiology , Sphingosine/analogs & derivatives , Animals , Antibodies/pharmacology , Cell Division/physiology , Cell Movement/physiology , Cell Survival/physiology , Cells, Cultured , Chick Embryo , Enzyme Activation , Gene Expression/drug effects , Humans , Hydrogen-Ion Concentration , Lysophospholipids/pharmacology , Neovascularization, Physiologic/drug effects , Oncogene Protein v-akt/metabolism , Peptide Fragments/immunology , Phosphatidylinositol 3-Kinases/metabolism , Phosphorylcholine/pharmacology , RNA, Small Interfering/pharmacology , Receptors, G-Protein-Coupled/genetics , Receptors, G-Protein-Coupled/immunology , Receptors, Vascular Endothelial Growth Factor/physiology , Sphingosine/pharmacology , Umbilical Veins , Vascular Endothelial Growth Factor A/pharmacology
10.
Article in English | MEDLINE | ID: mdl-12570723

ABSTRACT

Lysophospholipids (LPLs), including glycerol- and sphingoid-based lipids, stimulate cell signaling and play important pathophysiological roles in humans and other animals. These LPLs include lysophosphatidic acid (LPA), lysophosphatidylinositol (LPI), lysophosphatidylcholine (LPC), lysophosphatidylserine (LPS), sphingosine-1-phosphate (S1P), and sphingosylphosphorylcholine (SPC). Analyses of LPLs in human body fluids from subjects with different pathophysiological conditions reveal not only the relevance of LPLs in human diseases, but also their potential application as biomarkers and/or therapeutic targets. In recent years, the identification and/or characterization of the plasma membrane receptors for LPLs and enzymes regulating the metabolism of LPLs have greatly facilitated our understanding of their role and signaling properties. In vitro and in vivo functional and signaling studies have revealed the broad and potent biological effects of LPLs and the mechanisms of LPL actions in different cellular systems. Development of specific antagonists for each of the LPL receptors will provide powerful tools for dissecting signaling pathways mediated by receptor subtypes. More importantly, these antagonists may serve as therapeutics for relevant diseases. Genetic depletion of LPL receptors in mice has provided and will continue to provide critical information on the pathophysiological roles of LPL receptors. It is important to further evaluate the significance of targeting these bioactive LPL receptors, their downstream signaling molecules, and/or metabolic enzymes in the treatment of cancers and other diseases.


Subject(s)
Lysophospholipids/physiology , Signal Transduction/physiology , Animals , Biomarkers/chemistry , Humans , Lysophospholipids/chemistry , Lysophospholipids/metabolism
11.
Mol Pharmacol ; 62(3): 660-71, 2002 Sep.
Article in English | MEDLINE | ID: mdl-12181443

ABSTRACT

The signaling pathways that lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P) use to activate Akt in ovarian cancer cells are investigated here. We show for the first time, with the use of both pharmacological and genetic inhibitors, that the kinase activity and S473 phosphorylation of Akt induced by LPA and S1P requires both mitogen-activated protein (MAP) kinase kinase (MEK) and p38 MAP kinase, and MEK is likely to be upstream of p38, in HEY ovarian cancer cells. The requirement for both MEK and p38 is cell type- and stimulus-specific. Among 12 cell lines that we tested, 11 respond to LPA and S1P and all of the responsive cell lines require p38 but only nine of them require MEK. Among different stimuli tested, platelet-derived growth factor stimulates S473 phosphorylation of Akt in a MEK- and p38-dependent manner. However, epidermal growth factor, thrombin, and endothelin-1-stimulated Akt S473 phosphorylation require p38 but not MEK. Insulin, on the other hand, stimulates Akt S473 phosphorylation independent of both MEK and p38 in HEY cells. T308 phosphorylation stimulated by LPA/S1P requires MEK but not p38 activation. MEK and p38 activation were sufficient for Akt S473 but not T308 phosphorylation in HEY cells. In contrast to S1P and PDGF, LPA requires Rho for Akt S473 phosphorylation, and Rho is upstream of phosphatidylinositol 3-kinase (PI3-K). LPA/S1P-induced Akt activation may be involved in cell survival, because LPA and S1P treatment in HEY ovarian cancer cells results in a decrease in paclitaxel-induced caspase-3 activity in a PI3-K/MEK/p38-dependent manner.


Subject(s)
Lysophospholipids/pharmacology , MAP Kinase Kinase Kinase 1 , Mitogen-Activated Protein Kinase Kinases/metabolism , Mitogen-Activated Protein Kinases/metabolism , Proto-Oncogene Proteins/metabolism , Sphingosine/analogs & derivatives , Sphingosine/pharmacology , Acute-Phase Proteins/metabolism , Caspase 3 , Caspases/metabolism , Cell Line , Dose-Response Relationship, Drug , Endothelin-1/metabolism , Enzyme Activation/drug effects , Epidermal Growth Factor/metabolism , GTP-Binding Protein alpha Subunits, Gi-Go/metabolism , HeLa Cells , Humans , Insulin/metabolism , Paclitaxel/pharmacology , Phosphatidylinositol 3-Kinases/metabolism , Phosphorylation/drug effects , Platelet-Derived Growth Factor/metabolism , Protein Serine-Threonine Kinases/metabolism , Proto-Oncogene Proteins c-akt , Signal Transduction/drug effects , Thrombin/metabolism , Time Factors , Tumor Cells, Cultured , p38 Mitogen-Activated Protein Kinases
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