RESUMO
A single bout of cardiovascular exercise (CE) performed after practice can facilitate the consolidation of motor memory. However, the effect is variable and may be modulated by different factors such as the motor task's or participant's characteristics and level of awareness during encoding (implicit vs explicit learning). This study examines the effects of acute CE on the consolidation of motor sequences learned explicitly and implicitly, exploring the potential moderating effect of fitness level and awareness. Fifty-six healthy adults (24.1 ± 3.3 years, 32 female) were recruited. After practicing with either the implicit or explicit variant of the Serial Reaction Time Task (SRTT), participants either performed a bout of 16 min of vigorous CE or rested for the same amount of time. Consolidation was quantified as the change in SRTT performance from the end of practice to a 24 h retention test. Fitness level (VÌO2peak) was determined through a graded exercise test. Awareness (implicit vs explicit learning) was operationalized using a free recall test conducted immediately after retention. Our primary analysis indicated that CE had no statistically significant effects on consolidation, regardless of the SRTT's variant utilized during practice. However, an exploratory analysis, classifying participants based on the level of awareness gained during motor practice, showed that CE negatively influenced consolidation in unfit participants who explicitly acquired the motor sequence. Our findings indicate that fitness level and awareness in sequence acquisition can modulate the interaction between CE and motor memory consolidation. These factors should be taken into account when assessing the effects of CE on motor memory.
Assuntos
Aprendizagem , Consolidação da Memória , Adulto , Humanos , Feminino , Exercício Físico , Tempo de Reação , Rememoração Mental , Destreza MotoraRESUMO
PURPOSE: Our objective was to analyse the accuracy of the sentinel node biopsy, taking into consideration the scintigraphy detection rate after the intratumoural administration of the radiopharmaceutical in patients with breast cancer who received neoadjuvant chemotherapy. MATERIALS AND METHODS: The study included 60 patients with a diagnosis of invasive breast carcinoma, stage T1-T3, who received treatment with neoadjuvant chemotherapy, and were subsequently subjected to breast surgery and sentinel node biopsy after intra-tumour administration of the radiopharmaceutical. RESULTS: Scintigraphic detection of some sentinel node was achieved in 55/60 patients (91.6%). When those cases that received a second injection of the radiopharmaceutical, performed peri-areolarly due to a lack of tracer migration, were excluded, the detection rate dropped to 70% (42/60). When the detection of sentinel node, or its absence, was compared in those 42 patients, no differences were found with age, laterality-location of the lesion, size pre- and post-neoadjuvant chemotherapy, histological grade, or immunohistochemical profile. There were significant differences when comparing the groups according to the degree of pathological tumour response, both with the Miller-Payne system (non-detection 44.4%-detection 16.7%, p = 0.003) as well as the residual cancer burden (72.2%-28.6%, p<0.01). CONCLUSIONS: The scintigraphic detection of the sentinel node after intratumoural administration of the radiopharmaceutical in patients with breast cancer who received neoadjuvant chemotherapy was below the optimal value, and sometimes a further, peri-areolar, injection was necessary, probably in relation to an alteration in the lymphatic drainage pathways. There was a significant inverse relationship between the detection of the sentinel node and level of pathological tumour response.
Assuntos
Neoplasias da Mama/diagnóstico , Neoplasias da Mama/tratamento farmacológico , Cintilografia , Compostos Radiofarmacêuticos/administração & dosagem , Biópsia de Linfonodo Sentinela , Agregado de Albumina Marcado com Tecnécio Tc 99m/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Quimioterapia Adjuvante , Feminino , Humanos , Injeções Intralesionais , Pessoa de Meia-Idade , Terapia Neoadjuvante , Estudos RetrospectivosRESUMO
The purpose of this research was to determine the potential use of water-soluble anionic and cationic carbosilane dendrimers (generations 1-3) as mucoadhesive polymers in eyedrop formulations. Cationic carbosilane dendrimers decorated with ammonium -NH3(+) groups were prepared by hydrosylilation of Boc-protected allylamine and followed by deprotection with HCl. Anionic carbosilane dendrimers with terminal carboxylate groups were also employed in this study. In vitro and in vivo tolerance studies were performed in human ocular epithelial cell lines and rabbit eyes respectively. The interaction of dendrimers with transmembrane ocular mucins was evaluated with a surface biosensor. As proof of concept, the hypotensive effect of a carbosilane dendrimer eyedrop formulation containing acetazolamide (ACZ), a poorly water-soluble drug with limited ocular penetration, was tested after instillation in normotensive rabbits. The methodology used to synthesize cationic dendrimers avoids the difficulty of obtaining neutral -NH2 dendrimers that require harsher reaction conditions and also present high aggregation tendency. Tolerance studies demonstrated that both prototypes of water-soluble anionic and cationic carbosilane dendrimers were well tolerated in a range of concentrations between 5 and 10 µM. Permanent interactions between cationic carbosilane dendrimers and ocular mucins were observed using biosensor assays, predominantly for the generation-three (G3) dendrimer. An eyedrop formulation containing G3 cationic carbosilane dendrimers (5 µM) and ACZ (0.07%) (289.4 mOsm; 5.6 pH; 41.7 mN/m) induced a rapid (onset time 1 h) and extended (up to 7 h) hypotensive effect, and led to a significant increment in the efficacy determined by AUC0(8h) and maximal intraocular pressure reduction. This work takes advantage of the high-affinity interaction between cationic carbosilane dendrimers and ocular transmembrane mucins, as well as the tensioactive behavior observed for these polymers. Our results indicate that low amounts of cationic carbosilane dendrimers are well tolerated and able to improve the hypotensive effect of an acetazolamide solution. Our results suggest that carbosilane dendrimers can be used in a safe range of concentrations to enhance the bioavailability of drugs topically administered in the eye.
Assuntos
Dendrímeros/química , Dendrímeros/farmacocinética , Silanos/química , Silanos/farmacocinética , Acetazolamida/química , Administração Oftálmica , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Dendrímeros/administração & dosagem , Dendrímeros/farmacologia , Humanos , Masculino , Coelhos , Silanos/administração & dosagem , Silanos/farmacologia , Ressonância de Plasmônio de SuperfícieRESUMO
HER2-positive breast cancer, accounting for 15 % of the total breast cancer patient population, carries in itself a bad prognosis, which has now become much better after the advent of anti-HER2 drugs. HER2-targeted therapy has significantly improved disease free- and overall survival in HER2-positive breast cancer, and has rendered better disease control both in the early and advanced disease setting. Trastuzumab treatment duration is often prolonged and poses significant time and resource challenges both on the treatment institutions and on the patient. The recent development of a subcutaneous formulation has meant a significant advance in this respect. We review the drug development of the compound and the current evidence on its use.
Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Antineoplásicos/administração & dosagem , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Descoberta de Drogas , Feminino , Humanos , Injeções Subcutâneas , Receptor ErbB-2/metabolismo , TrastuzumabRESUMO
Labdane diterpenoids have a broad spectrum of biological activities including antibacterial, antiviral and anti-inflammatory properties. However, little is known about their possible role in the apoptotic cell death machinery. Here, we report that hispanolone derivatives, a group of labdane diterpenoids, induce apoptosis in different tumor cell lines by activating caspase-8 with subsequent participation of mitochondrial signaling. Activation of caspase-8 by hispanolone derivatives was followed by a decrease in mitochondrial membrane potential, the release of apoptotic factors from mitochondria to the cytosol, and activation of caspases-9 and 3. Hispanolone derivatives also led to a time-dependent cleavage of Bid. Inhibition of caspase-8 abrogated these processes, suggesting that the death receptor pathway has a critical role in the apoptotic events induced by hispanolone derivatives. In addition, silencing death receptors with small interfering RNA s or pretreating cells with neutralizing antibodies to Fas ligand, tumor necrosis factor receptor 1 (TNF-R1), and TNF-α receptor 2 (TRAIL) inhibited diterpenoid-induced apoptosis, revealing it to be dependent on these death receptors. Interestingly, hispanolone derivatives had no effect on non-tumor cells. Consistently, in vivo bioluminescence imaging corroborates this antineoplasic effect, as hispanolone derivatives significantly decrease cancer growth in tumor xenograft assays. These data demostrate the antitumoral effects of hispanolone derivatives and provide relevant preclinical validation for the use of these compounds as potent therapeutic agents in cancer treatment.
Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Apoptose/efeitos dos fármacos , Diterpenos/farmacologia , Receptores de Morte Celular/metabolismo , Animais , Anticorpos Neutralizantes/imunologia , Apoptose/genética , Caspase 3/metabolismo , Caspase 8/metabolismo , Caspase 9/metabolismo , Linhagem Celular Tumoral , Ativação Enzimática , Proteína Ligante Fas/imunologia , Perfilação da Expressão Gênica , Humanos , Células Jurkat , Macrófagos/metabolismo , Potencial da Membrana Mitocondrial , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias , Interferência de RNA , RNA Interferente Pequeno , Receptores de Morte Celular/antagonistas & inibidores , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/genética , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Transdução de Sinais , Proteína de Domínio de Morte Associada a Receptor de TNF/genética , Proteína de Domínio de Morte Associada a Receptor de TNF/metabolismoRESUMO
Several labdane diterpenes exert anti-inflammatory and cytoprotective actions; therefore, we have investigated whether these molecules protect cardiomyocytes in an anoxia/reperfusion (A/R) model, establishing the molecular mechanisms involved in the process. The cardioprotective activity of three diterpenes (T1, T2 and T3) was studied in the H9c2 cell line and in isolated rat cardiomyocyte subjected to A/R injury. In both cases, treatment with diterpenes T1 and T2 protected from A/R-induced apoptosis, as deduced by a decrease in the percentage of apoptotic and caspase-3 active positive cells, a decrease in the Bcl-2/Bax ratio and an increase in the expression of antiapoptotic proteins. Analysis of cell survival signaling pathways showed that diterpenes T1 and T2 added after A/R increased phospho-AKT and phospho-ERK 1/2 levels. These cardioprotective effects were lost when AKT activity was pharmacologically inhibited. Moreover, the labdane-induced cardioprotection involves activation of AMPK, suggesting a role for energy homeostasis in their mechanism of action. Labdane diterpenes (T1 and T2) also exerted cardioprotective effects against A/R-induced injury in isolated cardiomyocytes and the mechanisms involved activation of specific survival signals (PI3K/AKT pathways, ERK1/2 and AMPK) and inhibition of apoptosis.
Assuntos
Diterpenos/farmacologia , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miócitos Cardíacos/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Hipóxia Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Masculino , Traumatismo por Reperfusão Miocárdica/metabolismo , Miócitos Cardíacos/metabolismo , Ratos , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos , Proteína X Associada a bcl-2/metabolismoRESUMO
The aim of this study was to determine the apoptotic pathways and mechanisms involved in electronegative LDL [LDL(-)]-induced apoptosis in RAW 264.7 macrophages and the role of Nrf2 in this process. Incubation of RAW 264.7 macrophages with LDL(-) for 24 h resulted in dose-dependent cell death. Activated caspases were shown to be involved in the apoptosis induced by LDL(-); incubation with the broad caspase inhibitor z-VAD prevented apoptosis in LDL(-)-treated cells. CD95 (Fas), CD95 ligand (FasL), CD36 and the tumor necrosis factor (TNF) ligand Tnfsf10 were overexpressed in LDL(-)-treated cells. However, Bax, Bcl-2 and Mcl-1 protein levels remained unchanged after LDL(-) treatment. LDL(-) promoted hyperpolarization of the mitochondrial membrane, elevated reactive oxygen species (ROS) production and translocation of Nrf2 to the nucleus, a process absent in cells treated with native LDL. Elicited peritoneal macrophages from Nrf2-deficient mice exhibited an elevated apoptotic response after challenge with LDL(-), together with an increase in the production of ROS in the absence of alterations in CD36 expression. These results provide evidence that CD36 expression induced by LDL(-) is Nrf2-dependent. Also, it was demonstrated that Nrf2 acts as a compensatory mechanism of LDL(-)-induced apoptosis in macrophages.
Assuntos
Apoptose , Lipoproteínas LDL/metabolismo , Macrófagos Peritoneais/patologia , Fator 2 Relacionado a NF-E2/fisiologia , Animais , Biomarcadores/metabolismo , Western Blotting , Antígenos CD36/genética , Antígenos CD36/metabolismo , Proteína Ligante Fas/genética , Proteína Ligante Fas/metabolismo , Feminino , Imunofluorescência , Perfilação da Expressão Gênica , Humanos , Macrófagos Peritoneais/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Análise de Sequência com Séries de Oligonucleotídeos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Natural products play a significant role in human health in relation to the prevention and treatment of inflammatory conditions. Among them, terpenoids (also referred to as terpenes), are the largest and most widespread class of secondary metabolites. They are found in higher plants, mosses, liverworts, algae and lichens, and also in insects, microbes or marine organisms. Some terpenoids have been used for therapeutic purposes for centuries as antibacterial, anti-inflammatory, antitumoral agents, and in recent decades research activity into the clinical potential of this class of compounds has increased continuously as a source of pharmacologically interesting agents. In the present review, molecular basis of the anti-inflammatory action of diterpenoids is presented with special emphasis on their ability to modulate critical cell signaling pathways involved in the inflammatory response of the body such as nuclear transcription factor-kappaB (NF-kappaB) activation. NF-kappaB plays an important role in the regulation of immune and inflammatory responses. Indeed, deregulated NF-kappaB expression is a characteristic phenomenon in several inflammatory diseases and NF-kappaB has become a major target in drug discovery. Hence, this article also introduces our recently elucidated findings about the potential of labdane diterpenoids as anti-inflammatory agents due to their ability to inhibit NF-kappaB. The future development of this class of compounds as anti-inflammatory drugs requires the introduction of novel molecular targets of therapeutic relevance in addition to biotechnological approaches for the production of these molecules.
Assuntos
Diterpenos/farmacologia , Medicina Tradicional , NF-kappa B/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Ativação Transcricional/efeitos dos fármacos , Animais , Anti-Inflamatórios/classificação , Anti-Inflamatórios/uso terapêutico , Doenças Autoimunes/tratamento farmacológico , Tratamento Farmacológico/tendências , Humanos , Hipersensibilidade/tratamento farmacológico , Terapia de Imunossupressão , Neoplasias/tratamento farmacológico , Transdução de Sinais/imunologia , Terpenos/classificação , Terpenos/uso terapêutico , Ativação Transcricional/imunologia , Fator de Necrose Tumoral alfa/antagonistas & inibidoresRESUMO
BACKGROUND AND PURPOSE: The kaurane diterpenes foliol and linearol are inhibitors of the activation of nuclear factor kappaB, a transcription factor involved in the inflammatory response. Effects of these diterpenes on apoptosis and phagocytosis have been analysed in cultured peritoneal macrophages and in the mouse macrophage cell line, RAW 264.7. EXPERIMENTAL APPROACH: Macrophages were maintained in culture and activated with pro-inflammatory stimuli in the absence or presence of diterpenes. Apoptosis and the phagocytosis in these cells under these conditions were determined. KEY RESULTS: Incubation of macrophages with a mixture of bacterial lipopolysaccharide (LPS)/interferon-gamma (IFN-gamma) induced apoptosis through a NO-dependent pathway, an effect significantly inhibited by foliol and linearol in the low muM range, without cytotoxic effects. Apoptosis in macrophages induced by NO donors was also inhibited. The diterpenes prevented apoptosis through a mechanism compatible with the inhibition of caspase-3 activation, release of cytochrome c to the cytosol and p53 overexpression, as well as an alteration in the levels of proteins of the Bcl-2 family, in particular, the levels of Bax. Cleavage of poly(ADP-ribose) polymerase, a well-established caspase substrate, was reduced by these diterpenes. Treatment of cells with foliol and linearol decreased phagocytosis of zymosan bioparticles by RAW 264.7 cells and to a greater extent by peritoneal macrophages. CONCLUSIONS AND IMPLICATIONS: Both diterpenes protected macrophages from apoptosis and inhibited phagocytosis, resulting in a paradoxical control of macrophage function, as viability was prolonged but inflammatory and phagocytic functions were impaired.
Assuntos
Apoptose/efeitos dos fármacos , Diterpenos do Tipo Caurano/farmacologia , Diterpenos/farmacologia , Macrófagos Peritoneais/efeitos dos fármacos , Óxido Nítrico/metabolismo , Animais , Caspase 3/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Citocromos c/metabolismo , Interferon gama/farmacologia , Lipopolissacarídeos/farmacologia , Macrófagos Peritoneais/citologia , Macrófagos Peritoneais/fisiologia , Masculino , Camundongos , Óxido Nítrico Sintase Tipo II/metabolismo , Fagocitose , Substâncias Protetoras/farmacologia , Proteínas Recombinantes , Proteína Supressora de Tumor p53/metabolismo , Proteína X Associada a bcl-2/metabolismoRESUMO
Genomic mutations occurring during reverse transcription of hepatitis B virus (HBV) could explain its genetic diversity and account for 8 genetically distinct genotypes that are geographically distributed quite differently. The main objectives of this study were to determine the prevalence of hepatitis B virus genotypes in patients with chronic hepatitis B and to see if there was a relationship between genotypes and risk factors for transmission based on HBeAg status. A total of 14 serum samples were analyzed using INNO-LIPA HBV genotyping assay. Genotype D was the most prevalent (64.3%) followed by genotype A (28.6%). There was one case of co-infection (D/E genotypes) that was confirmed by PCR sequencing. All patients except one were HBeAg-negative and anti-HBe-positive. The risk factors for HBV transmission were unknown in half of the cases; in the other half, sexual, transfusion, maternal or interfamilial transmission were observed. The results show that genotype D is the most prevalent genotype in our hospital, followed by genotype A. On the other hand, no relationship was found between HBeAg status and genotype.
Assuntos
Vírus da Hepatite B/genética , Hepatite B Crônica/virologia , Adolescente , Adulto , Feminino , Genótipo , Antígenos de Superfície da Hepatite B/imunologia , Vírus da Hepatite B/imunologia , Hepatite B Crônica/transmissão , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de RiscoRESUMO
Poly(L-valine-L-proline-L-alanine-L-valine-L-glycine) (VPAVG) is a new kind of proteinaceous polymer belonging to the Elastin-like family. These polymers are based on the recurrence of certain short peptide monomers that are considered as "building blocks" in the natural elastin. This smart thermoresponsive polymer has the ability to self-associate at physiological temperature to form aggregates with about 60% in water. This ability can be harnessed to prepare microparticles loaded with an active substance. The aim of this report is to evaluate, from the results of the experiment conducted, the biocompatibility of microparticles prepared from poly(VPAVG). We have studied the cytotoxic effects of microparticles, edema formation after subcutaneous injection (1 and 2.5 mg) in rats (n = 6), and also intraocular tolerance after the intravitreal injection of 2.5 mg of poly(VPAVG) microparticles into pigmented rabbits (n = 12). The polymer did not induce any cytotoxicity or nonspecific depression of cellular respiration on macrophages under the range of polymer concentrations investigated in this study (20, 30, 40, and 60 mg/mL). We observed no inflammatory response to microparticles after subcutaneous injection in the hind-paw of rats, with no significant differences between the control group (PBS) and experimental groups. Anterior and posterior segment signs were evaluated after intraocular injection of poly(VPAVG) microparticles. Only a few eyes (2/11) of the experimental group presented inflammation signs at day 28 postinjection. Nevertheless, 45% (5/11) of the eyes receiving microparticles showed tractional retinal detachment. The results observed in this work suggested certain fibroblastic activity induced by poly(VPAVG) microparticles after their intraocular injection.
Assuntos
Materiais Biocompatíveis , Elastina , Macrófagos Peritoneais/citologia , Peptídeos/química , Peptídeos/farmacologia , Alanina , Sequência de Aminoácidos , Animais , Sobrevivência Celular/efeitos dos fármacos , Conjuntivite/prevenção & controle , Edema/prevenção & controle , Glicina , Macrófagos Peritoneais/efeitos dos fármacos , Camundongos , Microscopia Eletrônica de Varredura , Peso Molecular , Peptídeos/administração & dosagem , Prolina , Valina , Corpo Vítreo/efeitos dos fármacos , Difração de Raios XRESUMO
Natural products research has lately undergone exponential growth owing to advances in isolation techniques and in synthetic methods design, as well as for the identification of a wide range of biological properties exhibited by these compounds. In the present review, general remarks on the chemical features, biosynthetic pathways, isolation and structure elucidation of terpenoids are briefly discussed. In addition to this, recent work done on anti-inflammatory terpenoids (diterpenoids, triterpenoids and sesquiterpene lactones) with special emphasis on the last new molecular targets evaluated is presented.
Assuntos
Anti-Inflamatórios não Esteroides , Inflamação/tratamento farmacológico , Terpenos , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/isolamento & purificação , Anti-Inflamatórios não Esteroides/uso terapêutico , Humanos , Estrutura Molecular , Terpenos/química , Terpenos/isolamento & purificação , Terpenos/uso terapêuticoRESUMO
The most important aim of this study was to describe the hypothetical relationship between the PePHD region variability (related to the synthesis of a cellular enzyme pseudosubstrate) of the hepatitis C virus and the response of patients to interferon therapy. This interaction could be a determining factor in the antiviral effect of interferon. All samples (from 24 patients with chronic hepatitis C infection) were analyzed using a previously described method based on RT-PCR and nested PCR mediated by single-strand conformation polymorphism assay (SSCP). The patients were divided into three groups with respect to the response to therapy: 8 patients with sustained response, 8 patients with transient response and 8 nonresponders. In all samples a low genetic heterogeneity pattern was detected, which was independent of other factors involved in the lack of response to treatment, such as age, sex or viral genotype. This genetic homogeneity is an indirect indication of the importance of the region on viral persistence. However, more studies are needed to evaluate the real role of this sequence on the interaction between cells and the virus.
Assuntos
Antivirais/uso terapêutico , Hepacivirus/genética , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/virologia , Interferon-alfa/uso terapêutico , Adulto , Antivirais/farmacologia , Feminino , Variação Genética , Hepacivirus/efeitos dos fármacos , Humanos , Interferon-alfa/farmacologia , MasculinoRESUMO
The aim of this study was to evaluate the relationship between the quasispecies in the HVR1 region of the hepatitis C virus and treatment evolution in order to determine whether genetic complexity is predictive of response to interferon therapy. The samples were analyzed by nested RT-PCR-mediated single-strand conformation polymorphism assay (SSCP). Twelve patients with chronic hepatitis C were studied and divided into three groups: three patients with sustained response, three patients with transient response and six nonresponders. The patients in the sustained response group showed a low genetic complexity pattern. By contrast, in three nonresponders and in one patient with transient response, the SSCP assay revealed a high complexity pattern. With regard to the remaining patients with transient response, new SSCP bands appeared, thereby modifying their genetic complexity pattern. Therefore, nonresponse to interferon treatment could be related to the presence of a high genetic complexity pattern, while the detection of a low genetic complexity pattern is necessary for a positive response to interferon therapy. Due to the limited number of patients involved in this study, it was not possible to predict the response to interferon based on the genetic complexity pattern. Larger studies are therefore required.
Assuntos
Antivirais/uso terapêutico , Hepacivirus/classificação , Hepacivirus/genética , Hepatite C/tratamento farmacológico , Interferon-alfa/uso terapêutico , HumanosRESUMO
The pentacyclic triterpene lupeol has been studied for its inhibitory effects on murine models of inflammation and peritoneal macrophage functions in-vitro. Lupeol (0.5 and 1 mg/ear) administered topically suppressed the mouse ear oedema induced by 12-0-tetradecanoyl-phorbol acetate (TPA), being less effective on ear oedema induced by arachidonic acid. Quantitation of the neutrophil specific marker myeloperoxidase demonstrated that its topical activity was associated with reduction in cell infiltration into inflamed tissues. When tested in-vitro, lupeol significantly reduced prostaglandin E2 (PGE2) production from A23187-stimulated macrophages, but failed to affect leukotriene C4 release. It was a weak inhibitor of nitrite release, but dose-dependently suppressed PGE2. Cytokine production (tumour necrosis factor-alpha and interleukin-1beta) was inhibited in the range 10-100 microM in lipopolysaccharide-treated macrophages. This study demonstrated that lupeol possessed anti-inflammatory activity which was likely to depend on its ability to prevent the production of some pro-inflammatory mediators.
Assuntos
Anti-Inflamatórios/farmacologia , Inflamação/tratamento farmacológico , Fitoterapia , Pimenta , Triterpenos/farmacologia , Animais , Ácido Araquidônico/farmacologia , Citocinas/metabolismo , Dinoprostona/metabolismo , Relação Dose-Resposta a Droga , Edema/induzido quimicamente , Edema/prevenção & controle , Interleucina-1/metabolismo , Leucotrieno C4/metabolismo , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/metabolismo , Masculino , Camundongos , Modelos Animais , Nitritos/metabolismo , Triterpenos Pentacíclicos , Extratos Vegetais/farmacologia , Acetato de Tetradecanoilforbol/farmacologia , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Phytochemical and biological studies aimed at the discovery and development of novel antiinflammatory agents from natural sources have been conducted in our laboratory for a number of years. In this communication, three naturally occurring furocoumarins (imperatorin, isoimperatorin and prantschimgin) were evaluated as potential inhibitors of some macrophage functions involved in the inflammatory process. These furocoumarins have been tested in two experimental systems: ionophore-stimulated mouse peritoneal macrophages serve as a source of cyclooxygenase-1 and 5-lipoxygenase, and mouse peritoneal macrophages stimulated with E. coli lipopolysaccharide are the means of testing for anti-cyclooxygenase-2 and nitric-oxidesynthase activity. All above-mentioned furocoumarins showed significant effect on 5-lipoxygenase (leukotriene C4) with IC50 values of < 15 microM. Imperatorin and isoimperatorin exhibited strong-to-medium inhibition on cyclooxygenase-1- and cyclooxygenase-2-catalysed prostaglandin E2 release, with inhibition percentages similar to those of the reference drugs, indometacin and nimesulide, respectively. Of the three furocoumarins, only imperatorin caused a significant reduction of nitric oxide generation. Imperatorin and isoimperatorin can be classified as dual inhibitors, since it was evident that both cyclooxygenase and lipoxygenase pathways of arachidonate metabolism were inhibited by these compounds. However, selective inhibition of the 5-lipoxygenase pathway is suggested to be the primary target of action of prantschimgin.
Assuntos
Fármacos Dermatológicos/farmacologia , Furocumarinas/farmacologia , Macrófagos Peritoneais/efeitos dos fármacos , Animais , Sobrevivência Celular/efeitos dos fármacos , Fármacos Dermatológicos/isolamento & purificação , Dinoprostona/metabolismo , Furocumarinas/isolamento & purificação , Leucotrieno C4/metabolismo , Macrófagos Peritoneais/metabolismo , Masculino , Camundongos , Óxido Nítrico/biossínteseRESUMO
The purpose of this study was to investigate possible protective effects of ursolic acid against CCl4-induced alterations of antioxidant defence enzymes in vivo as well as its effects against CCl4-intoxication in vitro. Pre-treatment of rats with ursolic acid significantly reduced serum levels of glutamate-oxalate-transaminase and glutamate-pyruvate-transaminase previously increased by administration of CCl4. Treatment with ursolic acid also significantly reversed the decreased superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase activities and glutathione levels in the liver, as the concentration of reduced glutathione was increased and the content of oxidized glutathione decreased in ursolic acid treated groups. Levels of lipid peroxidation were higher in the CCl4 group but the increase was also reduced after drug treatment (p < 0.01 for 1, 2.5 and 5 mmol/kg). In vitro results indicated that addition to the culture medium of ursolic acid (p < 0.01 for 500 microM) resulted in a reduction of glutamate-oxalate-transaminase, lactate dehydrogenase activities and in a good survival rate for the CCl4-intoxicated hepatocytes. Ursolic acid also ameliorated lipid peroxidation in primary cultured rat hepatocytes exposed to CCl4, as demonstrated by a reduction in malondialdehyde production. Moreover, ursolic acid (50-500 microM) showed radical scavenging properties in terms of hydroxyl formation. The results obtained suggest that ursolic acid treatment can normalize the disturbed antioxidant status of rats intoxicated with CCl4 by maintaining the levels of glutathione and by inhibiting the production of malondialdehyde due to its radical scavenging properties.
Assuntos
Antioxidantes/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Hepatócitos/efeitos dos fármacos , Triterpenos/farmacologia , Alanina Transaminase/metabolismo , Animais , Aspartato Aminotransferases/metabolismo , Tetracloreto de Carbono/toxicidade , Catalase/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Doença Hepática Induzida por Substâncias e Drogas/sangue , Relação Dose-Resposta a Droga , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Hepatócitos/citologia , Hepatócitos/enzimologia , Radical Hidroxila/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/enzimologia , Distribuição Aleatória , Ratos , Superóxido Dismutase/metabolismo , Ácido UrsólicoRESUMO
The anti-inflammatory activity of abietic acid, a diterpene isolated from Pimenta racemosa var. grissea (Myrtaceae), was evaluated in-vivo and in-vitro. This compound significantly inhibited rat paw oedema induced by carrageenan in a time- and dose-dependent manner, and mouse ear oedema induced by 12-O-tetradecanoylphorbol acetate, after oral or topical administration. The inhibition of myeloperoxidase enzyme showed that its topical activity was influenced by neutrophil infiltration into the inflamed tissues (ears). In addition, the effect of abietic acid on some macrophage functions was analysed in-vitro. Non-toxic concentrations of abietic acid inhibited prostaglandin E2 (PGE2) production in lipopolysaccharide-treated macrophages, whereas nitrite, tumour necrosis factor alpha and interleukin-1beta production were only weakly affected by this diterpene. PGE2 production from A23187-stimulated macrophages was only inhibited at high doses (100 microM) and it failed to modify leukotriene C4 production. These results indicate that abietic acid exerts in-vivo anti-inflammatory activity after oral or topical administration and has partial ability to prevent the production of some inflammatory mediators.
Assuntos
Abietanos , Diterpenos/farmacologia , Fibrinolíticos/farmacologia , Inflamação , Infiltração de Neutrófilos/efeitos dos fármacos , Fenantrenos/farmacologia , Extratos Vegetais/farmacologia , Administração Oral , Administração Tópica , Animais , Citocinas/efeitos dos fármacos , Edema/induzido quimicamente , Edema/tratamento farmacológico , Macrófagos/efeitos dos fármacos , Macrófagos/fisiologia , Masculino , Camundongos , Ratos , Ratos WistarRESUMO
A sterol fraction composed of campesterol (7.6%), stigmasterol (28.4%) and beta-sitosterol (61.1%) was obtained by activity-guided fractionation of the acetone extract of Sideritis foetens Clem. This sterol fraction showed anti-inflammatory activity in in vivo murine models of inflammation. It decreased carrageenan paw oedema in mice after oral administration of 30 and 60 mg/kg and inhibited mouse ear oedema induced by 12-O-tetradecanoylphorbol acetate (TPA) after topical application. Quantitation of the neutrophil specific marker myeloperoxidase (MPO) demonstrated that its topical anti-inflammatory activity was associated with reduction in neutrophil infiltration into inflamed tissues. Non-cytotoxic concentrations of the sterol fraction inhibited leukocyte granular enzyme release (beta-glucuronidase) and superoxide generation. However, it did not shown any significant inhibitory effect on histamine release from mast cells. In vitro modulatory activity towards the classical pathway of the complement system shown by this fraction would correlate with the anti-inflammatory profile shown in vivo.