RESUMO
Alzheimer's disease (AD) is a neurodegenerative disorder associated with cognitive impairment and cholinergic neuronal death, characteristic of the effect of time on biochemical neuronal function. The use of medicinal plants as an alternative form of prevention, or even as a possible treatment of AD, is therefore interesting areas of research, since the standard drugs have many side effects. Taraxerol (TRX) is a triterpene that has been isolated from several plant species, and its various pharmacological properties have already been identified, such the acetylcholinesterase (AChE) inhibition activity in vitro. There is a lack of information in literature that confirms the effect of TRX in an animal AD-like model. Seeking to fill this gap in the literature, in the present work we assessed the effect of TRX on AChE activity in the animals' encephalon and hippocampus. We also investigated the effect of TRX (1.77⯵M/side, 0.5⯵L) isolated from leaves of Eugenia umbelliflora Berg. on aversive memory impairments induced by scopolamine (2⯵g/side, 0.5⯵L) infused into rat hippocampus, and the effect of TRX (0.89 and 1.77⯵M/side, 0.5⯵L) on aversive memory impairments induced by streptozotocin (STZ) (2.5â¯mg/mL, 2.0⯵L) infused i.c.v. into mice, using the step-down inhibitory avoidance task. We found that TRX significantly inhibited AChE activity in the animal's hippocampus. Furthermore, TRX significantly improved scopolamine and STZ-induced memory impairment. Taking together, these results confirms its AChE activity inhibition in animals and indicate that TRX has anti-amnesic activity that may hold significant therapeutic value in alleviating certain memory impairments observed in AD.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Disfunção Cognitiva/induzido quimicamente , Disfunção Cognitiva/tratamento farmacológico , Memória/efeitos dos fármacos , Ácido Oleanólico/análogos & derivados , Escopolamina/efeitos adversos , Estreptozocina/efeitos adversos , Acetilcolinesterase/metabolismo , Doença de Alzheimer/fisiopatologia , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Ácido Oleanólico/farmacologia , Ácido Oleanólico/uso terapêutico , Ratos , Ratos WistarRESUMO
Pouteria ramiflora (Mart.) Radlk. (Sapotaceae) is a species used by inhabitants from the Cerrado for its edible fruits and medicinal value. Hexane crude extracts from leaves and fractions were evaluated for in vitro α-amylase inhibitory activity and antioxidant potential. The fraction with the highest α-amylase inhibitory activity was submitted to a phytochemical study. Three triterpenes were isolated, friedelin, epi-friedelanol, and taraxerol. This is the first report of these compounds isolated from P. ramiflora. Moreover, this is the first report of friedelin isolated from Pouteria sp. Epi-friedelanol was present in significant amounts, suggesting that this compound could be a candidate marker for this species.
Assuntos
Extratos Vegetais/química , Pouteria/química , Triterpenos/química , Animais , Antioxidantes/química , Antioxidantes/isolamento & purificação , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Estrutura Molecular , Ácido Oleanólico/análogos & derivados , Ácido Oleanólico/química , Ácido Oleanólico/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química , Suínos , Triterpenos/isolamento & purificação , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/químicaRESUMO
A phytochemical study of Pavonia multiflora A. St-Hil. (Malvaceae) led to the isolation through chromatographic techniques of 10 secondary metabolites: vanillic acid (1), ferulic acid (2), p-hydroxybenzoic acid (3), p-coumaric acid (4), loliolide (5), vomifoliol (6), 4,5-dihydroblumenol A (7), 3-oxo-α-ionol (9), blumenol C (10), and taraxerol 4-methoxybenzoate (8), the latter being a novel metabolite. Their structures were identified by (1) H- and (13) C-NMR, using one- and two-dimensional techniques, and X-ray crystallography. In this work, we report the effect of compounds 5 and 8 on several photosynthetic activities in an attempt to search for new compounds as potential herbicide agents that affect photosynthesis. Both compounds inhibited the electron flow from H2 O to methyl viologen; therefore, they act as Hill reaction inhibitors. Using polarographic techniques and studies of the fluorescence of chlorophyll a, the interaction sites of these compounds were located at photosystem II.
Assuntos
Malvaceae/química , Ácido Oleanólico/análogos & derivados , Fotossíntese/efeitos dos fármacos , Complexo de Proteínas do Centro de Reação Fotossintética/antagonistas & inibidores , Técnicas In Vitro , Ácido Oleanólico/química , Ácido Oleanólico/isolamento & purificação , Ácido Oleanólico/farmacologia , Complexo de Proteínas do Centro de Reação Fotossintética/metabolismoRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: The leaves of Pereskia aculeata Miller (Cactaceae), known as Barbados gooseberry, are used in Brazilian traditional medicine as emollients and to treat skin wounds and inflammation. This study investigated the topical anti-inflammatory activity of the hexane fraction (HF) obtained from the methanol extract of the leaves of this species in models of acute and chronic ear dermatitis in mice. MATERIAL AND METHODS: Mice ear edema was induced by topical application of croton oil, arachidonic acid, capsaicin, ethyl-phenylpropiolate and phenol; and by subcutaneous injection of histamine. Ear biopsies were obtained to determine the levels of IL-1ß, IL-6 and TNF-α cytokines by ELISA assay. Histopathological analysis was also performed to evaluate the HF activity in croton oil multiple application test. In addition, acute dermal irritation/corrosion test in rats was accomplished. HF chemical characterization was performed by GC-MS analysis. RESULTS: HF intensively reduced the inflammatory process induced by all irritant agents used, except for arachidonic acid. This activity is related, at least in part, to the reduction of IL-6 and TNF-α cytokines levels. Moreover, when the glucocorticoid receptor antagonist mifepristone was used, HF failed to respond to the croton oil application.The results strongly suggested a glucocorticoid-like effect, which was reinforced by the presence of considerable amounts of sterol compounds identified in HF. The acute dermal irritaton/corrosion test showed no signs of toxicity. CONCLUSIONS: This study showed that the acute and chronic anti-inflammatory activity of P. aculeata leaves is very promising, and corroborates to better understand their ethnopharmacological applications.
Assuntos
Anti-Inflamatórios/uso terapêutico , Cactaceae , Dermatite de Contato/tratamento farmacológico , Edema/tratamento farmacológico , Extratos Vegetais/uso terapêutico , Administração Tópica , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/toxicidade , Brasil , Doença Crônica , Dermatite de Contato/metabolismo , Edema/induzido quimicamente , Edema/metabolismo , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Masculino , Medicina Tradicional , Camundongos , Fitoterapia , Extratos Vegetais/farmacologia , Extratos Vegetais/toxicidade , Folhas de Planta , Ratos Wistar , Pele/efeitos dos fármacos , Pele/metabolismo , Testes de Irritação da Pele , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Channa punctatus was exposed to four different concentrations of Rutin, Taraxerol and Apigenin. Changes in some hematological parameters of Channa punctatus were assessed to determine the influence of these compounds on test fish. Fish were exposed to sublethal concentrations (80 percent of LC50 of 24h) of these compounds for one week. Control fish were also administered for one week. Thereafter, blood samples were obtained from the control and experimental fish. Blood was assayed for selected hematological parameters (hematocrit, hemoglobin, red blood cell count, white blood cell count total plasma protein and plasma glucose concentration). The derived hematological indices of mean corpuscular hemoglobin concentration (MCHC), mean corpuscular hemoglobin (MCH) and mean corpuscular volume (MCV) were calculated. Sublethal concentrations of these compounds caused a dose dependent decrease in hemoglobin values coupled with a decrease in hematocrit values and red blood cell counts are an obvious indication of anemia. The total white blood cell counts and the differential white blood cell counts were decreased except for the lymphocytes, where there was a slight increase. Plasma protein and glucose were also lower in exposed fish when compared with control. The hematological indices MCH, MCHC, MCV were also lowered. The result from this study reveals high mortality rate and deleterious consequences on the health of fish subjected to acute exposure of Rutin, Taraxerol and Apigenin and therefore, should not be used directly in aquaculture without having the proper knowledge.
Channa punctatus foi exposta a quatro diferentes concentrações de Rutina, Taraxerol e Apigenina. Alterações de alguns parâmetros hematológicos da Channa punctatus foram acessados para determinar a influência destes compostos no peixe teste. Peixes foram expostos a concentrações sub-letais (80 por cento 0f LC50 em 24h) destes compostos por uma semana. Os peixes controles foram também expostos durante uma semana. A seguir, amostras de sangue foram obtidas do peixe controle e do experimental. O sangue foi estudado por parâmetros hematológicos selecionados (hematócrito, hemoglobina, contagem de células vermelhas e brancas, proteína plasmática total e concentração de glucose plasmática). Os índices hematológicos derivados da média da concentração corpuscular da hemoglobina (MCHC), a média de hemoglobina corpuscular (MCH) e a média de volume corpuscular (MCV), foram calculados. Concentrações sub-letais destes compostos causaram decréscimo dose-dependente dos valores da hemoglobina unidos a decréscimo de valores de hematócrito e das contagens de células sanguíneas vermelhas o que caracteriza indicação óbvia de anemia. As contagens totais de células brancas e a contagem diferencial destas células estavam diminuídas exceto pelos linfócitos que mostraram leve aumento. A proteína plasmática e a glicose estavam também baixas nos peixes expostos quando comparados com o controle. Os índices hematológicos MCH, MCHC, MCV estavam também diminuídos. Os resultados deste estudo revelam alto percentual de mortalidade e conseqüências deletérias à saúde de peixes submetidos à exposição aguda de Rutina, Talaxerol e Apigenina e portanto eles não devem ser usados diretamente em aquacultura sem conhecimento apropriado.