RESUMO
This review work focuses on how the secondary chemistry could help in the survival of plants in high mountain habitats under extreme environmental conditions. The elevated levels of stress in high areas of the tropic and subtropic change dramatically not only by following the annual cycles of winter and summer but they also change in a single day. Some species, however, are able to successfully grow at heights more than 3000 m in the tropical mountains due, in part, to highly specialized physiological processes that affect their physical and chemical responses. In this study, it describes some strategies of how the secondary metabolites could help the plants to stand the high levels of stress in the high mountain ecosystems.
Este trabajo de revisioÌn se centra en coÌmo la quiÌmica secundaria podriÌa ayudar en la supervivencia de plantas en haÌbitats de alta montanÌa en condiciones ambientales extremas. Los altos niveles de estreÌs en las zonas altas del troÌpico y subtroÌpico cambian dramaÌticamente no solo al seguir los ciclos anuales de invierno y verano, sino que tambieÌn cambian en un solo diÌa. Sin embargo, algunas especies pueden crecer con eÌxito a alturas superiores a 3000 m en las montanÌas tropicales debido, en parte, a procesos fisioloÌgicos altamente especializados que afectan sus respuestas fiÌsicas y quiÌmicas. En esta revisioÌn, se describen algunas estrategias de coÌmo los metabolitos secundarios podriÌan ayudan a las plantas a soportar los altos niveles de estreÌs en los ecosistemas de alta montanÌa.
Assuntos
Plantas/química , Estresse Fisiológico , Óleos Voláteis/química , Altitude , Floroglucinol/análise , Floroglucinol/química , Terpenos/análise , Terpenos/química , Flavonoides/análise , Flavonoides/químicaRESUMO
Hypericum perforatum is a medicinal plant with anti-inflammatory and antioxidant properties, which is commercially available for therapeutic use in Brazil. Herein the effect of H. perforatum extract on paracetamol (acetaminophen)-induced hepatotoxicity, lethality, inflammation, and oxidative stress in male swiss mice were investigated. HPLC analysis demonstrated the presence of rutin, quercetin, hypericin, pseudohypericin, and hyperforin in H. perforatum extract. Paracetamol (0.15-3.0 g/kg, p.o.) induced dose-dependent mortality. The sub-maximal lethal dose of paracetamol (1.5 g/kg, p.o.) was chosen for the experiments in the study. H. perforatum (30-300 mg/kg, i.p.) dose-dependently reduced paracetamol-induced lethality. Paracetamol-induced increase in plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) concentrations, and hepatic myeloperoxidase activity, IL-1ß, TNF-α, and IFN-γ concentrations as well as decreased reduced glutathione (GSH) concentrations and capacity to reduce 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonate radical cation; ABTSË(+) ) were inhibited by H. perforatum (300 mg/kg, i.p.) treatment. Therefore, H. perforatum protects mice against paracetamol-induced lethality and liver damage. This effect seems to be related to the reduction of paracetamol-induced cytokine production, neutrophil recruitment, and oxidative stress.
Assuntos
Acetaminofen/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Hypericum/química , Inflamação/tratamento farmacológico , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/farmacologia , Alanina Transaminase/sangue , Animais , Antracenos , Anti-Inflamatórios/farmacologia , Antioxidantes/uso terapêutico , Aspartato Aminotransferases/sangue , Glutationa/metabolismo , Masculino , Camundongos , Perileno/análogos & derivados , Perileno/análise , Floroglucinol/análogos & derivados , Floroglucinol/análise , Plantas Medicinais/química , Quercetina/análise , Rutina/análise , Terpenos/análise , Fator de Necrose Tumoral alfa/metabolismoRESUMO
The aerial parts of Hypericum carinatum (Guttiferae) were extracted with supercritical carbon dioxide under constant temperature (40, 50 or 60°C) and gradual pressure increase (90, 120, 150 and 200 bar) aiming at the recovery of enriched fractions containing uliginosin B, cariphenone A and cariphenone B, compounds of pharmaceutical interest. The yields of these substances were determined by high-performance liquid chromatography and compared with those obtained with n-hexane maceration. The supercritical-fluid extraction showed higher selectivity than the conventional solvent extraction method. After defining 40°C and 90 bar as the best conditions to obtain the target compounds, a mathematical model was used for the extraction process and a good correlation was achieved with the experimental data.
Assuntos
Benzofenonas/análise , Benzofenonas/isolamento & purificação , Hypericum/química , Modelos Químicos , Floroglucinol/análise , Floroglucinol/isolamento & purificação , Extratos Vegetais/química , Benzofenonas/química , Cromatografia Líquida de Alta Pressão , Componentes Aéreos da Planta/químicaRESUMO
The aerial parts of Hypericum polyanthemum Klotzsch ex Reichardt (Guttiferae) were successively extracted with supercritical carbon dioxide (SC CO(2)) under pressures of 90, 120, 150 and 200 bar at different temperatures (40, 50 and 60 degrees C), and compared with the n-hexane extract obtained by ultrasound-assisted extraction. The samples obtained were examined regarding extraction yield and HPLC quantification of the main secondary metabolites, the benzopyrans HP1 (6-isobutyryl-5,7-dimethoxy-2,2-dimethylbenzopyran), HP2 (7-hydroxy-6-isobutyryl-5-methoxy-2,2-dimethyl-benzopyran) and HP3 (5-hydroxy-6-isobutyryl-7-methoxy-2,2-dimethyl) and the phloroglucinol derivative, uliginosin B. SFE presented higher selectivity than the n-hexane maceration, and the best condition to extract the target metabolites has been determined to be at 50 degrees C and for the high molecular-weight compound, uliginosin B, higher pressures were required.