RESUMO
This study aims to conduct an applied and innovative investigation to enhance the energy quality of wood residues through hydrothermal carbonization pretreatment. For this purpose, the treatment was carried out at three different temperatures: 180, 220, and 240 °C under autogenous pressure. The in natura material and the hydrochars were characterized, and thermogravimetric analyses were performed in an O2 atmosphere with heating rates of 2.5, 5, 10, and 20 °C min-1. The global activation energy for natura biomass combustion was determined to be 112.49 kJ.mol-1. On the other hand, the hydrothermal carbonization process promoted a reduction in this value for the 94.85 kJ.mol-1. The conversion function for the in natura biomass was characterized as 1 - α , order 1, while the hydrochars was 2(1-α) [-ln(1-α)] (1/2), Avrami-Erofe'ev I. Triple kinetic parameters were ascertained, and the conversion curves along with their respective derivatives were modeled, exhibiting minimal deviations between theoretical and experimental data. This facilitated the mathematical representation of the reaction processes and allowed for a comprehensive comparison of the results.
Assuntos
Termogravimetria , Cinética , Biomassa , Madeira/química , Carvão Vegetal/químicaRESUMO
The properties of oil-resin of copaiba, Copaifera multijuga are commonly mentioned in the literature, but there are few studies on extracts from its stem bark. We evaluated the antioxidant effects of ethanolic (EE) and ethyl acetate (EA) crude stem bark extracts from copaiba and compared them to rutin in a paracetamol (PCM)-induced oxidative stress model in mice. All test comparisons differed significantly. Hepatic catalase (CAT) and glutathione-S-transferase (GST) activity decreased in the PCM group, and there was an increase of protein carbonyls in the liver, kidney and brain. However, the protein carbonyls decreased in the liver for the PCM + EE group, in the kidneys for the PCM + EA and PCM + Rutin groups, and in the brain for all treatments. Hepatic GSH decreased in the PCM group and increased in the PCM + EE group. The extracts showed a positive effect on ascorbic acid (ASA), since they were able to restore the levels of parameters that had been changed by PCM. There was an increase of ALT and AST activity in the plasma within the PCM group. Even though ALT decreased in the PCM + Rutin, PCM + EE and PCM + EA groups, EE and EA did not have an effect on AST. The strongest antioxidant effect was observed for EE, due to the presence of the phenolic compounds epicatechin and epiafzelechin, as well as the highest concentration of total phenols and an excellent antioxidant potential observed in the DPPH· test.
As propriedades do óleo-resina da copaíba, Copaifera multijuga são comumente citadas na literatura, mas há poucos estudos sobre extratos da casca do caule. Avaliamos os efeitos antioxidantes de extratos brutos etanólico (EE) e acetato de etila (EA) da casca do caule da copaíba e os comparamos à rutina no modelo de estresse oxidativo induzido por paracetamol (PCM) em camundongos. Todas as comparações de teste diferiram significativamente. A atividade da catalase hepática (CAT) e da glutationa-S-transferase (GST) diminuiu no grupo PCM, e houve um aumento de proteínas carboniladas no fígado, rim e cérebro. No entanto, as proteínas carboniladas diminuíram no fígado para o grupo PCM + EE, nos rins para os grupos PCM + EA e PCM + rutina, e no cérebro para todos os tratamentos. A GSH hepática diminuiu no grupo PCM e aumentou no grupo PCM + EE. Os extratos mostraram um efeito positivo sobre o ácido ascórbico (ASA), uma vez que foram capazes de restaurar os níveis dos parâmetros que foram alterados pelo PCM. Houve um aumento da atividade de ALT e AST no plasma dentro do grupo PCM. Embora a ALT tenha diminuído nos grupos PCM + rutina, PCM + EE e PCM + EA, EE e EA não afetaram a AST. O efeito antioxidante mais forte foi observado para o EE, provavelmente devido à presença dos compostos fenólicos epicatequina e epiafzelequina, assim como à maior concentração de fenóis totais e um excelente potencial antioxidante observado no teste DPPH·(AU)
Assuntos
Animais , Masculino , Camundongos , Fabaceae , Extratos Vegetais/uso terapêutico , Substâncias Protetoras/farmacologia , Antioxidantes/farmacologia , Acetaminofen/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/terapia , Modelos AnimaisRESUMO
The properties of oil-resin of copaiba, Copaifera multijuga are commonly mentioned in the literature, but there are few studies on extracts from its stem bark. We evaluated the antioxidant effects of ethanolic (EE) and ethyl acetate (EA) crude stem bark extracts from copaiba and compared them to rutin in a paracetamol (PCM)-induced oxidative stress model in mice. All test comparisons differed significantly. Hepatic catalase (CAT) and glutathione-S-transferase (GST) activity decreased in the PCM group, and there was an increase of protein carbonyls in the liver, kidney and brain. However, the protein carbonyls decreased in the liver for the PCM + EE group, in the kidneys for the PCM + EA and PCM + Rutin groups, and in the brain for all treatments. Hepatic GSH decreased in the PCM group and increased in the PCM + EE group. The extracts showed a positive effect on ascorbic acid (ASA), since they were able to restore the levels of parameters that had been changed by PCM. There was an increase of ALT and AST activity in the plasma within the PCM group. Even though ALT decreased in the PCM + Rutin, PCM + EE and PCM + EA groups, EE and EA did not have an effect on AST. The strongest antioxidant effect was observed for EE, due to the presence of the phenolic compounds epicatechin and epiafzelechin, as well as the highest concentration of total phenols and an excellent antioxidant potential observed in the DPPH· test.
As propriedades do óleo-resina da copaíba, Copaifera multijuga são comumente citadas na literatura, mas há poucos estudos sobre extratos da casca do caule. Avaliamos os efeitos antioxidantes de extratos brutos etanólico (EE) e acetato de etila (EA) da casca do caule da copaíba e os comparamos à rutina no modelo de estresse oxidativo induzido por paracetamol (PCM) em camundongos. Todas as comparações de teste diferiram significativamente. A atividade da catalase hepática (CAT) e da glutationa-S-transferase (GST) diminuiu no grupo PCM, e houve um aumento de proteínas carboniladas no fígado, rim e cérebro. No entanto, as proteínas carboniladas diminuíram no fígado para o grupo PCM + EE, nos rins para os grupos PCM + EA e PCM + rutina, e no cérebro para todos os tratamentos. A GSH hepática diminuiu no grupo PCM e aumentou no grupo PCM + EE. Os extratos mostraram um efeito positivo sobre o ácido ascórbico (ASA), uma vez que foram capazes de restaurar os níveis dos parâmetros que foram alterados pelo PCM. Houve um aumento da atividade de ALT e AST no plasma dentro do grupo PCM. Embora a ALT tenha diminuído nos grupos PCM + rutina, PCM + EE e PCM + EA, EE e EA não afetaram a AST. O efeito antioxidante mais forte foi observado para o EE, provavelmente devido à presença dos compostos fenólicos epicatequina e epiafzelequina, assim como à maior concentração de fenóis totais e um excelente potencial antioxidante observado no teste DPPH·
Assuntos
Masculino , Animais , Camundongos , Antioxidantes/farmacologia , Extratos Vegetais/uso terapêutico , Fabaceae , Substâncias Protetoras/farmacologia , Acetaminofen/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/terapia , Modelos AnimaisRESUMO
BACKGROUND: Dipteryx alata Vogel popularly known as "baru" is an important commercial leguminous tree species from the Brazilian Cerrado, which possess medicinal properties, besides its fruits consumption by animals and humans. The use of the "naturally occurring plants" as herbal remedies and foods mainly from leaves, seeds, flowers and roots of plants or extracts require precautions before ensuring these are safe and efficacious. The objective of this study was to evaluate the safety of D. alata barks extract. METHODS: Vegetal drugs of D. alata barks were submitted to quality control assays and further to the safety assays under 1) in vitro parameter by Salmonella (Ames) mutagenicity, and 2) in vivo parameter on the pregnancy of rats. RESULTS: The extract was non-mutagenic to any of the assessed strains TA97a, TA98, TA100 and TA102 even after metabolic activation (+S9). All in vivo parameters (reproductive ability evaluation, physical development of rat offsprings, and neurobehavioral development assays) showed no changes related to control group. CONCLUSION: D. alata barks extract is neither mutagenic by the Ames test nor toxic in the pregnancy of rats, with no physical-neurobehavioral consequences on the rat offsprings development.
Assuntos
Dipteryx/efeitos adversos , Extratos Vegetais/efeitos adversos , Animais , Animais Recém-Nascidos , Feminino , Humanos , Masculino , Mutagênicos , Casca de Planta , Gravidez/efeitos dos fármacos , Ratos , Ratos Wistar , Reprodução/efeitos dos fármacos , Salmonella/efeitos dos fármacosRESUMO
Indigofera truxillensis and I. suffruticosa, are used as a source of indigo dye and to treat several diseases. The mutagenic activity of the methanolic extracts from aerial parts, glycerolipid, flavonoid and alkaloid fractions of the extract were evaluated by means of Salmonella/microsome assays using TA100, TA98, TA102 and TA97a strains. The methanolic extract of I. truxillensis showed mutagenic activity in the TA98 strain without S9 while glycerolipid fraction was devoid of activity. The flavonoid and alkaloid fractions of both plants showed mutagenicity. Chemical analysis of flavonoid fractions of I. truxillensis and I. suffruticosa resulted in the identification of kaempferol, quercetin and their derivatives. The alkaloid fraction of both the species contained indigo and indirubin and indigo was found mainly responsible for the mutagenic activity.
RESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Ethnopharmacological survey indicated leaves of Byrsonima fagifolia Nied. (Malpighiaceae) against gastrointestinal disorders. AIM OF THE STUDY: The methanolic extract from the leaves of Byrsonima fagifolia (denominated BF) was evaluated for toxic, mutagenic, gastroprotective, antidiarrheal, antibacterial and immunomodulatory activities. MATERIALS AND METHODS: The preventive and healing action of BF against gastric ulcer was evaluated in experimental models in rodents. We evaluated immunomodulatory (by murine peritoneal macrophages), antidiarrheal (by induced diarrhea with castor oil and intestinal motility) and antibacterial action of BF against standard strain of Escherichia coli, Staphylococcus aureus and Helicobacter pylori. The safety of use of BF was also evaluated by mutagenic (Ames assay) and by analyses of toxicity parameters. RESULTS: Phytochemical BF profile indicated the presence of phenolic compounds with antioxidant and radical-scavenging properties. BF significantly inhibited gastric lesions induced by ethanol and HCl/ethanol and endogenous mucosal sulphydryl groups (SHs) participated efficaciously in BF gastroprotection. BF blocked development of inflammation process and also has antidiarrheal actions. This extract accelerated the healing of the gastric ulcerated mucosa by stimulating proliferative factors and by increasing production of gastric mucus with no toxic action. The substances responsible for the protective action are concentrated in the ethyl acetate fraction that demonstrated no mutagenic action in vitro. CONCLUSIONS: Byrsonima fagifolia presents gastroprotective, healing and antidiarrheal activities supporting previous claims that its traditional use by Brazilians can treat these gastrointestinal ailments.
Assuntos
Antioxidantes/farmacologia , Malpighiaceae/química , Extratos Vegetais/farmacologia , Animais , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Antibacterianos/toxicidade , Antiulcerosos/isolamento & purificação , Antiulcerosos/farmacologia , Antiulcerosos/toxicidade , Antidiarreicos/isolamento & purificação , Antidiarreicos/farmacologia , Antidiarreicos/toxicidade , Antioxidantes/isolamento & purificação , Antioxidantes/toxicidade , Brasil , Modelos Animais de Doenças , Sequestradores de Radicais Livres/isolamento & purificação , Sequestradores de Radicais Livres/farmacologia , Sequestradores de Radicais Livres/toxicidade , Fatores Imunológicos/isolamento & purificação , Fatores Imunológicos/farmacologia , Fatores Imunológicos/toxicidade , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/metabolismo , Masculino , Medicina Tradicional , Camundongos , Testes de Mutagenicidade , Extratos Vegetais/toxicidade , Folhas de Planta , Ratos , Ratos Wistar , Úlcera Gástrica/tratamento farmacológico , Testes de ToxicidadeRESUMO
Byrsonima crassa is a plant pertaining to the Brazilian central savannah-like belt of vegetation and popularly used for the treatment of gastric dysfunctions and diarrhoea. The methanol extract contains catechin, tannins, terpenes and flavonoids; both mutagenic potential and antioxidant properties have been ascribed to flavonoids. The mutagenicity of some flavonoids is believed to be associated with the formation of reactive oxygen species and seems to depend on the number and position of hydroxyl groups. In the present study the mutagenic activity of the methanol, chloroform and 80% aqueous methanol extracts, as well as acetate and aqueous sub-fractions, of this medicinal plant were evaluated by Salmonella typhimurium assay, using strains TA100, TA98, TA102 and TA97a, and in mouse reticulocytes. The results showed mutagenic activity of the methanolic extract in the TA98 strain without S9, but no mutagenicity to mouse cells in any of the extracts. The acetate fraction showed strong signs of mutagenicity without S9, suggesting that in this enriched fraction were concentrated the compounds that induced mutagenic activity. The aqueous fraction showed no mutagenic activity. The TLC and HSCCC analyses of the acetate fraction with some standard compounds permitted the isolation of the quercetin-3-O-beta-D-galactopyranoside, quercetin-3-O-alpha-L-arabinopyranoside, amentoflavone, methyl gallate and (+)-catechin, of which only the amentoflavone exhibited positive mutagenicity to TA98 (+S9, -S9).
Assuntos
Biflavonoides/toxicidade , Malpighiaceae/química , Salmonella typhimurium/efeitos dos fármacos , Animais , Catequina/toxicidade , Feminino , Galactosídeos/toxicidade , Ácido Gálico/análogos & derivados , Ácido Gálico/toxicidade , Glicosídeos/toxicidade , Masculino , Metanol/química , Camundongos , Testes para Micronúcleos , Mutação , Extratos Vegetais/toxicidade , Plantas Medicinais/química , Quercetina/análogos & derivados , Quercetina/toxicidade , Salmonella typhimurium/genéticaRESUMO
Melampodium divaricatum is a member of the Asteraceae and in Brazil is known as false-calendula, its flowers being used in anti-inflammatory preparations, substituting the true calendula or marigold (Calendula officinalis L.). The flower extract was investigated for mutagenic and antimutagenic effect in the Salmonella/microsome assay. The tested extract was not mutagenic in the strains TA100, TA98, TA97a and TA102 and decreased the mutagenicity of aflatoxin B1, benzo(a)pyrene and daunomycin. Chlorophyll and triterpenes were detected in the extract, and they might have contributed to the observed effect. Our data suggest that these medicinal plants possess cancer chemopreventive properties.