RESUMO
This study aimed to isolate and identify flavonoids with hypoglycemic activity in Costus spiralis leaves. The methanolic extract (ME) was rich in flavonoids, while the powdered leaves (PL) contained considerable amounts of macro- and microelements. Oral acute treatment of streptozotocin (STZ)-induced diabetic rats for 18â h with the C. spiralis PL, ME and isolated guaijaverin (GUA) lowered glycemia, improved oral glucose tolerance and inhibited liver lipid peroxidation. GUA and ME lowered plasma levels of low-density and non-high density lipoproteins; GUA also lowered total cholesterol levels. PL, ME and GUA did not significantly alter the plasma levels of triglycerides, high-density lipoproteins, very low-density lipoproteins, creatinine and aspartate transaminase, and the total protein levels in the kidney and liver tissues. Therefore, C. spiralis leaves are promising raw materials and rich sources of bioactive flavonoids for the development of novel antidiabetic drugs due to their hypoglycemic, antidyslipidemic and antioxidant actions.
Assuntos
Glicemia/análise , Costus/química , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Flavonoides/uso terapêutico , Hipoglicemiantes/uso terapêutico , Lipídeos/sangue , Extratos Vegetais/uso terapêutico , Folhas de Planta/química , Animais , Antioxidantes/uso terapêutico , Aspartato Aminotransferases/sangue , Creatinina/sangue , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/fisiopatologia , Teste de Tolerância a Glucose , Hipolipemiantes/uso terapêutico , Testes de Função Renal , Testes de Função Hepática , Masculino , Metanol/química , Ratos Wistar , EstreptozocinaRESUMO
BACKGROUND: The genus Lippia comprises 150 species, most of which have interesting medicinal properties. Lippia sidoides (syn. L. origanoides) exhibits strong antimicrobial activity and is included in the phytotherapy program implemented by the Brazilian Ministry of Health. Since species of Lippia are morphologically very similar, conventional taxonomic methods are sometimes insufficient for the unambiguous identification of plant material that is required for the production of certified phytomedicines. Therefore, genetic and chemical analysis with chemotype identification will contribute to a better characterization of Lippia species. METHODS: Amplified Length Polymorphism and Internal Transcribed Spacer molecular markers were applied to determine the plants' genetic variability, and the chemical variability of Lippia spp. was determined by essential oil composition. RESULTS: Amplified Length Polymorphism markers were efficient in demonstrating the intra and inter-specific genetic variability of the genus and in separating the species L. alba, L. lupulina and L. origanoides into distinct groups. Phylogenetic analysis using Amplified Length Polymorphism and markers produced similar results and confirmed that L. alba and L. lupulina shared a common ancestor that differ from L. origanoides. Carvacrol, endo-fenchol and thymol were the most relevant chemical descriptors. CONCLUSION: Based on the phylogenetic analysis it is proposed that L. grata should be grouped within L. origanoides due to its significant genetic similarity. Although Amplified Length Polymorphism and Internal Transcribed Spacer markers enabled the differentiation of individuals, the genotype selection for the production of certified phytomedicines must also consider the chemotype classification that reflects their real medicinal properties.
Assuntos
Variação Genética/genética , Lippia/classificação , Lippia/genética , Filogenia , Fitoterapia , BrasilRESUMO
Costus spiralis, a plant used in traditional Brazilian medicine for the treatment of complications in diabetes, was investigated. Assay of hexane, ethyl acetate, methanol, and aqueous fractions obtained by partition of a crude methanol extract of dried leaves of C. spiralis revealed that AGI activity was confined to the ethyl acetate fraction. Purification of this fraction yielded schaftoside and isoschaftoside. The AGI activities of the two flavones were lower than, but comparable with, that of the anti-diabetic drug acarbose. In contrast, the IC50 value of the ethyl acetate fraction was 1.95-, 2.34-, and 2.22-fold higher than those of acarbose, schaftoside, and isoschaftoside, respectively. The results demonstrate for the first time that schaftoside and isoschaftoside are responsible, in part, for the AGI activity of C. spiralis. Our study suggests that further investigations into C. spiralis may lead to the discovery of additional compounds with antihyperglycemic activity.
Assuntos
Costus/química , Inibidores Enzimáticos/farmacologia , Flavonas/farmacologia , Hipoglicemiantes/farmacologia , Extratos Vegetais/farmacologia , alfa-Glucosidases/metabolismo , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Flavonas/química , Flavonas/isolamento & purificação , Hipoglicemiantes/química , Hipoglicemiantes/isolamento & purificação , Medicina Tradicional , Conformação Molecular , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química , Relação Estrutura-AtividadeRESUMO
Increased neutrophil activation significantly contributes to the tissue damage in inflammatory illnesses; this phenomenon has motivated the search for new compounds to modulate their effector functions. Coumarins are natural products that are widely consumed in the human diet. We have evaluated the antioxidant and immunomodulator potential of five 4-methylcoumarin derivatives. We found that the 4-methylcoumarin derivatives inhibited the generation of reactive oxygen species by human neutrophils triggered by serum-opsonized zymosan or phorbol-12-myristate-13-acetate; this inhibition occurred in a concentration-dependent manner, as revealed by lucigenin- and luminol-enhanced chemiluminescence assays. Cytotoxicity did not mediate this inhibitory effect. The 7,8-dihydroxy-4-methylcoumarin suppressed the neutrophil oxidative metabolism more effectively than the 6,7- and 5,7-dihydroxy-4-methylcoumarins, but the 5,7- and 7,8-diacetoxy-4-methylcoumarins were less effective than their hydroxylated counterparts. An analysis of the biochemical pathways suggested that the 6,7- and 7,8-dihydroxy-4-methylcoumarins inhibit the protein kinase C-mediated signaling pathway, but 5,7-dihydroxy-4-methylcoumarin, as well as 5,7- and 7,8-diacetoxy-4-methylcoumarins do not significantly interfere in this pathway of the activation of the human neutrophil oxidative metabolism. The 4-methylcoumarin derivatives bearing the catechol group suppressed the elastase and myeloperoxidase activity and reduced the 1,1-diphenyl-2-picrylhydrazyl free radical the most strongly. Interestingly, the 5,7-dihydroxy-4-methylcoumarin scavenged hypochlorous acid more effectively than the o-dihydroxy-substituted 4-methylcoumarin derivatives, and the diacetoxylated 4-methylcoumarin derivatives scavenged hypochlorous acid as effectively as the 7,8-dihydroxy-4-methylcoumarin. The significant influence of small structural modifications in the inhibitory potential of 4-methylcoumarin derivatives on the effector functions of neutrophil makes them interesting candidates to develop new drugs for the treatment of inflammatory diseases mediated by increased neutrophil activation.
Assuntos
Cumarínicos/farmacologia , Regulação para Baixo/efeitos dos fármacos , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Elastase Pancreática/antagonistas & inibidores , Adulto , Antioxidantes/química , Antioxidantes/farmacologia , Células Cultivadas , Cumarínicos/química , Humanos , Neutrófilos/enzimologia , Elastase Pancreática/metabolismo , Espécies Reativas de Oxigênio/metabolismoRESUMO
OBJECTIVES: The purpose of the present work was to characterize the pharmacological profile of different L. alba chemotypes and to correlate the obtained data to the presence of chemical constituents detected by phytochemical analysis. METHODS: Essential oils from each L. alba chemotype (LP1-LP7) were characterized by gas chromatography-mass spectrometry (GC-MS) and extracted non-volatile compounds were analysed by HPLC and GC-MS. The anticonvulsant actions of the extracted compounds were studied in pentylenetetrazole-induced clonic seizures in mice and their effect on motor coordination was studied using the rota-rod test in rats. The synaptosomes and synaptic membranes of the rats were examined for the influence of LP3 chemotype extract on GABA uptake and binding experiments. KEY FINDINGS: Behavioural parameters encompassed by the pentylenetetrazole test indicated that 80% ethanolic extracts of LP1, LP3 and LP6 L. alba chemotypes were more effective as anticonvulsant agents. Neurochemical assays using synaptosomes and synaptic membranes showed that L. alba LP3 chemotype 80% ethanolic extract inhibited GABA uptake and GABA binding in a dose-dependent manner. HPLC analysis showed that LP1, LP3 and LP6 80% ethanolic extracts presented a similar profile of constituents, differing from those seen in LP2, LP4, LP5 and LP7 80% ethanolic extracts, which exhibited no anticonvulsant effect. GC-MS analysis indicated the occurrence of phenylpropanoids in methanolic fractions obtained from LP1, LP3 and LP6 80% ethanolic extracts and also the accumulation of inositol and flavonoids in hydroalcoholic fractions. CONCLUSIONS: Our results suggest that the anticonvulsant properties shown by L. alba might be correlated to the presence of a complex of non-volatile substances (phenylpropanoids, flavonoids and/or inositols), and also to the volatile terpenoids (beta-myrcene, citral, limonene and carvone), which have been previously validated as anticonvulsants.
Assuntos
Anticonvulsivantes/uso terapêutico , Flavonoides/uso terapêutico , Lippia/química , Óleos Voláteis/uso terapêutico , Convulsões/tratamento farmacológico , Terpenos/uso terapêutico , Animais , Anticonvulsivantes/farmacologia , Cromatografia Líquida de Alta Pressão , Relação Dose-Resposta a Droga , Flavonoides/farmacologia , Cromatografia Gasosa-Espectrometria de Massas , Masculino , Camundongos , Destreza Motora/efeitos dos fármacos , Óleos Voláteis/isolamento & purificação , Óleos Voláteis/farmacologia , Pentilenotetrazol , Fitoterapia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Folhas de Planta/química , Ratos , Ratos Wistar , Teste de Desempenho do Rota-Rod , Convulsões/induzido quimicamente , Terpenos/farmacologia , Ácido gama-Aminobutírico/metabolismoRESUMO
Aiming at contributing with the search for neuroactive substances from natural sources, we report for the first time antinociceptive and anticonvulsant effects of some Lychnophora species. We verify the protective effects of polar extracts (600 mg/kg, intraperitoneally), and methanolic fractions of L. staavioides and L. rupestris (100 mg/kg, intraperitoneally) in pentylenetetrazole-induced seizures on mice. Previously, a screening was accomplished, evaluating the antinociceptive central activity (hot plate test), with different extracts of L. rupestris, L. staavioides and L. diamantinana. It was possible to select the possible extracts of Lychnophora with central nervous system activity. Some of the active extracts were submitted to fractionation and purification process and the methanolic fractions of L. rupestris (stem) and L. staavioides (stem), with anticonvulsant properties (100 mg/kg, intraperitoneally), yielded 4,5-di-O-[E]-caffeoylquinic acid. This substance was injected intraperitoneally in mice and showed anticonvulsant effect against pentylenetetrazole-induced seizures at doses of 25 and 50 mg/kg. It has often been shown that seizures induced by pentylenetetrazole are involved in inhibition and/or attenuation of GABAergic neurotransmission. However, other systems of the central nervous system such as adenosinergic and glutamatergic could be involved in the caffeoylquinic acid effects. Further studies should be conducted to verify that the target receptor could be participating in this anticonvulsant property. Although other investigations have reported a series of biological activities from Lychnophora species, this is the first report of central analgesic and anticonvulsant activity in species of this genus.
Assuntos
Analgésicos/farmacologia , Anticonvulsivantes/farmacologia , Asteraceae/química , Monossacarídeos/farmacologia , Ácido Quínico/análogos & derivados , Analgésicos/administração & dosagem , Analgésicos/isolamento & purificação , Animais , Anticonvulsivantes/administração & dosagem , Anticonvulsivantes/isolamento & purificação , Relação Dose-Resposta a Droga , Masculino , Camundongos , Monossacarídeos/administração & dosagem , Monossacarídeos/isolamento & purificação , Dor/tratamento farmacológico , Medição da Dor , Pentilenotetrazol , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Caules de Planta , Ácido Quínico/administração & dosagem , Ácido Quínico/isolamento & purificação , Ácido Quínico/farmacologia , Convulsões/tratamento farmacológicoRESUMO
GC analysis of the dichloromethane extracts obtained from cultivated specimens of Mikania glomerata Sprengel possibilited to verify that cuttings technique led to production of kaurenoic acid and coumarin while the same results have not been observed by propagation process using in vitro techniques.
A análise realizada por CG dos extratos diclorometânicos das folhas de Mikania glomerata Sprengel mostrou que a planta propagada por estaca produziu cumarina e ácido caurenóico, enquanto que o material micropropagado acumulou apenas cumarina.