RESUMO
Luteolin and its derived glycosides such as a cynaroside, cesioside, isoorientin and stereolensin have been isolated and identified from different kinds of plant species. A (13)C NMR spectroscopic analysis of stereolensin has been done for the first time. These structurally related flavonoids were examined in vitro for their abilities to inhibit enzymes for the synthesis of thromboxane B(2) and leukotriene B(4) as well as hydrogen peroxide scavenging activity. Luteolin exhibited a high inhibitory activity against both thromboxane and leukotriene synthesis. In particular, a remarkable inhibitory effect was observed against leukotriene enzyme activity. The glycosides, cynaroside and cesioside, possessed a moderate inhibition activity against both enzyme synthesis pathways, while isoorientin and stereolensin exhibited selectively good activity against thromboxane synthesis. All the flavonoids showed excellent scavenging activity for the hydrogen peroxide at all the concentrations tested. The results demonstrated that the reactivities of luteolin and its related glycosides against arachidonic acid synthesis and hydrogen peroxide scavenging are dependent on their molecular structures. The presence of ortho-dihydroxy groups at the B ring and OH substitution pattern at C-5 position of the A ring could significantly contribute to the antiinflammatory and antioxidant activities of flavonoids.
Assuntos
Anti-Inflamatórios/farmacologia , Sequestradores de Radicais Livres/farmacologia , Luteolina/farmacologia , Fitoterapia , Plantas Medicinais , Animais , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/química , Anti-Inflamatórios/uso terapêutico , Sequestradores de Radicais Livres/administração & dosagem , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/uso terapêutico , Gentiana , Glicosídeos/administração & dosagem , Glicosídeos/química , Glicosídeos/farmacologia , Glicosídeos/uso terapêutico , Peróxido de Hidrogênio/química , Leucócitos/efeitos dos fármacos , Luteolina/administração & dosagem , Luteolina/química , Luteolina/uso terapêutico , Masculino , Peritônio , Componentes Aéreos da Planta , Pyrola , Ratos , Ratos Wistar , Relação Estrutura-AtividadeRESUMO
The polar fractions (methanol and aqueous extract) and essential oil of Adesmia boronioides aerial parts were tested in vitro at concentrations of 15 and 50 microg/mL, for their effects on the COX and 5-LOX pathways of eicosanoid generation (TXB2, PGE2 and LTB4) in stimulated rat peritoneal leukocytes. Potent inhibition of LTB4 generation was displayed by the methanol extract and the essential oil, whereas the aqueous extract was essentially inactive. The methanol extract also caused potent inhibition of TXB2 generation but the essential oil and the aqueous extract were much less active. The effects on PGE2 production were much less striking, implying that the main effect is on thromboxane synthetase rather than on COX. Although the essential oil caused LDH release in leukocytes treated concurrently with ionophore, suggesting substantial toxicity to the cells, this extract did not affect cell viability according to the MTT test when incubated with the cells in the absence of ionophore. The two other extracts did not affect cell viability at the concentrations tested. It is concluded that Adesmia boronioides contains substance(s) that preferentially inhibit the 5-lipoxygenase activity of arachidonic acid metabolism and suggest that this may contribute to the antiinflammatory actions of extracts of this plant.
Assuntos
Anti-Inflamatórios/farmacologia , Eicosanoides/biossíntese , Fabaceae , Leucócitos/efeitos dos fármacos , Fitoterapia , Extratos Vegetais/farmacologia , Óleos de Plantas/farmacologia , Animais , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/uso terapêutico , Leucócitos/metabolismo , Masculino , Extratos Vegetais/administração & dosagem , Extratos Vegetais/uso terapêutico , Óleos de Plantas/administração & dosagem , Óleos de Plantas/uso terapêutico , Ratos , Ratos WistarRESUMO
The leaves of Acanthus ebracteatus, stembark of Oroxylum indicum and the stems of Cryptolepis buchanani and Derris scandens are used as traditional remedies in Thailand for arthritis. Aqueous and alcoholic extracts were tested using three different in vitro systems for effects relevant to anti-inflammatory activity. The aqueous extracts of O. indicum and D. scandens significantly reduced myeloperoxide release. Eicosanoid production was reduced only by the aqueous extracts of A. ebracteatus and D. scandens. D. scandens extract showed potent inhibitory activity against generation of leukotriene B(4) and also displayed antioxidant activity. In the rat hind paw edema test, D. scandens extract showed significant activity when given intraperitoneally but did not produce a significant reduction when given orally. The results therefore supported to some extent the traditional use of D. scandens for arthritic conditions and provided slight indication of activity which could explain the use of O. indicum and A. ebracteatus. No relevant activity was demonstrated in any of the tests for C. buchanani extracts.
Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Artrite/tratamento farmacológico , Fitoterapia , Plantas Medicinais/química , Acanthaceae , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Antioxidantes/farmacologia , Carragenina , Cryptolepis , Coleta de Dados , Derris , Edema/induzido quimicamente , Edema/prevenção & controle , Eicosanoides/antagonistas & inibidores , Técnicas In Vitro , Leucócitos/efeitos dos fármacos , Leucócitos/enzimologia , Medicina Tradicional do Leste Asiático , Peroxidase/metabolismo , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Ratos , TailândiaRESUMO
Salvia lavandulaefolia Vahl. (Spanish sage) essential oil and individual monoterpenoid constituents have been shown to inhibit the enzyme acetylcholinesterase in-vitro and in-vivo. This activity is relevant to the treatment of Alzheimer's disease, since anticholinesterase drugs are currently the only drugs available to treat Alzheimer's disease. Other activities relevant to Alzheimer's disease include antioxidant, anti-inflammatory and estrogenic effects. Results of in-vitro tests for these activities are reported here for S. lavandulaefolia extracts, the essential oil and its major constituents. Antioxidant activity (inhibition of bovine brain liposome peroxidation) was found in the EtOH extract of the dried herb (5 mg mL(-1)) and the monoterpenoids (0.1 M) alpha- and beta-pinene and 1,8-cineole. Thujone and geraniol had lower antioxidant effects, while camphor had no antioxidant effects. Possible anti-inflammatory activity (eicosanoid inhibition in rat leucocytes) was found in the EtOH extract (50 microg mL(-1)) and was shown by the monoterpenoids alpha-pinene and geraniol (0.2 mM), but not 1,8-cineole, thujone or camphor. Possible estrogenic activity (via induction of beta-galactosidase activity in yeast cells) was found in the essential oil (0.01 mg mL(-1)) and the monoterpenoid geraniol (0.1-2 mM). 1,8-Cineole, alpha- and beta-pinene and thujone did not exhibit estrogenic activity in this analysis. These results demonstrate that S. lavandulaefolia, its essential oil and some chemical constituents have properties relevant to the treatment of Alzheimer's disease and provide further data supporting the value of carrying out clinical studies in patients with Alzheimer's disease using this plant species.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Anti-Inflamatórios não Esteroides/farmacologia , Antioxidantes/farmacologia , Estrogênios não Esteroides/farmacologia , Isoflavonas , Óleos Voláteis/farmacologia , Fitoterapia , Salvia/química , Animais , Bovinos , Células Cultivadas , Eicosanoides/antagonistas & inibidores , Eicosanoides/biossíntese , Humanos , Técnicas In Vitro , Peroxidação de Lipídeos/efeitos dos fármacos , Fitoestrógenos , Preparações de Plantas , Receptores de Estrogênio/efeitos dos fármacos , Receptores de Estrogênio/metabolismo , Saccharomyces cerevisiae/efeitos dos fármacosRESUMO
The major phenolics from the polar fraction of virgin olive oil (caffeic acid, oleuropein, tyrosol and hydroxytyrosol) have well-established antioxidant activities but their effects on reactive nitrogen species and nitrergic neurotransmission have not been fully investigated. The three catechol compounds were active as scavengers of nitric oxide generated spontaneously from the decomposition of sodium nitroprusside (approximately 50% inhibition achieved at 75 microM), and had similar ability to scavenge chemically generated peroxynitrite, as determined by an alpha1-antiproteinase inactivation assay (67.2%-92.4% reduction when added at 1 mM). Tyrosol was less active in these tests, but does not possess the catechol functionality. Despite their ability to interact with chemically prepared nitric oxide, neither oleuropein nor hydroxytyrosol at 5 microM altered NO*-mediated relaxations of the nerve-stimulated rat anococcygeus preparation, but this may be because the nitrergic transmitter is protected from the effects of externally applied scavengers. In conclusion, the phenolics found in virgin olive oil possess ability to scavenge reactive oxygen and nitrogen species that are implicated in human pathologies, but their impact may be restricted to those species present in the extracellular environment.
Assuntos
Antioxidantes/farmacologia , Sequestradores de Radicais Livres/farmacologia , Condução Nervosa/efeitos dos fármacos , Óxido Nítrico/metabolismo , Fenóis/farmacologia , Álcool Feniletílico/análogos & derivados , Óleos de Plantas/farmacologia , Animais , Antioxidantes/química , Ácidos Cafeicos/isolamento & purificação , Ácidos Cafeicos/farmacologia , Relação Dose-Resposta a Droga , Sequestradores de Radicais Livres/química , Glucosídeos Iridoides , Iridoides , Masculino , Relaxamento Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Músculo Liso/inervação , Nitratos/síntese química , Nitratos/metabolismo , Nitroprussiato/metabolismo , Azeite de Oliva , Fenóis/química , Álcool Feniletílico/isolamento & purificação , Álcool Feniletílico/farmacologia , Óleos de Plantas/química , Piranos/isolamento & purificação , Piranos/farmacologia , Ratos , Ratos WistarRESUMO
We have used tachykinin neurokinin-1 receptor (NK1 receptor) knockout mice to learn of the link between NK1 receptors and neutrophil accumulation in normal naive skin, as compared with inflamed skin. Intradermal substance P (300 pmol) induced edema formation in wild-type mice, but not in NK1 knockout mice, as expected. However, in contrast to IL-1beta (0.3 pmol), substance P did not induce neutrophil accumulation in wild-type mice. IL-1beta-induced neutrophil accumulation was similar in wild-type and knockout mice, but a significant (p < 0.05) contributory effect of added NK1 agonists, which by themselves have no effect on neutrophil accumulation in normal skin, was observed. The results support the concept that NK1 agonists such as substance P cannot act on their own to mediate neutrophil accumulation in naive skin and provide direct evidence that in inflamed skin, under certain circumstances, the NK1 receptor can play a pivotal role in modulating neutrophil accumulation during the ongoing inflammatory process. We investigated responses to two inflammatory stimuli (carrageenin and zymosan). Neutrophil accumulation was significantly attenuated (p < 0.001) in carrageenin- but not zymosan-induced inflammation in NK1 knockout mice. The carrageenin (500 microg)-induced response was inhibited (p < 0.05) by a NK1 receptor antagonist, SR140333 (480 nmol/kg i.v. at -5 min), in the wild-type group. The bradykinin B1 and B2 receptor antagonists (desArg9[Leu8]bradykinin and HOE 140) each reduced neutrophil accumulation to carrageenin in wild-type animals (p < 0.05), but did not cause further reduction of the suppressed response of knockout mice. The results provide evidence that kinin receptors participate in NK1 receptor-dependent neutrophil accumulation in inflamed mouse skin.
Assuntos
Movimento Celular/imunologia , Neutrófilos/imunologia , Neutrófilos/patologia , Receptores da Neurocinina-1/agonistas , Receptores da Neurocinina-1/genética , Pele/imunologia , Pele/patologia , Animais , Bradicinina/administração & dosagem , Bradicinina/análogos & derivados , Antagonistas dos Receptores da Bradicinina , Carragenina/administração & dosagem , Movimento Celular/genética , Combinação de Medicamentos , Feminino , Injeções Intradérmicas , Injeções Intravenosas , Interleucina-1/administração & dosagem , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microcirculação/imunologia , Microcirculação/patologia , Receptores da Neurocinina-1/deficiência , Receptores da Neurocinina-1/fisiologia , Pele/irrigação sanguínea , Substância P/administração & dosagem , Zimosan/administração & dosagemRESUMO
1. The effects of an unfractionated heparin preparation (Multiparin), a low molecular weight heparin preparation (Fragmin) and a selectively O-desulphated derivative of heparin lacking anticoagulant activity, have been investigated for their effects on the adhesion of human polymorphonuclear leucocytes (PMNs) to cultured human umbilical vein endothelial cells (HUVECs) in vitro. The effect of poly-L-glutamic acid, a large, polyanionic molecule was also studied. 2. Unfractionated heparin (50-1000 U ml-1), the O-desulphated derivative (0.3-6 mg ml-1) and the low molecular weight heparin (50 U-1000 U ml-1) all inhibited significantly the adhesion of 51Cr labelled PMNs to HUVECs stimulated with interleukin-1 beta (IL-1 beta; 10 U ml-1), bacterial lipopolysaccharide (LPS; 2.5 micrograms ml-1) or tumour necrosis factor-alpha (TNF-alpha; 125 U ml-1) for 6 h, whereas poly-L-glutamic acid had no effect. In addition, the three heparin preparations in the same concentration range inhibited significantly the adhesion of f-met-leu-phe-stimulated PMNs to resting HUVECs. 3. The effects of unfractionated heparin upon the expression of adhesion molecules intercellular adhesion molecule-1 (ICAM-1) and E-selection were also investigated, as were the effects of unfractionated heparin upon adhesion of human PMNs to previously stimulated HUVECs. Heparin had little effect upon levels of expression of these adhesion molecules on stimulated HUVECs. However, a profound effect upon PMN adhesion to previously stimulated HUVECs was demonstrated using the same preparation, suggesting that inhibition of adhesion molecule expression is not a major component of the described inhibitory effects of heparin. 4. Pre-incubation of PMNs with heparin followed by washing inhibited their adhesion to HUVECs, under different conditions of cellular activation, implying that heparin can bind to these cells and exert its anti-adhesive effects even when not directly present in the system. 5. These observations would suggest that both heparin and a low molecular weight heparin are capable of inhibiting adhesion of human PMNs to endothelial cells, an effect not dependent solely upon the polyanionic nature of these molecules, nor dependent upon their ability to act as anticoagulants.
Assuntos
Anticoagulantes/farmacologia , Endotélio Vascular/citologia , Heparina/análogos & derivados , Heparina/farmacologia , Neutrófilos/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Endotélio Vascular/efeitos dos fármacos , Ensaio de Imunoadsorção Enzimática , Humanos , Indicadores e Reagentes , Interleucina-1/farmacologia , Lipopolissacarídeos/farmacologia , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Fator de Necrose Tumoral alfa/farmacologia , Cordão Umbilical/citologia , Cordão Umbilical/efeitos dos fármacosRESUMO
Enantiomeric resolution of butibufen has been achieved on a cellulose tris(3,5-dimethylphenylcarbamate) chiral stationary phase with hexane-isopropanol-trifluoroacetic acid, 100:1.2:0.02 (v/v/v) as mobile phase at a flow rate of 1.0 mL min(-1). Semi-preparative isolation of the enantiomers then chiroptical characterization indicated that the order of elution was (-)-R- before (+)-S-butibufen. When tested for their effects on the cyclooxygenase and 5-lipoxygenase pathways of eicosanoid metabolism in calcium ionophore-activated rat peritoneal leukocytes it was found that (+)-S-butibufen inhibited generation of thromboxane B2 (TXB2) and prostaglandin E2 (PGE2) (cyclooxygenase pathway), with an IC50 of 1.5 microM (approx.), whereas the (-)-R enantiomer was essentially inactive. Neither enantiomer inhibited the 5-lipoxygenase pathway. In this regard, (+)-S-butibufen was approximately five times less potent as a cyclooxygenase inhibitor than (+)-S-ibuprofen. These results show the enantiomeric specificity and pathway selectivity of this novel non-steroidal anti-inflammatory drug.
Assuntos
Ibuprofeno/farmacologia , Fenilbutiratos/farmacologia , Animais , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/isolamento & purificação , Anti-Inflamatórios não Esteroides/farmacologia , Araquidonato 5-Lipoxigenase/efeitos dos fármacos , Araquidonato 5-Lipoxigenase/metabolismo , Ácidos Araquidônicos/metabolismo , Líquido Ascítico/citologia , Cromatografia Líquida de Alta Pressão , Dicroísmo Circular , Inibidores de Ciclo-Oxigenase/farmacologia , Eicosanoides/metabolismo , Inibidores Enzimáticos/farmacologia , Ibuprofeno/química , Ibuprofeno/isolamento & purificação , Leucócitos/efeitos dos fármacos , Leucócitos/enzimologia , Leucócitos/metabolismo , Masculino , Fenilbutiratos/química , Fenilbutiratos/isolamento & purificação , Prostaglandina-Endoperóxido Sintases/efeitos dos fármacos , Prostaglandina-Endoperóxido Sintases/metabolismo , Ratos , Ratos Wistar , EstereoisomerismoRESUMO
During a herbal screening programme to find potential repigmenting agents for the treatment of vitiligo, Piper nigrum L. fruit (black pepper) extract was found to possess growth-stimulatory activity towards cultured melanocytes. Its aqueous extract at 0.1 mg/ml was observed to cause nearly 300% stimulation of the growth of a cultured mouse melanocyte line, melan-a, in 8 days (p < 0.01). Piperine (1-piperoylpiperidine), the main alkaloid from Piper nigrum fruit, also significantly stimulated melan-a cell growth. Both Piper nigrum extract and piperine induced morphological alterations in melan-a cells, with more and longer dendrites observed. The augmentation of growth by piperine was effectively inhibited by RO-31-8220, a selective protein kinase C (PKC) inhibitor, suggesting that PKC signalling is involved in its activity. This is the first full report on such an activity of black pepper and piperine.
Assuntos
Alcaloides , Melanócitos/efeitos dos fármacos , Mitógenos/farmacologia , Piperidinas/farmacologia , Plantas Medicinais/química , Animais , Benzodioxóis , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Frutas/química , Melaninas/biossíntese , Melanócitos/citologia , Melanócitos/metabolismo , Camundongos , Extratos Vegetais/farmacologia , Alcamidas Poli-InsaturadasRESUMO
Phosphodiesterase (PDE) 4, mixed PDE3/4, and non-selective PDE inhibitors have been shown to inhibit the proliferation of human peripheral blood mononuclear cells (HPBM). The aim of the present study was to examine whether endogenous prostaglandins, in particular prostaglandin E2 (PGE2), are involved in mediating the antiproliferative actions of PDE inhibitors, by comparing their effects with drugs which elevate or mimic adenosine 3',5'-cyclic monophosphate (cAMP) through mechanisms other than PDE inhibition. Indomethacin significantly reduced the antiproliferative effects of the PDE4 inhibitors rolipram and CDP840 and the mixed PDE3/4 inhibitor zardaverine, increasing the IC50 values from 2.51 microM to >10 microM, 0.81 microM to 2.82 microM, and 1.58 microM to 4.82 microM, respectively (P < 0.05), but did not alter the effects of theophylline. Forskolin, PGE2, and dibutyryl cAMP also inhibited HPBM proliferation, and in the presence of indomethacin the effects of forskolin and dibutyryl cAMP were reduced (although this was not significant), whereas PGE2 was not affected. Rolipram, CDP840, zardaverine, and dibutyryl cAMP all produced a concentration-related increase in PGE2 production (P < 0.05, ANOVA), but theophylline significantly increased PGE2 production only at the highest concentration examined, 1000 microM. The ability of indomethacin to reduce the antiproliferative effects of rolipram, CDP840, and zardaverine, together with the fact that these drugs can stimulate PGE2 production, suggests that their antiproliferative actions may be mediated in part by stimulation of endogenous PGE2 production. In contrast, it appears that endogenous PGE2 is not critical for the antiproliferative actions of theophylline, forskolin, and dibutyryl cAMP in HPBM. These results establish the importance of co-ordinated regulation of the cAMP phosphodiesterase and cyclooxygenase-PGE2 systems for the regulation of lymphocyte function in man, and have clinical implications for therapeutic approaches to diseases associated with lymphocyte dysregulation.
Assuntos
3',5'-AMP Cíclico Fosfodiesterases/antagonistas & inibidores , Dinoprostona/fisiologia , Leucócitos Mononucleares/efeitos dos fármacos , Inibidores de Fosfodiesterase/farmacologia , 3',5'-AMP Cíclico Fosfodiesterases/metabolismo , Divisão Celular/efeitos dos fármacos , AMP Cíclico/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 3 , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4 , Inibidores de Ciclo-Oxigenase/farmacologia , Interações Medicamentosas , Humanos , Técnicas In Vitro , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/enzimologia , Teofilina/farmacologiaRESUMO
We have undertaken a systematic survey of the genus Buddleja used in traditional Chinese medicine for antiinflammatory and other indications by testing extracts and isolated natural products for their activity against the enzymes of the arachidonate cascade. This was done by using elicited rat peritoneal leukocytes, a physiologically relevant established whole cell system that expresses both cyclo-oxygenase (COX) and 5-lipoxygenase (5-LOX) activity. Lipophilic extracts of B. globosa roots and B. myriantha stem exhibited inhibitory activities in the 5-LOX and COX enzyme assays, whereas those of B. officinalis flowers, B. yunanesis stems, and B. asiatica stems showed inhibitory activities only against COX. The phytochemical investigation of these extracts, and consequent structure elucidation of isolated compounds using spectroscopic data, led to the isolation from B. globosa of three new terpenoid compounds named dihydrobuddledin A, buddledone A, and buddledone B and four known compounds-buddledins A, B, and C and zerumbone; 12 known compounds from B. officinalis-calceolarioside, campneoside, verbascoside, echinacoside, forsythoside B, angoroside A, crocetin monogentibiosyl ester, acacetin, acacetin-7-O-alpha-L-rhamnopyranosyl (1-6)-beta-D-glucopyranoside, acacetin-7-O-alpha-L-rhamnopyranosyl (1-6)[alpha-L-rhamnopyranosyl (1-2)]-beta-D-glucopyranoside, songarosaponin A, delta-amyrone; and eight known compounds fromB. yunanesis-11,14-dihydroxy-8,11, 13-abietatrien-7-one, beta-sitosterol, verbascoside, echinacoside, forsythoside B, angoroside A, methylcatapol, and sucrose. Tests on the isolated compounds for inhibition of eicosanoid synthesis showed that buddledin A, crocetin monogentibiosyl ester, and acacetin exhibited an inhibitory effect on COX with IC(50) values of 13.7 microM, 28.2 microM, and 77.5 microM, respectively, whereas buddledin A exhibited inhibitory effect on 5-LOX with an IC(50) value of 50.4 microM.
Assuntos
Eicosanoides/antagonistas & inibidores , Glicosídeos/farmacologia , Leucócitos/efeitos dos fármacos , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Animais , Inibidores de Ciclo-Oxigenase/química , Inibidores de Ciclo-Oxigenase/farmacologia , Eicosanoides/biossíntese , Glicosídeos/química , Leucócitos/metabolismo , Inibidores de Lipoxigenase/química , Inibidores de Lipoxigenase/farmacologia , Medicina Tradicional Chinesa , Extratos Vegetais/química , Ratos , Análise EspectralRESUMO
The lipophilic aglycone 5,7-dihydroxy-3,8-dimethoxyflavone (gnaphalin) isolated from the aerial flowering parts of Helichrysum picardii Boiss. & Reuter (Asteraceae) was tested for interactions with the cyclo-oxygenase and 5-lipoxygenase pathways of arachidonate metabolism in stimulated rat peritoneal leukocytes, and for its effects on leukocyte granular enzyme release, cell viability and interactions with reactive oxygen species. Gnaphalin dose-dependently inhibited generation of the cyclo-oxygenase metabolite thromboxane B2 (IC50 = 39.9 +/- 3.9 microM), and of the 5-lipoxygenase metabolite leukotriene B4, although the potency was two-fold less (IC50 = 81.8 +/- 12.9 microM). At concentrations of 6 to 320 microM, gnaphalin did not affect secretion of the pro-inflammatory enzymes lysozyme, myeloperoxidase and beta-glucuronidase from the neutrophil secretory granules, and did not scavenge hydrogen peroxide or hypochlorous acid. However, gnaphalin effectively scavenged superoxide radicals generated in the hypoxanthine/xanthine oxidase system (IC50 = 40 microM) and by PMA-stimulated leukocytes (> 60% at 500 microM), directly inhibited xanthine oxidase (85% at 395 microM) and inhibited Fe(3+)-ascorbate-induced liposomal peroxidation (IC50 = 215 microM). Thus, like some other flavonoids found in medicinal herbs, gnaphalin possesses an array of potentially beneficial anti-eicosanoid and free-radical scavenging properties which may alongside other constituents contribute to the claimed medicinal properties of the plant from which it is derived.
Assuntos
Inibidores de Ciclo-Oxigenase/farmacologia , Eicosanoides/metabolismo , Flavonoides/farmacologia , Sequestradores de Radicais Livres/farmacologia , Leucócitos/fisiologia , Inibidores de Lipoxigenase/farmacologia , Plantas Medicinais , Animais , Inibidores de Ciclo-Oxigenase/química , Inibidores de Ciclo-Oxigenase/isolamento & purificação , Grânulos Citoplasmáticos/enzimologia , Flavonoides/química , Flavonoides/isolamento & purificação , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/isolamento & purificação , Glucuronidase/metabolismo , Leucócitos/efeitos dos fármacos , Inibidores de Lipoxigenase/química , Inibidores de Lipoxigenase/isolamento & purificação , Muramidase/metabolismo , Peroxidase/metabolismo , Ratos , Acetato de Tetradecanoilforbol/farmacologia , Xantina Oxidase/metabolismoRESUMO
A rapid 96-well plate assay using sulphorhodamine B (SRB) protein stain for cell number has been adopted to screen herbs used in traditional treatments of vitiligo for substances capable of stimulating melanocyte proliferation. Its applicability to melan-a cells, a mouse pigmented cell line, has been validated. SRB assay produced good linearity up to 11 x 10(4) cells/well and interference by melanin present in the cells accounted for less than 10% of the total optical density readings. The intra-assay variation was small but interassay variation was marked. For better assay precision, it is recommended that the results to be compared should be performed on the same day and controls should be plated in the same experiment, ideally in the same plate. Optimum conditions for exponential melan-a cell growth were established: viz. initial plating density (3-8 x 10(3) cells/well), incubation period (4 days) and foetal bovine serum concentration (5%). Under these conditions cells were responsive to the mitogen tetradecanoyl phorbol acetate (TPA). Out of 28 herbal extracts screened in this assay, significant stimulation (P < 0.05) of melanocyte proliferation was observed, in the absence of TPA, using aqueous extracts of Astragalus membranaceous root, Citrus reticulata peel, Dictamnus dasycarpus root bark. Ophiopogon japonicus root, Poria cocos sclerotium and Tribulus terrestris fruit.
Assuntos
Melanócitos/efeitos dos fármacos , Fitoterapia , Plantas Medicinais/uso terapêutico , Rodaminas , Vitiligo/tratamento farmacológico , Animais , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Avaliação Pré-Clínica de Medicamentos/métodos , Melaninas/farmacologia , Camundongos , Pigmentação/fisiologia , Extratos Vegetais/farmacologia , Reprodutibilidade dos TestesRESUMO
The lipophilic flavonoids in leaf and flower of Tanacetum parthenium and T. vulgaris have been compared. While those of T. parthenium are methyl ethers of the flavonols 6-hydroxykaempferol and quercetagetin, the surface flavonoids of T. vulgare are methyl ethers of the flavones scutellarein and 6-hydroxyluteolin. Apigenin and two flavone glucuronides are surprisingly present in glandular trichomes on the lower epidermis of the ray florets of T. parthenium. The opportunity has been taken to revise the structures of the four 6-hydroxyflavonol methyl ethers of T. parthenium based on NMR measurements. These are now shown to be uniformly 6- rather than 7-O-methylated. Tanetin, previously thought to be a new structure, is now formulated as the known 6-hydroxykaempferol 3,6,4'-trimethyl ether. The vacuolar flavonoids of both plants are dominated by the presence of apigenin and luteolin 7-glucuronides; nine other glycosides were present, including the uncommon 6-hydroxyluteolin 7-glucoside in T. vulgare. When the major flavonol and flavone methyl ethers of the two plants were tested pharmacologically, they variously inhibited the major pathways of arachidonate metabolism in leukocytes. There were significant differences in potency, with the tansy 6-hydroxyflavones less active than the feverfew 6-hydroxyflavonols as inhibitors of cyclo-oxygenase and 5-lipoxygenase.
Assuntos
Anti-Inflamatórios não Esteroides/química , Flavonoides/química , Neutrófilos/efeitos dos fármacos , Plantas Medicinais , Animais , Anti-Inflamatórios não Esteroides/isolamento & purificação , Anti-Inflamatórios não Esteroides/farmacologia , Calcimicina/farmacologia , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Flavonóis , Leucotrieno B4/sangue , Estrutura Molecular , Neutrófilos/citologia , Folhas de Planta , Caules de Planta , Ratos , Ratos Wistar , Tromboxano B2/sangueRESUMO
The effect of the non-peptide selective tachykinin NK1 receptor antagonist SR140333 has been investigated on oedema formation and neutrophil accumulation induced by thermal injury (50 degrees C for 5 min), mustard oil, substance P, the tachykinin NK1 agonist GR73632, and interleukin-1beta in the abdominal skin of the anaesthetised rat. SR140333 significantly inhibited (120 nmol/kg i.v.) or prevented (240 nmol/kg i.v.) the early oedema formation (0-10 min) induced by thermal injury. However, a dosing strategy which blocked NK1 receptors for 5 h (SR140333, 240 nmol/kg i.v. + 240 nmol/kg s.c.) failed to influence neutrophil accumulation measured 5 h after thermal injury. Thus, the neurogenic component mediated by NK1 receptors is important to elicit the early oedema formation, but does not influence subsequent neutrophil accumulation. Topical application of mustard oil (2%), a neurogenic inflammation stimulant, caused NK1 receptor-mediated early neurogenic plasma extravasation, but did not induce cutaneous neutrophil accumulation over 5 h. Substance P and GR73632 at high doses (1 nmol/site) also failed to elicit neutrophil accumulation. Neutrophil accumulation induced by interleukin-1beta (0.03-3 pmol i.d.) was not affected by SR140333 pretreatment. In conclusion, despite an early pronounced tachykinin NK1 receptor-dependent oedema response after thermal injury, the results suggest that subsequent neutrophil accumulation is not mediated by NK1 receptors. Furthermore, we have not obtained any evidence to suggest that either endogenous or exogenous tachykinins can directly induce neutrophil accumulation in the rat cutaneous microvasculature.
Assuntos
Queimaduras/fisiopatologia , Neutrófilos/fisiologia , Receptores da Neurocinina-1/fisiologia , Pele/irrigação sanguínea , Abdome/inervação , Animais , Bradicinina/farmacologia , Queimaduras/complicações , Relação Dose-Resposta a Droga , Edema/tratamento farmacológico , Edema/etiologia , Edema/fisiopatologia , Membro Posterior/inervação , Histamina/farmacologia , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Interleucina-1/farmacologia , Masculino , Microcirculação/efeitos dos fármacos , Mostardeira , Antagonistas dos Receptores de Neurocinina-1 , Neutrófilos/citologia , Neutrófilos/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Piperidinas/farmacologia , Extratos Vegetais/farmacologia , Óleos de Plantas , Quinuclidinas/farmacologia , Ratos , Ratos Wistar , Receptores da Neurocinina-1/agonistas , Pele/efeitos dos fármacos , Pele/patologia , Substância P/análogos & derivados , Substância P/farmacologia , Fatores de TempoRESUMO
Interest in the health-promoting effects of virgin olive oil, an important part of the 'Mediterranean diet', prompted us to determine the anti-eicosanoid and antioxidant effects in leukocytes of the principal phenolic compounds from the 'polar fraction': oleuropein, tyrosol, hydroxytyrosol, and caffeic acid. In intact rat peritoneal leukocytes stimulated with calcium ionophore, all four phenolics inhibited leukotriene B4 generation at the 5-lipoxygenase level with effectiveness hydroxytyrosol > oleuropein > caffeic acid > tyrosol (approximate EC50 values: 15, 80, 200, and 500 microM, respectively). In contrast, none of these compounds caused substantial inhibition of thromboxane generation via the cyclo-oxygenase pathway. Hydroxytyrosol, caffeic acid, oleuropein, and tyrosol (decreasing order of effectiveness) also quenched the chemiluminescence signal due to reactive oxygen species generated by phorbol myristate acetate-stimulated rat leukocytes. None of these compounds were toxic to leukocytes at the concentrations tested. We conclude that the phenolics found in virgin olive oil possess an array of potentially beneficial lipoxygenase-inhibitory, prostaglandin-sparing, and antioxidant properties.
Assuntos
Antioxidantes/isolamento & purificação , Gorduras Insaturadas na Dieta , Leucócitos/efeitos dos fármacos , Inibidores de Lipoxigenase , Óleos de Plantas/química , Animais , Antioxidantes/farmacologia , Ácidos Cafeicos/farmacologia , Eicosanoides/análise , Glucosídeos Iridoides , Iridoides , Masculino , Azeite de Oliva , Álcool Feniletílico/análogos & derivados , Álcool Feniletílico/síntese química , Álcool Feniletílico/farmacologia , Piranos/isolamento & purificação , Piranos/farmacologia , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismoRESUMO
We studied how administration of trihydroxyoctadecadienoic acids obtained from the roots of the native Armenian plant Bryonia alba L. (0.05 mg/kg/day for 15 days. i.m.) restores the disordered lipid metabolism of alloxan-diabetic rats. Diabetes was accompanied by an increase in total non-esterified fatty acid content of blood together with decreases in muscle and adipose tissue of total non-esterified fatty acids and triglycerides, together with marked alterations of phospholipid fatty acid distribution within the membranes from muscle, including increased short chain fatty acid and decreased arachidonate content. All these metabolic changes induced in diabetes were significantly restored by trihydroxyoctadecadienoic acid treatment towards their normal values (P < 0.005) with the exception of diminished triglyceride content of muscle which was not restored. In experiments on rat neutrophil leukocytes in vitro, it was found that the standardised preparation of Bryonia C-18 fatty acids (a mixture of four diastereoisomeric forms of the positional isomers I 12,13,16-trihydroxy-9Z,14E-octadecadienoic acid, II 12,15,16-trihydroxy-9Z,13E-octadecadienoic acid, III 9,10, 13-trihydroxy-11E,15Z-octadecadienoic acid and IV 9,12,13-trihydroxy-10E,14Z-octadecadienoic acid) had no effect on granular enzyme secretion or 5-lipoxygenase activity at 5-50 micrograms/ml, but dose-dependently reduced thromboxane B2 generation, with a corresponding increase in prostaglandin E2 release. We conclude that trihydroxyoctadecadienoic acids from B. alba can correct major metabolic abnormalities typical of severe diabetes mellitus, and that they can influence the profile of the formation of stable prostaglandins by actions downstream of prostaglandin endoperoxides.
Assuntos
Diabetes Mellitus Experimental/metabolismo , Ácidos Graxos Insaturados/farmacologia , Ácidos Graxos/metabolismo , Glucose/metabolismo , Hipoglicemiantes/farmacologia , Plantas Medicinais/química , Aloxano , Animais , Armênia , Células Cultivadas , Ácidos Graxos Insaturados/química , Ácidos Graxos Insaturados/isolamento & purificação , Hipoglicemiantes/química , Hipoglicemiantes/isolamento & purificação , Masculino , RatosRESUMO
Dichloromethane extracts of the stembark and root of Oroxylum indicum were found to have antimicrobial activities against Gram positive bacteria (Bacillus subtilis and Staphylococcus aureus), Gramnegative bacteria (Escherichia coli and Pseudomonas aeruginosa) and a yeast (Candida albicans). Bioassay-guided chromatographic fractionation led to the isolation of flavonoids (bacailein and chrysin) and a naphthoquinone, lapachol. Lapachol was found active against the Gram-positive bacteria, 5 µg giving a zone of inhibition equivalent to that shown by 5 µg streptomycin, whereas 5 µg chrysin gave inhibition zones of equal size to 5 µg streptomycin against Candida albicans and Pseudomonas aeruginosa. The inhibitory activity of lapachol from O. indicum root against soya 5-lipoxygenase (IC(50) 0.79 µg/ml) was equivalent to that of the positive control fisetin (IC(50) 0.97 µg/ml) and 50 µg/ml of the dichloromethane extract of the rootbark gave 100% inhibition of leukocyte lipoxygenase. These activities might indicate an antiinflammatory effect for the dichloromethane extract, mainly due to the lapachol content.
RESUMO
1. Mechanisms involved in the plasma extravasation observed following thermal injury of rat dorsal skin were investigated. 2. Heat applied to the dorsal skin of anaesthetized rats by a temperature-controlled skin heater (1 cm diameter) for 5 min induced temperature-dependent plasma protein extravasation at 48-48.5 degrees C, measured for up to 4 h following initiation of heat. 3. A tachykinin NK1 receptor antagonist (SR140333), a bradykinin B2 receptor antagonist (HOE 140) and a cyclo-oxygenase inhibitor (indomethacin), when given as cotreatments prior to the selected measurement period, markedly suppressed oedema formation observed over 0-1 h (P < 0.05) but not that observed over 3-4 h after injury. 4. These results indicate that although neurokinins, bradykinin and cyclo-oxygenase products may be important for the early response to thermal injury, they do not appear to play an important role in the ongoing oedema response. 5. Neutrophils accumulate at the inflammatory site by 4 h after thermal injury. Therefore, the effect of depletion of circulating neutrophils by a rat anti-neutrophil antiserum on oedema formation over the 0-4 h period was investigated. The results show that oedema formation was similar in control and anti-neutrophil-treated rats. 6. In conclusion, the data from the present study indicate that neuropeptides as well as other vasoactive mediators play a role in the acute plasma extravasation observed after thermal injury, but not in the ongoing inflammatory injury. Neutrophils, despite their presence at sites of thermal injury, do not appear to be involved in mediating the oedema formation observed up to 4 h after thermal injury.
Assuntos
Edema/etiologia , Febre/fisiopatologia , Taquicininas/fisiologia , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Bradicinina/análogos & derivados , Bradicinina/farmacologia , Antagonistas dos Receptores da Bradicinina , Masculino , Antagonistas dos Receptores de Neurocinina-1 , Piperidinas/farmacologia , Quinuclidinas/farmacologia , Ratos , Ratos Wistar , Receptor B2 da BradicininaRESUMO
Tetrandrine, an anti-inflammatory immunosuppressive bisbenzylisoquinoline alkaloid of Chinese herbal origin, is widely used to treat silicosis and interferes with the regulation of calcium in many cell types. We investigated its effect on the cellular integrity of macrophages and on their ability to generate prostaglandins and nitric oxide, mediators of inflammation with immunomodulatory roles. Tetrandrine at 10(-7) M to 10(-4) M caused dose- and time-dependent loss of cell viability of mouse peritoneal macrophages, guinea-pig alveolar macrophages and mouse macrophage-like J774 cells. Loss of viability (50%) occurred within 1-3 hr and required approximately 5 x 10(-6) M tetrandrine. Loss of macrophage viability after tetrandrine treatment was accompanied by the generation of large amounts of prostaglandin E2 (PGE2), to levels 285-877% of control. Coincubation with indomethacin abolished PGE2 generation, but did not prevent cell death. Tetrandrine did not cause generation of nitric oxide. Verapamil also reduced the viability of mouse peritoneal macrophages and J774 cells, but did not cause PGE2 overproduction, except at 10(-4) M in mouse peritoneal macrophages. In macrophages cultured with lipopolysaccharide and interferon-gamma to induce the generation of large amounts of both PGE2 and nitric oxide, tetrandrine reduced mediator release and their forming enzymes (cyclo-oxygenase-2 and inducible nitric oxide synthase), secondary to cytotoxicity. The predominant action of tetrandrine is to exert a cytotoxic effect on macrophages, perhaps by interfering with calcium homeostasis; this leads to overproduction of immunomodulatory but proinflammatory prostaglandin. This may be relevant to its protective actions in human fibrosing silicosis, in which there is alveolar macrophage involvement.