RESUMO
Total phenolic content (TPC) and antioxidant capacity of five different extracts (petroleum ether (40-60), dichloromethane, ethyl acetate, ethanol and ethanol-water (1:1 v/v)) of Artemisia turanica (A. turanica) aerial parts were determined and phytochemical study on the most promising extract was carried out. Folin-Ciocalteu method, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging test, ß-carotene bleaching (BCB) method, and ferrous ion chelating (FIC) assay were performed. Vacuum liquid chromatography (VLC) and semi-preparative HPLC were used for bioassay-guided phytochemical isolation. Structures of isolated compounds were established using spectroscopic analysis including NMR and MS. Among all the extracts analyzed, the hydroethanolic extract exhibited the highest phenolic content and antioxidant activity. VLC of this extract yielded seven fractions (A to G) which were subjected to all antecedent experiments. The same sample (Fraction D) showed the highest total phenolic content and free radical scavenging activity but the only statistically significant correlation between TPC and EC50 values was observed for BCB. 3,5-dicaffeoylquinic acid (isochlorogenic acid A), and 4,5-dicaffeoylquinic acid (isochlorogenic acid C) was isolated from the most active fraction. Antioxidant activity of A. turanica is probably partly due to the presence of isomers of isochlorogenic acid.
RESUMO
ABSTRACT Screening of medicinal plants from Iranian flora against human cancer cell-lines have shown that an hexane extract from roots of Salvia sahendica Boiss. & Buhse, Lamiaceae, is active against human cervical cancer (HeLa) and colorectal adenocarcinoma (Caco-2) cell-lines at the test concentration of 100 µg/ml (100% inhibition). Cytotoxicity of the extract was localized with the aid of HPLC-time-based activity profiling adapted to the tetrazolium colorimetric bioassay. Four abietane-type diterpenoids in active time-windows were identified as cytotoxic compounds namely: sahandone (1), sahandol (2), 12-deoxy-salvipisone (3) and sahandinone (4). Compound 1 showed the highest toxicity against HeLa cells (IC50 = 5.6 ± 0.1 µg/ml), which was comparable with betulinic acid (IC50 = 4.3 ± 1.2 µg/ml), the positive control. Compound 2 was active against the HeLa cells (IC50 = 8.9 ± 0.7 µg/ml) but not the Caco-2 cell-line. Compounds 1, 3 and 4 exhibited moderate activity (IC50 = 22.9-41.4 µg/ml) against the Caco-2 cells. This study reveals that the HeLa cells are more sensitive to all tested compounds than the Caco-2 cells. In silico molecular docking study showed a rigid binding of the compounds to tyrosine kinase pp60src, and proved their cytotoxic activity.
RESUMO
A dichloromethane extract from leaves of Searsia pyroides potentiated gamma aminobutyric acid-induced chloride currents by 171.8 ± 54% when tested at 100 µg/mL in Xenopus oocytes transiently expressing gamma aminobutyric acid type A receptors composed of α1ß2γ2s subunits. In zebrafish larvae, the extract significantly lowered pentylenetetrazol-provoked locomotion when tested at 4 µg/mL. Active compounds of the extract were tracked with the aid of HPLC-based activity profiling utilizing a previously validated zebrafish larval locomotor activity assay. From two active HPLC fractions, compounds 1â-â3 were isolated. Structurally related compounds 4â-â6 were purified from a later eluting inactive HPLC fraction. With the aid of 1H and 13C NMR and high-resolution mass spectrometry, compounds 1â-â6 were identified as analogues of anacardic acid. Compounds 1â-â3 led to a concentration-dependent decrease of pentylenetetrazol-provoked locomotion in the zebrafish larvae model, while 4â-â6 were inactive. Compounds 1â-â3 enhanced gamma aminobutyric acid-induced chloride currents in Xenopus oocytes in a concentration-dependent manner, while 4â-â6 only showed marginal enhancements of gamma aminobutyric acid-induced chloride currents. Compounds 2, 3, and 5 have not been reported previously.
Assuntos
Anacardiaceae/química , Ácidos Anacárdicos/farmacologia , GABAérgicos/farmacologia , Extratos Vegetais/farmacologia , Receptores de GABA-A/metabolismo , Ácido gama-Aminobutírico/metabolismo , Ácidos Anacárdicos/química , Ácidos Anacárdicos/isolamento & purificação , Animais , Bioensaio , Cloretos , Cromatografia Líquida de Alta Pressão , GABAérgicos/química , GABAérgicos/isolamento & purificação , Larva , Locomoção/efeitos dos fármacos , Cloreto de Metileno , Oócitos , Pentilenotetrazol , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química , Xenopus laevis , Peixe-ZebraRESUMO
Gamma-aminobutyric acid type A (GABAA) receptors are major inhibitory neurotransmitter receptors in the central nervous system and a target for numerous clinically important drugs used to treat anxiety, insomnia, and epilepsy. A series of allosteric GABAA receptor agonists was identified previously with the aid of HPLC-based activity profiling, whereby activity was tracked with an electrophysiological assay in Xenopus laevis oocytes. To accelerate the discovery process, an approach has been established for HPLC-based profiling using a larval zebrafish (Danio rerio) seizure model induced by pentylenetetrazol (PTZ), a pro-convulsant GABAA receptor antagonist. The assay was validated with the aid of representative GABAergic plant compounds and extracts. Various parameters that are relevant for the quality of results obtained, including PTZ concentration, the number of larvae, the incubation time, and the data analysis protocol, were optimized. The assay was then translated into an HPLC profiling protocol, and active compounds were tracked in extracts of Valeriana officinalis and Magnolia officinalis. For selected compounds the effects in the zebrafish larvae model were compared with data from in silico blood-brain barrier (BBB) permeability predictions, to validate the use for discovery of BBB-permeable natural products.
Assuntos
Barreira Hematoencefálica/metabolismo , Pentilenotetrazol/farmacologia , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Raízes de Plantas/química , Receptores de GABA-A/efeitos dos fármacos , Receptores de GABA-A/metabolismo , Convulsões/tratamento farmacológico , Valeriana/química , Animais , Estrutura Molecular , Pentilenotetrazol/administração & dosagem , Pentilenotetrazol/química , Extratos Vegetais/química , Raízes de Plantas/metabolismo , Receptores de GABA-A/química , Xenopus laevis , Peixe-ZebraRESUMO
Seeds of Securigera securidaca (Fabaceae) are used in Iranian folk medicine as an antidiabetic treatment. In this study, the antihyperglycemic activity of chloroform and methanol fractions (CF and MF) from S. securidaca seed extract was investigated and their bioactive constituents were identified. The antidiabetic effects of fractions were assessed by streptozocin-induced diabetic Naval Medical Research Institute mice. The hypoglycemic activity of MF at 100 mg/kg and CF at 400 mg/kg was comparable with glibenclamide (3 mg/kg). MF at 400 mg/kg and CF at 600 mg/kg showed equal hypoglycemic responses to 12.5 IU/kg insulin (P > 0.05). Three cardiac glycosides were isolated as active constituents responsible for the hypoglycemic activity. Securigenin-3- O -ß-glucopyranosyl-(1 â 4)-ß-xylopyranoside (1) was a major compound in seeds. Securigenin-3- O -inositol-(1 â 3)-ß-glucopyranosyl-(1 â 4)-ß-xylopyranoside (2) and securigenin-3- O -α-rhamnopyranosyl-(1 â 4)-α-glucopyranoside (3) were found as new natural products. When 1-3 were tested at 10 mg/kg there was a significant reduction of blood glucose levels in diabetic mice, comparable to that of 3 mg/kg glibenclamide (P > 0.05). The hypoglycemic effect was due to an increase in insulin secretion; the insulin levels in the diabetic mice significantly improved and were comparable with those in healthy animals (P > 0.05). Compounds responsible for the hypoglycemic properties of S. securidaca seeds were identified as cardiac glycosides and were found to act via an increase of insulin levels in a diabetic mouse model.
Assuntos
Glicemia/efeitos dos fármacos , Diabetes Mellitus Experimental/tratamento farmacológico , Fabaceae/química , Hipoglicemiantes/farmacologia , Extratos Vegetais/química , Securidaca/química , Sementes/química , Animais , Masculino , Camundongos , Extratos Vegetais/farmacologiaRESUMO
SCOPE: Kaempferol is a major flavonoid in the human diet and in medicinal plants. The compound exerts anxiolytic activity when administered orally in mice, while no behavioural changes were observed upon intraperitoneal administration, or upon oral administration in gut sterilized animals. 4-Hydroxyphenylacetic acid (4-HPAA), which possesses anxiolytic effects when administered intraperitoneally, is a major intestinal metabolite of kaempferol. Pharmacokinetic properties of the compounds are currently not clear. METHODS AND RESULTS: UHPLC-MS/MS methods were validated to support pharmacokinetic studies of kaempferol and 4-HPAA in rats. Non-compartmental and compartmental analyses were performed. After intravenous administration, kaempferol followed a one-compartment model, with a rapid clearance (4.40-6.44l/h/kg) and an extremely short half-life of 2.93-3.79min. After oral gavage it was not possible to obtain full plasma concentration-time profiles of kaempferol. Pharmacokinetics of 4-HPAA was characterized by a two-compartment model, consisting of a quick distribution phase (half-life 3.04-6.20min) followed by a fast elimination phase (half-life 19.3-21.1min). CONCLUSION: Plasma exposure of kaempferol is limited by poor oral bioavailability and extensive metabolism. Both compounds are rapidly eliminated, so that effective concentrations at the site of action do not appear to be reached. At present, it is not clear how the anxiolytic-like effects reported for the compounds can be explained.
Assuntos
Dieta , Quempferóis/farmacocinética , Fenilacetatos/farmacocinética , Administração Oral , Animais , Disponibilidade Biológica , Cromatografia Líquida de Alta Pressão , Meia-Vida , Injeções Intravenosas , Quempferóis/sangue , Masculino , Fenilacetatos/sangue , Ratos , Ratos Sprague-Dawley , Espectrometria de Massas em TandemRESUMO
Tryptanthrin and (E,Z)-3-(4-hydroxy-3,5-dimethoxybenzylidene)indolinone (indolinone) were recently isolated from Isatis tinctoria as potent anti-inflammatory and antiallergic alkaloids, and shown to inhibit COX-2, 5-LOX catalyzed leukotriene synthesis, and mast cell degranulation at low µM to nM concentrations. To assess their suitability for oral administration, we screened the compounds in an in vitro intestinal permeability assay using human colonic adenocarcinoma cells. For exact quantification of the compounds, validated UPLC-MS/MS methods were used. Tryptanthrin displayed high permeability (apparent permeability coefficient > 32.0 × 10(-6) cm/s) across the cell monolayer. The efflux ratio below 2 (< 1.12) and unchanged apparent permeability coefficient values in the presence of the P-glycoprotein inhibitor verapamil (50 µM) indicated that tryptanthrin was not involved in P-glycoprotein interactions. For indolinone, a low recovery was found in the human colon adenocarcinoma cell assay. High-resolution mass spectrometry pointed to extensive phase II metabolism of indolinone (sulfation and glucuronidation). Possible cardiotoxic liability of the compounds was assessed in vitro by measurement of an inhibitory effect on human ether-a-go-go-related gene tail currents in stably transfected HEK 293 cells using the patch clamp technique. Low human ether-a-go-go-related gene inhibition was found for tryptanthrin (IC50 > 10 µM) and indolinone (IC50 of 24.96 µM). The analysis of compounds using various in silico methods confirmed favorable pharmacokinetic properties, as well as a slight inhibition of the human ether-a-go-go-related gene potassium channel at micromolar concentrations.
Assuntos
Antialérgicos/farmacocinética , Anti-Inflamatórios não Esteroides/farmacocinética , Indóis/farmacocinética , Pirogalol/análogos & derivados , Quinazolinas/farmacocinética , Células CACO-2 , Permeabilidade da Membrana Celular , Cromatografia Líquida de Alta Pressão/métodos , Células HEK293 , Humanos , Absorção Intestinal , Isatis/química , Pirogalol/farmacocinética , Espectrometria de Massas em TandemRESUMO
Sedative and anxiolytic-like properties of flavonoids such as kaempferol and quercetin, and of some of their intestinal metabolites, have been demonstrated in pharmacological studies. However, routes of administration were shown to be critical for observing in vivo activity. Therefore, the ability to cross intestinal and blood-brain barriers was assessed in cell-based models for kaempferol (KMF), and for the major intestinal metabolite of KMF, 4-hydroxyphenylacetic acid (4-HPAA). Intestinal transport studies were performed with Caco-2 cells, and blood-brain barrier transport studies with an immortalized monoculture human model and a primary triple-co-culture rat model. UHPLC-MS/MS methods for KMF and 4-HPAA in Ringer-HEPES buffer and in Hank's balanced salt solution were validated according to industry guidelines. For all methods, calibration curves were fitted by least-squares quadratic regression with 1/X(2) as weighing factor, and mean coefficients of determination (R(2)) were >0.99. Data obtained with all barrier models showed high intestinal and blood-brain barrier permeation of KMF, and no permeability of 4-HPAA, when compared to barrier integrity markers.
Assuntos
Barreira Hematoencefálica/química , Barreira Hematoencefálica/metabolismo , Absorção Intestinal , Quempferóis/análise , Quempferóis/farmacocinética , Fenilacetatos/análise , Animais , Células CACO-2 , Calibragem , Células Cultivadas , Técnicas de Cocultura , Simulação por Computador , Humanos , Ratos , Ratos Wistar , Padrões de Referência , Reprodutibilidade dos Testes , Espectrometria de Massas em TandemRESUMO
Five antiplasmodial bisabololoxide sesquiterpene diesters were isolated from an EtOAc extract of the aerial parts of Artemisia persica following an HPLC-time-based activity profiling of the extract. Structure elucidation was achieved by 1D and 2D NMR experiments. Relative configurations of cyclohexenone/cyclohexene and tetrahydropyran moieties of 1-5 were established on the basis of ³J(H-H) coupling constants and NOE difference spectra. Stereochemical correlation of the two rings, and assignment of absolute configuration of 1-5 were achieved by comparison of experimental ECD spectra with simulated ECD data for possible stereoisomers, by using time dependent density function theory (TDDFT). Bisaboloids 1-4 exhibited in vitro antimalarial activity against Plasmodium falciparum, with IC50 values ranging from 2.8 to 20.1 µM, and selectivity indices (SI) in L-6 cells of 3.7-11.9.
Assuntos
Antimaláricos/química , Antimaláricos/farmacologia , Artemisia/química , Extratos Vegetais/química , Plasmodium falciparum/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Espectroscopia de Ressonância Magnética , Estrutura MolecularRESUMO
A methanolic extract from aerial parts of Polygonum hyrcanicum (Polygonaceae) showed high activity against Trypanosoma brucei rhodesiense (IC50 = 3.7 microg/mL). Bioassay-guided fractionation of the extract resulted in isolation of cinnamoylphenethyl amides, including N-trans-caffeoyltyramine (1), N-trans-p-coumaroyltyramine (7), and N-trans-feruloyltyramine (8) as the main active constituents (IC50s ranging from 2.2 to 13.3 microM). Some structurally related, but less active compounds, such as cannabisin B (2), tyrosol (3), p-coumaric acid (4), ferulic acid (5), and N-cis-feruloyltyramine (6) were also identified, along with N-trans-3,4-dimethoxycinnamoyldopamine (9). Cytotoxicity of the active compounds in L6 cells was determined, and selectivity indices (SI) of 7.9 to 33.4 were calculated.
Assuntos
Extratos Vegetais/química , Extratos Vegetais/farmacologia , Polygonaceae/química , Polygonum/química , Tripanossomicidas/química , Tripanossomicidas/farmacologia , Trypanosoma brucei rhodesiense/efeitos dos fármacos , Tiramina/química , Tiramina/farmacologia , Ácidos Cumáricos/química , Ácidos Cumáricos/farmacologia , Tiramina/análogos & derivadosRESUMO
Satureja spicigera (Lamiaceae) grows wildly in Northwest of Iran. In this study, bioassay-guided isolation and identification of the main compounds has been reported using various chromatographic methods and comparison of their spectral data with those reported in the literature. Brine shrimp lethality and four cancerous cell lines HT29/219, Caco(2), NIH-3T3, and T47D were used for cytotoxicity evaluations. From the aerial parts of S. spicigera, nine known compounds including two flavanones, 5,7,3',5'-tetrahydroxy flavanone (8) and 5,4'-dihydroxy-3'-methoxyflavanone-7-(6''-O-α-L-rhamnopyranosyl)-ß-D-glucopyranoside (9), one dihydrochalcone, nubigenol (7), together with thymoquinone (1), thymol (2), carvacrol (3), ß-sitosterol (4), ursolic acid (5) and oleanolic acid (6) were identified. Among the isolated chalcone and flavanones, compound 8 was effective against Artemia salina larva (LC(50)= 2 µg/mL) and only the compound 9 demonstrated IC(50) value of 98.7 µg/mL on the T47D (human, breast, ductal carcinoma). Other compounds did not show significant inhibition of the cell growth.
Assuntos
Antineoplásicos Fitogênicos/toxicidade , Flavanonas/toxicidade , Extratos Vegetais/toxicidade , Satureja/química , Animais , Artemia/efeitos dos fármacos , Células CACO-2 , Linhagem Celular Tumoral , Flores/química , Células HT29 , Humanos , Dose Letal Mediana , Camundongos , Células NIH 3T3 , Testes de ToxicidadeRESUMO
BACKGROUND AND THE PURPOSE OF THE STUDY: The early stage of diabetes mellitus type 2 is associated with postprandial hyperglycemia. Hyperglycemia is believed to increase the production of free radicals and reactive oxygen species, leading to oxidative tissue damage. In an effort of identifying herbal drugs which may become useful in the prevention or mitigation of diabetes, biochemical activities of Polygonum hyrcanicum and its constituents were studied. METHODS: Hexane, ethylacetate and methanol extracts of P. hyrcanicum were tested for α-glucosidase inhibitory, antioxidant and radical scavenging properties. Active constituents were isolated and identified from the methanolic extract in an activity guided approach. RESULTS: A methanolic extract from flowering aerial parts of the plant showed notable α-glucosidase inhibitory activity (IC50 = 15 µg/ml). Thirteen phenolic compounds involving a cinnamoylphenethyl amide, two flavans, and ten flavonols and flavonol 3-O-glycosides were subsequently isolated from the extract. All constituents showed inhibitory activities while compounds 3, 8 and 11 (IC50 = 0.3, 1.0, and 0.6 µM, respectively) were the most potent ones. The methanol extract also showed antioxidant activities in DPPH (IC50 = 76 µg/ml) and FRAP assays (1.4 mmol ferrous ion equivalent/g extract). A total phenol content of 130 mg/g of the extract was determined by Folin-Ciocalteu reagent. CONCLUSION: This study shows that P. hyrcanicum contains phenolic compounds with in vitro activity that can be useful in the context of preventing or mitigating cellular damages linked to diabetic conditions.
RESUMO
From the ethyl acetate and methanol extract of the aerial parts of Satureja atropatana Bonge, which belongs to the Lamiaceae family, four flavonoids were isolated. Their structures were determined to be 5,6,3'-trihydroxy-7,8,4'-trimethoxyflavone (1), 5,6-dihydroxy-7,8,3',4'-tetramethoxyflavone or 5-desmethoxynobiletin (2), 5,6,4'-trihydroxy-7,8,3'-trimethoxyflavone or thymonin (3) and luteolin (4) using (1)H and (13)C-NMR and MS spectra. Brine shrimp cytotoxicity effects of the crude extracts and isolated compounds were examined. Berberine hydrochloride (LC(50) = 26 microg mL(-1)) was used as a positive control. Among them, compounds 2 (199 microg mL(-1)) and 3 (157 microg mL(-1)) were effective against Artemia salina larva.