RESUMO
The complexation of herbal constituents with cyclodextrin has been a useful tool to improve their aqueous solubility. However, the simultaneous complexation of these compounds still lacks detailed studies. The present study investigated the multicomplexation of quercetin (QCT), luteolin (LUT), and 3-O-methylquercetin (3OMQ) with (2-hydroxypropyl)-ß-cyclodextrin (HPßCD), when they are simultaneously contained in a flavonoid-enriched fraction (FEF) of Achyrocline satureioides. The phase-solubility diagram revealed a linear correlation between the flavonoids solubility and the HPßCD concentration, demonstrating the formation of complexes with a 1:1 stoichiometric ratio, which was confirmed by ESI-MS. Negative ΔG0 values indicated that complexation was spontaneous. Flavonoids/HPßCD interactions were evidenced by FT-IR, DSC, SEM, and 1D and 2D NMR. The last one showed the formation of inclusion complexes by insertion of the B-ring of the flavonoids into the cavity of HPßCD. Unexpectedly, the FEF/HPßCD complex showed a radical scavenger potential lower than the FEF. The HPLC analysis revealed that the complex contained different flavonoid ratio than the fraction. Thus, the antioxidant capacity of the samples was demonstrated to be related to the ratio among the flavonoids, rather than to the total flavonoids. These new findings are very useful for developing herbal cyclodextrin-based products from A. satureioides or other herbal products.
Assuntos
Ciclodextrinas , Flavonoides , 2-Hidroxipropil-beta-Ciclodextrina , Antioxidantes , Luteolina/análise , Extratos Vegetais/química , Quercetina/análogos & derivados , Solubilidade , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
OBJECTIVES: This study was carried out to evaluate the effects of flavonoids present in leaves of Passiflora edulis fruit on complications induced by diabetes in rats. METHODS: The extract of P. edulis leaf was obtained by 70% ethanol maceration. From the dry extract, the fractions were obtained by consecutive liquid-liquid partition with hexane, ethyl acetate and n-butanol. The content of isoorientin of ethyl acetate and n-butanol fractions was determined by ultra-performance liquid chromatography coupled with electrospray and triple quadrupole ionization (TQD) analysis in tandem mass spectrometry (UPLC-ESI-Tq-MS). Only Fr-BuOH was used to treat diabetic or not Wistar rats. Biochemical parameters, platelet aggregation and production of reactive species were evaluated. KEY FINDINGS: The UPLC-ESI-Tq-MS analysis revealed the presence of several flavonoids, among which we identified five possible flavonoids c-heterosides (luteolin-7-O-pyranosyl-3-O-glucoside, apigenin-6-8-di-C-glycoside, apigenin-6-C-arabinoside-8-C-glycoside, isoorientin, isovitexin). The diabetic rats (treated intraperitoneally with alloxan, 150 mg/kg) treated with Fr-BuOH (20 mg/kg/day for 90 days) presented improvement in blood glucose, serum levels of fructosamine, lipid profile and urea. Furthermore, the Fr-BuOH reduced both platelet aggregation and the production of oxidant species in diabetic animals. CONCLUSIONS: These results suggested that flavonoid C-glycosides present in the Fr-BuOH may be beneficial for the diabetic state, preventing complications induced by diabetes.
Assuntos
Complicações do Diabetes/prevenção & controle , Diabetes Mellitus Experimental/tratamento farmacológico , Flavonoides/uso terapêutico , Glicosídeos/uso terapêutico , Passiflora/química , Fitoterapia , Extratos Vegetais/uso terapêutico , Animais , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Apigenina/análise , Apigenina/farmacologia , Apigenina/uso terapêutico , Glicemia/metabolismo , Cromatografia Líquida de Alta Pressão , Complicações do Diabetes/sangue , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/complicações , Flavonas/análise , Flavonas/farmacologia , Flavonas/uso terapêutico , Flavonoides/análise , Flavonoides/farmacologia , Frutosamina/sangue , Glucosídeos/análise , Glucosídeos/farmacologia , Glucosídeos/uso terapêutico , Glicosídeos/análise , Glicosídeos/farmacologia , Luteolina/análise , Luteolina/farmacologia , Luteolina/uso terapêutico , Masculino , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Agregação Plaquetária/efeitos dos fármacos , Ratos Wistar , Espectrometria de Massas em TandemRESUMO
Plants, through the photosynthesis process, produce the substances necessary for all the life cycles of nature, which are called "primary metabolites." Moreover, there are some plants that synthesize, in addition to these, other substances with more specific functions, which are known as "secondary metabolites." It is inside this group that flavonoids are located, whose main function is to protect organisms from damage caused by different oxidizing agents. Luteolin (3,4,5,7-tetrahydroxy-flavone) belongs to the sub-class of flavonoids known as flavones and is one of 10,000 flavonoids currently known, being one of the most bio-active flavonoids. Its various beneficial properties for health, together with the increasing reduction in the use of synthetic antioxidants, make the study of luteolin a very active field. Within this, the quantification of this molecule has become a subject of very special interest given that it is transversal to all fields. In this review article, we aim to give the reader a broad and deep vision of this topic, focusing on the events reported in the last 5 years and covering all possible techniques related to analytical determinations. We will discuss in terms of advantages and disadvantages between techniques, selectivity, sensitivity, costs, time consumption, and reagents as well as in the complexity of operations.
Assuntos
Cromatografia/métodos , Técnicas Eletroquímicas/métodos , Eletroforese/métodos , Luteolina/análise , Luteolina/química , Espectrometria de Fluorescência/métodosRESUMO
Capsicum peppers have not been investigated as sources of quorum sensing (QS) inhibitors. This study aimed to identify compounds in pimenta-malagueta (Capsicum frutescens) and red pepper (Capsicum annuum) extracts and to evaluate their effect on violacein production in Chromobacterium violaceum ATCC 12472 and C. violaceum CV026, as well as biofilm formation (BF) in Pseudomonas aeruginosa PAO1 and Serratia marcescens MG1. Among the extracts, pimenta-malagueta methanolic extract (PMME) was chosen because it contained capsaicin, dihydrocapsaicin, and luteolin in greater amount than the other extracts. In general, PMME partially inhibited bacterial growth at 2.5 and 5.0 mg/mL, as well as capsaicin at 100 µg/mL and luteolin at 62.5, 125, and 250 µg/mL. At lower concentrations, PMME and luteolin reduced violacein production in C. violaceum ATCC 12472 without affecting growth, a result that was not observed with capsaicin. We show that violacein inhibition by PMME is likely due to luteolin. In silico docking evaluation showed that luteolin binds to the CviR QS regulator. Crystal violet staining and confocal microscopy revealed that BF was increased by PMME and capsaicin, being remarkably superior for P. aeruginosa PAO1 at 30 °C. Capsaicin is not an effective QS inhibitor, while luteolin should be further investigated for its potential effects in QS regulated phenotypes. PRACTICAL APPLICATION: Quorum sensing (QS) is a form of bacterial communication targeted for studies aiming to inhibit bacterial virulence. QS regulates phenotypes that influence microbial activities across many areas, including Food Science. Capsicum frutescens is a type of chili pepper consumed in Brazil, rich in bioactive compounds such as capsaicin (which gives its pungency) and luteolin (a phenolic compound). We show that C. frutescens extract and luteolin inhibit QS in a model bacterium, along with the possible molecular mechanism of inhibition. Capsaicin did not inhibit QS neither biofilm formation. Luteolin should be further investigated for its QS inhibition properties and biotechnological applications.
Assuntos
Capsaicina/farmacologia , Capsicum/química , Luteolina/farmacologia , Extratos Vegetais/farmacologia , Percepção de Quorum/efeitos dos fármacos , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Brasil , Capsaicina/análogos & derivados , Capsaicina/análise , Chromobacterium/efeitos dos fármacos , Frutas/química , Luteolina/análise , Fenótipo , Extratos Vegetais/química , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/fisiologia , Serratia marcescens/efeitos dos fármacos , Serratia marcescens/fisiologiaRESUMO
INTRODUCTION: Phenolic compounds present in Achyrocline satureioides are known to have therapeutic benefits like antioxidant, anti-inflammatory, and antitumour properties. The main polyphenols present in the plant are quercetin (QCT), luteolin (LUT), 3-O-methylquercetin (3OMQ), and achyrobichalcone (ACB). However, the effective isolation and purification of these compounds from A. satureioides inflorescences are not an easy task. OBJECTIVE: To develop an efficient high-performance counter-current chromatography (HPCCC) method for quick separation and purification of naturally occurring phenolic compounds from the extract of A. satureioides. METHODOLOGY: A two-step HPCCC semi-preparative isolation method was developed using a solvent system composed of n-hexane/ethyl acetate/methanol/water (0.8:1.0:0.8:1.0) and dichloromethane/methanol/water (3.5:3.5:2.5). RESULTS: The HPCCC method was used to obtain two fractions. The first fraction (F1 ) contained high levels of ACB, among other constituents, while the second fraction (F2 ) contained mostly QCT, LUT, and 3OMQ. Besides the high ACB content, F1 contained three other flavonoid-aglycones (kaempferol, 97.3%; isokaempferide, 92.4%; and 3,3'-di-O-methylquercetin, 95.2%) identified by an ultra-performance liquid chromatography system coupled to a quadrupole time-of-flight with high-definition mass spectrometry (UPLC-QTOF/HDMS) and nuclear magnetic resonance (NMR) analysis. Purity levels of ACB, 3OMQ, QCT, and LUT were 98.0, 97.0, 97.5, and 90.2%, respectively. CONCLUSION: This is the first time that high purity ACB and six other flavonoids were obtained from A. satureioides inflorescences by HPCCC. These excellent results reveal the potential and versatility of HPCCC as a technique to produce different types of products from this plant species on a semi-preparative scale: enriched fractions, new metabolites, or high purity compounds.
Assuntos
Achyrocline/química , Distribuição Contracorrente/métodos , Polifenóis/isolamento & purificação , Biflavonoides/análise , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13/métodos , Luteolina/análise , Extratos Vegetais/química , Polifenóis/normas , Espectroscopia de Prótons por Ressonância Magnética/métodos , Quercetina/análogos & derivados , Quercetina/análise , Padrões de Referência , Espectrofotometria Ultravioleta/métodosRESUMO
Passiflora plants are strategic in the context of biodiversity for food and nutrition. We applied the procedures of a systematic review protocol to study the state of the art on identification of phenolic compounds from Passiflora plants. An automated literature search was conducted using six databases and a combination of seven keywords. All the analytical, chromatographic, and spectroscopic methods were included. The studies were classified according to their method of identification, phenolic classes, and method of extraction. In total, 8,592 abstracts were found, from which 122 studies were selected for complete reading and 82 were selected for further analysis. Techniques of extraction, evaluated parts of the plant and methods of identification were systematized. Studies with leaves were most conspicuous (54.4%), 34 species of Passiflora were evaluated and orientin, isoorientin, vitexin, isovitexin were commonly found structures. A High Performance Liquid Chromatography-diode array detector was the technique most applied, with which the same structures were identified all through the studies, although other unknown structures were detected, but not elucidated. The use of Nuclear Magnetic Resonance and Mass Spectrometry, which are more sensitive techniques, needs to be intensified, to identify other unconventional compounds detected in Passiflora, to enhance the comprehension of the bioactive compounds in these plants.
Assuntos
Flavonoides/análise , Análise de Alimentos , Passiflora/química , Compostos Fitoquímicos/análise , Apigenina/análise , Glucosídeos/análise , Luteolina/análise , Fenóis/análise , Extratos Vegetais/químicaRESUMO
BACKGROUND: Passion fruit rind (PFR) represents 90% of the total fruit weight and is wasted during juice processing. Passion fruit rind is known to contain flavonoids and pectin. An alternative use for this fruit juice industrial residue is to obtain these compounds. This study aimed to verify the influence of pressurized solvent extraction (PSE) or ultrasound assisted extraction (UAE) of flavonoid and pectin in a sequential process. RESULTS: The PSE using ethanol at 60:40 (v/v) yielded a total polyphenol content of 4.67 g GAE kg-1 PFR, orientin-7-O-glucoside (1.57 g kg-1 PFR) and luteolin-6-C-glucoside (2.44 g kg-1 PFR). Pectin yield was 165 g kg-1 PFR, either in PSE or UAE. Pectin characterization indicates that the pectic structure has basically homogalacturonans and galacturonate followed by a galacturonic acid ester unit, with methylation degree of 70%. CONCLUSION: With this study it can be concluded that mixtures of alcohols with water favor the extraction of bioactive compounds of passion fruit peel. Both PSE and UAE were effective in sequentially extracting flavonoids and pectin. The preferred solvent is ethanol due to its lower toxicity. © 2017 Society of Chemical Industry.
Assuntos
Flavonoides/isolamento & purificação , Frutas/química , Passiflora/química , Pectinas/isolamento & purificação , Etanol , Flavonoides/análise , Glucosídeos/análise , Ácidos Hexurônicos/química , Luteolina/análise , Pectinas/química , Polifenóis/análise , Pressão , Solventes , UltrassomRESUMO
In the present study we have studied the effect of 25, 50, 75 and 100 µM of luteolin on the transgenic Drosophila expressing human alpha synuclein. The doses of luteolin were established in diet and the PD flies were allowed to feed on it for 24 days. After 24 days of exposure the flies were assayed for climbing assay, oxidative stress markers, caspase-3 & 9 activity and dopamine content. The immunohistochemistry was also performed on the brain sections for the activity of tyrosine hydroxylase. The exposure of luteolin showed a dose dependent delay in the loss of climbing ability and activity, reduction in oxidative stress markers, caspase-3&9 activities and results in an increase in the dopamine content. The results obtained for the immunohistochemistry also supports the protective role of luteolin against the damage of the dopaminergic neurons
Assuntos
Doença de Parkinson/tratamento farmacológico , Luteolina/análise , Estresse Oxidativo/fisiologia , DrosophilaRESUMO
A selective and sensitive polar-reversed phase LC method was validated for simultaneous quantification of the main Achyrocline satureioides flavonoids (quercetin, luteolin, and 3-O-methylquercetin) in skin samples after permeation/retention studies from topical nanoemulsions. The method was linear in a range of 0.25 to 10.0 microg/mL exhibiting a coefficient of determination higher than 0.999 for all flavonoids. No interference of the nanoemulsion excipients or skin components was observed in the retention times of all flavonoids. The R.S.D. values for intra- and inter-day precision experiments were lower than 6.73%. Flavonoids recovery from nanoemulsions and skin matrices was between 90.05 and 109.88%. In a permeation/retention study with porcine ear high amount of 3-O-methylquercetin was found in the skin sample (0.92 +/- 0.22 microg/g) after two hours. The proposed method was suitable to quantify the main flavonoids of A. satureioides in skin permeation/retention studies from topical nanoemulsions.
Assuntos
Achyrocline/química , Flavonoides/análise , Flavonoides/farmacocinética , Absorção Cutânea/fisiologia , Animais , Cromatografia Líquida de Alta Pressão , Orelha Externa/metabolismo , Emulsões , Técnicas In Vitro , Indicadores e Reagentes , Luteolina/análise , Luteolina/farmacocinética , Extratos Vegetais/química , Extratos Vegetais/farmacocinética , Quercetina/análogos & derivados , Quercetina/análise , Quercetina/farmacocinética , Reprodutibilidade dos Testes , Espectrofotometria Ultravioleta , SuínosRESUMO
The present study evaluated the antioxidant potential of Vernonia condensata Baker (Asteraceae). Dried and powdered leaves were exhaustively extracted with ethanol by static maceration followed by partition to obtain the hexane, dichloromethane, ethyl acetate, and butanol fractions. Total phenols and flavonoids contents were determined through spectrophotometry and flavonoids were identified by HPLC-DAD system. The antioxidant activity was assessed by DPPH radical scavenging activity, TLC-bioautography, reducing power of Fe(+3), phosphomolybdenum, and TBA assays. The total phenolic content and total flavonoids ranged from 0.19 to 23.11 g/100 g and from 0.13 to 4.10 g/100 g, respectively. The flavonoids apigenin and luteolin were identified in the ethyl acetate fraction. The IC50 of DPPH assay varied from 4.28 to 75.10 µg/mL and TLC-bioautography detected the antioxidant compounds. The reducing power of Fe(+3) was 19.98 to 336.48 µg/mL, while the reaction with phosphomolybdenum ranged from 13.54% to 32.63% and 56.02% to 135.00% considering ascorbic acid and rutin as reference, respectively. At 30 mg/mL, the ethanolic extract and fractions revealed significant effect against lipid peroxidation. All these data sustain that V. condensata is an important and promising source of bioactive substances with antioxidant activity.