Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Adicionar filtros








Intervalo de ano
1.
Braz. J. Pharm. Sci. (Online) ; 58: e19723, 2022. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1394035

RESUMO

Abstract Passiflora nitida Kunth, an Amazonian Passiflora species, is little studied, although the specie's high biological potential. Herein the plant's pharmacognostic characterization, extract production, antioxidant potential evaluation, and application of this extract in cosmetic products is reported. The physical chemical parameters analyzed were particle size by sieve analysis, loss through drying, extractive yield, total ash content, laser granulometry, specific surface area and pore diameter (SBET), differential scanning calorimetry, thermogravimetry (TG), and wave dispersive X-Ray fluorescence (WDXRF). Total phenol/flavonoid content, LC-MS/MS analysis, DPPH and ABTS antioxidant radical assays, cytotoxicity, melanin, and tyrosinase inhibition in melanocytes test provided evidence to determine the content of the major constituent. P. nitida dry extract provided a fine powder with mesopores determined by SBET, with the TG curve showing five stages of mass loss. The antioxidant potential ranged between 23.5-31.5 mg∙mL-1 and tyrosinase inhibition between 400-654 µg∙mL-1. The species presented an antimelanogenic effect and an inhibitory activity of cellular tyrosinase (26.6%) at 25 µg/mL. The LC-MS/MS analysis of the spray-dried extract displayed the main and minor phenolic compounds constituting this sample. The results indicate that P. nitida extract has promising features for the development of cosmetic formulations


Assuntos
Extratos Vegetais/análise , Folhas de Planta/efeitos adversos , Cosméticos/classificação , Passiflora/classificação , Termogravimetria/métodos , Raios X/efeitos adversos , Varredura Diferencial de Calorimetria/métodos , Monofenol Mono-Oxigenase/antagonistas & inibidores , Compostos Fenólicos , Melaninas , Antioxidantes/efeitos adversos
2.
Bol. latinoam. Caribe plantas med. aromát ; 20(4): 427-442, jul. 2021. ilus, tab
Artigo em Inglês | LILACS | ID: biblio-1369497

RESUMO

The objective of this study was to evaluate biological and phytochemical properties of the aqueous extract from the leaves of Miconia chamissois Naudin (AEMC). Phytochemical properties were assessed by analyzing the chromatographic profile and the polyphenol content of AEMC. Biological properties evaluation was conducted based on cytotoxicity assay and by evaluating the antioxidant, antimicrobial, and enzymatic inhibition activities. Results indicated the presence of phytochemicals in AEMC such as flavonoids and polyphenols, including rutin, isoquercitrin and vitexin derivatives. AEMC showed antioxidant activity, which may be attributed to the high polyphenolic content. Moreover, AEMC demonstrated in vitro enzyme inhibition activity against tyrosinase and alpha-amylase, as well as showed low cytotoxicity. On the other hand, AEMC exhibited weak antimicrobial activity against S. aureusand C. albicans. Thus, AEMC is a promising alternative in search of potential drugs for the treatment of diseases induced by oxidative stress and inflammation, conditions due to hyperpigmentation processes, such as melisma, as well as for diabetes.


El objetivo de este estudio fue detectar las propiedades biológicas y fitoquímicos del extracto acuoso de las hojas de Miconia chamissois Naudin (AEMC). Las propiedades fitoquímicas se evaluaron analizando el perfil cromatográfico y el contenido de polifenoles de AEMC. La evaluación de las propiedades biológicas se realizó en base al ensayo de citotoxicidad y evaluando las actividades de inhibición antioxidante, antimicrobiana y enzimática. Los resultados indicaron la presencia de fitoquímicos en AEMC, como flavonoides y polifenoles, que incluyen derivados de rutina, isoquercitrina y vitexina. AEMC mostró una actividad antioxidante considerable, que puede atribuirse al alto contenido polifenólico. Además, AEMC exhibió actividad de inhibición enzimática in vitro contra tirosinasa y alfa-amilasa, así como mostró baja citotoxicidad. Por otro lado, AEMC demostró actividad antimicrobiana débil contra S. aureusy C. albicans. Por lo tanto, AEMC es una alternativa prometedora en busca de posibles drogas para el tratamiento de enfermedades inducidas por el estrés oxidativo y la inflamación, afecciones debidas a procesos de hiperpigmentación, como el melasma, así como para la diabetes.


Assuntos
Extratos Vegetais/farmacologia , Extratos Vegetais/química , Melastomataceae/química , Flavonoides/análise , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Monofenol Mono-Oxigenase/antagonistas & inibidores , alfa-Amilases/antagonistas & inibidores , Polifenóis/análise , Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia
3.
Bol. latinoam. Caribe plantas med. aromát ; 19(2): 161-166, mar. 2020. tab, ilus
Artigo em Inglês | LILACS | ID: biblio-1104063

RESUMO

The methanol extract of the Balkan endemic species Jurinea tzar-ferdinandii Davidov demonstrated weak antioxidant activity against DPPH• and ABTS+• and low inhibitory potential against acetylcholinesterase (8.3% Inh.) and tyrosinase (IC50 = 208 ± 8 µg/mL) enzymes. Phytochemical investigation of the extract led to isolation and identification of apigenin, luteolin, apigenin-7-O-glucoside, apigenin-4'-O-glucoside, apigenin-7-O-gentiobioside, luteolin-4'-O-glucoside, rutin, narcissin, chlorogenic and 1,5-dicaffeoylquinic acid. With exception of apigenin and rutin, all isolated compounds are reported for the first time in the representatives of genus Jurinea. The distribution of flavonoids was discussed from chemotaxonomic point of view.


El extracto de metanol de la especie endémica de los Balcanes Jurinea tzar-ferdinandii Davidov demostró una actividad antioxidante débil contra DPPH• y ABTS+• y un bajo potencial inhibidor contra las enzimas acetilcolinesterasa (8.3% Inh.) tirosinasa (IC50 = 208 ± 8 µg/mL). La investigación fitoquímica del extracto condujo al aislamiento e identificación de apigenina, luteolina, apigenina-7-Oglucósido, apigenina-4'-O-glucósido, apigenina-7-O-gentiobiósido, luteolina-4'-O-glucósido, rutina, narcissin, clorogénico y ácido 1,5- dicafeoilquinico. Con excepción de la apigenina y la rutina, todos los compuestos aislados se informan por primera vez en el género Jurinea. La distribución de flavonoides se discute desde el punto de vista quimiotaxonómico.


Assuntos
Asteraceae/química , Antioxidantes/farmacologia , Antioxidantes/química , Fenóis/análise , Flavonoides/análise , Inibidores da Colinesterase , Monofenol Mono-Oxigenase/antagonistas & inibidores , Metanol , Península Balcânica
4.
Artigo em Inglês | LILACS | ID: biblio-1283651

RESUMO

This study presents analyses on the chemistry, biology, pharmacology and chromatography of essential oils extracted from three species of the Ocotea genus: O. minor, O. ceanothifolia and O. leucoxylon. Leaves and stems, as well as the bark of O. minor, were processed using a modified Clevenger apparatus. Seven essential oils were obtained and analyzed using GC-FID and GC-MS, and their chemical compositions were determined. Assays of cytotoxicity, antioxidant and free radical scavenging activity, as well as tyrosinase and elastase inhibition were performed. In total, 25 constituents were identified, the principal being sesquiterpenes, such as spathulenol caryophyllene and its oxide. The oils did not present cytotoxicity using a hemolytic model, but also did not show antioxidant activity in the DPPH assay. Essential oil from stems of O. ceanothifolia, rich in spathulenol and caryophyllene oxide, demonstrated the capacity to inhibit 49.08% of tyrosinase activity at a concentration of 100 µg/mL. This research contributes to the chemical profile analysis of the three species of Ocoteathrough chemical investigations and biological activity, which are reported for the first time here in this study.


Este trabajo realiza un estudio químico, biológico, farmacológico y cromatográfico de aceites esenciales extraídos de tres especies del género Ocotea: O. minor, O. ceanothifoliay O. leucoxylon. Las hojas y tallos, así como la corteza de O. minor, se procesaron utilizando un aparato Clevenger modificado. Se obtuvieron siete aceites esenciales y se analizaron usando GC-FID y GC-MS, y se determinaron sus composiciones químicas. Se realizaron ensayos de citotoxicidad, actividad antioxidante y de atrapamiento de radicales libres, así como inhibición de tirosinasa y elastasa. En total, se identificaron 25 componentes, siendo los principales sesquiterpenos, como el spathulenol cariofileno y su óxido. Los aceites no presentaron citotoxicidad en un modelo hemolítico y tampoco mostraron actividad antioxidante en el ensayo con DPPH. El aceite esencial de tallos de O. ceanothifolia, rico en espatulenol y óxido de cariofileno, mostró capacidad para inhibir el 49.08% de la actividad de tirosinasa a una concentración de 100 µg/mL. Esta investigación contribuye al análisis del perfil químico de las tres especies de Ocotea a través de investigaciones químicas y actividad biológica la cual se informan por primera vez.


Assuntos
Óleos Voláteis/farmacologia , Monofenol Mono-Oxigenase/antagonistas & inibidores , Ocotea/química , Óxidos/análise , Sesquiterpenos/análise , Óleos Voláteis/química , Sequestradores de Radicais Livres , Lauraceae/química , Indústria Cosmética , Ionização de Chama , Cromatografia Gasosa-Espectrometria de Massas
5.
Biol. Res ; 51: 54, 2018. graf
Artigo em Inglês | LILACS | ID: biblio-1011398

RESUMO

BACKGROUND: Hyperpigmentation disorders such as post-inflammatory hyperpigmentation are major concerns not only in light-skinned people but also in Asian populations with darker skin. The anti-tyrosinase and immunomodulatory effects of sericin have been known for decades. However, the therapeutic effects of sericin on hyperpigmentation disorders have not been well documented. METHODS: In this study, we used an in vitro model to study the anti-tyrosinase, tolerogenic, and anti-melanogenic effects of sericin on Staphylococcus aureus peptidoglycan (PEG)-stimulated melanocytes, dendritic cells (DCs), and artificial skin (MelanoDerm™). Enzyme-linked immunosorbent assay, conventional and immunolabeled electron microscopy, and histopathological studies were performed. RESULTS: The results revealed that urea-extracted sericin has strong anti-tyrosinase properties as shown by a reduction of tyrosinase activity in melanin pigments both 48 h and 10 days after allergic induction with PEG. Anti-inflammatory cytokines including interleukin (IL)-4, IL-10, and transforming growth factor-p were upregulated upon sericin treatment (10, 20, and 50 µg/mL), whereas production of allergic chemokines, CCL8 and CCL18, by DCs was diminished 48 h after allergic induction with PEG. Moreover, sericin lowered the expression of micropthalmia-associated transcription factor (MITF), a marker of melanogenesis regulation, in melanocytes and keratinocytes, which contributed to the reduction of melanin size and the magnitude of melanin deposition. However, sericin had no effect on melanin transport between melanocytes and keratinocytes, as demonstrated by a high retention of cytoskeletal components. CONCLUSION: In summary, sericin suppresses melanogenesis by inhibition of tyrosinase activity, reduction of inflammation and allergy, and modulation of MITF function.


Assuntos
Humanos , Queratinócitos/efeitos dos fármacos , Monofenol Mono-Oxigenase/antagonistas & inibidores , Hiperpigmentação/tratamento farmacológico , Sericinas/farmacologia , Melanócitos/efeitos dos fármacos , Fatores de Transcrição/efeitos dos fármacos , Microscopia Eletrônica , Transdução de Sinais/efeitos dos fármacos , Queratinócitos/ultraestrutura , Células Cultivadas , Fator de Transcrição Associado à Microftalmia , Hipersensibilidade , Inflamação , Melanócitos/ultraestrutura
6.
Biol. Res ; 48: 1-11, 2015. graf, tab
Artigo em Inglês | LILACS | ID: lil-734617

RESUMO

BACKGROUND: Honey is a natural product obtained from the nectar that is collected from flowers by bees. It has several properties, including those of being food and supplementary diet, and it can be used in cosmetic products. Honey imparts pharmaceutical properties since it has antibacterial and antioxidant activities. The antibacterial and antioxidant activities of Thai honey were investigated in this study. RESULTS: The honey from longan flower (source No. 1) gave the highest activity on MRSA when compared to the other types of honey, with a minimum inhibitory concentration of 12.5% (v/v) and minimum bactericidal concentration of 25% (v/v). Moreover, it was found that MRSA isolate 49 and S. aureus were completely inhibited by the 50% (v/v) longan honey (source No. 1) at 8 and 20 hours of treatment, respectively. Furthermore, it was observed that the honey from coffee pollen (source No. 4) showed the highest phenolic and flavonoid compounds by 734.76 mg gallic/kg of honey and 178.31 mg quercetin/kg of honey, respectively. The antioxidant activity of the honey obtained from coffee pollen was also found to be the highest, when investigated using FRAP and DPPH assay, with 1781.77 mg FeSO4•7H2O/kg of honey and 86.20 mg gallic/kg of honey, respectively. Additionally, inhibition of tyrosinase enzyme was found that honey from coffee flower showed highest inhibition by 63.46%. CONCLUSIONS: Honey demonstrates tremendous potential as a useful source that provides anti-free radicals, anti-tyrosinase and anti-bacterial activity against pathogenic bacteria causing skin diseases.


Assuntos
Apiterapia , Flavonoides/análise , Mel/análise , Monofenol Mono-Oxigenase , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Fenóis/análise , Pólen/química , Antibacterianos/farmacologia , Antioxidantes/farmacologia , Compostos de Bifenilo , Café/química , Recuperação de Fluorescência Após Fotodegradação , Flores/química , Radicais Livres/análise , Mel/classificação , Testes de Sensibilidade Microbiana , Monofenol Mono-Oxigenase/antagonistas & inibidores , Monofenol Mono-Oxigenase/efeitos dos fármacos , Picratos , Pólen/classificação , Dermatopatias/microbiologia , Dermatopatias/terapia , Preparações Clareadoras de Pele/farmacologia , Tailândia , Fatores de Tempo , Viscosidade
7.
Bol. latinoam. Caribe plantas med. aromát ; 13(5): 488-497, sept.2014. tab
Artigo em Inglês | LILACS | ID: lil-786495

RESUMO

Chemical compositions of P. stylosum and P. ribesioides essential oils, and their antioxidant, antimicrobial and tyrosinase inhibition activities were determined. GC and GC–MS analysis of essential oils from leaves and stems of P. stylosum resulted in the identification of 50 (89.2 percent) and 45 (88.8 percent) components, respectively. The major components were aromadendrene (leaves 26.6 percent; stems 18.8 percent), sabinene (leaves 13.8 percent; stems 6.7 percent) and beta-caryophyllene (leaves 11.5 percent; stems 17.9 percent). A total of 60 (87.0 percent) and 39 (82.9 percent) components were identified from leaves and stems of P. ribesioides, respectively. The most abundant components were beta-caryophyllene (leaves 20.0 percent; stems 14.4 percent), camphene (leaves 16.3 percent; stems 12.3 percent) and delta-cadinene (leaves 4.4 percent; stems 7.8 percent). Antioxidant activity using DPPH and total phenolic content were tested for essential oils. However, the essential oils showed low antioxidant activity and phenolic content, compared to BHT. Studies of tyrosinase inhibition showed that the essential oils of P. ribesioides leaves had the highest inhibition (30.0 percent), although were lower than the control (kojic acid 81.8 percent). The evaluation of antimicrobial activities revealed that P. ribesioides essential oils showed strong activity against Bacillus cereus and Staphylococcus aureus, both with MIC value 62.5 micrograms/mL.


Se determinaron las composiciones químicas, las actividades antioxidante y antimicrobiana, y el contenido total de fenoles de los aceites esenciales de P. stylosum y P. ribesioides. El análisis GC y GC-MS de los aceites esenciaales de hojas y tallos de P. stylosum permitió la identificación de 50 (89.2 por ciento) y 45 (88.8 por ciento) de components, respectivamente. Los principales componentes fueron aromadendreno (hojas 26.6 por ciento; tallos 18.8 por ciento), sabineno (hojas 13.8 por ciento; tallos 6.7 por ciento) y beta-cariofileno (hoja 11.5 por ciento; tallo 17.9 por ciento). Se identificaron 60 (87.0 por ciento) y 39 (82.9 por ciento) components en los aceites esenciales de hojas y tallos de P. ribesioides. Los componentes más abundantes fueron beta-cariofileno (hojas 20.0 por ciento; tallos 14.4 por ciento), canfeno (hojas 16.3 por ciento; tallos 12.3 por ciento) y delta-cadineno (hojas 4.4 por ciento; tallos 7.8 por ciento). Los aceites esenciales se ensayaron para determinar sus actividades antioxidantes con DPPH y el contenido de fenoles totales. Para los aceites esenciales obtenidos se determinaron valores bajos en la actividad antioxidante con DPPH y el contenido total de fenoles, en comparación con BHT. Sin embargo, los ensayos de inhibición de tirosinasa most raron que el aceite esencial de las hojas de P. ribesioides presento la mayor inhibición (30.0 por ciento), aunque mas baja que el compuesto control (Àcido Kójico, 81.8 por ciento). Para el aceite esencial de P. ribesioides se determinó una MIC 62.5 mg/mL contra Bacillus cereus y Staphylococcus aureus.


Assuntos
Óleos Voláteis/química , Antibacterianos/química , Antioxidantes/química , Folhas de Planta/química , Inibidores Enzimáticos/química , Piper/química , Antibacterianos/farmacologia , Bacillus cereus , Sequestradores de Radicais Livres , Fenóis/análise , Cromatografia Gasosa-Espectrometria de Massas , Testes de Sensibilidade Microbiana , Monofenol Mono-Oxigenase/antagonistas & inibidores , Staphylococcus aureus , Caules de Planta/química
8.
Biol. Res ; 47: 1-14, 2014. graf, tab
Artigo em Inglês | LILACS | ID: biblio-950719

RESUMO

BACKGROUND: In recent years, the desire to adopt a healthy diet has drawn attention to legume seeds and food products derived from them. Mash bean is an important legume crop used in Pakistan however a systematic mapping of the chemical composition of mash bean seeds is lacking. Therefore seeds of four mash bean (Vigna mungo (L.) Hepper, family Leguminoseae) cultivars (NARC-Mash-1, NARC-Mash-2, NARC-Mash-3, NARC-Mash-97) commonly consumed in Pakistan have been analyzed for their chemical composition, antioxidant potential and biological activities like inhibition of formation of advanced glycation end products (AGE) activity and tyrosinase inhibition activity. RESULTS: The investigated cultivars varied in terms of biochemical composition to various extents. Mineral composition indicated potassium and zinc in highest and lowest amounts respectively, in all cultivars. The amino acid profile in protein of these cultivars suggested cysteine is present in lowest quantity in all cultivars while fatty acid distribution pattern indicated unsaturated fatty acids as major fatty acids in all cultivars. All cultivars were found to be rich source of tocopherols and sterols. Fourier transform infrared spectroscopy (FTIR) fingerprints of seed flour and extracts indicated major functional groups such as polysaccharides, lipids, amides, amines and amino acids. Results indicated that all investigated cultivars possessed appreciable antioxidant potential. CONCLUSIONS: All cultivars are rich source of protein and possess sufficient content of dietary fiber, a balanced amino acid profile, low saturated fatty acids and antioxidant capacity that rationalizes many traditional uses of seeds of this crop besides its nutritional importance. The collected data will be useful for academic and corporate researchers, nutritionists and clinical dieticians as well as consumers. If proper attention is paid, it may become an important export commodity and may fetch considerable foreign exchange for Pakistan.


Assuntos
Sementes/química , Produtos Agrícolas/química , Fabaceae/química , Paquistão , Fenóis/análise , Riboflavina/análise , Sementes/metabolismo , Esteróis/análise , Taninos/análise , Tiamina/análise , Oligoelementos/análise , Flavonoides/análise , Extratos Vegetais/química , Sequestradores de Radicais Livres , Monofenol Mono-Oxigenase/antagonistas & inibidores , Produtos Finais de Glicação Avançada/metabolismo , Produtos Agrícolas/metabolismo , Substâncias Redutoras/metabolismo , Cisteína/análise , Tocoferóis/análise , Fabaceae/metabolismo , Niacina/análise , Antioxidantes/metabolismo , Valor Nutritivo
9.
Rev. bras. plantas med ; 16(3,supl.1): 693-699, 2014. tab
Artigo em Português | LILACS | ID: lil-727197

RESUMO

Espécies de Jatobá (Hymenaea stigonocarpa Mart. ex Hayne) são tradicionalmente utilizadas para o tratamento de diversas doenças. Estudos quimiotaxonômicos têm relacionado o gênero Hymenaea como fonte potencial de compostos fenólicos, taninos, flavonoides, os quais apresentam atividade antioxidante, sendo assim substâncias potencialmente inibidoras da tirosinase, enzima responsável por defeitos da pigmentação da pele. Existem cerca de 15 espécies no gênero Hymenaea, das quais 13 ocorrem no Brasil. Assim, este trabalho foi realizado para avaliar os fenóis, a atividade antioxidante, a capacidade de quelação dos íons cobre, e a capacidade de inibição da tirosinase do extrato das folhas da espécie H. Stigonocarpa. O material botânico (folhas), foi colhido nas árvores da área de cerrado de preservação ambiental do campus universitário FESURV - Universidade de Rio Verde - GO, seco em estufa de circulação forçada a 42°C por 2 dias, seguindo para a obtenção dos extratos hexânico e etanólico. A determinação do conteúdo fenólico realizada através do reativo Folin Ciocalteau demonstrou ser o extrato bruto etanólico (EBE) o que apresentou a maior concentração dessa classe (235,7 mg equivalente de ácido gálico por grama de EBE). Na avaliação da atividade captadora de radical, empregando o radical livre DPPH, novamente o extrato etanólico demonstrou atividade antioxidante mais elevada (IC50 = 19 ± 0,1 ppm). Para o procedimento de quelação de íons cobre, o extrato bruto etanólico não demonstrou tal capacidade. Quanto a inibição da enzima tirosinase, o extrato bruto etanólico, após 30 e 60 minutos, apresentou inibição de 38 e 48%, respectivamente.


The jatobá species, also known as Brazilian cherry, are traditionally used for the treatment of various diseases. Chemotaxonomic studies have described the Hymenaea genus as a potential source of phenolic compounds, tannins and flavonoids, which have antioxidant activity, thus being potential inhibitors of tyrosinase, which is the enzyme responsible for skin pigmentation defects. There are approximately 15 species in the genus Hymenaea of which 13 are found in Brazil. This study was conducted to evaluate the phenols, the antioxidant activity, the ability to chelate copper ions and the ability to inhibit tyrosinase of the extract of the H. Stigonocarpa leaves. The plant material (leaves) was harvested from trees in the savannah (Brazilian Cerrado) area of environmental preservation of the FESURV campus - University of Rio Verde - state of Goiás, dried in a forced circulation oven at 42° C for 2 days and subjected to extraction with hexane (hexane crude extract) and extraction with absolute ethanol (ethanol crude extract). When determining the phenolic content performed with the Folin-Ciocalteu reagent, we found that the crude ethanol extract (CEE) presented the highest concentration (235.7 mg gallic acid equivalent per gram of CEE). In the evaluation of radical scavenging activity, using the DPPH free radical, the ethanol extract again showed higher antioxidant activity (IC50 = 19 ± 0.1 ppm). For the procedure for chelation of copper ions, the crude ethanol extract tested showed no such ability. For the process of inhibiting the tyrosinase enzyme, the crude ethanol extract tested after 30 and 60 minutes presented inhibition of 38 and 48%, respectively.


Assuntos
Extratos Vegetais/farmacocinética , Monofenol Mono-Oxigenase/antagonistas & inibidores , Folhas de Planta/metabolismo , Hymenaea/classificação , Antioxidantes/análise , Compostos Fenólicos/análise , Radicais Livres/efeitos adversos
10.
Pakistan Journal of Pharmaceutical Sciences. 2013; 26 (6): 1071-1076
em Inglês | IMEMR | ID: emr-148533

RESUMO

The flowers of African marigold [Tagetes erecta L], a medicinal plant widely cultivated in Thailand, were subjected to evaluation for total phenolics, DPPH scavenging and thiobarbituric acid-reactive substance [TBARs] assays as well as tyrosinase inhibitory activity. In preliminary studies, the ethyl acetate [EA] extract obtained by continuous extraction showed the highest activities with highest phenolic content among all extracts. Bioassay-guided fractionation of EA extract led to isolation of a flavonoid identified as quercetagetin. Interestingly, it was found that quercetagetin exhibited potent DPPH scavenging activity with IC50 of 3.70 Micro g/ml which is about 2-3 times higher activity than standard quercetin [IC50 5.07 Micro g/ml] and trolox [IC50 9.93 Micro g/ml]. Moreover, it exhibited tyrosinase inhibitory activity on L-tyrosine [IC50 89.31 Micro g/ml], higher than Alpha - and Beta -arbutins [IC50 157.77 and 222.35 Micro g/ml] and slightly higher [IC50 128.41 Micro g/ml] than ellagic acid [IC50 151.1 Micro g/ml] when using L-DOPA as substrate. Testing with skin fibroblasts, all the extracts and quercetagetin demonstrated no toxic effect. These finding strongly indicate that African marigold flower is a promising source of natural antioxidative and tyrosinase inhibitory substances with safe to skin


Assuntos
Flores , Extratos Vegetais , Fenol , Plantas Medicinais , Monofenol Mono-Oxigenase/antagonistas & inibidores , Cromonas , Antioxidantes
11.
Experimental & Molecular Medicine ; : 313-319, 2008.
Artigo em Inglês | WPRIM | ID: wpr-205425

RESUMO

Xanthohumol (XH), the principal prenylflavonoid of the hop plant (Humulus lupulus L.), dose-dependently inhibited isobutylmethylxanthine (IBMX)-induced melanogenesis in B16 melanoma cells, with little cytotoxicity at the effective concentrations. Decreased melanin content was accompanied by reduced tyrosinase enzyme activity, protein and mRNA expression. The levels of tyrosinase-related protein 1 and 2 mRNAs were decreased by XH. XH also inhibited alpha-melanocyte stimulating hormone- or forskolin-induced increases in melanogenesis, suggesting an action on the cAMP-dependent melanogenic pathway. XH downregulated the protein and mRNA expression of microphthalmia-associated transcription factor (MITF), a master transcriptional regulator of key melanogenic enzymes. These results suggest that XH might act as a hypo-pigmenting agent through the downregulation of MITF in the cAMP-dependent melanogenic pathway.


Assuntos
Animais , Camundongos , 1-Metil-3-Isobutilxantina/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Regulação para Baixo , Antagonismo de Drogas , Colforsina/farmacologia , Humulus , Oxirredutases Intramoleculares/antagonistas & inibidores , Melaninas/antagonistas & inibidores , Melanócitos/efeitos dos fármacos , Melanoma Experimental , Glicoproteínas de Membrana/antagonistas & inibidores , Fator de Transcrição Associado à Microftalmia/antagonistas & inibidores , Monofenol Mono-Oxigenase/antagonistas & inibidores , Oxirredutases/antagonistas & inibidores , Propiofenonas/farmacologia , Transdução de Sinais/efeitos dos fármacos , alfa-MSH/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA