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Exploring anti-tyrosinase bioactive compounds from the Cape floraSonka, Luveni January 2018 (has links)
>Magister Scientiae - MSc / Tyrosinase is an enzyme widely distributed in the biosphere and is found in many species of
bacteria, fungi, animals, and plants; it is associated with melanin production. Even though it
possesses many beneficial properties such as photoprotection, but overproduction causes
undesirable effects such melasma, solar lentigines etc. Therefore, tyrosinase enzyme inhibitors
are of far-ranging importance in cosmetics, medicinal products, and food industries.
This study is aimed to test anti-tyrosinase activity in 37 plants from 20 families using
mushroom tyrosinase inhibition method; each plant was extracted with methanol. The results
showed that 17 plant extracts, exerted a considerable level of in vitro tyrosinase inhibition
comparable to positive controls of kojic acid in the same solvent systems when evaluated
spectrophotometrically. Among plant extracts, those that showed an inhibition rate >50 % at
50 μg/ml and ˃60 % at 200 μg/ml were A. karroo (Hayne.), A. afra Jacq. Ex Willd, C.
geifolia (L.), E. racemosa (L.), H. petiolare Hilliard & B.L.Burt, M. quercifolia (L.), M.
communis (L.), P. rigida (Wikstr.), P. ecklonii (Benth.), P. ericoides (L.), S. Africanacaerulea
(L.), S. Africana-lutea (L.), S. antarcticus (Willd.), S. lucida (L.) F.A.Barkley, S.
hamilifolius (L.), S. furcellata R.Br and T riparia which exhibited great anti-tyrosinase
activity.
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Detection of selective tyrosinase inhibitors from some South African plant extracts of lamiaceae familyEtsassala, Ninon Geornest Eudes Ronauld January 2016 (has links)
Magister Scientiae - MSc / Various dermatological disorders, such as formation of black pigmented patches on the surface of the skin arise from the over-activity of tyrosinase enzyme's degenerative action. This enzyme is further implicated in the involvement of melanin in malignant melanoma, the most lifethreatening skin tumors. Although, synthetic products were found effective to combat this menace, nevertheless, overtime detrimental effect on human skin is a challenge. Investigation of natural tyrosinase inhibitors from methanol extracts of medicinal plants of Lamiaceae family using L-tyrosine as substrate on three different complementary assays (TLC bio-autography, spectrophotometry and cyclic voltammetry) was carried out accordingly. The result indicated Salvia chamelaeagnea, Salvia dolomitica, Plectranthus ecklonii, Plectranthus namaensis, and Plectranthus zuluensis, with significant zone of inhibition against tyrosinase on TLC bio-autography, spectrophotometry result showed that extracts of Plectranthus ecklonii (IC50 = 21.58 μg/mL), Plectranthus zuluensis (IC50 = 23.99 μg/mL), Plectranthus madagascariensis (IC50 = 23.99 μg/mL) and Salvia lanceolata (IC50 = 28.83) demonstrated good anti-tyrosinase activity when compared with kojic acid (IC50 = 3.607 μg/mL). On the other hand, cyclic voltammetry are in consonant with above results thereby supported the nomination of some of the extracts as strong anti-tyrosinase agents. Salvia chamelaeagnea showed strong activity in cyclic voltammetry and clear zone of inhibition on TLC bioautography, these reasons gave us justification for further chemical study to isolate the bioactive constituents. Phytochemical investigation of the bioactive extract of Salvia chamelaeagnea using different chromatographic methods including column chromatographic and semi preparative HPLC afforded six (6) known compounds viz carsonol (C1), carnosic acid (C2), 7- ethoxylrosmanol (C3), ursolic acid (C4), rosmanol (C5) and ladanein (C6). Their chemical structures were elucidated by analyses of spectroscopic (1H and 13C NMR) data as well as correlations with existing literature. The methanolic extract of S. chamelaeagnea (SC) showed moderate antityrosinase (IC50 = 267.4 μg/mL) activity, total antioxidant capacities measured as: Oxygen radicals absorbance capacity (ORAC; 14970 ± 5.16 μM TE/g), ferric-ion reducing antioxidant power (FRAP; 9869.43 ± 7.87 μM AAE/g) and trolox equivalent absorbance capacity (TEAC; 13706.5 ± 0.95 μM TE/g). Excellent total antioxidant capacities were demonstrated by C1 and C5 respectively as FRAP (9338.92 ± 1.72; 8622.73 ± 1.92) μM AAE/g; TEAC (16505 ± 0.86; 10641.5 ± 0.52) μM TE/g; ORAC (14550.5 ± 3.65; 14633.90 ± 3.84) μM TE/g and including the inhibition of Fe2+ -induced lipid peroxidation (IC50 = 32.5; 30.25) μg/mL. All the compounds except C4 are electro-active with well-defined oxidation-reduction peaks while C1 demonstrated the highest tyrosinase inhibitory activity by strongly decreased the inhibition current with time using cyclic voltammetry method. The isolated compounds especially C1, C2 and C5 are well known to combat with ageing problems and documented for their powerful activity against oxidative stress and alzheimer's diseases, which are ageing related symptoms. The isolation of such bioactive compounds indicated the synergetic effect of the results of the three methods used in this thesis. This is the first report on the evaluation of both anti-tyrosinase and total antioxidant capacities of the isolated compounds from S. chamelaeagnea. The findings therefore can be used as background information for exploitation of skin depigmentation and antioxidant agents from natural source.
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Potencial citotóxico e antimicrobiano de plantas da reserva florestal Adolpho Ducke, Manaus-AMCarneiro, Ana Lúcia Basílio 15 June 2015 (has links)
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Previous issue date: 2015-06-15 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / Tropical forests are species-rich reserves for the discovery and development of
antimicrobial drugs. The aim of this work is to investigate the in vitro antimicrobial
potential of Amazon plants found within the National Institute on Amazon
Research’s Adolpho Ducke forest reserve, located in Manaus, state of Amazonas,
Brazil. 75 methanol, chloroform and water extracts representing 12 plant species
were tested for antimicrobial activity towards strains of Mycobacterium smegmatis,
Escherichia coli, Streptococcus sanguis, Streptococcus oralis, Staphylococcus
aureus and Candida albicans using the gel-diffusion method. Active extracts were
further evaluated to establish minimum inhibitory concentrations (MIC) and
antimicrobial profiles using bioautography on normal-phase thin-layer
chromatography plates. Diclinanona calycina presented extracts with good
antimicrobial activity and S. oralis and M. smegmatis were the most sensitive
bacteria. D. calycina and Lacmellea gracilis presented extracts with the lowest
MIC (48.8 μg/ml). D. calycina methanol and chloroform leaf extracts presented the
best overall antimicrobial activity. All test organisms were sensitive to D. calycina
branch chloroform extract in the bioautography assay. This is the first evaluation of
the biological activity of these plant species and significant in vitro antimicrobial
activity was detected in extracts and components from two species, D. calycina
and L. gracilis. / O objetivo deste trabalho foi avaliar a atividade citotóxica, antitumoral e
antimicrobiana de espécies vegetais amazônicas da Reserva Florestal Adolpho
Ducke do Instituto Nacional de Pesquisas da Amazônia (INPA). As espécies
vegetais sem estudos anteriores selecionadas e coletadas foram: Diclinanona
calycina Benoist, (Annonaceae), Lacmellea gracilis (Mull. Arg.) Markgr.
(Apocynaceae), Pleurisanthes parviflora (Ducke) Howard (Icacinaceae), Dilkea
johannesii Berb. Rodr. (Passifloraceae), Sterigmapetalum obovatum Kuhlm.
(Rhizophoraceae), Elaeoluma nuda (Baehni) Aubrév. (Sapotaceae). Após coleta e
extração as amostras foram avaliadas quanto a citotoxicidade frente a Artemia
franciscana e em linhagens de células tumorais. O potencial antimicrobiano foi
determinado pelo método de difusão em ágar frente a Mycobacterium smegmatis,
Escherichia coli, Streptococcus sanguis, S. oralis, Staphylococcus aureus e
Candida albicans. Extratos ativos foram conduzidos a avaliação da concentração
inibitórioa mínima (CIM) e bioautografia para identificar Rfs de componentes
antimicrobianos. Prospecção fitoquímica das espécies promissoras foi realizada
para detecção dos principais constituintes químicos. Dos 38 extratos avaliados
para toxicidade em A. franciscana, dois apresentaram valores de CL50 inferiores a
100 μg/mL, portanto, tóxicos para essa espécie. A menor CL50 foi do extrato de D.
calycina obtido em clorofórmio com valor de 22,9 ± 0,8 μg/mL. No screening para
atividade antitumoral, nove extratos representando quatro espécies vegetais
foram considerados muito ativos (MA) frente à célula tumoral de sistema nervoso
(E. nuda e S. obovatum), cólon (S. obovatum), mama (E.nuda) e leucemia (L.
gracilis, P. parviflora, S. obovatum). A maioria dos 75 extratos analisados inibiram
o crescimento dos microrganismos teste com halos entre 8 e 40 mm de diâmetro.
Extratos de D. calycina demonstraram atividade antimicrobiana com CIM de 48,8
μg/mL frente a S. aureus, S. oralis e S. sanguis e 97,7 μg/mL e 195 μg/mL frente
a M. smegmatis. L. gracilis foi ativa apenas contra M. smegmatis (CIM 48,8
μg/mL). A bioautografia confirmou o potencial antimicrobiano de D. calycina e L.
gracilis. Todos os microrganismos avaliados por bioautografia foram sensíveis ao
extrato de galho de D. calycina obtido em clorofórmio. Na prospecção fitoquímica
detectou-se a presença de fenóis, taninos, flavonóides, alcalóides e
antraquinonas, em extratos de D. calycina e antraquinonas e cumarinas na
espécie L. gracilis. Assim, a seleção permitiu identificar espécies vegetais
amazônicas com atividade antimicrobiana e antitumoral in vitro e sugerir as
espécies D. calycina, L. gracilis, E. nuda e S. obovatum para apreciação
detalhada em outros estudos, pois poderão ter aplicação terapêutica no
tratamento de doenças infecciosas e câncer.
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Análise da atividade antimicrobiana de extratos e frações purificadas da planta arrabidaea chica verlMota, Milena Rodrigues Soares 25 March 2011 (has links)
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Previous issue date: 2011-03-25 / Não Informada / This study describes the therapeutic potential of extracts and standardized fractions
of Arrabidaea chica leaves. A. chica is a Bignoniaceae popularly known as “crajiru”.
The genus Arrabidaea occurs in Tropical America, from the Southern Mexico to the
Southern Brazil. The red color of its dried leaves is attributed to two flavonoidal
pigments: carajurina (main pigment) and carajurona. Chemical studies described the
isolation of saponins and flavonoids from the plant leaves; purified 3-
desoxyanthocyanidins were reported as anti-inflammatory. The infusion or decoction
of the plant leaves is used in the folk medicine to treat anemia, inflammation and in
skin wound-healing. In this work, the antimicrobial activity of the standardized
extracts and fractions of A. chica cultivated at Embrapa Amazônia Ocidental,
Manaus, were evaluated against fungal and bacterial microorganisms grown either
from local domestic dogs and cats, or from human samples supplied by the
Microorganism Collection of FIOCRUZ, in Manaus, Brazil. The plant dried leaves
were extracted with increasing polarity solvents and progressively purified in
preparative thin layer chromatography (TLC) and silica-gel column; the semi-purified
extracts were standardized in TLC. The agar diffusion method; bioautography;
minimum inhibitory concentrations tested against Staphylococcus epidermidis
(CBAM 293), Staphylococcus aureus (CBAM 324), Pseudomonas aeruginosa
(CBAM 232), Escherichia coli (CBAM 002), Trichophyton mentagrophytes (CFAM
1288), Microsporum canis (CFAM 1289), Malassezia pachydermatis (CFAM 1290) e
Candida albicans (CFAM 1285). The standardized fractions were effective against all
these microorganisms, but more intensively against Microsporum canis and
Staphylococcus epidermidis. The results might favour the use of the standardized
sub-fractions of A. chica as topic phytotherapic agent to treat canine external otitis.
So far oleanolic and ursolic acids were identified as the main compounds in the
active semi-purified fraction but other compounds of the leaves extract were not
discarded. Later studies will consider the veterinarian use of the standardized extract,
of the active pure entities and the convenience of the natural active antibiotic mix. / Este estudo analisou o potencial terapêutico de extratos e frações purificadas da
planta amazônica Arrabidaea chica visando seu uso tópico como medicamento e
eficácia comprovada em doenças cutâneas. A. chica Verl., é uma Bignoniaceae
conhecida popularmente como crajiru. O gênero Arrabidaea ocorre na América
tropical, do sul do México ao sul do Brasil. A cor avermelhada da folha seca e sua
propriedade tintorial são devidas a dois pigmentos flavonoídicos: a carajurina, que é
o pigmento principal e a carajurona. Dela foram isolados saponinas e flavonóides;
As 3-desoxiantocianidinas, descritas na planta parecem possuir atividade
antiinflamatória. A medicina popular utiliza o decocto ou a infusão das folhas para
tratar anemia, inflamações e na cicatrização da pele. Neste trabalho, a atividade
antimicrobiana de extratos e frações padronizadas da A. chica cultivada na Embrapa
Amazônia Ocidental, em Manaus/AM, foi avaliada contra fungos e bactérias de
amostras clínicas coletadas de animais domésticos e contra amostras humanas
depositadas na coleção de Microrganimos da FIOCRUZ, Manaus/AM. Para isso, as
folhas secas da planta foram extraídas com solventes de polaridade crescente, as
frações foram progressivamente purificadas em cromatografia de placa ou coluna de
sílica-gel, os extratos semi-purificados foram padronizados em cromatografia líquida
de alta eficiência acoplada à espectrometria de massas. Os testes de difusão em
ágar, bioautografia e concentração inibitória mínima foram usados para avaliar a
atividade antimicrobiana das subfrações padronizadas frente aos microrganismos
Staphylococcus epidermidis (CBAM 293), Staphylococcus aureus (CBAM 324),
Pseudomonas aeruginosa (CBAM 232), Escherichia coli (CBAM 002), Trichophyton
mentagrophytes (CFAM 1288), Microsporum canis (CFAM 1289), Malassezia
pachydermatis (CFAM 1290) e Candida albicans (CFAM 1285). As frações
padronizadas foram ativas contra todos esses microrganismos, com melhores
resultados contra M. pachydermatis e S. epidermidis. Os resultados foram favoráveis
à utilização das subfrações padronizadas na formulação de um produto fitoterápico
para uso tópico em otite canina. Nas frações ativas foram identificados os ácidos
oleanólico e ursólico. Estudos posteriores deverão avaliar a possibilidade de uso
humano das frações purificadas ou dos compostos identificados.
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