Radical scavenging and xanthine oxidase inhibitory activity of phenolic compounds from <i>Bridelia ferruginea</i> stem bark

Cimanga, K.; Li, Ying; Bruyne, Tess De; Apers, Sandra; Cos, Paul; Hermans, Nina; Bakana, P.; Tona, L.; Kambu, K.; Kalenda, Dibungi T.; Pieters, Luc; Berghe, Dirk Vanden; Vlietinck, A. J.

doi:10.1211/0022357011775893

Cited by 67 publications

(44 citation statements)

References 15 publications

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“…However, there is no evidence to support specific roles for these compounds in grape. Myricetin has also been linked to radicalscavenging activity, xanthine oxidase inhibitory activity, and antioxidant activity in extracts of Ginkgo biloba leaves and Bridelia ferruginea stem bark (Kobus et al, 2009;Cimanga et al, 2001), but in both investigations the tested mixture contained several other flavonols and methylated derivatives.…”

Section: Possible Roles Of Methylated Myricetins In Tomato Glandular mentioning

confidence: 99%

Polymethylated Myricetin in Trichomes of the Wild Tomato Species Solanum habrochaites and Characterization of Trichome-Specific 3′/5′- and 7/4′-Myricetin O-Methyltransferases

Schmidt

Shi

et al. 2011

Plant Physiology

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Flavonoids are a class of metabolites found in many plant species. They have been reported to serve several physiological roles, such as in defense against herbivores and pathogens and in protection against harmful ultraviolet radiation. They also serve as precursors of pigment compounds found in flowers, leaves, and seeds. Highly methylated, nonglycosylated derivatives of the flavonoid myricetin flavonoid, have been previously reported from a variety of plants, but O-methyltransferases responsible for their synthesis have not yet been identified. Here, we show that secreting glandular trichomes (designated types 1 and 4) and storage glandular trichomes (type 6) on the leaf surface of wild tomato (Solanum habrochaites accession LA1777) plants contain 3,7,3#-trimethyl myricetin, 3,7,3#,5#-tetramethyl myricetin, and 3,7,3#,4#,5#-pentamethyl myricetin, with gland types 1 and 4 containing severalfold more of these compounds than type 6 glands and with the tetramethylated compound predominating in all three gland types. We have also identified transcripts of two genes expressed in the glandular trichomes and showed that they encode enzymes capable of methylating myricetin at the 3# and 5# and the 7 and 4# positions, respectively. Both genes are preferentially expressed in secreting glandular trichome types 1 and 4 and to a lesser degree in storage trichome type 6, and the levels of the proteins they encode are correspondingly higher in types 1 and 4 glands compared with type 6 glands.

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Section: Possible Roles Of Methylated Myricetins In Tomato Glandular mentioning

confidence: 99%

Polymethylated Myricetin in Trichomes of the Wild Tomato Species Solanum habrochaites and Characterization of Trichome-Specific 3′/5′- and 7/4′-Myricetin O-Methyltransferases

Schmidt

Shi

et al. 2011

Plant Physiology

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“…The inhibition of xanthine oxidase (XOD)-generated superoxide formation was evaluated by measuring the UV absorbance at 295 nm of uric acid production [47] [48]. In fact, 1 mol of xanthine is converted in the presence of xanthine oxidase to 1 mol of uric acid and 2 mol of superoxide anion.…”

Section: Experimental Partmentioning

confidence: 99%

Comparative Study of Cyperus rotundus Essential Oil by a Modified GC/MS Analysis Method. Evaluation of Its Antioxidant, Cytotoxic, and Apoptotic Effects

Kilani

Ledauphin

Bouhlel

et al. 2008

Chemistry & Biodiversity

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Gas chromatography coupled with mass spectrometry (GC/MS), using both electron impact (EI) and chemical ionization (CI) detection modes on apolar and polar stationary phases, led to the determination of the volatile composition of the essential oil obtained from tubers of Cyperus rotundus (Cyperaceae). In this study, more than 33 compounds were identified and then compared with the results obtained in our previous work. Cyperene, alpha-cyperone, isolongifolen-5-one, rotundene, and cyperorotundene were the principal compounds comprising 62% of the oil. An in vitro cytotoxicity assay with MTT indicated that this oil was very effective against L1210 leukaemia cells line. This result correlates with significantly increased apoptotic DNA fragmentation. The oxidative effects of the essential oil were evaluated using the 1,1-diphenyl-2-picrylhydrazyl (DPPH), xanthine/xanthine oxidase assays, and the scavenging of superoxide radical assay generated by photo-reduction of riboflavin. The antimutagenic activity of essential oil has been examined by following the inhibition of H(2)O(2) UV photolysis which induced strand-break formation in pBS plasmid DNA scission assay. Based on all these results, it is concluded that C. rotundus essential-oil composition established by GC/MS analysis, in EI- and CI-MS modes, presents a variety of a chemical composition we were not able to detect with only GC/MS analysis in our previous work. This essential oil exhibited antioxidant, cytotoxic, and apoptotic properties.

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“…52 No método utilizado para avaliar a capacidade de inibição da atividade da XO no sistema xantina/xantina oxidase, a atividade é medida pela avaliação da produção do ácido úrico, que é formado juntamente com o radical superóxido, por espectrofotometria em 290 nm. 53 Cos et al 54 utilizaram esta metodologia para avaliar a atividade inibitória de flavonoides sobre a XO, concluindo que flavanonas, di-hidroflavonóis e flavanóis não são capazes de inibir a ação da enzima. No entanto, entre as flavonas e flavonóis a presença de grupos hidroxilas nas posições C-5 e C-7 aumenta a ação inibitória, enquanto a presença destes grupos ligados em C-6 e C-3 diminui consideravelmente este efeito.…”

Section: Sequestro De Radical Superóxido -Xantina Oxidaseunclassified

Métodos para determinação de atividade antioxidante in vitro em substratos orgânicos

Alves¹,

David²,

David³

et al. 2010

Quím. Nova

191

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Recebido em 21/6/10; aceito em 17/8/10; publicado na web em 20/10/10 METHODS FOR DETERMINATION OF IN VITRO ANTIOXIDANT ACTIVITY FOR EXTRACTS AND ORGANIC COMPOUNDS. In the literature there are a considerable number of chemical and biochemical tests for evaluation of in vitro antioxidant activities of pure compounds or fractions and organic extracts. These tests are important tools for screening of synthetic and natural bioactive compound as well as they can be employed in food chemistry. This work is a critical review of the main methods employed for in vitro antioxidant determination.Keywords: antioxidant activity; oxygen reactive species; radicalar quenching. INTRODUÇÃOO termo oxidação de uma substância era comumente definido como a incorporação de oxigênio em sua estrutura. Atualmente, pode ser mais precisamente definido como sendo a conversão de uma substância química em um derivado com menor número de elétrons. Oxidação, portanto, é a perda de um ou mais elétrons para outra substância e o procedimento inverso pode ser considerado como redução. 1 A transferência de elétrons é um dos processos químicos mais fundamentais para a sobrevivência das células. O efeito colateral dessa dependência é a produção de radicais livres e outras espécies reativas de oxigênio (ERO) que podem causar dano oxidativo. Radicais livres são átomos ou moléculas produzidos continuamente durante os processos metabólicos e atuam como mediadores para a transferência de elétrons em várias reações bioquímicas, desempenhando funções relevantes ao metabolismo.2 As principais fontes de radicais livres são as organelas citoplasmáticas que metabolizam oxigênio, nitrogênio e cloro, gerando grande quantidade de metabólitos. Os radicais livres possuem diferentes papéis no organismo e encontram-se envolvidos na produção de energia, fagocitose, regulação do crescimento celular, sinalização intercelular e síntese de substâncias biológicas importantes. Entretanto, seu excesso apresenta efeitos deletérios, tais como danos ao DNA, proteínas e organelas celulares, como mitocôndrias e membranas, provocando alterações na estrutura e funções celulares e, dessa forma, se encontram envolvidos em diversas patologias a exemplo de câncer, envelhecimento precoce, doenças cardiovasculares, degenerativas e neurológicas, choque hemorrágico, catarata, disfunções cognitivas, etc.4 Para combater os radicais livres os organismos vivos produzem substâncias que são capazes de regenerar ou prevenir os danos oxidativos, exercendo seu papel como antioxidante. Além destes, substâncias com habilidade de sequestrar radicais livres podem ser obtidas de fontes externas, como alimentos e bebidas. Quando os antioxidantes produzidos pelo corpo são insuficientes para combater os radicais livres produzidos pelo organismo, este sofre ações degenerativas através do distúrbio conhecido como estresse oxidativo.Os estudos sobre radicais livres e o desenvolvimento de novos métodos para avaliação de atividade antioxidante (AA) têm aumentado consideravelmente nos últimos anos. As descobertas d...

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Radical scavenging and xanthine oxidase inhibitory activity of phenolic compounds from Bridelia ferruginea stem bark

Cited by 67 publications

References 15 publications

Polymethylated Myricetin in Trichomes of the Wild Tomato Species Solanum habrochaites and Characterization of Trichome-Specific 3′/5′- and 7/4′-Myricetin O-Methyltransferases

Polymethylated Myricetin in Trichomes of the Wild Tomato Species Solanum habrochaites and Characterization of Trichome-Specific 3′/5′- and 7/4′-Myricetin O-Methyltransferases

Comparative Study of Cyperus rotundus Essential Oil by a Modified GC/MS Analysis Method. Evaluation of Its Antioxidant, Cytotoxic, and Apoptotic Effects

Métodos para determinação de atividade antioxidante in vitro em substratos orgânicos

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