Natural Polyphenols (Vegetable Tannins) as Drugs:  Possible Modes of Action

Haslam, Edwin

doi:10.1021/np960040+

Cited by 1,178 publications

(864 citation statements)

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“…7 It is strong enough to bring on the subsequent precipitation of the complex, thus modifying the lubricating properties of saliva. 8 The principal source of wine tannins comes from the grape, and particularly from its solids parts, skins, seeds and stems. They are transferred to wine during wine-making operations (crushing, maceration and fermentation).…”

Section: Introductionmentioning

confidence: 99%

A 3D structural and conformational study of procyanidin dimers in water and hydro‐alcoholic media as viewed by NMR and molecular modeling

Tarascou

Barathieu

Simon

et al. 2006

Magnetic Reson in Chemistry

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The three-dimensional structures of 5 procyanidin dimers have been determined in a hydro-alcoholic medium and in water using 2D NMR and molecular mechanics. They are made from monomers of catechin (CAT) and epicatechin (EPI)-B1: EPI-CAT, B2: EPI-EPI, B3: CAT-CAT, B4: CAT-EPI and B2g: EPI-EPI-3-O-gallate. These tannins exist in two conformations that are in slow exchange in the NMR timescale (s), one is compact and the other extended. The compact form is found to dominate (76-98%) when the dimer is made of at least one CAT monomer (B1, B3, B4). Both forms are found in even proportions only in the case of procyanidin B2. The latter tannin can be converted into a dominant compact form when the lower EPI unit is galloylated. The finding of a predominant compact form for procyanidin dimers is discussed in relation with tannin-saliva protein interactions that are of importance for the wine-tasting/making processes. Copyright  2006 John Wiley & Sons, Ltd. KEYWORDS: procyanidin dimers; NMR; molecular modeling; 3D structure INTRODUCTIONTannins play a central role in red wine flavour and in mouth-feel sensations such as astringency. 1 It is now well established that astringency is a tactile sensation 2,3 that results from the binding of polyphenols with one category of salivary proteins, the Proline-Rich Proteins (PRP). 4 -6 Interestingly, this type of interaction governs also leather tanning processes. 7 It is strong enough to bring on the subsequent precipitation of the complex, thus modifying the lubricating properties of saliva. 8 The principal source of wine tannins comes from the grape, and particularly from its solids parts, skins, seeds and stems. They are transferred to wine during wine-making operations (crushing, maceration and fermentation). 9 They are polymers of flavan-3-ols, also called proanthocyanidins or condensed tannins and they are able to reach a concentration up to 3 g/l, depending on vine variety, vintage, soil and wine-making practice. 10 Procyanidins are able to self-associate in a nonspecific way, leading to colloidal and/or aggregate formation. 11,12 Understanding this physicochemical behavior in a wine-like medium is of importance because it first determines the limpidity of wine, a quality that is demanded by consumers. Secondly, it governs the tannins' bioavailability by reducing their effective concentration with regard to their astringency partner, saliva proteins. Because 3D structure can influence physicochemical behavior, we firstly focus our attention on the comparison of the three-dimensional structure of procyanidin dimers throughout five examples (Scheme 1) that differ by the nature of their constitutive units and by the presence of a galloyl group on the lower unit. In this study, two approaches were simultaneously developed: NMR with its classical battery of two-dimensional experiments, which gave access to structural data throughout, coupling constant values and NOE values, and molecular modeling calculations in order to obtain clusters of minimized structures. The structures ...

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Section: Introductionmentioning

confidence: 99%

A 3D structural and conformational study of procyanidin dimers in water and hydro‐alcoholic media as viewed by NMR and molecular modeling

Tarascou

Barathieu

Simon

et al. 2006

Magnetic Reson in Chemistry

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“…Foi também descrita a atuação regulatória dos taninos sobre algumas enzimas intracelulares. A atividade antimicrobiana exercida por essa classe de compostos ocorre por mecanismos distintos: atividade antioxidante e seqüestradora de radicais livres, complexação com íons metálicos e capacidade de se complexar com moléculas orgânicas, como, por exemplo, proteínas e carboidratos da classe dos polissacarídeos (Haslam, 1996). Outras atividades biológicas dos taninos atribuídas à fisiologia humana são: a estimulação de células fagocitárias e a ação tumoral e atividades anti-infectivas (Loguércio, 2005).…”

Section: Discussionunclassified

Atividade Antinociceptiva e Antimicrobiana da Casca do Caule de Psidium Cattleyanum Sabine

Alvarenda

Royo

Mota

et al. 2015

Rev. bras. plantas med.

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RESUMO:Psidium cattleyanum Sabine, conhecida como "araçá", é espécie nativa do Bioma Cerrado brasileiro comumente utilizado, segundo levantamento etnobotânico, como planta medicinal para tratar várias doenças tais como: patologias hepáticas, gástricas, lesões teciduais incluindo processos dolorosos. O objetivo deste trabalho foi realizar a triagem fitoquímica com propósito exploratório, investigar a atividade analgésica e antimicrobiana do extrato hidroalcoólico da casca do caule de Psidium cattleyanum Sabine (ECPCS) para apoiar o uso dessa espécie como planta medicinal. Para isso, foram obtidos extratos e frações com solventes orgânicos de polaridade crescente (hexano, diclorometano, acetato de etila e isobutanol) avaliando-se o perfil fitoquímico para determinar as principais classes de metabólitos secundários presentes na espécie. Investigou-se a atividade analgésica pelo teste de contorções abdominais em camundongos induzidas pelo ácido acético (0,6%). A Concentração Inibitória Mínina (CIM) e Concentração Bactericida Mínima (CBM) foram avaliadas através da técnica de microdiluição em caldo contra micro-organismos da microbiota oral. A triagem fitoquímica identificou a presença de taninos, saponinas, flavonoides e terpenos e/ou esteroides. O ECPCS exibiu atividade analgésica periférica nas doses de 200 e 400 mg/kg. O EAC (extrato acetato de casca) o EDC (extrato diclorometânico de casca) desempenharam melhor ação inibitória sobre o crescimento bacteriano de Estafilococos oralis com CIM 100 e 150 respectivamente. O ECPCS desempenhou ação inibitória sobre o crescimento bacteriano. Os resultados dos estudos experimentais comprovaram a presença de compostos secundários tais como, taninos e flavonoides, o que, provavelmente, pode ser associado à atividade analgésica e ao efeito inibitório sobre os micro-organismos testados com o ECPCS, o que justifica o uso medicinal planta.Palavras Chave: Myrtaceae, araçá, atividade biológica, inibição álgica, atividade antibacteriana.ABSTRACT: Antiniciceptive and antimicrobial activity of the stem bark of Psidium cattleyanum Sabine. The Psidium cattleyanum Sabine, known as "araçá", is a native species from the Brazilian Cerrado biome, commonly used, according to ethnobotanical surveis, as a medicinal plant to treat several sicknesses such as liver and , gastric diseases and tissue lesions with painful treatments. The aim of this study was to perform an exploratory screening, investigating the analgesic and antimicrobial activity of the hydroalcoholic extract of the Psidium cattleyanum Sabine (BEPCS) stem bark, in order to support the use of this species as a medicinal plant. For that, the BEPCS and its parts were obtained from the extraction with organic solvents of increasing polarity (hexane, dichloromethane, ethyl acetate and isobutanol), evaluating its phytochemical profile in order to determine the main types of secondary metabolites present in the species. The analgesic activity, through the twisting test in mice, was investigated and induced by acetic acid (0.6%). The Min...

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“…For example, Hirtellin C, woodfordin C, oenothein B, cuphiins D 1 and D 2 , and other macrocyclic hydrolyzable tannins have antitumor effects in vivo and in vitro (Miyamoto et al, 1993a;Kashiwada et al, 1992;Wang et al, 1999). Haslam also suggested that the molecular size of the polyphenol is important; in the galloyl-D-glucose series, the efficacy of binding increases as the number of galloyl groups increases in the order of: triB tetraB penta (Haslam, 1996). Moreover, as to hydrolysable tannin-induced DNA fragmentation, the highest activity was detected in gallic acid, a component unit of tannin (Sakagami et al, 1995).…”

Section: Discussionmentioning

confidence: 99%

“…In a previous report, we isolated and characterized a macrocyclic hydrolyzable tannin dimer, camelliin B (CB), from the leaves of this plant (Chang et al, 1994). Hydrolyzable tannins have been shown to have antiviral (Nakashima et al, 1992), antimicrobial (Burapadaja and Bunchoo, 1995), antioxidant (Satoh and Sakagami, 1996), and hepatoprotective activities (Miyamoto et al, 1993a) as well as antitumor effects (Haslam, 1996). The potency of the activities depends on the structure of the tannins.…”

Section: Introductionmentioning

confidence: 99%