This review summarizes the current knowledge of condensed tannins (proanthocyanidins), their chemical structure, classification and biological effects. These compounds are widely distributed in higher plants and are an important part of the human diet. Recent interest in these substances has been stimulated by their potential health benefits, which are believed to arise mainly from their antioxidant activity. The mechanisms of their antioxidation action, like free radical scavenging activity, chelation of transition metals and inhibition of prooxidative enzymes and lipid peroxidation are discussed. Health prevention properties like anticarcinogenic, cardiovascular system preventing and antiinflammatory effects of proanthocyanidins are also presented. Their health benefit is promising, but additional research on the mechanism of action and metabolic fate after consumption of proanthocyanidins is required.
Plants and their secondary metabolites, including flavonoids, exhibit a wide range of biological effects. Consequently, natural substances are receiving an increased attention in medicinal research. Owing to these facts, in vitro antiplatelet activity of ethanol summary extract and four flavonoids from Leuzea carthamoides was determined in human platelet-rich plasma. Arachidonic acid (AA), adenosine diphosphate (ADP), collagen (COL), and thrombin were used as agonists of platelet aggregation. The summary extract showed a significant inhibition of the aggregation induced by COL and ADP. Of the tested flavonoids, eriodictyol (1) and patuletin (2) influenced COL- and AA-induced aggregation. Their IC(50) values are presented. Flavonoid glycosides eriodictyol-7-beta-glucopyranoside (3) and 6-hydroxykaempferol-7-O-(6''-O-acetyl-beta-D[small cap]-glucopyranoside) (4) were found to be weak antiplatelet agents. These results confirmed the fact that glucosylation decreases the antiplatelet activity. Quantitative composition of tested flavonoids in L. carthamoides extract was also determined. Though two of the tested flavonoids inhibited platelet aggregation, further evaluation of L. carthamoides, in order to discover other antiplatelet active compounds and possible adverse health effects, is needed.
- MeSH
- adenosindifosfát metabolismus MeSH
- agregace trombocytů účinky léků MeSH
- chromony farmakologie MeSH
- financování organizované MeSH
- flavanony farmakologie MeSH
- flavonoidy farmakologie izolace a purifikace MeSH
- inhibitory agregace trombocytů farmakologie izolace a purifikace MeSH
- kempferoly farmakologie MeSH
- kolagen metabolismus MeSH
- kyselina arachidonová metabolismus MeSH
- Leuzea chemie MeSH
- lidé MeSH
- listy rostlin MeSH
- thrombin metabolismus MeSH
- trombocyty metabolismus účinky léků MeSH
- vyšetření funkce trombocytů MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- techniky in vitro MeSH
In recent years, great attention has been given to the search for natural compounds or extracts with the purpose of medical use. Evolvulus alsinoides L. (Convolvulaceae) is a plant used in traditional medicine of East Asia in many indications and has known nootropic and anti-inflammatory activity. However, the bioactive constituents have been described poorly in the literature. Four substances isolated from the ethanol extract of E. alsinoides by means of polyamide and Silica-gel chromatography are reported here. Their molecular structures were determined using NMR analyses. There were identified as scopoletin, umbelliferone, scopolin and 2-methyl-1,2,3,4-butanetetrol. The quantity of these substances was determined using HPLC-UV and GC-FID detection. Antioxidant activity of the isolated substances was measured by DPPH assay using the SIA method. Antioxidant activity and total phenolic content of the prepared fractions are also described. The prepared fractions and isolated substances did not exhibit any significant activity in DPPH test.
In recently, there has been a great interest in natural antioxidants as bioactive components of food, nutraceuticals or potential drugs against several diseases. In our study, 88 extracts from various parts of plants from European Asteraceae and Cichoriaceae were assayed for radical scavenging activity by means of DPPH (1,1-diphenyl-2-picryl hydrazyl radical) test using the SIA (Sequential injection analysis) method developed for this purpose in our laboratory. DPPH radical scavenging activity of all tested plant extracts was evaluated according to the IC(50) parameter. 29 extracts exhibited IC(50) value lower than 0.1 mg/mL. The leaves of Leuzea carthamoides (IC(50) = 0.046 mg/mL) were chosen as the most promising sample for a subsequent phytochemical study, which resulted in isolation of seven natural compounds, namely, 4',5,7-trihydroxy-6-methoxyflavone (hispidulin) (1), 5, 7, 3', 4'- tetrahydroxyflavanone (eriodictyol) (2), 3',4',5,7-pentahydroxy-6-methoxyflavonol (patuletin) (3), eriodictyol-7-beta-glucopyranoside (4), 6-hydroxykaempferol-7-O-(6''-O-acetyl-beta-D-glucopyranoside) (5), 4-hydroxybenzoic acid (6) and 3,4-dihydroxybenzoic acid (protocatechuic acid) (7). Antioxidant activity of the isolated compounds was evaluated by DPPH test and ferric reducing antioxidant power (FRAP) test and compared with trolox and quercetin. Both tests evaluated the flavonoid (5) as the most active antioxidant. This result was confirmed by comparison with known data concerning the structure/activity relationships of flavonoids.
- MeSH
- antioxidancia farmakologie chemie MeSH
- Asteraceae chemie MeSH
- bifenylové sloučeniny MeSH
- biologické přípravky farmakologie chemie MeSH
- chromany (dihydrobenzopyrany) chemie izolace a purifikace MeSH
- financování organizované MeSH
- hydraziny MeSH
- Leuzea chemie MeSH
- molekulární struktura MeSH
- pikráty MeSH
- preklinické hodnocení léčiv MeSH
- quercetin chemie izolace a purifikace MeSH
- Rhodophyta chemie MeSH
- rostlinné extrakty farmakologie chemie izolace a purifikace MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Geografické názvy
- Evropa MeSH
Natural polyphenols are a wide class of secondary plant metabolites and represent an abundant antioxidant component of human diet. An important, but often neglected group of natural polyphenols, are tannins. This review offers a general description of chemistry of both hydrolysable and condensed tannins (proanthocyanidins), the mechanisms of their antioxidation action, like free radical scavenging activity, chelation of transition metals, inhibition of prooxidative enzymes and lipid peroxidation. The mechanisms of action of antibacterial, antiviral, anticarcinogenic, cardiovascular system preventing, and antiinflammatory effects as well as the absorption, metabolic fate and positive in vivo effects of tannins are enclosed.
- MeSH
- antiflogistika nesteroidní farmakologie chemie terapeutické užití MeSH
- antiinfekční látky farmakologie chemie terapeutické užití MeSH
- antikarcinogenní látky farmakologie chemie terapeutické užití MeSH
- antioxidancia farmakologie chemie terapeutické užití MeSH
- financování organizované MeSH
- hydrolyzovatelné taniny farmakologie chemie terapeutické užití MeSH
- křenová peroxidasa antagonisté a inhibitory MeSH
- lidé MeSH
- lipoxygenasa účinky léků MeSH
- peroxidace lipidů účinky léků MeSH
- synthasa oxidu dusnatého antagonisté a inhibitory MeSH
- zdraví MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- přehledy MeSH
We have characterized a panel of commercially available anti-human monoclonal antibodies (mAbs) suitable for B-cell identification in pigs and dogs. The specificities of the mAbs were against CD20, CD21, CD22, and CD86. In addition to HM57, originally raised against human CD79alpha the broad cross-reactivity of which was documented more than 10 years ago, we recommend here a panel of several other mAbs as a useful tool for immunophenotyping and multicolor flow cytometry of canine and porcine B-lymphocytes. All six investigated antibodies did bind weakly to either canine or porcine lymphocytes (or both), but considerable weaker than for the human control cells. Four of them did bind to canine or porcine spleen section in immunohistochemistry. Monoclonal antibody against CD22 (clone RFB-4) was the only antibody in the tested panel the cross-reactivity of which was confirmed by Western blot. The advantages and limits of cross-reactive mAbs in studies on animal B-cells are discussed.
- MeSH
- B-lymfocyty imunologie MeSH
- CD antigeny imunologie MeSH
- financování organizované MeSH
- imunofenotypizace MeSH
- lidé MeSH
- monoklonální protilátky imunologie MeSH
- prasata imunologie MeSH
- průtoková cytometrie MeSH
- psi imunologie MeSH
- zkřížené reakce MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- psi imunologie MeSH
- zvířata MeSH
BACKGROUND: Ankylosing enthesopathy (ANKENT) with progressive stiffening of ankle and tarsal joints of the hind limbs is a naturally occurring arthropathy in B10.BR mice. Some features are similar to those of the spondyloarthropathies in humans. OBJECTIVE: To study the role of sexual dimorphism and testosterone in the development of ANKENT. METHODS: The incidence of ANKENT was observed in non-castrated, castrated, and testosterone substituted castrated male mice, and in control and testosterone treated female mice. RESULTS: ANKENT occurred only in males; it did not develop in males castrated at age 2-3 months but occurred in castrated males injected with testosterone. Females injected with testosterone did not develop ANKENT. CONCLUSION: Testosterone can replace what castration eliminates, at least in the postpubertally castrated males, but is itself not sufficient to induce joint disease.
