Disease relevance of Proanthocyanidins

• Inhibition of the adherence of P-fimbriated Escherichia coli to uroepithelial-cell surfaces by proanthocyanidin extracts from cranberries [1].
• Grape seed proanthocyanidin reduces cardiomyocyte apoptosis by inhibiting ischemia/reperfusion-induced activation of JNK-1 and C-JUN [2].
• Herein, we investigated the in vitro and in vivo anticancer effects and associated mechanisms of grape seed extract (GSE), a rich source of proanthocyanidins, against colorectal cancer [3].
• RESULTS: In rats treated with 50 and 100 mg grape seed proanthocyanidins/kg, the incidence of reperfusion-induced ventricular fibrillation was reduced from its control value of 92% to 42% and 25%, respectively (P < 0.05 for both) [4].
• Grape seed proanthocyanidins induce apoptosis and inhibit metastasis of highly metastatic breast carcinoma cells [5].

High impact information on Proanthocyanidins

• Anthocyanidin reductase encoded by the BANYULS (BAN) gene is the core enzyme in proanthocyanidin (PA) biosynthesis [6].
• Therefore, our results strongly suggest that stringent spatial and temporal BAN expression, and thus proanthocyanidin accumulation, are determined at least partially by TT2 [7].
• In Arabidopsis, proanthocyanidins specifically accumulate in the endothelium during early seed development [7].
• Microscopic analysis of tt12 developing and mature testas revealed a strong reduction of proanthocyanidin deposition in vacuoles of endothelial cells [8].
• The Arabidopsis TT2 gene encodes an R2R3 MYB domain protein that acts as a key determinant for proanthocyanidin accumulation in developing seed [7].

Chemical compound and disease context of Proanthocyanidins

• The O-glycosidic flavonoids and the oligomeric proanthocyanidins exhibited significant inhibitory activity against herpes simplex virus type 1 (HSV-1), which was shown to be due to an extracellular mechanism for procyanidin C-1 [9].
• This study examined the effects of 3 flavonoid-enriched fractions (a crude fraction, an anthocyanin-enriched fraction, and a proanthocyanidin-enriched fraction), which were prepared from lowbush blueberries (Vaccinium angustifolium), on MMP activity in DU145 human prostate cancer cells in vitro [10].
• Prodelphinidin B-2 3'-O-gallate, a proanthocyanidin gallate isolated from green tea leaf, was investigated for its anti-proliferative activity in human non-small cell lung cancer A549 cells [11].
• The genotoxic and antigenotoxic activities of catechin, hamamelitannin and two proanthocyanidin fractions prepared from the bark of Hamamelis virginiana L. were investigated in a human derived, metabolically competent hepatoma cell line (Hep G2) using single cell gel electrophoresis (SCGE) for the detection of DNA-damage [12].
• In this report, we provide evidence that red wine extract as well as resveratrol and proanthocyanidins are equally effective in reducing myocardial ischemic reperfusion injury, which suggests that these red wine polyphenolic antioxidants play a crucial role in cardioprotection [13].

Biological context of Proanthocyanidins

• TT2 expression was restricted to the seed during early embryogenesis, consistent with BAN expression and the proanthocyanidin deposition profile [7].
• Grape seed proanthocyanidins inhibit UV-radiation-induced oxidative stress and activation of MAPK and NF-kappaB signaling in human epidermal keratinocytes [14].
• Although bioavailability and metabolism data on polyphenols in general and proanthocyanidins in particular are still largely unavailable, the first reports indicate that at least monomers and smaller oligomeric procyanidins are absorbed [15].
• Leucocyanidin reductase, the enzyme that controls entry of metabolites into the proanthocyanidin pathway, was activated both in foliage and in developing seeds of the Lc transgenic alfalfa genotypes [16].
• In addition, the protective role of proanthocyanidins against lipid peroxidation and peroxynitrite, as well as their antimicrobial properties will be discussed [15].

Anatomical context of Proanthocyanidins

• A plasma membrane H+-ATPase is required for the formation of proanthocyanidins in the seed coat endothelium of Arabidopsis thaliana [17].
• Upregulation of oxidant-induced VEGF expression in cultured keratinocytes by a grape seed proanthocyanidin extract [18].
• The results indicated significant induction of JNK-1 and c-fos proteins in the ischemic/reperfused myocardium, which was inhibited by the proanthocyanidin extract [2].
• The Arabidopsis TDS4 gene encodes leucoanthocyanidin dioxygenase (LDOX) and is essential for proanthocyanidin synthesis and vacuole development [19].
• BACKGROUND: Proanthocyanidins, the most abundant polyphenols in chocolate, are not depolymerized in the stomach and reach the small intestine intact, where they are hardly absorbed because of their high molecular weight [20].

Associations of Proanthocyanidins with other chemical compounds

• Immunohistochemistry indicates that a reduction in caspase-3 activity and apoptotic cells by the extract, beside other potential action mechanisms of proanthocyanidin, trans-resveratrol, and flavonoid components of the extract, could be responsible for the cardioprotection in ischemic-reperfused myocardium [21].
• Subfraction F2.4 is composed of proanthocyanidin polymers of prodelphinidin and prorobinetinidin units and gallic acid of molecular weight 2114 Da [22].
• In an in vitro experiment using human plasma, proanthocyanidin-rich extract added to the plasma inhibited the oxidation of cholesteryl linoleate in LDL, but not in the LDL isolated after the plasma and the extract were incubated in advance [23].
• Concentrations of total soluble phenolics, catechin, proanthocyanidins (PA), lignin and nitrogen (N) were measured in loblolly pine (Pinus taeda L.) needles exposed to either ambient CO(2) concentration ([CO(2)]), ambient plus 175 or ambient plus 350 micromol CO(2) mol(-1) in branch chambers for 2 years [24].
• Phenylpropanes, flavonol derivatives, biflavones, proanthocyanidins, xanthones, phloroglucinols, some amino acids, naphthodianthrones and essential oil constituents are the natural plant products known from the crude drug of Hypericum perforatum, Hyperici herba [25].

Gene context of Proanthocyanidins

• Grape seed extract proanthocyanidins downregulate HIV-1 entry coreceptors, CCR2b, CCR3 and CCR5 gene expression by normal peripheral blood mononuclear cells [26].
• In contrast, the PA contents decreased in seeds of transgenic plants transformed with a PAP1 cDNA or with a PAP1 chimeric repressor, although the amount of soluble anthocyanins increased in seeds of transgenic plants over-expressing PAP1 cDNA [27].
• Suppression of the biosynthesis of proanthocyanidin in Arabidopsis by a chimeric PAP1 repressor [28].
• The crude extracts, anthocyanin and proanthocyanidin fractions were not highly active in QR induction whereas the ethyl acetate extracts were active QR inducers [29].
• The intragastric administration of proanthocyanidin (200 mg kg(-1) daily) significantly inhibited tumour growth, and increased NK cell cytotoxicity, lymphocyte proliferation, CD4+/CD8+ ratio, IL-2 and INF-gamma production [30].

Analytical, diagnostic and therapeutic context of Proanthocyanidins

• Proanthocyanidin biosynthesis in plants. Purification of legume leucoanthocyanidin reductase and molecular cloning of its cDNA [31].
• Newly isolated proanthocyanidins, structure elucidation, syntheses, HPLC/MS analysis, NMR/ conformational analysis, and the effects of proanthocyanidins on human nutrition and health are reported [32].
• In rats treated with 100 mg proanthocyanidins/kg, the recovery of coronary flow, aortic flow, and developed pressure after 60 min of reperfusion was improved by 32% +/- 8%, 98% +/- 8%, and 37% +/- 3%, respectively (P < 0.05 for all) compared with untreated control rats [4].
• Determination of proanthocyanidins in grape products by liquid chromatography/mass spectrometric detection under low collision energy [33].
• As part of our efforts to develop newer and effective chemopreventive agents for PCA, we evaluated the effect of proanthocyanidins from grape seeds (GSP) on metastasis-specific MMP-2 and -9 in human prostate carcinoma DU145 cells by employing western blot and gelatinolytic zymography [34].

References