Targeted mutations of BnPAP2 lead to a yellow seed coat in Brassica napus L.

The yellow seed trait is preferred by breeders for its potential to improve the seed quality and commercial value of Brassica napus.In the present study,we produced yellow seed mutants using a CRISPR/Cas9 system when the two BnPAP2 homologs were knocked out.Histochemical staining of the seed coat demonstrated that proanthocyanidin accumulation was significantly reduced in the pap2 double mutants and decreased specifically in the endothelial and palisade layer cells of the seed coat.Transcriptomic and metabolite profiling analysis suggested that disruption of the BnPAP2 genes could reduce the expression of structural and regulated genes in the phenylpropanoid and flavonoid biosynthetic pathways.The broad suppression of these genes might hinder proanthocyanidin accumulation during seed development,and thereby causing the yellow seed trait in B.napus.These results indicate that BnPAP2 might play a vital role in the regulatory network controlling proanthocyanidin accumulation.

Quality Evaluation of Fermented Mulberry Wine

[Objectives]This study to conducted to clarify various nutritional components and the composition and contents of aromatic substances in mulberry wine prepared by fermentation,and promote the quality improvement and product development of mulberry wine.[Methods]Mulberry wine was prepared with mulberry Shengguo 1 as the material using Saccharomyces cerevisiae,and its contents of total sugars,total phenols,total acids,resveratrol,protein,dry extract,ethanol content,Fe,methanol,sulfur dioxide,volatile acids,total flavonoids and proanthocyanidins were determined.Aromatic substances were extracted by n-hexane,and their components and relative contents were determined by gas chromatography-mass spectrometry(GC-MS).[Results]The physical and chemical indexes of the mulberry wine prepared by fermentation were in accordance with the national standards,and it was rich in resveratrol(10.5±0.6 mg/L),protein(381±11 mg/L),total flavonoids(406±18 mg/L)and proanthocyanidins(855±22 mg/L),which were 8.95,19.49,3.76 and 1.63 times higher than those of grape wine,respectively.The aromatic substances were mainly composed of ethyl formate(9.9%),ethyl acetate(7.6%),acetal(6.2%),propanol(5.7%),isobutanol(5.6%)and isoamyl acetate(5.3%).[Conclusions]The results of this study demonstrated that mulberry wine was rich in active substances,which suggested that mulberry wine has great potential in the fruit wine market.

Proanthocyanidins prevent tau protein aggregation and disintegrate tau filaments

Occurrence of neurofibrillary tangles of the tau protein is a hallmark of tau-related neurodegenerative diseases, i.e. Alzheimer's disease(AD) and frontotemporal dementia. The pathological mechanism underlying AD remains poorly understood, and effective treatments are still unavailable to mitigate the disease.Inhibiting of tau aggregation and disrupting the existing fibrils are key targets in drug discovery towards preventing or curing AD. In this study, grape seed proanthocyanidins(GSPs) was found to effectively inhibit the repeat domain of tau(tau-RD) aggregation and disaggregate tau-RD fibrils in a concentrationdependent manner by inhibiting β-sheet formation of tau-RD. In cells, GSPs relieved cytotoxicity induced by tau-RD aggregates. Molecular dynamics simulations indicated that strong hydrogen bonding,hydrophobic interaction and π-π stacking between GSPs and tau-RD protein were major reasons why GSPs had high inhibitory activity on tau-RD fibrillogenesis. These results provide preliminary data to develop GSPs into medicines, foodstuffs or nutritional supplements for AD patients, suggesting that GSPs could be a candidate molecule in the drug design for AD therapeutics.

Transcriptome and weighted gene co-expression network analysis of jujube(Ziziphus jujuba Mill.)fruit reveal putative genes involved in proanthocyanin biosynthesis and regulation

Proanthocyanidin(PA)is an important bioactive compound with multiple physiological benefits in jujube(Ziziphus jujube Mill.).However,the molecular mechanisms underlying PA biosynthesis in jujube fruit have not been investigated.Here,the profiling of PA,(+)-catechin and(–)-epicatechin and transcriptome sequencing of three jujube cultivars from Xinjiang Uyghur Autonomous Region of China at five developmental stages were analyzed.The levels of total PAs and catechin exhibited a decreased trend over jujube ripening,and epicatechin content of two jujube cultivars increased first and then declined.Transcriptome analysis revealed that the differentially expressed genes(DEGs)were mainly enriched in ribosome,glycolysis/gluconeogenesis,fructose and mannose metabolism.17 DEGs encoding PAL,CHS,CHI,CHS,F3'H,LAR,ANR,C4Hs,4CLs,FLSs,DFRs and UFGTs involved in PA biosynthesis were relatively abundant.The highly transcribed LAR gene may greatly contribute to epicatechin accumulation.A weighted gene co-expression network analysis(WGCNA)was performed,and a network module including 1620 genes highly correlated with content of Pas and catechin was established.We identified 58 genes including 9 structural genes and 49 regulatory genes related to PA biosynthesis and regulation in the WGCNA module.Sixteen genes encoding 9 families of transcriptional factors(i.e.,MYB,bHLH,ERF,bZIP,NAC,SBP,MIKC,HB,WRKY)were considered as hub genes.The results of qRT-PCR analysis validating 10 genes were well consistent with the transcriptome data.These findings provide valuable knowledge to facilitate its genetic studies and molecular breeding.

The contribution of different polyphenol compositions from chokeberry produced in China to cellular antioxidant and antiproliferative activities

Abundant polyphenols make chokeberry have beneficial antioxidant and antiproliferative activity. In order to explore the contribution of different polyphenols in chokeberry to these activities, this study was conducted to determine polyphenol composition from 7 chokeberry varieties produced in China. Totally, 11 kinds of main polyphenol monomers were identified and quantified by UPLC-Q-TOF-MS and UPLC-PDA. HepG2 cells were used to evaluate their cellular antioxidant and antiproliferative activities. Partial least squares method was utilized to analyze multivariate correlations between proportion of different composition and monomers in total polyphenols with these activities. The results showed that the highest proportion in chokeberry polyphenols was proanthocyanidins. In comparing the bioactivities of 7 varieties of chokeberry, ‘Viking' and purple chokeberry had the strongest antioxidant activity, while 'Fukangyuan 1#' had the strongest antiproliferative activity. In terms of the contribution sources of these bioactivities, the total antioxidant activity of chokeberry mainly depended on the contribution of free polyphenols. As the main source of cellular antioxidant activity, anthocyanins and neochlorogenic acid can provide more contribution. The antiproliferative activity mainly depended on the proportion of free polyphenols and proanthocyanidins in total polyphenols. The results may provide some new possibilities for the comprehensive utilization of polyphenols from chokeberry.

BnbHLH92a negatively regulates anthocyanin and proanthocyanidin biosynthesis in Brassica napus

Yellow seed trait is a desirable characteristic with potential for increasing seed quality and commercial value in rapeseed,and anthocyanin and proanthocyanidins(PAs)are major seed-coat pigments.Few transcription factors involved in the regulation of anthocyanin and PAs biosynthesis have been characterized in rapeseed.In this study,we identified a transcription factor gene BnbHLH92a(BnaA06T0441000ZS)in rapeseed.Overexpressing BnbHLH92a both in Arabidopsis and in rapeseed reduced levels of anthocyanin and PAs.Correspondingly,the expression profiles of anthocyanin and PA biosynthesis genes(TT3,BAN,TT8,TT18,and TTG1)were shown by quantitative real-time PCR to be inhibited in BnbHLH92a-overexpressing Arabidopsis seeds,indicating that BnbHLH92a represses the anthocyanin and PA biosynthesis pathway in Arabidopsis.BnbHLH92a physically interacts with the BnTTG1 protein and represses the biosynthesis of anthocyanins and PAs in rapeseed.BnbHLH92a also binds directly to the BnTT18 promoter and represses its expression.These results suggest that BnbHLH92a is a novel upstream regulator of flavonoid biosynthesis in B.napus.

苹果露中多酚物质的含量测定

利用HPLC法对苹果露中的生理活性成分进行含量测定。HPLC法采用Kromasil C18(4.6 mm×150 mm)色谱柱,流动相采用甲醇(A)-水(B)梯度洗脱,流速为1 mL/min,柱温为25℃,检测波长为290 nm,测定苹果露中儿茶素和原花青素B2的含量,苹果多酚采用分光光度法测定;结果表明:苹果露中儿茶素和原花青素B2的平均含量分别为26.77mg/L和45.43 mg/L,苹果多酚为2.92 mg/mL;儿茶素、原花青素B2和苹果多酚在苹果露中均能检测到,且含量较高,为人们饮用苹果露对人体的保健作用提供了理论依据。

Grape Seed Proanthocyanidin Extract Alleviates Arsenic-induced Oxidative Reproductive Toxicity in Male Mice

Objective To determine the ability of grape seed proanthocyanidin extract （GSPE） in alleviating arsenic-induced reproductive toxicity. Methods Sixty male Kunming mice received the following treatments by gavage： normal saline solution （control）; arsenic trioxide （ATO; 4 mg/kg）; GSPE （400 mg/kg）; ATO＋GSPE （100 mg/kg）; ATO＋GSPE （200 mg/kg） and ATO＋GSPE （400 mg/kg）. Thereafter, the mice were sacrificed and weighed, and the testis was examined for pathological changes. Nuclear factor （erythroid-derived 2）-like 2 （Nrf2）, heme oxygenase 1 （HO1）, glutathione S-transferase （GST）, NAD（P）H dehydrogenase, and quinone 1 [NQO1） expression in the testis was detected by real-time PCR. Superoxide dismutase （SOD）, glutathione （GSH）, total antioxidative capability （T-AOC）, malondialdehyde （MDA）, 8-hydroxydeoxyguanosine （8-OHdG）, and reproductive indexes were analyzed. Results ATO-treated mice showed a significantly decreased sperm count and testis somatic index and activity levels of SOD, GSH, and T-AOC than control group. Compared to the ATO-treated group, ATO ＋GSPE group showed recovery of the measured parameters. Mice treated with ATO＋high-dose GSPE showed the highest level of mRNA expression of Nrf2, HO, NO.O1, and GST. Conclusion GSPE alleviates oxidative stress damage in mouse testis by activating Nrf2 signaling, thus counteracting arsenic-induced reproductive toxicity.

Anti-proteolytic capacity and bonding durability of proanthocyanidin-biomodified demineralized dentin matrix

Our previous studies showed that biomodification of demineralized dentin collagen with proanthocyanidin（PA） for a clinically practical duration improves the mechanical properties of the dentin matrix and the immediate resin–dentin bond strength. The present study sought to evaluate the ability of PA biomodification to reduce collagenase-induced biodegradation of demineralized dentin matrix and dentin/adhesive interfaces in a clinically relevant manner. The effects of collagenolytic and gelatinolytic activity on PA-biomodified demineralized dentin matrix were analysed by hydroxyproline assay and gelatin zymography. Then, resin-/dentin-bonded specimens were prepared and challenged with bacterial collagenases. Dentin treated with 2% chlorhexidine and untreated dentin were used as a positive and negative control, respectively. Collagen biodegradation, the microtensile bond strengths of bonded specimens and the micromorphologies of the fractured interfaces were assessed. The results revealed that both collagenolytic and gelatinolytic activity on demineralized dentin were notably inhibited in the PA-biomodified groups, irrespective of PA concentration and biomodification duration. When challenged with exogenous collagenases, PA-biomodified bonded specimens exhibited significantly less biodegradation and maintained higher bond strengths than the untreated control. These results suggest that PA biomodification was effective at inhibiting proteolytic activity on demineralized dentin matrix and at stabilizing the adhesive/dentin interface against enzymatic degradation, is a new concept that has the potential to improve bonding durability.

Inhibitory Effects of Grape Seed Proanthocyanidin Extract on Selenite-induced Cataract Formation and Possible Mechanism

This study investigated the inhibitory effect of grape seed proanthocyanidin extract(GSPE) on selenite-induced cataract formation in rats and the possible mechanism.Eighty 8-day-old Sprague-Dawley rats were divided randomly into 5 groups:control group,model group,three GSPE groups(low dose,medium dose and high dose).Control group received subcutaneous injection of physiological saline.Model group was given subcutaneous injection of sodium selenite(20 μmol/kg body weight) on the postpartum day 10,and once every other day for consecutive three times thereafter.GSPE treated groups were respectively administered GSPE at doses of 50,100,and 200 mg/kg body weight intragastrically 2 days prior to the selenite injection(that was,on the postpartum day 8),and once daily for fourteen consecutive days thereafter.The opacity of lenses was observed,graded and photographed under the slit lamp microscopy and the maximal diameter of the nuclear cataract plaques was measured.The lenses were analyzed for superoxide dismutase(SOD),catalase(CAT),glutathione peroxidase(GSH-PX),malondialdehyde(MDA),calcium(Ca 2+),nitric oxide(NO) and anti-hydroxyl radical ability(anti-OH).The histomorphology of lenses was observed with HE staining under a light microscope.The levels of calpainⅡ,and iNOS protein and mRNA expression in lenses were detected by using immunohistochemistry and real-time quantitative RT-PCR.The results showed subcutaneous injection of sodium selenite led to severe nuclear cataract in model group,and the achievement ratio of model group was 100%.As compared with model group,the degree of lenses opacity and the maximal diameter of nuclear cataract plaques were significantly reduced in GSPE-treated groups.Moreover,we observed selenite treatment caused a significant decrease in the activities of antioxidative enzymes(SOD,CAT,GSH-PX) and anti-OH ability,accompanied by a significant increase in the levels of MDA,NO,Ca 2+ as well as iNOS,and calpainⅡ protein and mRNA expression.Administration of GSPE could dose-dependently preserve the activities of these antioxidative enzymes and anti-OH ability,accompanied by a significant reduction in the levels of MDA,NO,Ca 2+ as well as iNOS,and calpainⅡ protein and mRNA expression.These results suggested that GSPE markedly prevented selenite-induced cataract formation probably by suppressing the generation of lipid peroxidation and free radicals as well as the activation of iNOS,and calpainⅡ in the lenses.

Grape Seed Proanthocyanidin Extract Ameliorates Streptozotocin-induced Cognitive and Synaptic Plasticity Deficits by Inhibiting Oxidative Stress and Preserving AKT and ERK Activities

Progressive memory loss and cognitive impairment are the main clinical manifestations of Alzheimer’s disease(AD).Currently,there is no effective drug available for the treatment of AD.Previous studies have demonstrated that the cognitive impairment of AD is associated with oxidative stress and the inhibition of AKT and ERK phosphorylation.Grape seed proanthocyanidin extract(GSPE)has been shown to have strong antioxidant effect and can protect the nervous system from oxidative stress damage.This study aimed to investigate the protective effect of GSPE on the cognitive and synaptic impairments of AD using a sporadic AD rat model induced by intracerebroventricular(ICV)injection of streptozotocin(STZ)(ICV-STZ).Rats were treated with GSPE(50,100,or 200 mg/kg every day)by intragastrical(ig.)administration for continuous 7 weeks,and ICV-STZ(3 mg/kg)was performed on the first day and third day of week 5.Learning and memory abilities were assessed by the Morris water maze(MWM)test at week 8.After behavioral test,hippocampal long-term potentiation(LTP)was recorded,and the levels of malondialdehyde(MDA),superoxide dismutases(SOD),glutathione(GSH)and the protein expression of AKT and ERK were measured in the hippocampus and cerebral cortex of rats.Our study revealed that ICV-STZ significantly impaired the working learning ability and hippocampal LTP of rats,significantly increased the levels of MDA,and decreased the activity of SOD and GSH in the hippocampus and cerebral cortex.In contrast,GSPE treatment prevented the impairment of cognitive function and hippocampal LTP induced by ICV-STZ,decreased the level of MDA,and increased the level of SOD and GSH.Furthermore,Western blot results showed that GSPE treatment could prevent the loss of AKT and ERK activities in the hippocampus and cerebral cortex induced by ICV-STZ.Our findings demonstrate that GSPE treatment could ameliorate the impairment of cognitive ability and hippocampal synaptic plasticity in a rat model of sporadic AD by inhibiting oxidative stress and preserving AKT and ERK activities.Therefore,GSPE may be an effective agent for the treatment of cognitive deficits associated with sporadic AD.

Quantitative Mitochondrial Proteomics Study on Protective Mechanism of Grape Seed Proanthocyanidin Extracts Against Ischemia/Reperfusion Heart Injury in Rat

Cardiac ischemia/reperfusion（I/R） injury is a critical condition,often associated with high morbidity and mortality.The cardioprotective effect of grape seed proanthocyanidin extracts（GSPE） against oxidant injury during I/R has been described in previous studies.However,the underlying molecular mechanisms have not been fully elucidated.This study investigated the effect of GSPE on reperfusion arrhythmias especially ventricular tachycardia（VT） and ventricular fibrillation（VF）,the lactic acid accumulation and the ultrastructure of ischemic cardiomyocytes as well as the global changes of mitochondria proteins in in vivo rat heart model against I/R injury.GSPE significantly reduced the incidence of VF and VT,lessened the lactic acid accumulation and attenuated the ultrastructure damage.Twenty differential proteins related to cardiac protection were revealed by isobaric tag for relative and absolute quantitation（iTRAQ） profiling.These proteins were mainly involved in energy metabolism.Besides,monoamine oxidase A（MAOA） was also identified.The differential expression of several proteins was validated by Western blot.Our study offered important information on the mechanism of GSPE treatment in ischemic heart disease.

Phytochemical and biological activities of Crataegus sinaica growing in Egypt

Objective:To evaluate the cardiac activity and hepatoprotection of Crataegus sinaica (C.sinaica).Methods:All the isolated compounds were isolated by open-column liquid chromatography(CC) using sephadex LH-20 as stationary phase.Elution of the column was performed with EtOH or MeOH.The phytochemical investigation of the young stem of C.sinaica for the first time together with the leaves and flowers lead to the isolation and identification of quercetin,hyperoside,vitexin-2"-0-rhamnoside,epicatechin,procyanidin B2 and procyanidins CI.Results:Rats treated with the low and high dose of C.sinaica leaves with flowers extract showed 15%and 17%reduction in the heart rate,and reduction in the STsegment by 107%and 57%;respectively.The T-amplitude was decreased by 59%of the high dose extract.On the other hand,the young steins and leaves with flowers extracts of C.sinaica on primary culture of rat hepatocytes monolayer indicated a hepatoprotection for the total extract,ethyl acetate,butanol,and chlor of orm fractions at 100μg/mL,75μg/mL,50μg/mL,and 25μg/mL; respectively.Conclusions:The results of these chemical and biological studies suggest the use of C.sinaica growing in Egypt as a preventive drug against cardiovascular and hepatic diseases. The chemical studies suggest the use of woody young stems as a newly investigated bioactive organ.The extraction of unsaturated fatty acids from the seeds of the plant would serve as a good health and nutritive product.

Overexpression of the LoMYB29 gene of Larix olgensis contributes to the regulation of proanthocyanidin biosynthesis in Arabidopsis thaliana

Proanthocyanidins(PAs)are the most broadly distributed secondary metabolites that play important roles in various aspects of plant development and response to biotic and abiotic stresses.In this study,we cloned a R2R3 MYB gene LoMYB29,which has a full-length coding sequence of 921 bp identified in Larix olgensis.Quantitative real-time reverse transcription polymerase chain reaction analysis indicates that LoMYB29 is expressed under mechanical wounding,high light intensity,and NaCl,PEG6000,Methyl Jasmonate,and abscisic acid treatments.Subcellular localization analysis and yeast twohybrid assay localized LoMYB29 to the nucleus,acting as a transcriptional activator.Staining with 4-dimethylaminocinnamaldehyde showed a darker blue-purple color in LoMYB29-overexpressing Arabidopsis seeds compared to that of wild seeds.LoMYB29-overexpression resulted in a significant increase in leaf PA content.The expression of early flavonoid biosynthesis-related gene CHI and late flavonoid biosynthesis-related genes,including DFR,LDOX,and ANR(PA branch gene),were also activated in transgenic plants overexpressing LoMYB29.The results indicate that LoMYB29 plays a positive role in the regulation of PA biosynthesis by activating the expression of PA biosynthetic genes.

Grape seed proanthocyanidin protects liver against ischemia/reperfusion injury by attenuating endoplasmic reticulum stress

AIM: To explore the effect of grape seed proanthocyanidin(GSP) in liver ischemia/reperfusion(IR) injury and alleviation of endoplasmic reticulum stress.METHODS: Male Sprague-Dawley rats(220-250 g) were divided into three groups, namely, sham, IR, and GSP groups(n = 8 each). A liver IR(70%) model was established and reperfused for 6 h. Prior to reperfusion, the GSP group was administered with GSP(100 mg/kg) for 15 d, and liver histology was then investigated. Serum aminotransferase and inflammatory mediators coupled with superoxide dismutase and methane dicarboxylic aldehyde were detected. Western blot was conducted to analyze the expression of glucoseregulated protein 78, CCAAT/enhancer-binding protein homologous protein, activating transcription factor-4, inositol-requiring enzyme-1, procaspase-12, and nuclear factor-κb. Apoptotic cells were detected by TUNEL staining.RESULTS: The serum aminotransferase, apoptotic cells, and Suzuki scores decreased in the GSP group compared with the IR group(P s < 0.05). The methanedicarboxylic aldehyde level was decreased in the GSP group, but the superoxide dismutase level was reversed(P s < 0.05). Similarly, GSP downregulated the proinflammatory factors and upregulated the levels of anti-inflammatory factors(Ps < 0.05). Western blot data showed that GSP increased glucose-regulated protein 78 expression and suppressed expression of CCAAT/enhancer-binding protein homologous protein, activating transcription factor-4, inositol-requiring enzyme-1, procaspase-12, and nuclear factor-κb compared with the IR group.CONCLUSION: GSP possesses antioxidative, anti-inflammatory, and antiapoptotic effects by relieving endoplasmic reticulum stress through regulation of related signaling pathways to protect the liver against IR injury.

Protective effect of ginkgo proanthocyanidins against cerebral ischemia/reperfusion injury associated with its antioxidant effects

Proanthocyanidins have been shown to effectively protect ischemic neurons, but its mechanism remains poorly understood. Ginkgo proan-thocyanidins （20, 40, 80 mg/kg） were intraperitoneally administered 1, 24, 48 and 72 hours before reperfusion. Results showed that ginkgo proanthocyanidins could effectively mitigate neurological disorders, shorten infarct volume, increase superoxide dismutase activity, and de-crease malondialdehyde and nitric oxide contents. Simultaneously, the study on grape seed proanthocyanidins （40 mg/kg） confirmed that different sources of proanthocyanidins have a similar effect. The neurological outcomes of ginkgo proanthocyanidins were similar to that of nimodipine in the treatmen＇t of cerebral ischemia/reperfusion injury. （Sur results suggestthat-ginkgo proanthocyanidins can effectively lessen cerebral ischemia/reperfusion injury and protect ischemic brain tissue and these effects are associated with antioxidant properties.

Protective effects of proanthocyanidins on beta-amyloid peptide (25-35)-induced PC12 cell apoptosis by blocking S-phase and increasing p53 gene expression

BACKGROUND： Current studies related to the effects of proanthocyanidins on Alzheimer＇s disease have focused primarily on the signal transduction pathway of cellular apoptosis. However, the influence of p53 gene expression on cell cycle regulation, with regard to the protective mechanisms of proanthocyanidins, has not been reported. OBJECTIVE： To observe the effect of proanthocyanidins on cell cycle distribution, cellular apoptosis and p53 gene expression in β-amyloid peptide （25-35） （Aβ25-35）-induced PC12 cells cultured in serum-free media, and to investigate the molecular neuroprotective mechanisms of proanthocyanidins with regard to cell cycle regulation. DESIGN, TIME AND SETTING： A parallel, controlled, at the Institute of Biochemistry and Molecular Biology cellular, and molecular study was performed Guangdong Medical College from July 2006 to July 2008. MATERIALS： Proanthocyanidins were provided by Nanjing Xuezi Medical and Chemical Research Center, China; Aβ25-35 was provided by Sigma, USA; PC12 cells were provided by the Institute of Basic Medical Science, Academy of Military Medical Sciences; and rabbit anti-p53 polyclonal antibody was provided by Santa Cruz Biotechnology, USA. METHODS： PC12 cells were cultured in serum-free media for 24 hours. Cells from the model group were treated with 25 μmol/L Aβ25-35 for 24 hours. Cells in the drug protection group were pre-treated with 30 mg/L proanthocyanidins for 1 hour and then treated with 25 μmol/LAβ2^-35 for 24 hours. The control group was not treated. MAIN OUTCOME MEASURES： Flow cytometry was used to detect cell cycle distribution and rate of apoptosis; reverse-transcriptase polymerase chain reaction was used to detect p53 mRNA expression; and Western blot was used to detect p53 protein expression. RESULTS： After treating with 25 μmol/LAβ25-35 for 24 hours, the rate of apoptosis and the percentage of cells in S phase were significantly increased （P 〈 0.01 ）, and p53 mRNA and protein expressions were decreased. Pretreatment with proanthocyanidins for 1 hour blocked the increase in apoptosis and the percentage of cells in S phase in Aβ25-35-induced PC12 cells （P 〈 0.01 ） and increased p53 mRNA and protein expressions. CONCLUSION： Proanthocyanidins blocked apoptosis and S-phase arrest in Aβ25-35-induced PC12 cells cultured in serum-free media. The protective mechanism could be related to increased p53 mRNA and protein expressions.

Dietary flavonoid intake and risk of stomach and colorectal cancer

Stomach and colorectal cancers are common cancers and leading causes of cancer deaths.Because the alimentary tract can interact directly with dietary components,stomach and colorectal cancer may be closely related to dietary intake.We systematically searched published literature written in English via PubMed by searching for terms related to stomach and colorectal cancer risk and dietary flavonoids up to June 30,2012.Twenty-three studies out of 209 identified articles were finally selected for the analysis.Log point effect estimates and the corresponding standard errors were calculated using covariate-adjusted point effect estimates and 95%CIs from the selected studies.Total dietary flavonoid intake was not associated with a reduced risk of colorectal or stomach cancer [odds ratio(OR)(95%CI) = 1.00(0.90-1.11) and 1.07(0.70-1.61),respectively].Among flavonoid subclasses,the intake of flavonols,flavan-3-ols,anthocyanidins,and proanthocyanidins showed a significant inverse association with colorectal cancer risk [OR(95%CI) = 0.71(0.63-0.81),0.88(0.79-0.97),0.68(0.56-0.82),and 0.72(0.61-0.85),respectively].A significant association was found only between flavonols and stomach cancer risk based on a limited number of selected studies [OR(95%CI) = 0.68(0.46-0.99)].In the summary estimates from casecontrol studies,all flavonoid subclasses except flavones and flavanones were inversely associated with colorectal cancer risk,whereas neither total flavonoids nor any subclasses of flavonoids were associated with colorectal cancer risk in the summary estimates based on the cohort studies.The significant association between flavonoid subclasses and cancer risk might be closely related to bias derived from the case-control design.There was no clear evidence that dietary flavonoids are associated with reduced risk of stomach and colorectal cancer.

Comparative Analysis of Proanthocyanidins and Polysaccharides on Wild Lycium ruthenicum

[Objectives] To compare content of proanthocyanidins and polysaccharides in wild Lycium ruthenicum. [Methods] The wild L. ruthenicum collected from different regions such as Qinghai, Inner Mongolia, Ningxia and Gansu Province were taken as the research objects. The conventional indicators such as proanthocyanidins and polysaccharides of the experimental materials were determined, and the proanthocyanidins and polysaccharides of the experimental materials in different regions were compared and analyzed. The difference in content and correlation, and the cluster analysis method were used to divide clusters of the experimental materials. [Results] The absorbance of proanthocyanidins in the fruit of wild L. ruthenicum was No.4>No.1>No.5>No.6>No.3>No.2, among which the absorbance of anthocyanin(2.43) of wild L. ruthenicum variety No.4 was significantly higher than other experimental materials(P<0.05), and proanthocyanidin of No.2 had the lowest absorbance value of 1.35. There was no significant difference between No.3 and No.6(P>0.05), and there were significant differences among other experimental materials(P<0.05). The content of polysaccharides was: No.3>No.7>No.2>No.4>No.5>No.6>No.1; there was no significant difference between No.3 and No.7(P>0.05), but significantly higher than other materials(P<0.05). Besides, proanthocyanidins and polysaccharides showed significant variability, but there was no consistency in the correlation between them. [Conclusions] In terms of the absorbance of proanthocyanidins, the experimental materials No.1 and No.4 can be classified into a cluster; experimental materials No.2, No.3, No.5 and No.6 can be classified into another cluster. This can provide a theoretical basis for the introduction and breeding of fine varieties.

Study on Differences in Procyanidine Content Between Muscat Hamburg Grape From Different Producing Areas

[Objectives] This study was conducted to analyze the differences in procyanidine content in grapes caused by different producing areas. [Methods]With Muscat Hamburg grape from different producing areas as an experimental material,procyanidine content was determined by n-butanol-hydrochloric acid colorimetry. [Results] The procyanidins contents in different parts of the same variety ranked as grape seed > grape skin > grape flesh. The procyanidins contents in grapes from different producing areas were in order of Changli County,Hebei Province > Dazeshan Town,Shandong Province > Hangu District,Tianjin City.[Conclusions]The procyanidins contents in Muscat Hamburg grapes from different producing areas differ to a certain degree.