141 research outputs found

    High expression of the Pi-transporter SLC20A1/Pit1 in calcific aortic valve disease promotes mineralization through regulation of Akt-1

    Get PDF
    The regulation of phosphate (Pi) handling is crucial during calcification of the aortic valve. Gene profiling of Pi transporters revealed that VIC culture expresses SLC201A1/Pit1 and SLC20A2/Pit2. On exposure to a mineralizing medium (2 mM Pi), the expression of Pi transporters in VIC culture is increased several folds, with the highest magnitude for SLC20A1. By using siRNAs, we established that silencing SLC20A1 significantly reduced Pi-induced mineralization of VICs. In human pathological specimens, we found that the expression of SCL20A1 was increased in CAVD tissues compared to control nonmineralized aortic valves. Treatment of VIC culture with Pi promoted the loss of mitochondrial membrane potential (DYm) and cytochrome c release within the cytosol, leading to apoptosis. Inhibition of Pi transporters with phosphonoformic acid (PFA) prevented Pi-mediated apoptosis of VICs. Moreover, we discovered that the level of the Akt-1 transcript is diminished in CAVD tissues compared with control valves. Accordingly, treatment with Pi caused a reduction of the Akt-1 transcript in VIC culture, and treatment with PFA or siRNA against SLC20A1 restored the level of Akt-1. Overexpression of Akt-1 (pCMVAkt-1) prevented both Pi-induced apoptosis and mineralization of VIC culture. These results strongly suggest that overexpression of SLC20A1 promotes apoptosis and mineralization by altering the level of Akt-1

    Optimization of Extraction Process for Antidiabetic and Antioxidant Activities of Kursi Wufarikun Ziyabit Using Response Surface Methodology and Quantitative Analysis of Main Components

    Get PDF
    By using extraction yield, total polyphenolic content, antidiabetic activities (PTP-1B and α-glycosidase), and antioxidant activity (ABTS and DPPH) as indicated markers, the extraction conditions of the prescription Kursi Wufarikun Ziyabit (KWZ) were optimized by response surface methodology (RSM). Independent variables were ethanol concentration, extraction temperature, solid-to-solvent ratio, and extraction time. The result of RSM analysis showed that the four variables investigated have a significant effect (p<0.05) for Y1, Y2, Y3, Y4, and Y5 with R2 value of 0.9120, 0.9793, 0.9076, 0.9125, and 0.9709, respectively. Optimal conditions for the highest extraction yield of 39.28%, PTP-1B inhibition rate of 86.21%, α-glycosidase enzymes inhibition rate of 96.56%, and ABTS inhibition rate of 77.38% were derived at ethanol concentration 50.11%, extraction temperature 72.06°C, solid-to-solvent ratio 1 : 22.73 g/mL, and extraction time 2.93 h. On the basis of total polyphenol content of 48.44% in this optimal condition, the quantitative analysis of effective part of KWZ was characterized via UPLC method, 12 main components were identified by standard compounds, and all of them have shown good regression within the test ranges and the total content of them was 11.18%

    Characterization of phenolic compounds in Helichrysum melaleucumby high-performance liquid chromatography with on-line ultraviolet and mass spectrometry detection

    Get PDF
    Helicrysum melaleucum is a medicinal plant traditionally used in the islands of the Macaronesia region for the treatment of respiratory diseases. In this work, the phenolic compounds of Helicrysum melaleucum plants collected in different geographical locations of Madeira Island and their morphological parts (total aerial parts, leaves, flowers and stems) were extracted and analyzed separately by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC-DAD/ESI-MS(n)). A total of 68 compounds were characterized based mainly on their UV and mass spectra. These included derivatives of O-glycosylated flavonoids (flavonol and flavones type), quinic acid, caffeic acid, lignans and polyphenols. The flowers were found to be the morphological part with higher variety of phenolic compounds. The large differences in the phenolic composition of plants collected from different geographical locations allowed the identification of a few components, such as pinoresinol and methoxylated flavone derivatives, likely to be useful as geographical markers. Also, these results promote further comparison of the bioactivities of the different samples analyzed. This paper marks the first report on the chemical analysis of Helichrysum melaleucum species.info:eu-repo/semantics/publishedVersio

    Impact of plasma Lp-PLA2 activity on the progression of aortic stenosis : the PROGRESSA study.

    Get PDF
    Objectives : The purpose of this prospective study was to examine the relationship between plasma lipoprotein–associated phospholipase A2 (Lp-PLA2) activity and the progression rate of aortic stenosis (AS). Background : We recently reported that Lp-PLA2 is highly expressed in stenotic aortic valves where it may contribute to the mineralization of valvular interstitial cells. Methods : Patients with AS were prospectively recruited in the PROGRESSA (Metabolic Determinants of the Progression of Aortic Stenosis) study. AS progression rate was assessed by annualized increase in peak aortic jet velocity (Vpeak), mean gradient (MG), and aortic valve area index (AVAi). Circulating Lp-PLA2 activity was measured and dichotomized based on the median value. Results : Of 183 patients included in this subanalysis of the PROGRESSA study, 70% were men and the mean age was 66 ± 13 years. Over the 2.5 ± 1.4 years of follow up, the AS progression rate tended to be higher in patients with high versus low Lp-PLA2 activity (annualized Vpeak = 0.17 ± 0.23 m/s vs. 0.12 ± 0.18 m/s; p = 0.14). There was a significant interaction (p < 0.05) between baseline AS severity and Lp-PLA2 activity with respect to impact on AS progression rate. In patients with mild AS (i.e., Vpeak <3 m/s; n = 123), increased Lp-PLA2 activity was associated with a significantly faster AS progression rate (Vpeak 0.16 ± 0.18 m/s vs. 0.09 ± 0.14 m/s; p = 0.01) but not in patients with moderate or severe AS (p = 0.99). After adjustment for other risk factors, increased Lp-PLA2 activity remained independently associated with faster AS progression rate (p = 0.005) in the former subset. Conclusions : There was no significant association between plasma Lp-PLA2 activity or mass and stenosis progression in the whole cohort. However, increased Lp-PLA2 activity was associated with a faster stenosis progression rate in the subset of patients with mild AS. These findings provide an impetus for the elaboration of a randomized trial targeting Lp-PLA2 activity in patients with early stages of calcific aortic valve disease

    Analysis of phenolic compounds from different morphological parts of Helichrysum devium by liquid chromatography with on-line UV and electrospray ionization mass spectrometric detection

    Get PDF
    A simple and rapid method has been used for the screening and identification of the main phenolic compounds from Helichrysum devium using high-performance liquid chromatography with on-line UV and electrospray ionization mass spectrometric detection (LC-DAD/ESI-MS(n)). The total aerial parts and different morphological parts of the plant, namely leaves, flowers and stems, were analyzed separately. A total of 34 compounds present in the methanolic extract from Helichrysum devium were identified or tentatively characterized based on their UV and mass spectra and retention times. Three of these compounds were positively identified by comparison with reference standards. The phenolic compounds included derivatives of quinic acid, O-glycosylated flavonoids, a caffeic acid derivative and a protocatechuic acid derivative. The characteristic loss of 206 Da from malonylcaffeoyl quinic acid was used to confirm the malonyl linkage to the caffeoyl group. This contribution presents one of the first reports on the analysis of phenolic compounds from Helichrysum devium using LC-DAD/ESI-MS(n) and highlights the prominence of quinic acid derivatives as the main group of phenolic compounds present in these extracts. We also provide evidence that the methanolic extract from the flowers was significantly more complex when compared to that of other morphological parts.info:eu-repo/semantics/publishedVersio

    Multi-substrate flavonol O-glucosyltransferases from strawberry (Fragaria×ananassa) achene and receptacle

    Get PDF
    In an effort to characterize fruit ripening-related genes functionally, two glucosyltransferases, FaGT6 and FaGT7, were cloned from a strawberry (Fragaria×ananassa) cDNA library and the full-length open reading frames were amplified by rapid amplification of cDNA ends. FaGT6 and FaGT7 were expressed heterologously as fusion proteins in Escherichia coli and target protein was purified using affinity chromatography. Both recombinant enzymes exhibited a broad substrate tolerance in vitro, accepting numerous flavonoids, hydroxycoumarins, and naphthols. FaGT6 formed 3-O-glucosides and minor amounts of 7-O-, 4′-O-, and 3′-O-monoglucosides and one diglucoside from flavonols such as quercetin. FaGT7 converted quercetin to the 3-O-glucoside and 4′-O-glucoside and minor levels of the 7- and 3′-isomers but formed no diglucoside. Gene expression studies showed that both genes are strongly expressed in achenes of small-sized green fruits, while the expression levels were generally lower in the receptacle. Significant levels of quercetin 3-O-, 7-O-, and 4′-O-glucosides, kaempferol 3-O- and 7-O-glucosides, as well as isorhamnetin 7-O-glucoside, were identified in achenes and the receptacle. In the receptacle, the expression of both genes is negatively controlled by auxin which correlates with the ripening-related gene expression in this tissue. Salicylic acid, a known signal molecule in plant defence, induces the expression of both genes. Thus, it appears that FaGT6 and FaGT7 are involved in the glucosylation of flavonols and may also participate in xenobiotic metabolism. The latter function is supported by the proven ability of strawberries to glucosylate selected unnatural substrates injected in ripe fruits. This report presents the first biochemical characterization of enzymes mainly expressed in strawberry achenes and provides the foundation of flavonoid metabolism in the seeds

    Historical textile dyeing with Genista tinctoria L.:a comprehensive study by UPLC-MS/MS analysis

    Get PDF
    Polyphenolic components from Genista species have been well characterised because of their potential as antioxidants and as therapeutic leads; however, the identification of dyer's greenweed (Genista tinctoria L.) in historical textiles has been the subject of only limited studies. This paper presents a comprehensive UPLC-PDA MS/MS study of reference and historical yarns dyed with this species. Several so far unreported dye components that could assist with the identification of this dye source, were characterised by MS/MS. Furthermore, the effect of photo-degradation and textile preparation techniques (such as over-dyeing) on the dye fingerprint was investigated and the results correlated with those obtained from historical samples from the Burrell and Bodleian collections, UK
    corecore