Flavonols Quercetin Research Articles

The Effect of Standardised Flower Extracts of Sorbus aucuparia L. on Proinflammatory Enzymes, Multiple Oxidants, and Oxidative/Nitrative Damage of Human Plasma Components In Vitro.

Polyphenol-rich plant extracts might alleviate the negative impact of oxidative stress and inflammation, but careful phytochemical standardisation and evaluation of various mechanisms are required to fully understand their effects. In this context, flower extracts of Sorbus aucuparia L.—a traditional medicinal plant—were investigated in the present work. The LC-MS/MS profiling of the extracts, obtained by fractionated extraction, led to the identification of 66 constituents, mostly flavonols (quercetin and sexangularetin glycosides with dominating isoquercitrin), pseudodepsides of quinic and shikimic acids (prevailing isomers of chlorogenic acid and cynarin), and flavanols (catechins and proanthocyanidins). Minor extract components of possible chemotaxonomic value were flavalignans (cinchonain I isomers) and phenylamides (spermidine derivatives). As assessed by HPLC-PDA and UV-spectrophotometric studies, the extracts were polyphenol-abundant, with the contents up to 597.6 mg/g dry weight (dw), 333.9 mg/g dw, 382.0 mg/g dw, and 169.0 mg/g dw of total phenolics, flavonoids, proanthocyanidins, and caffeoylquinic acids, respectively. Their biological in vitro effects were phenolic-dependent and the strongest for diethyl ether, ethyl acetate, and n-butanol fractions of the methanol-water (7 : 3, v/v) extract. The extracts showed significant, concentration-dependent ability to scavenge in vivo-relevant radical/oxidant agents (O2∙−, OH∙, H2O2, ONOO–, NO∙, and HClO) with the strongest effects towards OH∙, ONOO–, HClO, and O2∙− (compared to ascorbic acid). Moreover, the extracts efficiently inhibited lipoxygenase and hyaluronidase (compared to indomethacin) but were inactive towards xanthine oxidase. At in vivo-relevant levels (1-5 μg/mL), they also effectively protected human plasma components (proteins and lipids) against ONOO–-induced oxidative damage (reduced the levels of 3-nitrotyrosine, lipid hydroperoxides, and thiobarbituric acid-reactive substances) and normalised/enhanced the total nonenzymatic antioxidant capacity of plasma. In cytotoxicity tests, the extracts did not affect the viability of human PBMCs and might be regarded as safe. The results support the application of the extracts in the treatment of oxidative stress-related pathologies cross-linked with inflammatory changes.

High-Performance Liquid Chromatographic Method for the Simultaneous Determination of Four Flavonols in Food Supplements and Pharmaceutical Formulations

A method using high-performance liquid chromatography with diode array detection (HPLC-DAD) as a powerful separation technique has been developed for the simultaneous determination of the four flavonols rutin, quercetin, kaempferol and isorhamnetin in food supplements and pharmaceutical formulations. The chromatographic separation was achieved in 36 min using a Symmetry C18 column (250 × 3 mm; 5 µm) as the stationary phase and a mixture of methanol, acetonitrile, and pH 2.5 aqueous acetic acid as the mobile phase in gradient elution mode. The analytical wavelengths were 256 nm for rutin, quercetin and isorhamnetin, and 368 nm for kaempferol. An ultrasound-assisted extraction protocol was performed using methanol as solvent. The detection and quantification limits were lower than 0.03 µg mL−1 and 0.08 µg mL−1, respectively. The inter-day and intra-day precisions were less than 4.8 and 5.1%, respectively, and the average recoveries were in the range from 96 to 107%. The method was applied for the determination of the studied flavonols in food supplements and pharmaceutical preparations. The satisfactory recovery values demonstrate the potential of the developed method for the determination of the analytes in these samples. In addition, the method is suitable for routine quality control due its ease of operation.

Can agronomic practices and cold-pressing extraction parameters affect phenols and polyphenols content in hempseed oils?

Hemp seed oil is an extraordinary dietary source of polyunsaturated fatty acids (PUFAs), to huge health benefits are related. PUFAs abundance could indeed contribute the oil turning rancid and deteriorating through oxidation. Thus, antioxidant compounds, characteristic of hemp seed matrix, should be more favorably extract to hopefully safeguard the oil stability. Moreover, antioxidants ability to counteract the onset of oxidative stress-related diseases could be employed to further enhance hemp seed oil functional value. In this context, phenols and polyphenols, which are poorly explored in hempseed oil so far, are thoroughly investigated by untargeted UHPLC-HRMS and MS/MS techniques in seed oils from Cannabis sativa L. cv USO31. Data recorded highlighted that hemp seed oil could contain, as minor constituents, saccharides, phenol compounds (some of them never described before - e.g. tyrosol hexoside, caffeoyl tartaric acid isomers), as well as flavonoids, of which glycosides of flavonols quercetin, kaempferol and isorhamnetin were the most representative. Glucuronide derivatives were also present. Multivariate principal-component analysis (PCA) highlighted that agronomic practices (e.g. plant density/m2, use of fertilizers) and cold-pressing extraction parameters (e.g. temperature, nozzle size) massively affected the relative content of each compounds’ class. Hemp seeds from soils, which did not undergo pre-seeding fertilization, and with 60 plant/m2crop density, ensured the highest production of phenols and polyphenols, whereas their abundance could be compromised when the plant density was halved.

A Crucial Role of GA-Regulated Flavonol Biosynthesis in Root Growth of Arabidopsis

Flavonols have been demonstrated to play many important roles in plant growth, development, and communication with other organisms. Flavonol biosynthesis is spatiotemporally regulated by the subgroup 7 R2R3-MYB (SG7 MYB) transcription factors including MYB11/MYB12/MYB111. However, whether SG7-MYB activity is subject to post-translational regulation remains unclear. Here, we show that gibberellic acid (GA) inhibits flavonol biosynthesis via DELLA proteins in Arabidopsis. Protein-protein interaction analyses revealed that DELLAs (RGA and GAI) interacted with SG7 MYBs (MYB12 and MYB111) both in vitro and in vivo, leading to enhanced affinity of MYB binding to the promoter regions of key genes for flavonol biosynthesis and thus increasing their transcriptional levels. We observed that the level of auxin in the root tip was negatively correlated with root flavonol content. Furthermore, genetic assays showed that loss-of-function mutations in MYB12, which is predominantly expressed in roots, partially rescued the short-root phenotype of the GA-deficient mutant ga1-3 by increasing root meristem size and mature cell size. Consistent with these observations, exogenous application of the flavonol quercetin restored the root meristem size of myb12 ga1-3 to that of ga1-3. Taken together, our data elucidate a molecular mechanism by which GA promotes root growth by directly reducing flavonol biosynthesis.

Determination of Ascorbic Acid, Rutin and Antioxidant Capacities of Wild <i/>Allium roseum</i> from Italy

This study is designed to investigate the antioxidant status and the presence of biologically-active compounds in Allium roseum L. and to compare the results with those of Allium sativum L. The content of thiosulfinates (Thio) and the levels of flavonols (quercetin and rutin), ascorbic acid (AA), glutathione reduced (GSH), glutathione oxidized (GSSG) and the antioxidant enzymes activities of glutathione peroxidase (GPx), glutathione reductase (GR) and catalase (CAT), were evaluated in bulbs, bulblets, flowers bulblets, leaves and flowers. Our study shows that bulbs of Allium roseum contain levels significantly higher of GSH, GSSG, AA, Thio, rutin and the activity of GPx and GR significantly higher than bulbs of Allium sativum. Moreover, the bulbs of Allium roseum show a significantly higher content of GPx, GR, CAT, GSH and GSSG than bulblets, flowers bulblets, leaves and flowers of Allium roseum. In Allium roseum, the greatest content of Thio is present in the flowers bulblets, while the levels of AA, quercetin and rutin are greater in the flowers. In conclusion, our result shows how Allium roseum exhibits antioxidant capabilities in all its fresh organs. The bulbs, bulblets, flowers bulblets, leaves and flowers are a good source of important bioactive compounds. Allium roseum possesses properties comparable to garlic indicating its possible nutritional and medicinal value.

ANTIOKSIDAN BIJI KAKAO: PENGARUH FERMENTASI DAN PENYANGRAIAN TERHADAP PERUBAHANNYA (ULASAN)

The main cocoa antioxidant compounds are flavanols that consist of monomer (epicatechin and catechin) and oligomers from dimers to decamers (procyanidin), with small quantity of anthocyanin (cyaniding glucoside) and flavonol (quercetin glycoside). Cocoa processing stages that affect antioxidant compounds changes atre fermentation and roasting. Fermentation causes decrease of polyphenol content due to polyphenols diffusion out of the cotyledons, furthermore polyphenols undergo oxidation and condensation. Roasting temperature more than 70oC cause loss of (+)-catechin. During roasting, protein that bounded to the cell wall (cellulose and pectin) undergo Maillard reaction where its products potentially as antioxidants. This study is useful to know the proper of cocoa beans processing so antioxidant content can be maximized.

Polyphenolic profile of fresh chokeberry and chokeberry products

Chokeberry (Aronia melanocarpa) fruits and its products are one of the richest sources of pholyphenols which may play important role in human health as for example in regulation of blood pressure levels, reducing concentrations of triglycerides, low density and total cholesterol. The objective of this study was to identify and quantify the content of pholyphenols, specifficaly phenolic acids (gallic, caffeic, p-coumaric, ellagic, chlorogenic) and flavonols (quercetin and kaempferol) using high performance liquid chromatography (HPLC) in two varieties of fresh chokeberry fruit (type Nero and Viking) and in different types of chokeberry products available from Croatian market: eleven samples of juices, three samples of powders, two samples of both capsules and dried berries and four samples of teas. The results showed that there is a difference in amount of examined polyphenols between different product categories, and significant difference was also observed within the same product group (p≤0.05). In all analysed samples the highest phenolic acid quantified was p-coumaric acid, and gallic acid was the lowest one. Berry juices from fresh chokeberry fruits had higher amount of p-coumaric acid (284.55±6.34 mgL-1) compared to commercially available juices (195.48±3.05 mgL-1). The same phenolic composition was observed within the rest of the products where capsules have the higher amount of phenolic acids, followed by powders, dried berries and teas (eg. p-coumaric 81.36; 79.76; 36.28; 28.81 mg/100 g dry matter, respectively). According to flavonol amount, all observed products had higher values of quercetin compared to kaempferol. Obtained results represents a valuable set of data for novel and under-examined plant source of health promoting bioactivecompounds.

Effects of flavonol quercetin on activity of lipid peroxide oxidation in experimental bacterial-immune periodontitis.

The article presents the results of lipid peroxidation activity in blood serum, which were assessed on the base changes in the level of oxidative modification of proteins, TBA-active products, and total amount of nitrogen (II) oxide metabolites (NO2− + NO3−). Indices were determined on the 14th day of development in experimental periodontitis both without correction, and in condition treatment with a water-soluble flavonol quercetin (corvitin). The treated animals take intramuscular injections of corvitin in a dose 100 mg/kg weight for 7 days. For further testing, blood serum was selected. The results were statistically analyzed using parametric and non-parametric indices. In this investigation, characterized dynamics of changes in the indices of oxidative processes activity were revealed both during the period of formation and the course of periodontitis. In particular, it was found that, for the period of the most expressed inflammatory reaction in the periodontal complex, intensive increase in the level of reactive forms of oxygen. The treatment with flavonol quercetin for 7 days resulted in stabilization of free radical processes and the suppression of the inflammatory reaction.

Manilkara zapota (L.) Royen Fruit Peel: A Phytochemical and Pharmacological Review

Manilkara zapota (L.) Royen fruit is a popular fruit crop commonly cultivated in most of the tropical reasons and used for its nutritional values over the world. Two varieties of the fruit are available, round and elongated. Present review revealed the scientific information on the phytochemicals and pharmacological evaluations of Manilkara zapota (L.) Royen fruit peel (MZFP), a juice byproduct often considered as a waste or garbage. MZFP constitutes about 20 % of the fruit. The literature survey postulate that main phenolic compounds are primarily concentrated in the peel portion of this fruit which includes, flavonoids, tannins, phenolic acids, hydroxybenzoic acids (p-hydroxybenzoic, gallic and ellagic), flavanols (catechin and epicatechin), flavonols (quercetin), hydroxycinnamic acids (ferulic, chlorogenic and trans-cinnamic), kaempferol, 5-caffeoyl quinic acid conjugates and lycopene a carotenoid. It is generally accepted that bioactive components can be more efficiently recovered from MZFP by optimizing the extraction condition or efficiency. A widespread assessment of phytochemicals is included while possible mechanisms and phytochemicals involved have been correlated. The curative relevance of these compounds has been mainly evaluated by in vitro experimentation. Therefore, convincing clinical trials of the bioactive principles present in MZFP are essential for correct validation of their health benefits.

The nutraceutical potential of Lepidium sativum L. seed flavonoid-rich extract in managing metabolic syndrome components.

The present study aimed to investigate the phytochemical and pharmacological identities of a Lepidium sativum L. (LS) flavonoid-rich extract and its beneficial effects on metabolic, hormonal, and histological status. Chemical screening, as well as high-performance liquid chromatography with diode-array detection (HPLC-DAD) identified high concentrations of the main flavonoid compounds in LS crude extract such as flavonols (quercetin, kaempferol), flavones (luteolin, apigenin), and especially flavanones (naringin, naringenin). Examinations of the biochemical and histopathological aspects showed the curative effects carried by LS flavonoid-rich extracts on high-fat diet-fed Wistar rats. In this study, we propose that these molecules probably exerted the bioactivity observed in the treated group through improving insulin sensitivity, dyslipidemia, inflammation, and pancreas β cell integrity. PRACTICAL APPLICATIONS: The LS seed is widely used in traditional medicine to treat hyperglycemia and inflammation. During the traditional mixture preparation, the thermal procedures could impair the bioactions of the most interesting group of LS phytoconstituants, flavonoids. In the present study, we propose an appropriate procedure to preserve those phytochemicals and suggest them as a substitute for the management of metabolic diseases. The dried LS extract showed an incredible set of effective flavonoids, which revealed hypoglycemic, hypolipidemic, anti-inflammatory, cytoprotective, and antidiabetic activities. Thus, LS flavonoids constitute a remarkable product to consider in pharmaceutical industry targeting diabetes and heart diseases. Due to their enormous antioxidant potential, the LS flavonoids could be also used in food engineering and cosmetic preparations. Their practical applications is however often limited by low solubility and stability in lipophilic media. Therefore, a modification of the flavonoid structure is possibly required.

Combined cereal and pulse flavonoids show enhanced bioavailability by downregulating phase II metabolism and ABC membrane transporter function in Caco-2 model

Predominant flavonoids in cereals and pulses are structurally different and may positively interact to enhance bioactivity in combined diet. This work investigated the effects of combined cereal 3-deoxyflavonoids (apigenin, naringenin) and pulse flavonols (quercetin), along with natural extracts, on their bioavailability and underlying mechanisms using Caco-2 monolayer model. Membrane permeability, phase II metabolism, and ATP binding cassette (ABC) membrane transporter expression and function were measured. Apparent absorption of quercetin and apigenin increased (p < 0.05) 3.3× and 1.5×, respectively, while both compounds were significantly less metabolized in combined treatments. Combinations with naringenin had insignificant effect, suggesting a role for flavonoid C2C3 conjugation. Both natural extracts and apigenin-quercetin combinations synergistically (3–40 fold) downregulated ABC transporter expression, and inhibited P-glycoprotein activity, suggesting direct binding and inhibition of ATPase. Combination of conjugated cereal and pulse flavonoids enhances their potential bioavailability through synergistic inhibition of membrane transporter and phase II enzyme function.

Can plant phenolic compounds reduce Fusarium growth and mycotoxin production in cereals?

ABSTRACTTo assess the in vitro activity of three phenolic acids (ferulic acid, p-hydroxybenzoic acid, vanillic acid) and two flavonols (quercetin, rutin) on mycelial growth and mycotoxin accumulation of Fusarium graminearum (FG), F. langsethiae (FL) and F. poae (FP), two different approaches were chosen. First, grains from oat varieties were inoculated with a suspension of three FL isolates to determine the influence of phenolic compounds on the accumulation of mycotoxins. The oat variety Zorro showed a tendency for lower accumulation of T-2/HT-2, diacetoxyscirpenol and neosolaniol. Second, a mycelium growth assay was conducted to follow FG, FL and FP growth on cereal based media supplemented with phenolic compounds. Increasing concentrations of ferulic acid substantially inhibited growth of FG and FL, while FP growth was reduced to 57%. In contrast, p-hydroxybenzoic acid, vanillic acid, quercetin, and rutin slightly stimulated mycelium growth. Results about mycotoxin production in cereal based media were less conclusive.

Characterization of a heat responsive UDP: Flavonoid glucosyltransferase gene in tea plant (Camellia sinensis).

Tea plant (Camellia sinensis) accumulates abundant flavonoid glycosides that are the major bioactive ingredients in tea. Biosynthesis of flavonoid glycosides are catalyzed by UDP-glucosyltransferases (UGTs) that are widely present in plants. Among one hundred and seventy-eight UGTs genes that we have previously identified in tea plant, few of them have been functionally characterized. In the present study, we further identified UGT73A17 gene that is responsible for the biosynthesis of a broad range of flavonoid glycosides. Sequence analysis revealed that the deduced UGT73A17 protein showed high identity with 7-O-glycosyltransferases at amino acid level and it was clustered into the clade containing several 7-O-glycosyltransferases from other plant species. Enzymatic assays revealed that the recombinant UGT73A17 protein (rUGT73A17) exhibited activity toward flavonols (kaempferol, quercetin, and myricetin), flavones (apigenin, luteolin, and tricetin), flavanone (naringenin), isoflavones (genistein) and epicatechin gallate, yielding 7-O-glucosides as the major in vitro products. In particular, rUGT73A17 displayed higher activity at high temperatures (eg. 50°C) than at low temperatures, which was consistent with its relatively high expression level at high temperatures. Two amino acid substitutions at I296L and V466A improved the enzymatic activity of rUGT73A17. Our study demonstrated that UGT73A17 is responsible for the biosynthesis of a broad range of flavonoid glucosides, which is also involved in heat response and quality of tea plant.

QTL mapping of insect resistance components of Solanum galapagense

Key messageQTLs for insect resistance parameters, trichome type IV development, and more than 200 non-volatile metabolites, including 76 acyl sugars, all co-locate at the end of Chromosome 2 of Solanum galapagense.Host plant resistance is gaining importance as more and more insecticides are being banned due to environmental concerns. In tomato, resistance towards insects is found in wild relatives and has been attributed to the presence of glandular trichomes and their specific phytochemical composition. In this paper, we describe the results from a large-scale QTL mapping of data from whitefly resistance tests, trichome phenotyping and a comprehensive metabolomics analysis in a recombinant inbred line population derived from a cross between the cultivated Solanum lycopersicum and the wild relative S. galapagense, which is resistant to a range of pest insects. One major QTL (Wf-1) was found to govern the resistance against two different whitefly species. This QTL co-localizes with QTLs for the presence of trichomes type IV and V, as well as all 76 acyl sugars detected and about 150 other non-volatile phytochemicals, including methyl esters of the flavonols myricetin and quercetin. Based on these results, we hypothesize that Wf-1 is regulating the formation of glandular trichome type IV on the leaf epidermis, enabling the production and accumulation of bioactive metabolites in this type of trichomes.

Protein-Ligand Fishing in planta for Biologically Active Natural Products Using Glutathione Transferases.

Screening for natural products which bind to proteins in planta has been used to identify ligands of the plant-specific glutathione transferase (GST) tau (U) and phi (F) classes, that are present in large gene families in crops and weeds, but have largely undefined functions. When expressed as recombinant proteins in Escherichia coli these proteins have been found to tightly bind a diverse range of natural product ligands, with fatty acid-and porphyrinogen-derivatives associated with GSTUs and a range of heterocyclic compounds with GSTFs. With an interest in detecting the natural binding partners of these proteins in planta, we have expressed the two best characterized GSTs from Arabidopsis thaliana (At), AtGSTF2 and AtGSTU19, as Strep-tagged fusion proteins in planta. Following transient and stable expression in Nicotiana and Arabidopsis, respectively, the GSTs were recovered using Strep-Tactin affinity chromatography and the bound ligands desorbed and characterized by LC-MS. AtGSTF2 predominantly bound phenolic derivatives including S-glutathionylated lignanamides and methylated variants of the flavonols kaempferol and quercetin. AtGSTU19 captured glutathionylated conjugates of oxylipins, indoles, and lignanamides. Whereas the flavonols and oxylipins appeared to be authentic in vivo ligands, the glutathione conjugates of the lignanamides and indoles were artifacts formed during extraction. When tested for their binding characteristics, the previously undescribed indole conjugates were found to be particularly potent inhibitors of AtGSTU19. Such ligand fishing has the potential to both give new insight into protein function in planta as well as identifying novel classes of natural product inhibitors of enzymes of biotechnological interest such as GSTs.

Chemical composition, antioxidant and gastrointestinal properties of Sedum dendroideum Moc & Sessé ex DC leaves tea infusion

Ethnopharmacological relevanceSedum dendroideum Moc & Sessé ex DC (Crassulaceae) is a medicinal plant employed in Mexican and Brasilian folk medicine as juice or infusion, as remedy for the treatment of different diseases, including gastric disorders. Aim of the studyAlthough some studies carried out with Sedum dendroideum have demonstrated its gastroprotective effect, the purpose of this study was to elucidate the chemical constituents, antioxidant, cytotoxic and mechanisms underlying the gastrointestinal properties of Sedum dendroideum accordingly its traditional use, as fresh leaves tea infusion (SDI). Materials and methodsChemical constituents were analyzed using high performance liquid chromatography and mass spectrometry (HPLC-MS). Antioxidant and cytotoxicity were evaluated in in vitro assays. The efficacy of the SDI on macroscopic ulcer appearance, mucus and GSH maintenance on ethanol- and indomethacin-induced ulcer models, gastric acid secretion and gastrointestinal motility were investigated. ResultsPhytochemical analysis by HPLC–MS revealed the presence of different flavonol glycosides, containing myricetin and quercetin, along with the kaempferol as aglycones. In vitro pharmacological investigation of SDI demonstrated potent antioxidant activity in DPPH assay (IC50: 13.25 ± 3.37 µg/mL) and absence of cytotoxicity in Caco-2 cells by MTT method. Oral administration of SDI (ED50 of 191.00 ± 0.08 mg/kg) in rats promoted gastroprotection against ethanol or indomethacin in rats through reinforcement of gastric wall mucus, GSH content and nitric oxide release, without present antisecretory properties. The gastroprotective effect was maintained when SDI (19 mg/kg) was administrated by intraperitoneal route. Furthermore, SDI (150 mg/kg) unchanged the gastric emptying but increase small bowel transit in mice through cholinergic pathways. ConclusionsCollectively, this study confirmed that Sedum dendroideum promotes gastroprotection through preventing of endogenous defense mechanisms, represented by mucus and GSH without changes gastric acid secretion. Sedum dendroideum tea infusion features a chemical profile that contributes to the antioxidant and gastric health-promoting effects, supporting the use in folk medicine for the treatment of gastrointestinal disorders.

Comparison of (poly)phenolic compounds and antioxidant properties of pomace extracts from kiwi and grape juice

The aim of this study was to evaluate the phenolic profile of grape and kiwi juice pomace by HPLC-ESI-MS, and their correlation with antioxidant properties determined with DPPH, FRAP and OH scavenging assays. A total of 32 compounds have been identified including anthocyanins, flavonols, flavan-3-ols and phenolic acids. Significantly higher relative amounts of anthocyanin monoglucosides, flavan-3-ols (catechin, epicatechin, and procyanidin), and flavonols (quercetin and its derivatives) were found for grape pomace. Whereas kiwi pomace contained higher amounts of quinic acid, caffeic acid and its derivatives. Although grape pomace had higher total phenolic content (TPC), it showed lower OH scavenging capacity than kiwi pomace, but better DPPH scavenging activity and reducing power. This indicated that the antioxidant activities do not only rely on the TPC but also associate with their phenolic profiles. Overall the two pomaces could potentially be exploited as an inexpensive source of natural antioxidants for food production.

Effect of alpha-linolenic acid in combination with the flavonol quercetin on markers of cardiovascular disease risk in healthy, non-obese adults: A randomized, double-blinded placebo-controlled crossover trial.

Alpha-linolenic acid (ALA) and quercetin are characteristic compounds in plant-based diets. Cardioprotective effects have been described for both substances, although a possible benefit of combining ALA and quercetin has not, to our knowledge, been evaluated yet. The aim of this study was to investigate the potential independent and additive effects of ALA and quercetin on blood pressure (BP) and lipid and glucose metabolism, as well as on biomarkers of inflammation, oxidative stress, and antioxidant status in healthy, non-obese men and women. Another aim was to examine whether chronic supplementation of supranutritional doses of quercetin would result in an accumulation of plasma quercetin concentration over time. In a double-blinded, placebo-controlled crossover trial, healthy volunteers were randomized to receive 3.6 g/d ALA plus 190 mg/d quercetin or placebo for 8 wk. Data from 67 individuals (34 men, 33 women, mean age: 24.6 y) were assessed. Plasma quercetin, tamarixetin, isorhamnetin, and kaempferol increased significantly from baseline to study end with ALA + quercetin but not with ALA + placebo. No significant effect on office systolic BP, mean 24 h ambulatory BP (ABP), or mean daytime ABP was seen in either study group. Both interventions significantly decreased total cholesterol, low-density lipoprotein cholesterol, non-high-density lipoprotein cholesterol, and apolipoprotein B to a similar extent. No effect on high-density lipoprotein cholesterol, apolipoprotein A1, glucose, uric acid, oxidized low-density lipoprotein, C-reactive protein, or lipid-adjusted retinol, α-tocopherol, or β-carotene was seen in either group. Although dietary supplements of 3.6 g/d ALA over an 8-wk period improved lipid profiles in healthy adults, antioxidative and oxidative status, inflammation, and BP remained unchanged. No evidence was seen for an additive or synergistic effect of ALA plus quercetin on markers of cardiovascular disease risk.

Transcriptional responses of soybean roots to colonization with the root endophytic fungus Piriformospora indica reveals altered phenylpropanoid and secondary metabolism

Piriformospora indica, a root endophytic fungus, has been shown to enhance biomass production and confer tolerance to various abiotic and biotic stresses in many plant hosts. A growth chamber experiment of soybean (Glycine max) colonized by P. indica compared to uninoculated control plants showed that the fungus significantly increased shoot dry weight, nutrient content, and rhizobial biomass. RNA-Seq analyses of root tissue showed upregulation of 61 genes and downregulation of 238 genes in colonized plants. Gene Ontology (GO) enrichment analyses demonstrated that upregulated genes were most significantly enriched in GO categories related to lignin biosynthesis and regulation of iron transport and metabolism but also mapped to categories of nutrient acquisition, hormone signaling, and response to drought stress. Metabolic pathway analysis revealed upregulation of genes within the phenylpropanoid and derivative pathways such as biosynthesis of monolignol subunits, flavonoids and flavonols (luteolin and quercetin), and iron scavenging siderophores. Highly enriched downregulated GO categories included heat shock proteins involved in response to heat, high-light intensity, hydrogen peroxide, and several related to plant defense. Overall, these results suggest that soybean maintains an association with this root endosymbiotic fungus that improves plant growth and nutrient acquisition, modulates abiotic stress, and promotes synergistic interactions with rhizobia.

Changes in Glucosinolates, Sinapine and Flavonols during Seed Development of Camelina sativa (L.) Crantz

Camelina sativa (L.) Crantz is an oilseed crop whose oil is used as biofuel and the meal as animal feed. While the seed composition is widely documented, little is known about variations in the concentration of some compounds during seed development of camelina. The aim of this study was to characterize changes in the content of glucosinolates, sinapine, sinapic acid and flavonols (quercetin and koempferol) at different stages of seed maturation. Glucosinolates are accumulated in camelina seed in the first 4 weeks after pollination, while the other substances were transiently accumulated during development and may play a role in seed development.