Resveratrol Accumulation Research Articles

Resveratrol enhances trans-intestinal cholesterol excretion through selective activation of intestinal liver X receptor alpha

Resveratrol (RSV) is a dietary polyphenol with well-documented cardio-protective activity, but its effects on blood cholesterol levels remain to be established. Due to its poor bioavailability, tissue accumulation of RSV is extremely low except for that in the small intestine. In the present study, we aimed to investigate the dose-dependent effects of RSV on blood cholesterol levels and the involvement of small intestine in the cholesterol-lowering impacts of RSV. Mice were administrated with RSV at various doses with high-fat diet (HFD) or high-fat and high-cholesterol diet (HCD) for 12 weeks. The fecal neutral sterol contents were analyzed, and intestinal perfusion test was performed. An enteric barrier model using Caco-2 cells was established. We observed that RSV reduced blood cholesterol levels in a dose-dependent manner in mice fed with HFD or HCD. Further investigation revealed that RSV administration increased the bile acid pool size but did not affect cholesterol consumption or de novo cholesterol synthesis. Interestingly, RSV promoted trans-intestinal cholesterol excretion (TICE) by 2-fold in the intestinal perfusion test. In addition, RSV upregulated the expressions of ATP-binding cassette sub-family G member 5 or 8 (Abcg5/8) and ATP-binding cassette sub-family B member 1a or 1b (Abcb1a/b) by up to 8 times in the duodenum mucosa but not in the liver. RSV also significantly downregulated the expression of intestinal Niemann-Pick C1-Like 1 (Npc1l1). Knock-down of liver X receptor alpha (LXRα) but not Sirt1 by siRNA significantly blocked RSV-induced cholesterol excretion in Caco-2 cells. In conclusion, RSV could decrease circulating cholesterol levels through enhancing TICE and limiting cholesterol absorption via selective activation of intestinal LXRα.

Polyphenols and Resveratrol from Discarded Leaf Biomass of Grapevine (Vitis sp.): Effect of Cultivar and Viticultural Practices in Estonia

Grapevine leaves are a major by-product of viticulture practices derived from the leaf-removal from the fruit cluster zone in all vine growing regions. These leaves can be a valuable source of antioxidants to be used in pharmaceuticals or other health-related products. In this study, the leaves of grapevine cultivars were analysed by ultra-high performance liquid chromatograph-diode array detector () for the total polyphenols (TPC) and resveratrol affected by cultivar, leaf-removal time and viticultural practice. The effect of cultivar varied yearly, European grapevine cv. ‘Regent’ had increased TPC and resveratrol in comparison to ‘Boskoop’s Glory’, ‘Rondo’ and ‘Solaris’ in 2017, but ‘Solaris’ in 2018. TPC (1213–1841 mg 100 g−1) and resveratrol (1.061 mg 100 g−1) were higher in leaves of interspecific hybrid cvs. ‘Zilga’ and ‘Hasansky Sladky’ during full fruit ripeness. Cv. ‘Rondo’ grown under the polytunnel had decreased TPC in leaves. In conclusion, cultivar selection, viticultural practice and leaf-removal time contribute significantly to the accumulation of total polyphenols and resveratrol. Results of this study will contribute to better utilization of biomass produced in the vineyards, help to decrease the negative environmental impacts, and provide an overview on various factors affecting the biochemical constituents, especially in leaves.

Overexpressing codon-adapted fusion proteins of 4-coumaroyl-CoA ligase (4CL) and stilbene synthase (STS) for resveratrol production in Chlamydomonas reinhardtii

Resveratrol is a plant phenolic secondary metabolite derived from phenylpropane metabolic pathway. It is a phytoalexin of high pharmaceutical interest produced in the defense response of plants. To produce resveratrol in Chlamydomonas reinhardtii, 4-coumaroyl-CoA ligase (4CL) and stilbene synthase (STS), two enzymes in the last two steps of resveratrol synthesis in higher plants, were fused together by a glycine–serine–glycine (GSG) tripeptide linker after codon adaptation according to the genome of C. reinhardtii. The fusion protein 4CL-GSG-STS was overexpressed in a wild-type (CC125) and a wall-deficient C. reinhardtii (CC 425). A high level of resveratrol accumulation (22.8 μg g−1, dry weight) was obtained in CC125 transformed with codon-adapted 4CL-GSG-STS after supplementary of cinnamic acid in the culture medium.

Insight into the assembly of root-associated microbiome in the medicinal plant Polygonum cuspidatum

Polygonum cuspidatum (Polygonum cuspidatum Sieb. & Zucc.), a medicinal plant that is abundantly accumulating bioactive compounds in its roots, is the primary source of resveratrol in industry and has long been recognized as raw materials for traditional Chinese medicine. Plant root secondary metabolism is correlated to its surrounding microbial communities. However, the root-associated microbiomes of P. cuspidatum and the potential correlation between the bioactive compounds and microbiomes are poorly understood. To unveil the root-associated bacterial community, the microbiome compositions of P. cuspidatum roots across four cultivation years were analyzed by using 16S rRNA gene sequencing. Furthermore, the relationships among root-associated bacteria, soil properties, and four major bioactive compounds (polydatin, resveratrol, emodin, and physcion) were explored by a multivariate correlation study. The composition of the rhizosphere microbiome significantly differed from that of the endosphere microbiome. The composition of the rhizosphere microbiome significantly varied across different cultivation years and soil properties, contributing to the majority of variance. Regarding different cultivation years and soil properties, the compositions of the root endosphere microbiome remained relatively stable, indicating a strong selection effect in P. cuspidatum roots. Among root endosphere microbes, Stenotrophomonas was specifically enriched from rhizosphere with a 15 times increase of relative abundance, exhibiting no significant variation across different cultivation years. The relative abundance of rhizosphere Stenotrophomonas was positively correlated with the content of emodin. Taken together, this study demonstrated that the stability of the root endosphere microbiome with a dominance of Stenotrophomonas may maintain the growth of P. cuspidatum through the combined effect of emodin. The contents of bioactive compounds in roots exhibited distinct correlations with specific bacteria, suggesting that Bacteroides, Acinetobacter, Erysipelatoclostridium, and Achromobacter may enhance the accumulation of resveratrol. This study provides insights into the interaction networks among P. cuspidatum root-associated bacteria, cultivation years, soil properties, and bioactive compounds, giving us a new opportunity to manipulate the production of bioactive compounds, and thus improve the industrial and medicinal value of P. cuspidatum in future.

DPPC-coated lipid nanoparticles as an inhalable carrier for accumulation of resveratrol in the pulmonary vasculature, a new strategy for pulmonary arterial hypertension treatment

In this study, we investigated the feasibility of dipalmitoylphosphatidylcholine-coated lipid nanoparticles (DPPC-LNs) as a carrier for preferential accumulation into lungs of Resveratrol (Res), a potentially promising drug for the treatment of pulmonary arterial hypertension (PAH). Res-loaded DPPC-LNs were prepared following a thin film hydration-ultrasonic dispersion technique using glyceryl monostearate as lipid core. DPPC can reduce the interactions between nanoparticles and pulmonary surfactant. The optimal formulation was prepared and characterized for physicochemical properties, storage stability and in vitro release profiles. The optimal formulation was evaluated for uptake by pulmonary arterial smooth muscle cells (PASMCs) using fluorescence microscopy. The efficacy of Res-loaded DPPC-LNs in reducing hyperplasia was tested in 5-HT induced proliferated PASMCs. The drug absorption profiles upon intratracheal administration were monitored in healthy rats. Optimized spherical DPPC-LNs – with mean size of 123.7 nm, zeta potential of –19.4 mV and entrapment efficiency of 94.40% – exhibited an 80% cumulative drug release over 48 h. Fluorescence microscopic study revealed an time-dependent enhancement of cellular uptake of Rh123-labeled DPPC-LNs by PASMCs. PASMC proliferation induced by 5-HT was significantly inhibited by Res-loaded DPPC-LNs. Optimized DPPC-LNs appeared to be safe when incubated with PASMCs. Besides, plasma and lung tissue data analysis indicated higher value of accumulation after intratracheal administration of Res-loaded DPPC-LNs in comparison with the intravenously dosed Res solution, indicating longer retention of Res in the lungs and their slower entry to the systemic blood circulation. DPPC-LNs could be a viable delivery system for site-specific treatment of PAH.

Molecular Analysis of UV-C Induced Resveratrol Accumulation in Polygonum cuspidatum Leaves.

Resveratrol is one of the most studied plant secondary metabolites owing to its numerous health benefits. It is accumulated in some plants following biotic and abiotic stress pressures, including UV-C irradiation. Polygonum cuspidatum represents the major natural source of concentrated resveratrol but the underlying mechanisms as well as the effects of UV-C irradiation on resveratrol content have not yet been documented. Herein, we found that UV-C irradiation significantly increased by 2.6-fold and 1.6-fold the resveratrol content in irradiated leaf samples followed by a dark incubation for 6 h and 12 h, respectively, compared to the untreated samples. De novo transcriptome sequencing and assembly resulted into 165,013 unigenes with 98 unigenes mapped to the resveratrol biosynthetic pathway. Differential expression analysis showed that P. cuspidatum strongly induced the genes directly involved in the resveratrol synthesis, including phenylalanine ammonia-lyase, cinnamic acid 4-hydroxylase, 4-coumarate-CoA ligase and stilbene synthase (STS) genes, while strongly decreased the chalcone synthase (CHS) genes after exposure to UV-C. Since CHS and STS share the same substrate, P. cuspidatum tends to preferentially divert the substrate to the resveratrol synthesis pathway under UV-C treatment. We identified several members of the MYB, bHLH and ERF families as potential regulators of the resveratrol biosynthesis genes.

Expression of stilbene synthase VqSTS6 from wild Chinese Vitis quinquangularis in grapevine enhances resveratrol production and powdery mildew resistance.

In grape (Vitis), stilbene phytoalexins can either be in situ synthesized or transported to the site of response during powdery mildew infection, enhancing disease resistance. Resveratrol is a phytoprotective stilbenoid compound that is synthesized by stilbene synthase (STS) in response to biotic and abiotic stresses, and is also known to have health benefits in the human diet. We have previously shown that transgenic Vitis vinifera cv. Thompson Seedless plants overexpressing a stilbene synthase gene, VqSTS6, from wild Chinese Vitis quinquangularis had a higher stilbenoid content, leading to an enhanced resistance to powdery mildew (Uncinula necator (Schw.) Burr). However, the biosynthesis and transportation in the plant tissue under powdery mildew infection are still unclear. Here, inhibitor and micro-grafting technologies were used to study the accumulation of resveratrol following powdery mildew infection. We observed that the levels of STS expression and stilbenoids increased in response to powdery mildew infection. Powdery mildew and inhibitor treatment on detached grape branches showed that resveratrol was in situ synthesized. Experiments with grafted plantlets showed that the abundance of stilbenoid compounds increased in the shoot during VqSTS6 overexpression in the root, while VqSTS6-Flag fusion was not tranported to the scions and only expressedin thetransgenic rootstocks. Compared with wild-type Thompson Seedless plants, the non-transgenic/VqSTS6 transgenic (scion/rootstock) grafted Thompson Seedless plantlets exhibited increased resistance to powdery mildew. In addition, overexpression of VqSTS6 in roots led to increased levels of stilbenoid compounds in five other European grape varieties (V. vinifera cvs. Chardonnay, Perlette, Cabernet Sauvignon, Riesling and Muscat Hamburg). In conclusion, stilbenoid compounds can be either in situ synthesized or transported to the site of powdery mildew infection, and overexpression of VqSTS6 in the root promotes stilbenoids accumulation and disease resistance in European grapevine varieties.

Regulation of resveratrol O-methyltransferase gene in pterostilbene defensing the sour rot of wine grape.

Sour rot, caused by Geotrichum citriaurantii (G. citri-aurantii.), is one of the most serious grapevine secondary infection diseases in China. We have determined that pterostilbene, the most important phytoalexin, effectively inhibits the activity of G. citri-aurantii. To study the synthesis mechanism of pterostilbene against G. citri-aurantii in grape, we initially detected the content of pterostilbene present in grapes infected by G. citri-aurantii with the use of UHPLC-QQQ-MS2 . Pterostilbene levels are controlled by the resveratrol O-methyltransferase (ROMT) gene, and within grape samples is positively related to the accumulation of resveratrol. The pPIC9k-ROMT vector and plasmid pCAMBIA2300-GFP-ROMT were constructed for expression purposes. The pPIC9k-ROMT vector was expressed in Pichia pastoris GS115 and plasmid pCAMBIA2300-GFP-ROMT was expressed in onion. Analysis of qRT-PCR amplification samples revealed that gene expression was induced rapidly in grape as a defense against G. citri-aurantii. Western blot analysis verified that the recombinant protein was successfully expressed. PRACTICAL APPLICATIONS: Pterostilbene is a trace and efficient phytoalexins produced by plant' secondary metabolism, which exhibits good pharmacological activity. As an important protective agent in plants, it can improve the antioxidant capacity and resistance to adversity of plants. However, the method which could be used for mass production of pterostilbene has not been reported currently. The key gene of pterostilbene biosynthesis was investigated and verified in this paper, which provides the theoretical basis for the industrial production of pterostilbene. The study of pterostilbene is significant for the prevention and treatment of G. citri-aurantii disease, and has important practical applications for the development and production of pesticides.

Changes in stilbene composition during postharvest ozone treatment of 'Moscato bianco' winegrapes.

Stilbenes, including trans-resveratrol and its derivatives, are compounds naturally present in grapes and have gained a growing interest due to reported health-promoting properties. The production of resveratrol-enriched table grapes has promoted recent research on stress-induced synthesis of stilbenes. The oxidizing properties of ozone have been successfully exploited to its use as sanitizing agent and stilbene elicitor during table grapes storage. In winegrapes, this study represents the first research focused on the effect of postharvest ozone treatments on the accumulation of stilbene compounds. The study was carried out on Moscato bianco winegrapes (Vitis vinifera L.) and several gaseous ozone treatments were investigated differing in ozone dose (30 and 60 μL/L), exposure time (24 h, 48 h, and several days until 30% of weight loss), and delay time until processing (just after and several days after treatment). The stilbene production induced by ozone exposure was assessed in fresh and partially dehydrated winegrapes up to 5, 10, 15, 20, and 30% of weight loss aiming to evaluate the single and combined effect of oxidative and osmotic stresses. The results obtained showed that short-term exposure of fresh winegrapes at 60 μL/L of ozone for 48 h was not effective in inducing resveratrol accumulation just after treatment, but it had an elicitor effect on total stilbenes (+36%) in grapes subsequently dehydrated up to 20% of weight loss with a significant overproduction of trans-resveratrol and trans-piaceatannol. In addition, long-term and continuous treatments under ozone-enriched atmosphere can be also used during dehydration to sanitize winegrapes without affecting negatively the concentration of stilbenes. Therefore, the use of gaseous ozone during storage and dehydration could be indicated to reduce the use of sulfur dioxide and, depending on ozone dose and exposure time, the synthesis of stilbene compounds could increase.

Overexpressing fusion proteins of 4-coumaroyl-CoA ligase (4CL) and stilbene synthase (STS) in tobacco plants leading to resveratrol accumulation and improved stress tolerance

Resveratrol (trans-3,4′,5-trihydroxystilbene) is a phytoalexin produced in plants in response to pathogen attack as a part of plant defense response and it is also a highly bioactive substance of pharmaceutical interest. To obtain transgenic plants with a high level of resveratrol, two enzymes in the last two steps of resveratrol synthesis, 4-coumaroyl-CoA ligase (4CL) and stilbene synthase (STS), were fused together by a glycine–serine–glycine (GSG) tripeptide linker, and the 4CL-GSG-STS construct driven by a CaMV35S promoter was transformed into tobacco (Nicotiana benthamiana) by Agrobacterium-mediated method. In the transgenic plants, a high resveratrol level was detected (21.05 µg/g fresh weight) by high-pressure liquid chromatography (HPLC), which is higher than previous transgenic plants with only STS gene overexpression. In addition to resistance to pathogen, transgenic plants showed improved tolerance to salt and osmotic stresses, and the lower level of malondialdehyde (MDA) in transgenic plants suggested that resveratrol could protect plant membrane lipid from peroxidation under abiotic stresses.

A Plant Extract Acts Both as a Resistance Inducer and an Oomycide Against Grapevine Downy Mildew.

Protecting vineyards from cryptogamic diseases such as downy mildew, caused by Plasmopara viticola, generally requires a massive use of phytochemicals. However, the issues on unintentional secondary effects on environment and human health, and the occurrence of P. viticola resistant strains, are leading to the development of alternative strategies, such as the use of biocontrol products. In this paper, we evidenced the ability of a plant extract to protect grapevine from P. viticola. Further experiments carried out both on cell suspensions and on plants revealed that plant extract activates typical defense-related responses such as the production of H2O2, the up-regulation of genes encoding pathogenesis-related proteins and stilbene synthase, as well as the accumulation of resveratrol or its derivative piceid. We also brought to light a strong direct effect of PE on the release and motility of P. viticola zoospores. Furthermore, we found out that PE application left dried residues on leaf surface, impairing zoospores to reach stomata. Altogether, our results highlight the different modes of action of a new biocontrol product able to protect grapevine against downy mildew.

Phenolic compounds profiling in shake flask and bioreactor system cell cultures of Scrophularia striata Boiss

Variation in levels of phenolic acids and flavonoids in Scrophularia striata Boiss. cells cultured in both shake flask and bioreactor in vitro systems, was studied at different growth phases. Four phenolic acids (cinnamic, salicylic, coumaric, and caffeic acid), one stilbenoid (resveratrol), and seven flavonoids (diosmin, rutin, kaempferol, catechin, myricetin, quercetin, and luteolin) were analyzed by high-performance liquid chromatography with photodiode array detection. Production of phenolics in the bioreactor was higher than in shake flasks. Catechin was the most abundant flavonoid in both culture systems, while quercetin, which was detected only in the bioreactor, was the lowest amount represented (32.82 μg g−1 DW). Resveratrol accumulation in bioreactor cultures was 59.84-fold higher than that in shake flasks. Moreover, hierarchical clustering analysis based on Pearson’s correlation coefficient confirmed a positive correlation between the growth phase and some metabolites. The flavonoid accumulation increased with the cells’ physiological age in the bioreactor. Principal component analysis showed that the time course of induction of phenolic acids, flavonoids, and a stilbenoid (resveratrol) was significantly correlated. These findings highlight the capacity of S. striata for large-scale production of desired phenolics using a bioreactor system.

Rosa hybrida orcinol O-methyl transferase-mediated production of pterostilbene in metabolically engineered grapevine cell cultures

Stilbenes are naturally scarce high-added-value plant compounds with chemopreventive, pharmacological and cosmetic properties. Bioproduction strategies include engineering the metabolisms of bacterial, fungal and plant cell systems. Strikingly, one of the most effective strategies consists in the elicitation of wild grapevine cell cultures, which leads to vast stilbene resveratrol accumulation in the extracellular medium. The combination of both cell culture elicitation and metabolic engineering strategies to produce resveratrol analogs proved more efficient for the hydroxylated derivative piceatannol than for the dimethylated derivative pterostilbene, for which human hydroxylase HsCYP1B1- and grapevine O-methyltransferase VvROMT-transformed cell cultures were respectively used. Rose orcinol O-methyltransferase (OOMT) displays enzymatic properties, which makes it an appealing candidate to substitute VvROMT in the combined strategy to enhance the pterostilbene production level by engineered grapevine cells upon elicitation. Here we cloned a Rosa hybrida OOMT gene, and created a genetic construction suitable for Agrobacterium-mediated plant transformation. OOMT’s ability to catalyze the conversion of resveratrol into pterostilbene was first assessed in vitro using protein extracts of agroinfiltrated N. benthamiana leaves and transformed grapevine callus. The grapevine cell cultures transformed with RhOOMT produced about 16 mg/L culture of pterostilbene and reached an extracellular distribution of up to 34% of total production at the best, which is by far the highest production reported to date in a plant system. A bonus large resveratrol production of ca. 1500–3000 mg/L was simultaneously obtained. Our results demonstrate a viable successful metabolic engineering strategy to produce pterostilbene, a resveratrol analog with enhanced pharmacological properties.

Self-Nanoemulsifying System in the Accumulation of Resveratrol and N- Acetylcysteine in the Epidermis and Dermis

Trans-resveratrol (RES) and N-acetylcysteine (NAC) have protective effects on biological processes; therefore, they are frequently included in food supplements. Their possible applications for the prevention of free radical-induced damage to the skin are of particular physiological relevance; however, their usefulness is limited by their metabolic fate and the unpredictability of their delivery to the skin following oral administration. In this work, we evaluated the concomitant and direct application of RES and NAC on the skin using a self-nanoemulsifying system we previously developed for the oral delivery of poorly absorbed food supplements. We evaluated the capability of this system to increase RES and NAC accumulation in porcine skin using permeation studies in Franz diffusion cells. The ascorbyl palmitate (ASP) self-nanoemulsifying system considerably increased RES and NAC accumulation in the epidermis and dermis, which peaked 6 h after application. This study reveals a new formulation strategy to improve the bioavailability of ingredients, which was previously used in the health supplements field, but has rarely been employed in dermatology because of its poor distribution in the skin.

Improvement of Phenolic Antioxidant-linked Cancer Cell Cytotoxicity of Grape Cell Culture Elicited by Chitosan and Chemical Treatments

Grape (Vitis vinifera cv. Pok Dum) is a rich source of health relevant phenolic antioxidants and can be targeted to mitigate chronic oxidative stress commonly associated with noncommunicable chronic diseases (NCDs), such as cancer. Furthermore, improving health relevant phenolic bioactives and associated antioxidant properties of fruits by using chemical elicitation strategy has significant merit. Based on this biochemical rationale, chitosan and other chemical elicitors potassium dihydrogen phosphate (KH2PO4), potassium nitrate (KNO3), sodium selenite (Na2SeO3), and aluminum sulphate [Al2(SO4)3] were targeted to improve phenolic bioactive profiles and associated antioxidant and anticancer properties of cultured grape cells grown for 28 days. After chemical elicitor treatments, phenolic content, resveratrol content, antioxidant activity, phenylalanine ammonia-lyase (PAL) enzyme activity, and cytotoxicity (cell inhibition) against cancer cell lines of cultured grape cells were investigated using in vitro assay models. Overall, stimulation of phenolic bioactives and improvement in associated cytotoxicity against cancer cell lines were found in cultured grape cells after chemical elicitation treatments. Chitosan and other chemical elicitors resulted in lower growth of cultured grape cells; however, they enhanced phenolic biosynthesis on a cell weight basis when compared with the control. Chemical elicitor treatments, such as Na2SeO3 (50 mg·L−1 and 100 mg·L−1) and Al2(SO4)3 (50 mg·L−1), resulted in enhanced phenolic content at the end of 14 days of culture (1.7, 1.4, and 1.0-fold increase, respectively). Higher accumulation of resveratrol and higher antioxidant activity with Al2(SO4)3 (50 mg·L−1) and Na2SeO3 (100 mg·L−1) elicitation treatments were also observed. Enhanced phenolic bioactives in cultured grape cells in response to chemical elicitation treatment, such as Na2SeO3, also resulted in higher cytotoxicity against different cancer cell lines. Therefore, this study indicates that chemical elicitors, such as Na2SeO3 and Al2(SO4)3, as well as chitosan in select doses can be targeted to improve phenolic bioactives and associated antioxidant and anticancer properties in cultured grape cells and such strategy has relevance for wider applications with other phenolic antioxidant-enriched fruits.

Electrical stimulation: An abiotic stress generator for enhancing anthocyanin and resveratrol accumulation in grape berry

Abstract Plants are known to utilize electrical signals under several physiological conditions and electrical stimulation from the outside induces physiological changes in plants. In this study, to improve grape berry composition in field-grown grapevines, electrical stimulation of grapevine using solar panels was undertaken as an abiotic stress generator in 2015 and 2016 growing seasons. Electrical stimulation had a notable effect on grapevine growth and development as well as photosynthetic performance. Berry weight and tartaric acid and total phenolic contents in berries of grapevines exposed to electrical stimulation were similar among the grapevines tested. Brix in berries of grapevines exposed to electrical stimulation and electrode-treated grapevines was higher than that in control grapevines in both years. Electrical stimulation increased anthocyanin and resveratrol contents in berries of grapevines in both years relative to those of control grapevines and electrode-treated grapevines. The alteration of Brix and anthocyanin and resveratrol contents in berries was supported by the results of microarray analysis demonstrating the transcriptional upregulation of genes related to sucrose metabolism, phenylpropanoid biosynthesis, flavonoid biosynthesis, stilbenoid biosynthesis, and anthocyanin biosynthesis in grape cells exposed to electrical stimulation. Taken together, the results suggested that electrical stimulation of grapevine enhanced anthocyanin and resveratrol biosynthesis by activating their biosynthetic pathways.

Resveratrol accumulation and its involvement in stilbene synthetic pathway of Chinese wild grapes during berry development using quantitative proteome analysis

Attention has become focused on resveratrol not only because of its role in grapevine fungal resistance but also because of its benefits in human health. This report describes the Chinese wild grapevine Vitis quinquangularis accession Danfeng-2 in relation to the high resveratrol content of its ripe berries. In this study, we used isobaric tags for relative and absolute quantification (iTRAQ) tandem mass spectrometry strategy to quantify and identify proteome changes, resulting in the detection of a total of 3,751 proteins produced under natural conditions. Among the proteins quantified, a total of 578 differentially expressed proteins were detected between Danfeng-2 and Cabernet Sauvignon during berry development. Differentially expressed proteins are involved in secondary metabolism, biotic stress, abiotic stress and transport activity and indicate novel biological processes in Chinese wild grapevine. Eleven proteins involved in phenylpropanoid metabolism and stilbene synthesis were differently expressed between Danfeng-2 and Cabernet Sauvignon at the veraison stage of berry development. These findings suggest that Chinese wild V. quinquangularis accession Danfeng-2 is an extremely important genetic resource for grape breeding and especially for increasing the resveratrol content of European grape cultivars for disease resistance and for improved human nutritional benefits.

Use of Ultrasonication Technology for the Increased Production of Plant Secondary Metabolites.

Plant secondary metabolites (PSMs) provide taste, color, odor, and resistance to plants, and they are also used to treat cancer and cardiovascular diseases. Synthesis of PSMs in plants is stimulated in response to different forms of external stress. Use of ultrasonication (US) to clean or decontaminate fruits and vegetables leads to physical stress that finally results in the accumulation of PSMs. US can stimulate accumulation of taxol, ginsenoside saponins, shikonin, and resveratrol, e.g., up to 319-fold increase of resveratrol synthesis has been observed in grape due to US. US also increases carotenoids, total phenolics, and isoflavonoids accumulation. Furthermore, US shows synergistic effects in PSMs synthesis-when combined with ultraviolet (UV) irradiation, jasmonic acid (JA) or salicylic acid (SA). It has been observed that US stimulates the production of reactive oxygen species (ROS) which then upregulates expression of phenylalanine ammonia lyase (PAL), resulting in the synthesis of PSMs. In this review, we summarize the effects of US, as a physical stress, to maximize the accumulation of PSMs in crop produce and in cell cultures.

An Overview of Stress-Induced Resveratrol Synthesis in Grapes: Perspectives for Resveratrol-Enriched Grape Products.

Resveratrol is the most important stilbene phytoalexin synthesized naturally or induced in plants, as a part of their defense mechanism. Grapes and their derivative products, including juice and wine, are the most important natural sources of resveratrol, consisting of notably higher amounts than other natural sources like peanuts. Consumption of red wine with its presence of resveratrol explained the “French Paradox”. Hence, the demand of resveratrol from grapes is increasing. Moreover, as a natural source of resveratrol, grapes became very important in the nutraceutical industry for their benefits to human health. The accumulation of resveratrol in grape skin, juice, and wine has been found to be induced by the external stimuli: microbial infection, ultrasonication (US) treatment, light-emitting diode (LED), ultra violet (UV) irradiation, elicitors or signaling compounds, macronutrients, and fungicides. Phenylalanine ammonia lyase, cinnamate-4-hydroxylase, coumaroyl-CoA ligase, and stilbene synthase play a key role in the synthesis of resveratrol. The up-regulation of those genes have the positive relationship with the elicited accumulation of resveratrol. In this review, we encapsulate the effect of different external stimuli (biotic and abiotic stresses or signaling compounds) in order to obtain the maximum accumulation of resveratrol in grape skin, leaves, juice, wine, and cell cultures.

Horticultural Production of Ultra High Resveratrol Peanut

Background: Resveratrol naturally occurring antioxidant in peanut (Legume: Arachis hypogaea) has phytochemical human health dietary effects associated with reduced inflammatory cancer risks. Its levels in peanut are ultra-low and variable (0 to 26 μg·g-1), which has made it difficult to market as a consistent high resveratrol produce. Objective: Understanding the regulation of resveratrol accumulation in peanut might lead to development of new techniques for optimizing and stabilizing its yield. Method: Peanuts were cultivated in horticultural field plots and treated with solutions of mineral salts (sulfate, potassium, phosphate, ammonium ion) that were optimized in stoichiometric (reactive) ratios. Peanut seed’s RNAs were subjected to Northern blot analysis for profiling the RNAs synthesized by glutamate dehydrogenase (GDH), and mRNAs encoding resveratrol synthase. The seed’s extracts were analyzed by GC-MS for determination of the resveratrol and fatty acid compositions. Result: Stoichiometric mixes of mineral ions induced the peanut GDH to synthesize some RNA that silenced the mRNAs encoding resveratrol synthase, phosphoglucomutase, isocitrate lyase, malate synthase, enolase, phosphoenolpyruvate carboxylase, malate dehydrogenase, and phosphoglycerate mutase in the control, KN-, and NPKS-treated but not in the NPPK-treated peanut. These resulted to decreased resveratrol content (6.0 μg·g-1) in the control peanut but maximized it (1.15 mg·g-1) in the NPPK-treated peanut. Therefore, resveratrol accumulation was optimized by coupling of glycolysis and citric-glyoxylic acid cycles to resveratrol biosynthesis. Fatty acid content of control (55.6 g·kg-1) was higher than the NPKS-treated (48.5 g·kg-1) and NPPK-treated peanut (44.9 g·kg-1) meaning that malonyl-CoA intermediate in both fatty acid and stilbenoid pathways was diverted to support maximum resveratrol biosynthesis in the NPPK-treated peanut. Conclusion: The functional coupling of citric-glyoxylic acid cycles and glycolysis to optimize resveratrol biosynthesis may encourage development of horticultural technology specific for production of ultra-high resveratrol peanuts.