Bioactive Resveratrol Research Articles

Semi-solid-state fermentation of Polygonum cuspidatum roots by a novel endophytic fungus Penicillium rubens with capabilities of cell wall hydrolysis and polydatin deglycosylation to improve the yield of high-value resveratrol

Resveratrol (a high-value natural polyphenolic compound with numerous pharmacological activities) is predominantly present in the form of the glycoside polydatin in Polygonum cuspidatum roots. In this study, a novel endophytic fungus, Penicillium rubens, capable of producing both cellulase (0.71 ± 0.09 U/mL) and β-glucosidase (4.35 ± 0.38 U/mL) for cell wall hydrolysis and polydatin deglycosylation, was used to ferment P. cuspidatum roots to improve the yield of valuable resveratrol. Results showed that the semi-solid-state fermentation (SSSF) using the homogeneous cultures of P. rubens was the appropriate strategy to obtain a higher yield of resveratrol from P. cuspidatum roots. Under the optimal fermentation conditions (temperature 30 °C, inoculation dose 4.0 mL/g, and time 72 h), the yield of resveratrol (19.95 ± 0.83 mg/g DW) in P. cuspidatum roots fermented by P. rubens was 19.18-fold higher than that in the unfermented control (1.04 ± 0.47 mg/g DW). Moreover, the digestibility of P. cuspidatum roots by P. rubens in terms of dry matter weight and cellulose content was 40.04% and 21.91%, respectively. Scanning electron microscope observation indicated that P. rubens fermentation could effectively disrupt the cell walls of P. cuspidatum roots, thus contributing to the release of more polydatin for deglycosylation. In addition, the extracts of P. cuspidatum roots fermented by P. rubens exhibited higher antioxidant and antibacterial activities compared with those of the unfermented control. The economic analysis showed that the benefit of SSSF approach for resveratrol production was much greater than that of the unfermented control. Overall, this study proposed a cost-effective SSSF method using the novel P. rubens to obtain bioactive resveratrol from P. cuspidatum roots, which had promising potential in the pharmaceutical, nutraceutical, and cosmetic industries.

High hydrostatic pressure improved properties of peanut sprout juice and its effect on resveratrol

HHP was a nonthermal technology which was widely used in food processing. In this study, HHP was used to process the peanut sprout juice and microbial load, physicochemical properties and antioxidant capacities of peanut sprout juice were found to be improved during 90-day storage. Compared with heat treatment (HT, 95 °C, 10 min), the treatment at 400–600 MPa resulted in greater microbiological stability. No more than 2 lg CFU/g of total plate count (TPC) was observed at 600 MPa for 5 min during a 90-day storage period at 4 °C. The significant negative correlation between the total number of colonies and resveratrol was confirmed, which has bactericidal and bacteriostatic effects. Additionally, resveratrol treated with HHP would degrade and generate new degradation products like p-methylphenol, resorcinol, oxidized resveratrol with higher DPPH scavenging rate, which resulted the higher antioxidation capacity in HHP treated peanut sprout juice. In a word, this study focused on the effect of HHP on peanut sprout juice and the possible degradation behavior of the bioactive resveratrol with HHP treatment, providing a promising processing technology for peanut sprout juice with higher quality.

Production of Resveratrol Glucosides and Its Cosmetic Activities

A biocatalytic system that could produce bioactive resveratrol poly-glucosides, using sucrose as a low-cost source of UDP-glucose donors and amylosucrase DgAS from Deinococcus geothermalis, was developed in this study. This system boasts several advantages, including the rapid and direct conversion of substrates to products, thermostability, regio-stereospecificity, and effectiveness, both in vitro and in vivo, at 40 °C. The results showed that the optimal reaction condition of the production of resveratrol glucosides was obtained by 2.0 µg/mL DgAS and 100 mM sucrose at pH 7.0, incubated at 40 °C for 5 h. With a success rate of around 97.0% in vitro and 95.0% in vivo in a short period of time, resveratrol-O-glucosides showed exciting outcomes in cosmetic applications, including antioxidant, anti-inflammatory, anti-aging, and whitening effects when tested with Raw 264.7, B16, and HS68 cell lines. DgAS is recognized as an important biocatalyst due to its high thermostability, effectiveness, and specificity among all known amylosucrases (ASases) in the production of poly-glucosides in a chain of polyphenols, such as resveratrol, making it an ideal candidate for industrial use in the cost-effective production of cosmetic items.

Down regulation of inflammatory cytokines by the bioactive resveratrol-loaded chitoniosomes in induced ocular inflammation model

Resveratrol (RSV); a natural polyphenol possess anti-inflammatory property through reduction of proinflammatory cytokines tumor-necrosis factor-alpha (TNFα) and interleukin (IL)-6 which play a key role in eye inflammation. Ocular inflammation results in irreversible tissues damage and impaired vision if left untreated. Surface coating of niosomes with chitosan can enhance their efficacy. Therefore the aim was to develop RSV-loaded chitosan-coated niosomes (Chitoniosomes) for topical ocular delivery. Chitoniosomes were formulated by ethanol-injection method. The selected formula (RSV.CsNiPolx) was composed of Span 60, Poloxamer407 and Cholesterol (3.5:3.5:3) coated with 0.6% w/v Chitosan. RSV.CsNiPolx showed particle size 363.1nm, PDI (0.21), zeta potential (+17.9), 90.3% entrapment efficiency, mucoadhesive efficiency with a sustained-release profile (56%) after 6 h. TEM showed circular shape niosomes surrounded by a relatively faded coat. The formula kept stable at 4 °C for 6 months storage. Good ocular tolerance of Chitoniosomes formulation without any inflammatory response to the rabbit eyes was confirmed by histological examination. Invivo antiinflammatory effects after 3 days treatment revealed reduced gene expressions of TNFα and IL-6, down to 49% and 55% respectively, in treated groups compared to control group. In conclusion, the results offer a promising nanoplatforms for topical application of the natural bioactive resveratrol in ocular inflammation.

Synthesis of Short-Chain-Fatty-Acid Resveratrol Esters and Their Antioxidant Properties.

To expand the applications and enhance the stability and bioactivity of resveratrol (RE), and to simultaneously include the potential health benefits of short chain fatty acids (SCFA) esters of RE were prepared by Steglich reactions with acetic, propionic, and butyric acids, respectively. RE and the esterified RE-SCFA products (including RAE, RPE, and RBE) were analyzed using nuclear magnetic resonance (NMR), Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), differential thermal analysis (DTA), and liquid chromatography–mass spectrometry (LC–MS). The FTIR and 13C NMR spectra of the esterified products included ester-characteristic peaks at 1751 cm−1 and 171 ppm, respectively. Moreover, the peaks in the range of 1700 to 1600 cm−1 in the FTIR spectra of the esterified products indicated that the esterification of RE-SCFA was successful. The TGA results revealed that the RE-SCFA esters decomposed at lower temperatures than RE. The peaks in the LC–MS profiles of the esterified products indicated the formation of mono- and diesters, and the calculated monoester synthesis rates ranged between 45.81 and 49.64%. The RE esters inhibited the Cu2+-induced low-density lipoprotein oxidation reaction, exhibited antioxidant activity in bulk oil, and effectively inhibited the hydroxyl radical-induced DNA scission. Moreover, the RE-SCFA esters had better hydrogen peroxide scavenging activity than RE. Our results are the first in the literature to successfully including short chain fatty acids in the esters of resveratrol, and the products could be used as a functional food ingredient in processed foods or can be used as dietary supplements to promote health.

Screening of Natural Stilbene Oligomers from Vitis vinifera for Anticancer Activity on Human Hepatocellular Carcinoma Cells.

The characterization of bioactive resveratrol oligomers extracted from Vitis vinifera canes has been recently reported. Here, we screened six of these compounds (ampelopsin A, trans-ε-viniferin, hopeaphenol, isohopeaphenol, R2-viniferin, and R-viniferin) for their cytotoxic activity to human hepatocellular carcinoma (HCC) cell lines p53 wild-type HepG2 and p53-null Hep3B. The cytotoxic efficacy depended on the cell line. R2-viniferin was the most toxic stilbene in HepG2, with inhibitory concentration 50 (IC50) of 9.7 ± 0.4 µM at 72 h, 3-fold lower than for resveratrol, while Hep3B was less sensitive (IC50 of 47.8 ± 2.8 µM). By contrast, hopeaphenol (IC50 of 13.1 ± 4.1 µM) and isohopeaphenol (IC50 of 26.0 ± 3.0 µM) were more toxic to Hep3B. Due to these results, and because it did not exert a large cytotoxicity in HH4 non-transformed hepatocytes, R2-viniferin was selected to investigate its mechanism of action in HepG2. The stilbene tended to arrest cell cycle at G2/M, and it also increased intracellular reactive oxygen species (ROS), caspase 3 activity, and the ratio of Bax/Bcl-2 proteins, indicative of apoptosis. The distinctive toxicity of R2-viniferin on HepG2 encourages research into the underlying mechanism to develop the oligostilbene as a therapeutic agent against HCC with a particular genetic background.

<p>Metabolic profile and structure–activity relationship of resveratrol and its analogs in human bladder cancer cells</p>

Purpose: Resveratrol (RV), a promising anti-cancer candidate, is limited in application for its poor bioavailability. However, the better bioavailability has been found in some RV derivatives. So in this paper, we explore the structure–activity relationship and the metabolic profiles of RV and its analogs (polydatin [PD], oxyresveratrol [ORV], acetylresveratrol [ARV]) in human bladder cancer T24 cells, and then evaluate their active forms and key chemical functional groups which may determine the fate of tumor cells.Methods: Drug sensitivity is evaluated by MTT assay, HE staining and flow cytometry analysis after T24 cells treated with RV, PD, ORV and ARV, respectively. Then the drug metabolites, in alive and dead T24 cells, also in T24 cell supernatant and lysates, are qualitatively and quantitatively analyzed by high-performance liquid chromatography, liquid chromatography coupled with tandem mass spectrum and high-resolution mass spectrometry technologies, respectively.Results: RV, ORV and ARV inhibit bladder cancer cells growth in a dose- and time-dependent manner, and exert the anti-tumor potency to T24 cells in order of ORV>ARV>RV>PD. Meanwhile, similar metabolic profiles of the above compounds are found not only in cell supernatant and lysate, but also in dead and alive T24 cells after drug treatment, and the main metabolites of RV, ORV and PD are their prototypes, but ARV is mainly metabolized to RV.Conclusion: The inhibitory potencies to T24 cells in the order of ORV>ARV>RV>PD are related to the structure and metabolism of RV and its analogs. Meanwhile, the number and position of free phenolic hydroxyl groups play a prominent role in antitumor activities. Therefore, protecting phenolic hydroxyl groups, and inhibiting drug metabolism to keep phenolic hydroxyl groups free would be the promising strategies to ensure the bioactivity of RV and its analogs, and thus to improve RV’s bioactivity and promote RV clinical translation.

Mechanism research on a bioactive resveratrol- PLA-gelatin porous nano-scaffold in promoting the repair of cartilage defect.

BackgroundArticular cartilage defects are difficult to treat, but drug-loaded tissue engineering scaffolds provide a possible treatment option for these types of injuries.PurposeIn this study, we designed a bioactive resveratrol–PLA–gelatin porous nano-scaffold using electrospinning, freeze drying, and uniform dispersion techniques to repair articular cartilage defects, and then investigated the possible mechanism behind the successful repair.MethodsWe established an articular cartilage defect rat model with a 2 mm diameter wound in the middle of the knee joint femoral condyle non-weight-bearing area, with a depth reaching the full thickness of the subchondral bone. Postmodel specimens and micro computed tomography (CT) were used to observe any macroscopic morphological changes in the articular cartilage and subchondral bone, whereas multiple staining methods were used to observe all microcosmic morphological changes. Gross scores and Mankin scores were used to evaluate the repair condition. Immunohistochemical staining was employed to detect protein expression.ResultsWhen the repair included the resveratrol–PLA–gelatin porous nano-scaffold, the repaired cartilage and subchondral bone were in better condition. The expression levels of SIRT1, type II collagen, and PI3K/AKT signaling pathway-related proteins (AKT, VEGF, PTEN, Caspase 9, and MMP13) changed significantly. The expression levels of SIRT1,AKT and type II collagen proteins increased significantly, while the expression levels of VEGF, PTEN, Caspase9 and MMP13 proteins decreased significantly compared with the repair included blank porous PLA–gelatin nano-scaffold and without scaffold.ConclusionWe designed a bioactive resveratrol–PLA–gelatin porous nano-scaffold with better performance, which promoted the repair of cartilage injury as a whole, and explained its possible mechanism in accelerating cartilage repair via the PI3K/AKT signaling pathway.

Polypharmacology or Promiscuity? Structural Interactions of Resveratrol With Its Bandwagon of Targets.

Resveratrol (3, 4′, 5-trihydroxy-trans-stilbene) is a natural phytoalexin found in grapes and has long been thought to be the answer to the “French Paradox.” There is no shortage of preclinical and clinical studies investigating the broad therapeutic activity of resveratrol. However, in spite of many comprehensive reviews published on the bioactivity of resveratrol, there has yet to be a report focused on the variety and complexity of its structural binding properties, and its multi-targeted role. An improved understanding of disease mechanisms at the systems level has enabled targeted polypharmacology to mature into a rational drug discovery approach. Unlike traditional hit-to-lead campaigns that typically optimize activity and selectivity for a single target, polypharmacological drugs aim to selectively target multiple proteins, while avoiding critical off target interactions. This strategy bears promise of improved efficacy and reduced clinical attrition. This review seeks to investigate whether the bioactivity of resveratrol is due to a polypharmacological effect or promiscuity of the phenolic small molecule by examining the modes of binding with its diverse collection of protein targets. We focused on annotated targets, identified via the ChEMBL database, and matched these targets to a representative structure deposited in the Protein Data Bank (PDB), as crystal structures are most informative in understanding modes of binding at the atomic level. We discuss the structural aspects of resveratrol itself that permits binding to multiple proteins in various signaling pathways. Furthermore, we suggest that resveratrol’s bioactivity is a result of scaffold promiscuity rather than polypharmacology, and the variety of binding modes across targets display little similarity in the pattern of target interaction.

De novo biosynthesis of pterostilbene in an Escherichia coli strain using a new resveratrol O-methyltransferase from Arabidopsis

BackgroundPterostilbene, a structural analog of resveratrol, has higher oral bioavailability and bioactivity than that of the parent compound; but is far less abundant in natural sources. Thus, to efficiently obtain this bioactive resveratrol analog, it is necessary to develop new bioproduction systems.ResultsWe identified a resveratrol O-methyltransferase (ROMT) function from a multifunctional caffeic acid O-methyltransferase (COMT) originating from Arabidopsis, which catalyzes the transfer of a methyl group to resveratrol resulting in pterostilbene production. In addition, we constructed a biological platform to produce pterostilbene with this ROMT gene. Pterostilbene can be synthesized from intracellular l-tyrosine, which requires the activities of four enzymes: tyrosine ammonia lyase (TAL), p-coumarate:CoA ligase (CCL), stilbene synthase (STS) and resveratrol O-methyltransferase (ROMT). For the efficient production of pterostilbene in E. coli, we used an engineered E. coli strain to increase the intracellular pool of l-tyrosine, which is the initial precursor of pterostilbene. Next, we tried to produce pterostilbene in the engineered E. coli strain using l-methionine containing media, which is used to increase the intracellular pool of S-adenosyl-l-methionine (SAM). According to this result, pterostilbene production as high as 33.6 ± 4.1 mg/L was achieved, which was about 3.6-fold higher compared with that in the parental E. coli strain harboring a plasmid for pterostilbene biosynthesis.ConclusionAs a potential phytonutrient, pterostilbene was successfully produced in E. coli from a glucose medium using a single vector system, and its production titer was also significantly increased using a l-methionine containing medium in combination with a strain that had an engineered metabolic pathway for l-tyrosine. Additionally, we provide insights into the dual functions of COMT from A. thaliana which was characterized as a ROMT enzyme.

255 - Polyphenol-Protein Interaction Influences the Stability and Bioactivity of Resveratrol Analogues

The bioavailability and bioactivity of resveratrol and its analogues are obviously influenced by their stability. Most data of bioactivity from resveratrol and its analogues have been reported by in vitro cell culture experiments. FBS is a universal growth supplement of cell and tissue culture media. Herein, the influences of FBS on the stability and antioxidant activity of 21 resveratrol analogues were investigated by a polyphenol-protein interaction approach. The structure-stability relationships of resveratrol analogues in FBS showed that the hydroxylation of resveratrol analogues obviously decreased their stability in the order: resorcinol-type > pyrogallol-type > catechol-type. The glycosylation and methoxylation of resveratrol analogues enhanced their stability. A linear relationship between the stability of resveratrol analogues in FBS and the affinity of resveratrol analogues-FBS interaction was found. The oxidation process is not the single factor governing the stability of resveratrol analogues in FBS.

Bioconversion of piceid to resveratrol by selected probiotic cell extracts.

Resveratrol exerts several pharmacological activities, including anti-cancer, anti-inflammatory, cardioprotective, or antioxidant effects. However, due to its occurrence in plants more in glycosidic form as piceid, the bioavailability and bioactivity are limited. The enzymatic potential of probiotics for the transformation of piceid to resveratrol was elucidated. Cell extract from Bifidobacteria (B.) infantis, B. bifidum, Lactobacillus (L.) casei, L. plantarum, and L. acidophilus was evaluated for their effect in this bioconversion using high-performance liquid chromatography (HPLC) as analytical tool. Cell extract of B. infantis showed the highest effect on the deglycosylation of piceid to resveratrol, already after 30 min. Cell extracts of all other tested strains showed a significant biotransformation with no further metabolization of resveratrol. The conversion of piceid to resveratrol is of importance to increase bioavailability and bioactivity as shown for anti-inflammation in this study. Cell extracts from probiotics, especially from B. infantis, may be added to piceid containing products, for achieving higher biological effects caused by the bioactivity of resveratrol or by health promoting of the probiotics. These findings open a new perspective of novel combination of cell extracts from probiotics and piceid, in health-promoting pharmaceutical and food products.

Production of highly bioactive resveratrol analogues pterostilbene and piceatannol in metabolically engineered grapevine cell cultures.

SummaryGrapevine stilbenes, particularly trans‐resveratrol, have a demonstrated pharmacological activity. Other natural stilbenes derived from resveratrol such as pterostilbene or piceatannol, display higher oral bioavailability and bioactivity than the parent compound, but are far less abundant in natural sources. Thus, to efficiently obtain these bioactive resveratrol derivatives, there is a need to develop new bioproduction systems. Grapevine cell cultures are able to produce large amounts of easily recoverable extracellular resveratrol when elicited with methylated cyclodextrins and methyl jasmonate. We devised this system as an interesting starting point of a metabolic engineering‐based strategy to produce resveratrol derivatives using resveratrol‐converting enzymes. Constitutive expression of either Vitis vinifera resveratrol O‐methyltransferase (Vv ROMT) or human cytochrome P450 hydroxylase 1B1 (Hs CYP1B1) led to pterostilbene or piceatannol, respectively, after the engineered cell cultures were treated with the aforementioned elicitors. Functionality of both gene products was first assessed in planta by Nicotiana benthamiana agroinfiltration assays, in which tobacco cells transiently expressed stilbene synthase and Vv ROMT or Hs CYP1B1. Grapevine cell cultures transformed with Vv ROMT produced pterostilbene, which was detected in both intra‐ and extracellular compartments, at a level of micrograms per litre. Grapevine cell cultures transformed with Hs CYP1B1 produced about 20 mg/L culture of piceatannol, displaying a sevenfold increase in relation to wild‐type cultures, and reaching an extracellular distribution of up to 45% of total production. The results obtained demonstrate the feasibility of this novel system for the bioproduction of natural and more bioactive resveratrol derivatives and suggest new ways for the improvement of production yields.

9-Membered Carbocycle Formation: Development of Distinct Friedel-Crafts Cyclizations and Application to a Scalable Total Synthesis of (±)-Caraphenol A

Explorations into a series of different approaches for 9-membered carbocycle formation have afforded the first reported example of a 9-exo-dig ring closure via a AuIII-promoted reaction between an alkyne and an aryl ring as well as several additional, unique Friedel–Crafts-type cyclizations. Analyses of the factors leading to the success of these transformations are provided, with the application of one of the developed 9-membered ring closures affording an efficient and scalable synthesis of the bioactive resveratrol trimer caraphenol A. That synthesis proceeded with an average yield of 89 % per step (7.8 % overall yield) and has provided access to more than 600 mg of the target molecule.

9-Membered carbocycle formation: development of distinct Friedel-Crafts cyclizations and application to a scalable total synthesis of (±)-caraphenol A.

Explorations into a series of different approaches for 9-membered carbocycle formation have afforded the first reported example of a 9-exo-dig ring closure via a Au(III)-promoted reaction between an alkyne and an aryl ring as well as several additional, unique Friedel-Crafts-type cyclizations. Analyses of the factors leading to the success of these transformations are provided, with the application of one of the developed 9-membered ring closures affording an efficient and scalable synthesis of the bioactive resveratrol trimer caraphenol A. That synthesis proceeded with an average yield of 89% per step (7.8% overall yield) and has provided access to more than 600 mg of the target molecule.

Bioactivity of Resveratrol

ABSTRACT: Resveratrol (3,5,4′‐trihydroxystilbene) is a natural polyphenolic phytochemical with a variety of bioactivities associated with health promotion. Resveratrol is readily absorbed with the other absorbable digestion products of its main human dietary sources (peanuts, peanut butter, grapes, and red wine). The polyphenolic structure of resveratrol confers antioxidant activity and may reduce oxidant‐induced apoptosis and low‐density lipoprotein (LDL) oxidation. Resveratrol may be responsible, in part, for the correlation between increased wine consumption and decreased risk of coronary heart disease. The cardioprotective activity of resveratrol is associated with the inhibition of platelet aggregation and LDL oxidation and the promotion of artery vasorelaxation. As a chemoprevention agent, resveratrol has been shown to inhibit tumor initiation, promotion, and progression, as well as inhibit the growth of cancerous cells through increased apoptosis and/or cell cycle blockage. Inflammatory processes are associated in the pathogenesis of many chronic diseases including heart disease and cancer. Resveratrol has been shown to reduce inflammation via inhibition of prostaglandin production, cyclooxygenase‐2 activity, and nuclear factor‐кB activity. In addition, the estrogenic activity of resveratrol may help prevent post‐menopausal bone loss. Modulation of cellular signal transduction pathways (such as mitogen‐activated protein kinases) may explain, in part, the diverse bioactivities associated with resveratrol. Scientific information summarized in this review supports the many potential health benefits of resveratrol; however, further understanding of the bioavailability, metabolism, and cellular effects of resveratrol is necessary.