Polyphenol Derivatives Research Articles

Dihydro-resveratrol ameliorates NLRP3 inflammasome-mediated neuroinflammation via Bnip3-dependent mitophagy in Alzheimer's disease.

Dihydro-resveratrol (DHR), a polyphenol derivative, that has been demonstrated to suppress inflammation-mediated injury. However, it is still unknown whether it has anti-neuroinflammatory and neuroprotective effects, and a therapeutic action in Alzheimer's disease (AD). The anti-inflammatory and anti-Alzheimer's disease actions of dihydro-resveratrol were investigated using lipopolysaccharide (LPS) and AD mice models, and primary microglial cells. The changes in behaviour in mice were detected by the Morris water maze test and open-field test. Flow cytometry assay, western blotting, immunofluorescence assays and co-immunoprecipitation were used to investigate the changes in the NLRP3 inflammasome activation and mitophagy. In this study, in vivo observations indicated that the administration of dihydro-resveratrol (DHR) dramatically restored spatial learning, memory ability, autophagy and mitophagy, attenuated NLRP3 inflammasome activation, neuroinflammation and amyloid precursor protein pathology in LPS mice and AD mice. In addition, the inhibition of autophagy and mitophagy, or the activation of NLRP3 in vivo greatly abolished DHR-generated therapeutic efficacy on neuroinflammation, amyloid precursor protein pathology and cognitive loss. Further examination indicated that the application of DHR after the LPS and ATP exposure significantly inhibited the NLRP3 inflammasome activation, neuroinflammation and enhanced autophagic and mitophagic activation in microglia. Additionally, in vitro results show that DHR protects microglial cells against LPS and ATP-induced cytotoxicity by inhibiting NLRP3 inflammasome through activating Bnip3-dependent mitophagy and ULK phosphorylation. In summary, these findings suggest that dihydro-resveratrol (DHR) possesses potent anti-neuroinflammatory property and can act as a potential therapeutic agent for the treatment of AD.

Strobilanthes sarcorrhiza root phenolic extract prevent diabetic nephropathy in mice by regulating NF-κB/IL-1β signaling and glycerophospholipid metabolism

Strobilanthes sarcorrhiza, a folk medicine from China, is known to treat kidney deficiency and lumbago. However, its protective effects and mechanisms against diabetic nephropathy (DN) remain unclear. This study aimed to investigate the effects and mechanisms of Strobilanthes sarcorrhiza root phenolic extract (CTS) on streptozotocin (STZ)-induced DN in mice. Firstly, the constituents in CTS were characterized by UPLC-QTOF-MS. Thirty-three constituents were identified, including 12 phenylethanoid glycosides and their derivatives, 14 phenylpropanoid glycosides derivatives, 6 polyphenols derivatives, and 1 other constituent. Then, utilizing the identified constituents of CTS, network pharmacology was used to anticipate potential pathways against DN. Thirty-two out of thirty-three constituents showed anti-DN activity; their mechanism of action was significantly linked to tumor-, glycosylation-, metabolism-related pathways, etc. Furthermore, the effectiveness of CTS against DN and its in vivo mechanism was assessed by combining immunohistochemistry, untargeted metabolomics, biochemical evaluation, and histopathological examination. The findings showed that CTS improved blood glucose and lipid levels in diabetic mice, reduced serum levels of ALT, CREA, UREA, IL-1β, and IL-17, decreased pathological damage and fibrosis in kidney tissue, and lowered the protein expression of VEGF, Laminin, TNF-α, and NF-κB in kidney tissue. Metabolomics results indicated that CTS alleviated DN mainly by regulating glycerophospholipid metabolism. To the best of our knowledge, this study is the first to report that Strobilanthes sarcorrhiza attenuates DN, potentially through the inhibition of the NF-κB pathway, leading to a reduction in the inflammatory response and fibrosis of renal tissue. These findings suggest that Strobilanthes sarcorrhiza could be a promising therapeutic agent for DN.

Wetting and emulsification properties of cellulose nanocrystals modified with tannic acid and alkyl cellulose derivatives

HypothesisCellulose nanocrystals (CNCs) are sustainable rod-like nanoparticles that can be used to stabilize oil-in-water emulsions and can create hydrophilic coatings. Modifying the surface of CNCs can improve emulsion properties and allow for adjustable wettability. ExperimentsThis study explores the improvement of Pickering emulsion properties for various oils and the adjustability of coated surfaces through the physical modification of CNCs, without chemical functionalization and with bio-based additives, including antioxidant tannic acid (TA), methyl cellulose (MC), and ethyl cellulose (EC) as surface modifiers. The identification of optimal formulations involved varying the weight fraction of both the polyphenol and cellulose derivative. FindingsThe findings suggest that, akin to pure CNCs, Pickering emulsions stabilized with TA and/or MC-modified CNCs demonstrate comparably high stability. The introduction of MC at a low weight fraction enhances hydrophilicity, and AFM analysis reveals smooth surfaces, mitigating the potential influence of roughness. In contrast, EC-modified CNCs result in less stable emulsions but exhibit more hydrophobic surfaces. This translates to a broad spectrum of characteristics, ranging from quasi-superhydrophilic to nearly hydrophobic (with contact angles spanning from below 11° up to 75°), all controllable through a straightforward physical coating process. This facile preparation of coated CNCs provides a versatile approach to customizing the wetting and emulsification properties of nanomaterials.

The beneficial impact of curcumin on cardiac lipotoxicity.

Lipotoxicity is defined as a prolonged metabolic imbalance of lipids that results in ectopic fat distribution in peripheral organs such as the liver, heart, and kidney. The harmful consequences of excessive lipid accumulation in cardiomyocytes cause cardiac lipotoxicity, which alters the structure and function of the heart. Obesity and diabetes are linked to lipotoxic cardiomyopathy. These anomalies might be caused by a harmful metabolic shift that accumulates toxic lipids and shifts glucose oxidation to less fatty acid oxidation. Research has linked fatty acids, fatty acyl coenzyme A, diacylglycerol, and ceramide to lipotoxic stress in cells. This stress can be brought on by apoptosis, impaired insulin signaling, endoplasmic reticulum stress, protein kinase C activation, p38 Ras-mitogen-activated protein kinase (MAPK) activation, or modification of peroxisome proliferator-activated receptors (PPARs) family members. Curcuma longa is used to extract curcumin, a hydrophobic polyphenol derivative with a variety of pharmacological characteristics. Throughout the years, curcumin has been utilized as an anti-inflammatory, antioxidant, anticancer, hepatoprotective, cardioprotective, anti-diabetic, and anti-obesity drug. Curcumin reduces cardiac lipotoxicity by inhibiting apoptosis and decreasing the expression of apoptosis-related proteins, reducing the expression of inflammatory cytokines, activating the autophagy signaling pathway, and inhibiting the expression of endoplasmic reticulum stress marker proteins.

Portulaca Oleracea L. Phenolic Amide Methyl (3,4,5-Trimethoxybenzoyl) Valylprolinate Attenuates Diethylhexyl Phthalate-Induced Human Umbilical Vein Endothelial Cells' Inflammation Through NLRP3 and NF-κB Pathways.

Twelve polyphenol derivatives were obtained in a protective activity-guided isolation from the Portulaca oleracea L. extract on a cell model of human umbilical vein endothelial cells (HUVECs) under diethylhexyl phthalate (DEHP) exposure. Among them, methyl (3,4,5-trimethoxybenzoyl) valylprolinate (PP-10) performed the most protective activity and inhibited DEHP exposure-induced HUVECs' apoptosis. PP-10 also inhibited the DEHP-induced inflammatory cytokines (TNF-α, IL-6, IL-1β, and IL-8) and adhesion molecule (ICAM-1 andVCAM-1) overexpression. Furthermore, DEHP-induced NLRP3 inflammasomes' and NF-κB signaling pathway activation was significantly inhibited after the PP-10 treatments. Of note, the current results suggest the potential application of Portulaca oleracea L. and PP-10 in the prevention of DEHP-induced inflammatory damages in HUVECs.

DETERMINATION OF POLYPHENOLIC COMPOUNDS IN PHYTOEXTRACTS WITH ANTIBACTERIAL PROPERTIES AND STUDY POTENTIAL EFFECTS

Objectives. The research work is a comparative study of the polyphenolic compounds and flavonoid content of the phytoextracts obtained from the ultrasonic extraction process (Stegler DG-360) with 95% ethanol and ethanol-propyleneglycol mixture (in 95 : 5 ratio) from the Clove buds (Caryophyllos aromaticus L. Myrtaceae), hibiscus flowers (Hibiscus sabdariffa L. (Hs, roselle; Malvaceae)) and common yarrow (Achillea millefolium L. Asteraceae) plants, which are rich in biologically active substances with high therapeutic effect, as well as their devoted to the investigation of antioxydant activity and antimicrobial potential. Material and methods. The research work was carried out in the Central Research and Application Laboratory of Ağrı İbrahim Çeçen University (MERLAB), Republic of Turkey, using a Japanese Shimadzu brand Mistral-AB SCIEX 4000 QTRAP liquid chromatograph-mass spectrometer device. Results.It was found that in both extraction processes, the active substances penetrated sufficiently from the medicinal-plant raw materials into the extractant. 20 names of compounds containing polyphenol, flavonoid and anthocyanin derivatives have been determined. However, the amount of active substances in the phytoextract obtained with the presence of the penetrate (propylene glycol) was higher. In particular, rutin ( 75.74 ± 4.91mg/g), quercetin (110.12 ± 1.30 mg/g), gallic acid (4503.19 ± 46.83mg/g), quinic acid (4041.99 ± 187.3 mg/g), chlorogenic acid (582.30 ± 1.30mg/g), vanilin (155.6g/g1 ± 3.95mg/g) prevailed. Conclusion. The research work proves once again that the studied phytoextracts are rich in polyphenolic compounds and flavonoids. The amount of biologically active substances in the phytoextract obtained with the ethanol-propylene glycol mixture which is the penetrate substance (in the ratio of 95:5) is higher than that of the other sample (with 95% ethanol). The resulting amount of biologically active substances is a clear proof that the phytoextract has sufficient antioxidant and antimicrobial properties.

Inhibition of Cancer Stem-like Cells by Curcumin and Other Polyphenol Derivatives in MDA-MB-231 TNBC Cells.

Triple-negative breast cancer (TNBC) accounts for 15% of all breast cancers and is highly aggressive. Despite an initial positive response to chemotherapy, most patients experience rapid disease progression leading to relapse and metastasis. This is attributed to the presence of breast cancer stem cells (BCSCs) within the tumor, which are characterized by self-renewal, pluripotency, and resistance mechanisms. Targeting BCSCs has become critical as conventional therapies fail to eradicate them due to a lack of specific targets. Curcumin, a polyphenol derived from turmeric (Curcuma longa), exhibits anticancer effects against breast cancer cells and BCSCs. The use of curcumin derivatives has been suggested as an approach to overcome the bioavailability and solubility problems of curcumin in humans, thereby increasing its anticancer effects. The aim of this study was to evaluate the cellular and molecular effects of six synthetic compounds derived from the natural polyphenol epigallocatechin gallate (EGCG) (TL1, TL2) and curcumin derivatives (TL3, TL4, TL5, and TL6) on a TNBC mesenchymal stem-like cell line. The activity of the compounds against BCSCs was also determined by a mammosphere inhibition assay and studying different BCSC markers by Western blotting. Finally, a drug combination assay was performed with the most promising compounds to evaluate their potential synergistic effects with the chemotherapeutic agents doxorubicin, cisplatin, and paclitaxel. The results showed that compounds exhibited specific cytotoxicity against the TNBC cell line and BCSCs. Interestingly, the combination of the curcumin derivative TL3 with doxorubicin and cisplatin displayed a synergistic effect in TNBC cells.

Anti-tumoral Immunity and Chemo-preventive Effectiveness of Herbal Extracts of Curcumin, Ginger, Clove and Amygdaline in Ehrlich Ascites Carcinoma-Challenging Mice.

Due to its systemic toxicity, traditional chemotherapy of tumors is being taken into consideration. Herbal therapy, containing phytochemical polyphenol derivatives such as Curcumin (Cur), Ginger (Gin), Cloves (Clov) and Amygdaline (Amyg), is one of the numerous complementary and alternative approaches as an anti-cancer therapy and holds great promise for cancer chemo-prevention with fewer side effects. The current study was designated to assess anti-tumoral immunity and anti-cancer and chemo-preventive effectiveness of herbal extracts of Cur, Ginger, Clov and Amyg in Ehrlich Ascites Carcinoma (EAC)-challenging mice. Chemo-preventive efficacy of herbal extracts of Cur, Gin, Clov and Amyg were analyzed in vivo by examination of the apoptosis rate of EAC tumor cells by flow cytometry. The total numbers of EAC cells, splenocytes counts and leucocytes count with their differentials relative % in peripheral blood (PB) of EACchallenging mice were investigated. EAC-challenging mice treated with herbal extracts of Cur, Gin, Clov and Amyg showed a marked decline in EAC tumor cell count and a noticeable increase in apoptosis rate of EAC tumor cells, a remarkable decrease in serum level of cancer antigen 125 (CA-125) with an obvious increase in the number of splenocytes comparing to that in EAC-challenging mice treated with PBS alone. Moreover, the data indicated an insignificant change in the total leucocytes count and their differentials relative % of eosinophil, neutrophils, monocytes and lymphocytes in EAC-challenging mice treated with Cur and Amyg, but these parameters were markedly increased in EAC-challenging mice injected with Gin and Clov compared to that in EAC-challenging mice treated with PBS alone. To conclude, the herbal extracts of Cur, Gin, Clov and Amyg may have anti-tumoral immunity and anti-cancer potency and potential to reduce the resistance to cancer conventional chemotherapy and exert cancer chemo-protective approaches with low adverse effects. Further research is necessary to determine the regimen's toxicity on various tissues and organs and to connect the diagnostic and therapeutic approaches used in the regimen's biomedical use.

Polyphenolic tannin-based polyelectrolyte multilayers on poly(vinyl chloride) for biocompatible and antiadhesive coatings with antimicrobial properties

Poly(vinyl chloride) (PVC), a synthetic polymer, is used in various biomedical applications, particularly in the development of catheters. PVC-based catheters are engineered for blood-contacting applications. However, these materials lack antimicrobial properties, resulting in bacterial proliferation and subsequent infections. To overcome this disadvantage, blood-compatible and antimicrobial polyphenolic tannin-based surface coatings, known as polyelectrolyte multilayers (PEMs), were adsorbed onto PVC for the first time. PEMs were created on reduced PVC (Red-PVC) or oxidized PVC (Oxi-PVC) substrates using the layer-by-layer (LbL) approach. An amino-functionalized polyphenolic tannin derivative (TN-NH2), commercially known as Tanfloc, and an unmodified polyphenolic tannin (TN), commercially known as Weibull black, were assembled (15 layers) on Oxi-PVC or Red-PVC at pH 5.0. PVC substrates and PEMs were characterized through atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and water contact angle (WCA) measurements. The PEMs showed enhanced wettability compared to the unmodified PVC, with water contact angles ranging from 42° to 38°. The root mean square (Rq) roughness of the PEMs ranged from 64.5 nm to 74.1 nm, while the unmodified PVC surface displayed a relatively smooth surface with a roughness of 5.4 nm. Stability tests demonstrated that the PEMs maintained their integrity in phosphate buffer (pH 7.4) over seven days at 37°C. The obtained PEMs were not toxic to human fibroblasts and human erythrocytes. The Live/Dead antimicrobial assay results indicated that the PEMs possessed biocidal activity against Pseudomonas aeruginosa (P. aeruginosa) and antiadhesive capacity toward Staphylococcus aureus (S. aureus) and P. aeruginosa after 24 h of incubation. Cytocompatible and antimicrobial tannin-based PEMs on modified PVC surfaces can represent a significant advancement in mitigating bacterial infections associated with PVC-based catheters.

Design and Synthesis of Polyphenolic Imidazo[4,5-c]quinoline Derivatives to Modulate Toll Like Receptor-7 Agonistic Activity and Adjuvanticity.

TLR-7/8 agonists are a well-known class of vaccine adjuvants, with a leading example now included in Covaxin, a licensed human COVID-19 vaccine. This thereby provides the opportunity to develop newer, more potent adjuvants based on structure-function studies of these classes of compounds. Imidazoquinoline-based TLR7/8 agonists are the most potent, but when used as a vaccine adjuvant side effects can arise due to diffusion from the injection site into a systemic circulation. In this work, we sought to address this issue through structural modifications in the agonists to enhance their adsorption capacity to the classic adjuvant alum. We selected a potent TLR7-selective agonist, BBIQ (EC50 = 0.85 μM), and synthesized polyphenolic derivatives to assess their TLR7 agonistic activity and adjuvant potential alone or in combination with alum. Most of the phenolic derivatives were more active than BBIQ and, except for 12b, all were TLR7 specific. Although the synthesized compounds were less active than resiquimod, the immunization data on combination with alum, specifically the IgG1, IgG2b and IgG2c responses, were superior in comparison to BBIQ as well as the reference standard resiquimod. Compound 12b was 5-fold more potent (EC50 = 0.15 μM in TLR7) than BBIQ and induced double the IgG response to SARS-CoV-2 and hepatitis antigens. Similarly, compound 12c (EC50 = 0.31 μM in TLR7) was about 3-fold more potent than BBIQ and doubled the IgG levels. Even though compound 12d exhibited low TLR7 activity (EC50 = 5.13 μM in TLR7), it demonstrated superior adjuvant results, which may be attributed to its enhanced alum adsorption capability as compared with BBIQ and resiquimod. Alum-adsorbed polyphenolic TLR7 agonists thereby represent promising combination adjuvants resulting in a balanced Th1/Th2 immune response.

Three New Polyphenol Derivatives from the Fruits of Macaranga Monandra and their Antioxidant Potential.

Phytochemical investigation of the methanol extract from the fruits of Macaranga monandra (Euphorbiaceae Muell. et Arg.) afforded one new geranylated 1',2'-dihydrophenanthrene and two new flavonoid derivatives, named macamondrin (1), macamondrione A (2) and B (3) respectively. The structures of these compounds were elucidated mainly by NMR, mass spectral data and in comparison with data from the literature. Along with compounds 1-3, nine known compounds among which oleanolic acid (4); daucosterol (5); 3β-acetoxy-11α,12α-epoxytaraxerol (6); 3,3',4-tri-O-methylellagic acid (7); 3,3',4,4'-tetra-O-methylellagic acid (8); 4'-O-methyl-6-isoprenylapigenin (9); 4'-O-methyl-8 isoprenylkaempférol (10); 4'-O-methyl-6-isoprénylkaempférol (11); 6-isoprénylkaempférol (12), were also isolated. Crude extracts as well as isolated compounds were evaluated for their antioxidant activity using the ABTS, DPPH and FRAP methods. It appears that the 50 % radical scavenging concentrations ranging from 6.26 to 11.7 μg/ml on the ABTS radical, from 1.77 to 48.22 μg/ml on the DPPH radical, and from 1.54 to 67.97 μg/ml with the FRAP method. For the compounds tested, very good antioxidant activities were observed, which clearly shows that these molecules can have an anti oxidative stress potentiel.

The Effect of Salvia tomentosa Miller Extracts, Rich in Rosmarinic, Salvianolic and Lithospermic Acids, on Bacteria Causing Opportunistic Infections.

Methanolic-aqueous extracts of Salvia tomentosa Miller roots, aerial parts, and inflorescences were examined for their content of polyphenolic derivatives and the antimicrobial and cytotoxic effect. In the polyphenolic-rich profile, rosmarinic, salvianolic, and lithospermic acids along with various derivatives were predominant. A total of twenty phenolic compounds were identified using the UPLC/DAD/qTOF-MS technique. These were caffeic acid, rosmarinic acid derivatives, lithospermic acid derivatives, salvianolic acids B, F, and K derivatives, as well as sagerinic acid, although rosmarinic acid (426-525 mg/100 g of dry weight-D.W.) and salvianolic acid B (83-346.5 mg/100 g D.W.) were significantly predominant in the metabolic profile. Strong antibacterial activity of S. tomentosa extracts was observed against Staphylococcus epidermidis (MIC/MBC = 0.625 mg/mL) and Bacillus cereus (MIC = 0.312-1.25 mg/mL). The extracts showed low cytotoxicity towards the reference murine fibroblasts L929 and strong cytotoxicity to human AGS gastric adenocarcinoma epithelial cells in the MTT reduction assay. The observed cytotoxic effect in cancer cells was strongest for the roots of 2-year-old plant extracts.

Mitochondria dysfunction induced by decyl-TPP mitochondriotropic antioxidant based on caffeic acid AntiOxCIN6 sensitizes cisplatin lung anticancer therapy due to a remodeling of energy metabolism

The pharmacological interest in mitochondria is very relevant since these crucial organelles are involved in the pathogenesis of multiple diseases, such as cancer. In order to modulate cellular redox/oxidative balance and enhance mitochondrial function, numerous polyphenolic derivatives targeting mitochondria have been developed. Still, due to the drug resistance emergence in several cancer therapies, significant efforts are being made to develop drugs that combine the induction of mitochondrial metabolic reprogramming with the ability to generate reactive oxygen species, taking into consideration the varying metabolic profiles of different cell types. We previously developed a mitochondria-targeted antioxidant (AntiOxCIN6) by linking caffeic acid to lipophilic triphenylphosphonium cation through a 10-carbon aliphatic chain. The antioxidant activity of AntiOxCIN6 has been documented but how the mitochondriotropic compound impact energy metabolism of both normal and cancer cells remains unknown. We demonstrated that AntiOxCIN6 increased antioxidant defense system in HepG2 cells, although ROS clearance was ineffective. Consequently, AntiOxCIN6 significantly decreased mitochondrial function and morphology, culminating in a decreased capacity in complex I-driven ATP production without affecting cell viability. These alterations were accompanied by an increase in glycolytic fluxes. Additionally, we demonstrate that AntiOxCIN6 sensitized A549 adenocarcinoma cells for CIS-induced apoptotic cell death, while AntiOxCIN6 appears to cause metabolic changes or a redox pre-conditioning on lung MRC-5 fibroblasts, conferring protection against cisplatin. We propose that length and hydrophobicity of the C10-TPP+ alkyl linker play a significant role in inducing mitochondrial and cellular toxicity, while the presence of the antioxidant caffeic acid appears to be responsible for activating cytoprotective pathways.

Synergistic inhibition of glioblastoma multiforme through an in-silico analysis of luteolin and ferulic acid derived from Angelica sinensis and Cannabis sativa: Advancements in computational therapeutics.

The primary objective of this study is to uncover novel therapeutic agents for the treatment of Glioblastoma Multiforme (GBM), a highly aggressive form of brain cancer, and Alzheimer's Disease (AD). Given the complexity and resistance associated with both conditions, the study underscores the imperative need for therapeutic alternatives that can traverse the biological intricacies inherent in both neuro-oncological and neurodegenerative disorders. To achieve this, a meticulous, target-based virtual screening was employed on an ensemble of 50 flavonoids and polyphenol derivatives primarily derived from plant sources. The screening focused predominantly on molecular targets pertinent to GBM but also evaluated the potential overlap with neural pathways involved in AD. The study utilized molecular docking and Molecular Dynamic (MD) simulation techniques to analyze the interaction of these compounds with a key biological target, protein tyrosine phosphatase receptor-type Z (PTPRZ). Out of the 50 compounds examined, 10 met our stringent criteria for binding affinity and specificity. Subsequently, the highest value of binding energy was observed for the synergistic binding of luteolin and ferulic acid with the value of -10.5 kcal/mol. Both compounds exhibited inherent neuroprotective properties and demonstrated significant potential as pathway inhibitors in GBM as well as molecular modulators in AD. Drawing upon advanced in-silico cytotoxicity predictions and sophisticated molecular modeling techniques, this study casts a spotlight on the therapeutic capabilities of polyphenols against GBM. Furthermore, our findings suggest that leveraging these compounds could catalyze a much-needed paradigm shift towards more integrative therapeutic approaches that span the breadth of both neuro-oncology and neurodegenerative diseases. The identification of cross-therapeutic potential in flavonoids and polyphenols could drastically broaden the scope of treatment modalities against both fatal diseases.

The Effect of Theaflavins on the Gut Microbiome and Metabolites in Diabetic Mice.

With the development of diabetes, the gut microbiome falls into a state of dysbiosis, further affecting its progression. Theaflavins (TFs), a type of tea polyphenol derivative, show anti-diabetic properties, but their effect on the gut microbiome in diabetic mice is unclear. It is unknown whether the improvement of TFs on hyperglycemia and hyperlipidemia in diabetic mice is related to gut microbiota. Therefore, in this study, different concentrations of TFs were intragastrically administered to mice with diabetes induced by a high-fat-diet to investigate their effects on blood glucose, blood lipid, and the gut microbiome in diabetic mice, and the plausible mechanism underlying improvement in diabetes was explored from the perspective of the gut microbiome. The results showed that the TFs intervention significantly improved the hyperglycemia and hyperlipidemia of diabetic mice and affected the structure of the gut microbiome by promoting the growth of bacteria positively related to diabetes and inhibiting those negatively related to diabetes. The changes in short-chain fatty acids in mice with diabetes and functional prediction analysis suggested that TFs may affect carbohydrate metabolism and lipid metabolism by regulating the gut microbiome. These findings emphasize the ability of TFs to shape the diversity and structure of the gut microbiome in mice with diabetes induced by a high-fat diet combined with streptozotocin and have practical implications for the development of functional foods with TFs.

A Comparative Study of the Inhibitory Effect of Some Flavonoids and a Conjugate of Taxifolin with Glyoxylic Acid on the Oxidative Burst of Neutrophils.

During the storage, processing, and digestion of flavonoid-rich foods and beverages, a condensation of flavonoids with toxic carbonyl compounds occurs. The effect of the resulting products on cells remains largely unknown. The aim of the present study was to evaluate the effects of quercetin, taxifolin, catechin, eriodictyol, hesperetin, naringenin, and a condensation product of taxifolin with glyoxylic acid on the oxidative burst of neutrophils. It was found that the flavonoids and the condensation product inhibited the total production of ROS. Flavonoids decreased both the intra and extracellular ROS production. The condensation product had no effect on intracellular ROS production but effectively inhibited the extracellular production of ROS. Thus, the condensation of flavonoids with toxic carbonyl compounds may lead to the formation of compounds exhibiting potent inhibitory effects on the oxidative burst of neutrophils. The data also suggest that, during these reactions, the influence of a fraction of flavonoids and their polyphenolic derivatives on cellular functions may change. On the whole, the results of the study provide a better understanding of the effects of polyphenols on human health. In addition, these results reveal the structure-activity relationship of these polyphenols and may be useful in a search for new therapeutic agents against diseases associated with oxidative stress.

Modular design of vegetable polyphenols enables covalent bonding with collagen for eco-leather

Natural renewable materials have been engineered to synthesize functional products because of their wide availability and excellent biodegradability. Particularly, vegetable polyphenols have been regarded as sustainable tanning agents in the leather industry. However, the non-covalent binding nature and high consumption of polyphenols in the leather matrix have limited its potential for replacing chrome tannage. In this work, we developed a series of new polyphenol derivatives by selectively conjugating cyanuric chloride (CC) with phenolic group, and therefore introduced covalent binding moieties in polyphenol for the tanning process. Specifically, polyphenols with different molecular sizes, i.e., tannic acid (TA), ellagic acid (EA), and gallic acid (GA), were modified and evaluated in a comparative study. The obtained triazine-conjugated polyphenol derivatives (i.e., GACC, EACC, and TACC) exhibited appropriate molecular weight (460−1130 Da) and superior stability in the tanning bath (pH ∼8.0), which can effectively penetrate collagen networks. We further investigated the tanning performance of GACC, EACC, TACC, and a commercial triazine tanning agent (i.e., SACC). These polyphenol derivatives exhibited covalent and non-covalent synergistic interaction with collagen, endowing leather with excellent fiber dispersion and overall performance (i.e., thermal stability, organoleptic and physical properties). Of note, the tanning system effectively reduced the dosage of polyphenols and organic carbon emission and improved the biodegradability of wastewater. Together with these outstanding results, we envision that this work will pave the promising way for eco-leather manufacturing.

Comparison of the contents of total polyphenol, total flavonoid, and flavonoid derivatives in unfermented and fermented barley sprouts

Comparison of the contents of total polyphenol, total flavonoid, and flavonoid derivatives in unfermented and fermented barley sprouts

Tailor-made highly negatively charged nanofiltration membrane prepared by polyphenol derivatives for anionic dye/salt separation

Nanofiltration (NF) techniques are becoming increasingly advantageous for treating salt-containing dye wastewater. A novel NF membrane was successfully fabricated using grape seed oligomeric proanthocyanidins (OPC) as aqueous phase monomer by interfacial polymerization with isophorone diisocyanate (IPDI). The membrane surface exhibited an extremely high negative zeta potential. The experimental results showed that the negatively charged OPC/IPDI nanofiltration membranes could effectively remove anionic dyes and exhibited high NaCl/dye selectivity. Specifically, the optimal OPC/IPDI membrane exhibited a rejection of 99.4 % against Reactive Red 195 with a high permeance of 67.9 L m−2 h−1 bar−1 and a desirable NaCl/RR 195 selectivity factor of 85.3. In addition, the smooth and hydrophilic surface endowed the membranes with a desirable antifouling property. The optimized membrane achieved high flux recovery ratio values of 89.1 %, 85.5 %, and 24.75 % for the foulants of Reactive Red 195, humic acid, and bovine serum albumin, respectively. A 50-hour investigation of continuous cross-flow filtration processes showed the outstanding separation stability of the membranes. Furthermore, the membranes exhibited excellent anti-bacterial activity. Integrating all the findings, the strategy proposed in this paper for the use of polyphenol derivatives to prepare highly negatively charged membranes for the removal of anionic pollutants from saline wastewater is feasible.

Electrospinning of poly(vinyl alcohol) and poly(vinyl alcohol)/tannin solutions: A critical viewpoint about crosslinking

Poly(vinyl alcohol) (PVA) is a hydrophilic and cytocompatible polymer used in biomedical, pharmaceutical, food, and environmental applications. However, the PVA aqueous solubility restricts its direct application. To overcome this disadvantage, PVA chains can be chemically crosslinked to impart stability and durability to the engineered materials. This work presents PVA/Tanfloc (PVA/TN) electrospun fibers for the first time. TN is an amino-functionalized polyphenolic tannin derivative. PVA/TN materials were created from PVA/TN blends in water (W)/acetic acid (HAc) (99/1 v/v) and W/formic acid (FA) (50/50 v/v) mixtures. FA and glutaraldehyde (GA) were evaluated as crosslinkers for the electrospun fibers. GA vapor was also tested as a crosslinker. PVA and PVA/TN materials (before and after crosslinking) were characterized by infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). The as-prepared PVA/TN fibers quickly dissolved in ethanol and water but not in acetone. Fiber durability increased in acetone when the TN content was at least 20 wt%. PVA/TN fibers were crosslinked in acetone containing GA (1.0 wt%) and HAc (1.0 % v/v). However, GA-crosslinked fibers had no stability in water after washing. The stability of PVA-based electrospun fibers after GA crosslinking has not been previously reported in the literature. PVA/TN fibers were also crosslinked by thermal treatment. This strategy maintained the fiber structure after water immersion over 15 days. This study presents a critical viewpoint concerning strategies to crosslink PVA-based fibers, focusing on fiber durability and stability after crosslinking. The thermal treatment is by far the best method to crosslink PVA-based fibers because it can maintain fiber morphology, promoting aqueous durability.