Cyanidin-3-glucoside Research Articles

Interactions with peanut protein isolate regulate the bioaccessibility of cyanidin-3-O-glucoside: Multispectral analysis, simulated digestion, and molecular dynamic simulation

Anthocyanins are susceptible to degradation owing to environmental factors. Combining them with proteins can improve their stability; however, the interaction mechanism is difficult to elucidate. This study used multispectral and molecular dynamics simulations and molecular docking methods to investigate the interaction mechanism between peanut protein isolate (PPI) and cyanidin-3-O-glucoside (C3G). The UV absorption peak and PPI turbidity increased, while the fluorescence intensity decreased with greater C3G content. Protein secondary structure changes suggested that PPI and C3G coexisted in spontaneous covalent and non-covalent interactions via static quenching. The complex structures were stable over time and C3G stably bound to the peanut globulin Ara h 3 cavity through hydrogen bonding and hydrophobic interactions. Furthermore, PPI enhanced the C3G antioxidant activity and bioaccessibility by increasing its retention rate during in-vitro simulated digestion. This study elucidates the binding mechanism of PPI and C3G and provides insight into applications of the complex in food development.

Macrophage MAPK7/AhR/STAT3 Signaling Mediates Mitochondrial ROS Burst and Enterohepatic Inflammatory Responses Induced by Deoxynivalenol Relevant to Low-Dose Exposure in Children.

Deoxynivalenol (DON) can induce endoplasmic reticulum (ER) stress, mitochondrial ROS burst, and macrophage polarization. Here, we investigated the mechanism linking the above three aspects with the dose range relevant to low-level exposure in children. At 0.5 μg/kg bw/day, we found remarkable liver and gut inflammatory responses after 6-week exposure in mice age comparable to humans 7-12 years old. Through antioxidant intervention, we found that ROS played a driver role in macrophage polarization and inflammatory responses induced by DON in the liver and gut. Further bioinformatics analysis uncovered that ER stress-associated protein MAPK7 (ERK5) may bind with AhR to initiate a mitochondrial ROS burst and macrophage M1 polarization. The downstream cellular events of MAPK7-AhR interaction may be mediated by the AhR/STAT3/p-STAT(Ser727) pathway. This mechanism was further supported by DON toxicity mitigation using cyanidin-3-glucoside (C-3-G), which docks to MAPK7 oligomerization region 200-400 aa and disrupts MAPK7-AhR interaction. Overall, our study provides novel evidence and mechanism for DON-induced inflammatory responses in the liver and gut system. Our findings call attention to the health risks associated with low-level DON exposure in the prepuberty children population.

Enhanced Antibacterial and Anti‐Biofilm Functions of Black Bean Skin Anthocyanins Against V. parahaemolyticus

ABSTRACTBlack bean skin anthocyanins (BBSAs), as by‐products of black beans, have not been fully exploited. BBSAs are rich in anthocyanins and have a wide range of health benefits. In this study, the antibacterial and antibiofilm action mode of BBSAs against Vibrio parahaemolyticus (V. parahaemolyticus) was evaluated. The antibacterial and antibiofilm efficiency was evaluated under different conditions, shedding light on their mode of action against V. parahaemolyticus. The results showed that the inactivation efficacy of BBSAs on V. parahaemolyticus was positively correlated with its concentration and incubating time. The MIC value for BBSAs was determined to be 10 μg/mL. The formation of V. parahaemolyticus biofilm was hindered by the presence of the BBSAs, especially at higher concentrations of BBSAs and during the early intervention stage. After exposure to 1 MIC of BBSA, the inhibition rate of biofilm reached 91.94%. The release of cellular components and alterations in membrane morphology indicated that BBSAs can damage the integrity of V. parahaemolyticus cell membrane. Furthermore, BBSAs may interact with membrane proteins, causing a notable conformational change in membrane proteins. HPLC and UPLC‐MS analysis confirmed that the major antibacterial compound in BBSAs was Cyanidin‐3‐O‐glucoside (C3G), which can form a stable complex with LolB protein in the outer membrane via hydrogen bonding. This study can provide strong technical support for the accurate control of V. parahaemolyticus and pave the way for the application of natural antibacterial agents in the realm of food‐borne bacterial control.

Blanching-Induced Changes in Polyphenol Oxidase, Antioxidants and Phenolic Profile of Mangosteen Pericarp.

Anthocyanin pigments in mangosteen pericarp can serve as natural colourants; however, their stability is compromised by enzymatic browning caused by polyphenol oxidase (PPO). Thus, this study aims to investigate how hot water and steam blanching affect the PPO activity, phenolic profile and antioxidant properties of mangosteen pericarp. Fresh mangosteen pericarp was blanched in hot water or steam at 100 °C for 0, 30, 60, 90 and 120 s and the residual PPO activity, total phenolic content (TPC), total anthocyanins, antioxidant activity, browning index and colour properties were evaluated. Additionally, the phenolic compounds were identified using liquid chromatography-mass spectrometry (LC-MS). Zero-order reaction kinetics (R2>0.800) showed that residual PPO activity was significantly (p<0.05) reduced in both blanched and steamed mangosteen pericarp. As expected, PPO was inactivated more rapidly in hot water (t 1/2=59.0 s) than in steam blanching (t 1/2=121.1 s). However, the principal component analysis (PCA) showed that steam blanching for 90 s was the most efficient method, preserving the highest levels of antioxidant capacity, expressed as Trolox equivalents (TE; 9135 µmol/g), Fe(III)-reducing power, expressed as TE, (9729 µmol/g), total anthocyanins (3.03 mg/g), and TPC, expressed as gallic acid equivalents (1057 mg/g). Overall, steam blanching for 90 s was the most efficient method because it best preserved the phenolic compounds and is also a cost-effective method compared to hot water, which needs to be replaced after a few applications. This is the first study to report the effects of blanching on the anthocyanins mainly present in mangosteen pericarp, in particular cyanidin-3-O-sophoroside (C3S) and cyanidin-3-O-glucoside (C3G), using high-performance liquid chromatography (HPLC) and LC-MS. This study makes a significant scientific contribution to the food industry by providing suitable blanching methods to preserve the quality of bioactive compounds, especially anthocyanins in mangosteen pericarp, which can be used as a natural colourant.

In Silico Analysis of the Molecular Interaction between Anthocyanase, Peroxidase and Polyphenol Oxidase with Anthocyanins Found in Cranberries.

Anthocyanins are bioactive compounds responsible for various physiological processes in plants and provide characteristic colors to fruits and flowers. Their biosynthetic pathway is well understood; however, the enzymatic degradation mechanism is less explored. Anthocyanase (β-glucosidase (BGL)), peroxidase (POD), and polyphenol oxidase (PPO) are enzymes involved in degrading anthocyanins in plants such as petunias, eggplants, and Sicilian oranges. The aim of this work was to investigate the physicochemical interactions between these enzymes and the identified anthocyanins (via UPLC-MS/MS) in cranberry (Vaccinium macrocarpon) through molecular docking to identify the residues likely involved in anthocyanin degradation. Three-dimensional models were constructed using the AlphaFold2 server based on consensus sequences specific to each enzyme. The models with the highest confidence scores (pLDDT) were selected, with BGL, POD, and PPO achieving scores of 87.6, 94.8, and 84.1, respectively. These models were then refined using molecular dynamics for 100 ns. Additionally, UPLC-MS/MS analysis identified various flavonoids in cranberries, including cyanidin, delphinidin, procyanidin B2 and B4, petunidin, pelargonidin, peonidin, and malvidin, providing important experimental data to support the study. Molecular docking simulations revealed the most stable interactions between anthocyanase and the anthocyanins cyanidin 3-arabinoside and cyanidin 3-glucoside, with a favorable ΔG of interaction between -9.3 and -9.2 kcal/mol. This study contributes to proposing a degradation mechanism and seeking inhibitors to prevent fruit discoloration.

Effects of L-Proline on the Stability of Mulberry Anthocyanins and the Mechanism of Interaction between L-Proline and Cyanidin-3-O-Glycoside.

The protective effects of L-aspartic acid, L-valine, and L-proline on the stability of mulberry anthocyanins were investigated. Results showed that L-aspartic acid, L-valine, and L-proline significantly enhanced (p < 0.05) the stability of mulberry anthocyanins under constant light or ascorbic acid (AA). L-Proline had the best protective effect against anthocyanin degradation. The interaction between L-proline and cyanidin-3-O-glucoside (C3G) through hydrogen bonding and van der Waals forces, which improved the stability of C3G, was confirmed using FT-IR, 1H NMR, XRD, and molecular docking analyses, as well as molecular dynamics modes. In vitro digestion experiments yielded that both 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical scavenging capacities of the C3G/Pro group were increased in the intestinal fluid (p < 0.05). The above findings suggest that L-proline effectively slowed down the degradation of mulberry anthocyanins, and that it could be used as an auxiliary pigment and food additive to extend the optimal flavor period of products containing mulberry anthocyanins, and can improve the bioavailability of mulberry anthocyanins.

Assessment of Enzymatically Derived Blackcurrant Extract as Cosmetic Ingredient-Antioxidant Properties Determination and In Vitro Diffusion Study.

Blackcurrant is an anthocyanin-rich berry with proven antioxidant and photoprotective activity and emerging prebiotic potential, widely applied in cosmetic products. Hereby, highly efficient enzyme-assisted extraction of blackcurrant polyphenols was performed, giving extract with very high antioxidant activity. Obtained extract was characterized in terms of anthocyanin composition, incorporated into three different cosmetic formulations and subjected to Franz cell diffusion study. Experimental values obtained using cellulose acetate membrane for all four dominant anthocyanins (delphinidin 3-glucoside, delphinidin 3-rutinoside, cyanidin 3-glucoside and cyanidin 3-rutinoside) were successfully fitted with the Korsmeyer-Peppas diffusion model. Calculated effective diffusion coefficients were higher for hydrogel compared to oil-in-water cream gel and oil-in-water emulsion, whereas the highest value was determined for cyanidin 3-rutinoside. On the other hand, after a 72 h long experiment with transdermal skin diffusion model (Strat-M® membrane), no anthocyanins were detected in the receptor fluid, and only 0.5% of the initial quantity from the donor compartment was extracted from the membrane itself after experiment with hydrogel. Present study revealed that hydrogel is a suitable carrier system for the topical delivery of blackcurrant anthocyanins, while dermal and transdermal delivery of these molecules is very limited, which implies its applicability for treatments targeting skin surface (i.e., prebiotic, photoprotective).

The effects of the interaction between cyanidin-3-O-glucoside (C3G) and walnut protein isolate (WPI) on the thermal and oxidative stability of C3G.

This study explores the interaction between cyanidin-3-O-glucoside (C3G), a water-soluble pigment known for its diverse functional activities, and walnut protein isolate (WPI) as a potential stabilizing agent. Given the inherent instability of C3G, particularly its limited application in the food industry due to sensitivity to thermal and oxidative conditions, this research study aims to enhance its stability. According to the results of the fluorescence quenching experiment, C3G can efficiently quench WPI's intrinsic fluorescence through static quenching. Structural exploration revealed that C3G bound WPI via hydrophobic interaction force, with the number of bound C3G molecules (n) almost equivalent to 1. The ΔG value denoting change in Gibbs free energy for C3G binding with WPI was -8.05 kJ/mol, which indicated that the interaction between C3G and WPI is spontaneous. Moreover, the conformational structures of WPI were altered by C3G binding with a decrease in α-helix contents and an increase in β-turn, β-sheet, and random coil contents. The thermal degradation kinetics indicate that after interacting with WPI, the half-life of C3G increased by 1.62 times and 1.05 times at 80 and 95°C, respectively. The results of the oxidation stability test showed that the presence of WPI effectively reduced the discoloration and degradation of C3G caused by oxidation, and improved the oxidation stability of C3G. This study's findings will help to clarify the interaction mechanism between C3G and WPI, and broaden C3G's application scope in the food processing field.

Exploring the effects of whey protein components on the interaction and stability of cyanidin-3-O-glucoside.

Anthocyanins are susceptible to degradation due to external factors. Despite the potential for improved anthocyanin stability with whey protein isolate (WPI), the specific effects of individual components within WPI on the stability of anthocyanins have yet to be studied extensively. This study investigated the interaction of WPI, β-lactoglobulin (β-Lg), bovine serum albumin (BSA), and lactoferrin (LF) with cyanidin-3-O-glucoside (C3G), and also considered their effects on stability. Fluorescence analysis revealed static quenching effects between C3G and WPI, β-Lg, BSA, and LF. The binding constants were 1.923 × 103 L · mol⁻¹ for WPI, 24.55 × 103 L · mol⁻¹ for β-Lg, 57.25 × 103 L · mol⁻¹ for BSA, and 1.280 × 103 L · mol⁻¹ for LF. Hydrogen bonds, van der Waals forces, and electrostatic attraction were the predominant forces in the interactions between C3G and WPI and between C3G and BSA. Hydrophobic interaction was the main binding force in the interaction between C3G and β-Lg and between C3G and LF. The binding of C3G with WPI, β-Lg, BSA, and LF was driven by different thermodynamic parameters. Enthalpy changes (∆H) were -38.76 kJ · mol⁻¹ for WPI, -17.59 kJ · mol⁻¹ for β-Lg, -16.09 kJ · mol⁻¹ for BSA, and 39.50 kJ · mol⁻¹ for LF. Entropy changes (∆S) were -67.21 J · mol⁻¹·K⁻¹ for WPI, 3.72 J · mol⁻¹·K⁻¹ for β-Lg, 37.09 J · mol⁻¹·K⁻¹ for BSA, and 192.04 J · mol⁻¹·K⁻¹ for LF. The addition of C3G influenced the secondary structure of the proteins. The decrease in the α-helix content suggested a disruption and loosening of the hydrogen bond network structure. The presence of proteins enhanced the light stability and thermal stability (stability in the presence of light and heat) of C3G. In vitro simulated digestion experiments demonstrated that the addition of proteins led to a delayed degradation of C3G and to improved antioxidant capacity. The presence of WPI and its components enhanced the thermal stability, light stability, and oxidation stability of C3G. Preheated proteins exhibited a more pronounced effect than unheated proteins. These findings highlight the potential of preheating protein at appropriate temperatures to preserve C3G stability and bioactivity during food processing. © 2024 Society of Chemical Industry.

Comprehensive structural analysis of anthocyanins in blue honeysuckle (Lonicera caerulea L.), bilberry (Vaccinium uliginosum L.), cranberry (Vaccinium macrocarpon Ait.), and antioxidant capacity comparison

The objectives of this research were to analyze anthocyanins in blue honeysuckle (Lonicera caerulea L.), bilberry (Vaccinium vitis-idaea L), and cranberry (Vaccinium macrocarpon Ait.), using HPLC-ESI-QTOF-MS2, Fourteen, fifteen, and eight anthocyanins were identified in blue honeysuckle, bilberry, and cranberry, respectively. Cyanidin-3-glucoside (C3G) and peonidin-3-glucoside were detected in all three types of berries, with blue honeysuckle showing the highest C3G content at 5686.28 mg/100 g DW. Total phenolic content (TPC) and total flavonoid content (TFC), along with ABTS, DPPH, and FRAP assays, were measured. Blue honeysuckle exhibited the highest levels of TPC and TFC. The SOD, POD, and CAT activities in blue honeysuckle were 1761.17 U/g, 45,525.65 U/g, and 1043.24 U/g, respectively, which were significantly superior to those in bilberry and cranberry. The antioxidant mechanisms of these enzymes were investigated by molecular docking, C3G showed a higher affinity for POD, confirming the effectiveness of C3G as an antioxidant.

Study on the stability of four flavonoid glycoside components in Myrica Rubra pomace and their mechanism of in vitro hypoglycaemic activity

SummaryIn order to investigate the hypoglycaemic mechanism and potential applications of four hypoglycaemic flavonoid glycosides, namely myricitrin, Cyanidin‐3‐O‐glucoside (C3G), hyperoside and quercitrin in Myrica rubra pomace, the stability of these four flavonoid glycosides and their binding mechanisms were studied using molecular docking. The results demonstrated that pH value affects on the stability of these four components in M. rubra pomace. C3G exhibited the most significant inhibitory effect on α‐glucosidase at pH 5, with myricitrin, hyperoside and quercitrin showing the highest inhibitory effect at pH 7. Moreover, an increase in temperature and storage time reduced the inhibitory effect of these four glycosidic components on α‐glucosidase. Molecular docking analysis revealed that myricitrin formed hydrogen bonds with the active site residues of α‐glucosidase, namely Phe550, Ile552, Asp555, Ser574 and Arg576, and also engaged in hydrophobic interactions with Lys551. Hyperoside formed hydrogen bonds with α‐glucosidase, formed hydrophobic interactions with Lys50 and exhibited π‐cation interaction with Lys53. Quercitrin formed hydrogen bonds with α‐glucosidase, formed hydrophobic interactions with Lys500 and established salt bridges with Lys50. C3G formed hydrogen bonds and hydrophobic interactions with α‐glucosidase and showed π‐π interactions with Phe301. These findings will provide valuable insights for the application of these four chemicals.

Extraction of Bioactive Compounds from the Fruits of Jambolan (Syzygium cumini (L.)) Using Alternative Solvents.

This work demonstrates the effectiveness of using alternative solvents to obtain jambolan extracts with a high content of bioactive compounds compared to conventional organic solvents, being the first study to evaluate the best ecological solvent alternative for Syzygium cumini (L.) Skeels. Five alternative solvents were used for extraction: water at 25 °C (W25), water at 50 °C (W50), water at 75 °C (W75), water with citric acid at 2.4% (CA2), and water with citric acid at 9.6% (CA9) in comparison with three conventional solvents: ethanol (EtOH), water with ethanol at 50% (WE), and water with methanol at 50% (WM). A protocol was then established for the extraction and concentration of samples obtained with these solvents. The highest content of total phenolic compounds (TPCs) in the extracts was obtained with the solvent W75 (1347.27 mg GAE/100 g), while in the concentrates it was the solvents EtOH (3823.03 mg GAE/100 g) and WM (4019.39 mg GAE/100 g). Total monomeric anthocyanins (TMAs) increased by 209.31% and 179.95% in extractions with CA2 and CA9, respectively, compared to pulp (35.57 mg eq c-3-g/100 g), demonstrating that they are the most efficient alternative solvents in this extraction. The levels of bioactive compounds and antioxidant activity varied according to the solvents used. Delphinidin 3,5-diglucoside, cyanidin 3,5-diglucoside, delphinidin 3-glucoside, petunidin 3,5-diglucoside, cyanidin 3-glucoside, peonidin 3,5-diglucoside, malvidin 3,5-diglucoside, petunidin 3-glucoside, and malvidin 3-glucoside were identified in most of the samples by UPLC-MS/MS. This study suggests that a simple procedure using alternative solvents can be used as an environmentally friendly strategy to achieve efficient extraction of bioactive compounds in jambolan.

Unveiling the influence of high hydrostatic pressure and protein interactions on the color and chemical stability of cyanidin-3-O-glucoside

This study explored how high hydrostatic pressure (HHP) and proteins (i.e., BSA and HSA) influence the color and chemical stability of cyanidin-3-O-glucoside (C3G) at neutral pH. HHP treatments (100–500 MPa, 0–20 min, 25 °C) did not affect C3G content in phosphate buffer (PB) and MOPS buffer. However, significant color loss of C3G occurred in PB due to pressure-induced pH reduction (e.g., from 7 to 4.8 at 500 MPa), which accelerated the hydration of C3G, converting it from colored to colorless species. Consequently, MOPS buffer was employed for subsequent stability experiments to assess the impact of protein and HHP on the thermal, storage, and UV light stability of C3G. Initially, rapid color loss occurred during heating and storage, primarily due to the reversible hydration of C3G until equilibrium with colorless species was reached, followed by slower parallel degradation. HSA increased the fraction of colored species at equilibrium but accelerated thermal degradation, while BSA had minimal effects. UV light irradiation accelerated the degradation of C3G colored species, causing direct degradation without conversion to colorless species, a process further intensified by the presence of proteins. HHP exhibited a negligible effect on C3G stability regardless of protein addition. These findings provide insights into anthocyanin stability under HHP and protein interactions, contributing to the development of future formulation and processing strategies for improved stability and broader applications.

Enzymatic acylation of cyanidin-3-O-glucoside with aromatic and aliphatic acid methyl ester: Structure–stability relationships of acylated derivatives

Anthocyanins are water-soluble pigments, but they tend to be unstable in aqueous solutions. Modification of their molecular structure offers a viable approach to alter their intrinsic properties and enhance stability. Aromatic and aliphatic acid methyl esters were used as acyl donors in the enzymatic acylation of cyanidin-3-O-glucoside (C3G), and their analysis was conducted using ultraperformance liquid chromatography–mass spectrometry (UPLC-MS). The highest conversion rate achieved was 96.41 % for cyanidin-3-O-(6″-feruloyl) glucoside. Comparative evaluations of stability revealed that aromatic acyl group–conjugated C3G exhibited superior stability enhancement compared with aliphatic acyl group derivatives. The stability of aliphatic C3G decreased with increasing carbon chain length. The molecular geometries of different anthocyanins were optimized, and energy level calculations using density functional theory (DFT) identified their sites with antioxidant activities. Computational calculations aligned with the in vitro antioxidant assay results. This study provided theoretical support for stabilizing anthocyanins and broadened the application of acylated anthocyanins as food colorants and nutrient supplements.

Covalent Interactions of Anthocyanins with Proteins: Activity-Based Protein Profiling of Cyanidin-3-O-glucoside.

Anthocyanins are common natural pigments with a variety of physiological activities. Traditional perspectives attribute their molecular mechanism to noncovalent interactions influencing signaling pathways. However, this ignores the nature of its benzopyrylium skeleton, which readily reacts with the electron-rich groups of proteins. Here, we modified cyanidin-3-O-glucoside (C3G) via activity-based protein profiling technology by our previous synthesis route and prepared the covalent binding probe (C3G-Probe) and the noncovalent photoaffinity probe (C3G-Diazirine). The properties of C3G's covalent binding to proteins were also discovered by comparing the labeling of the two probes to the whole HepG2 cell proteome. We further explored its target proteins and enriched pathways in HepG2 and HeLa cells. Western blot analysis further confirmed the covalent binding of C3G to four target proteins: insulin-degrading enzyme, metal cation symporter ZIP14, spermatid perinuclear RNA-binding protein, and Cystatin-B. Pathway analysis showed that covalent targets of C3G were concentrated in metabolic pathways and several ribonucleoprotein complexes that were also coenriched. The results of this study provide new insights into the interaction of the naturally active molecule C3G with proteins.

Transcriptomic and multi-cytokines profile analysis revealed new insights into the integrating mechanisms of cyanidin-3-O-glucoside on male reproductive damage amelioration

Ulcerative colitis is a public health issue with a rising worldwide incidence. It has been found that current medications for treating UC may cause varying degrees of damage to male fertility. Our previous study demonstrated that cyanidin-3-O-glucoside (C3G) treatment could effectively restore reproductive damage in a mouse model of DSS induced colitis. However, the underlying mechanism of C3G alleviates UC induced male reproductive disorders remain scarce. The aim of this study is to discover the molecular mechanisms of C3G on the amelioration of UC stimulated reproductive disorders. The targeted genes toward UC-induced reproductive injury upon C3G treatments were explored by transcriptomic analysis. Hematological analysis, histopathological examination, and real time transcription-polymerase chain reaction (RT-PCR) analysis were applied for conjoined identification. Results showed that C3G may effectively target for reducing pro-inflammatory cytokine IL-6 in testis through cytokine-cytokine receptor interaction pathway. Transcriptome sequencing found that a series of genetic pathways involved in the protective effects of C3G on male reproduction were identified by gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Further results presented that C3G could effectively restore mRNA expression levels of Ly6a and Col1a1, closely linked with UC induced male reproductive damage pathways. Sufficient results implied that Ly6a and Col1a1 may be treated as the promising therapeutic targets for the mechanism of C3G in treating UC induced reproductive impairment. C3G administration might be an effective dietary supplementation strategy for male reproduction improvement.

Cyanidin-3-O-glucoside attenuates LPS-induced endometritis in mice via regulating PPARγ activation

Endometritis is a common disease that endangers human and animal health. Cyanidin-3-O-glucoside (C3G), a kind of anthocyanin, exists in a variety of plants and shows many biological activities. Here, we investigated the effect and mechanism of C3G on LPS-induced endometritis in mice. The results showed that C3G significantly decreased wet to dry weight (W/D) ratio of uterine, improved uterine pathological injury, and inhibited MPO activity. Further mechanism investigation showed that the activation of NFκB pathway and the levels of TNF-a, IL-1β, and IL-6 were significantly suppressed after C3G treatment. Conversely, C3G promoted LPS-induced the activation of the PPARγ/ABCA1 pathway. Interestingly, the anti-inflammatory effect of C3G was significantly weakened by GW9662, a PPARγ inhibitor. In addition, the anti-oxidative stress effect of C3G was also found. For the first time, our results showed that treatment with C3G might be a new strategy for treating endometritis.

Effect of pH and temperature on the stability of the natural dye from the roselle flower (Hibiscus sabdariffa L.) and its application in flavored milk.

In recent years, global trends indicate consumer interest in functional foods. Thus, there is a trend to replace the use of artificial colors with natural colors that, in addition to being attractive to consumers, provide benefits to the biological functions of the human organism. The objective of this research was the solvent extraction of a natural dye from the roselle flower, its identification and evaluation of its behavior at different pH and temperatures. In addition, its application in flavored milk was evaluated sensorially. The anthocyanins located in the roselle flower were extracted by fragmentation and milling. The separation of pigments was carried out with ethanol (96%v/v) for 72h. The qualitative tests of identification, physics and chemistry revealed the presence of anthocyanins (delphinidin 3-glucoside and cyanidin 3-glucoside). The pigments present in roselle flower are relatively stable with temperature. However, at temperatures above 80°C a gradual degradation occurs. At different pH values, two visible absorption points are shown at 519.6 and 320.4nm, which correspond to the two characteristic bands of anthocyanins. The milk flavored and dyed with roselle extract had a shelf life of 7days in refrigerated storage and was sensorially accepted by consumers, but the color was unattractive.

Effect of different pectin sources and structures on the stability of cyanidin-3-O-glucoside (C3G)

The physicochemical properties of cyanidin-3-O-glucoside (C3G) were investigated after binding with pectin from different sources (apple and peach) and fractions (water-soluble fraction (WSF), chelator soluble fraction (CSF) and sodium carbonate soluble fraction (NSF)). Apple WSF and peach CSF were high esterification degree pectin (DE) (63.23% and 55.66%). CSF of both AP and PP was abundant in HG and exhibited a much more linear structure than WSF and NSF. The maximum binding percentage was obtained at pH 2.0 for apple pectin (AP) (46%–50%) and at pH 3.5 for peach pectin (PP) (50%–54%). Binding with both pectins increased the color stability of C3G at pH 2.0. High DE pectin increased C3G light stability by reducing the degradation rate (0.03 h−1) compared to C3G alone (0.05 h−1). All the pectins reduced the thermal degradation rate of C3G, thus exhibiting a protective effect. A negative correlation was found between the relative RG I area and the particle size of the pectin-C3G complexes. Pectin played a leading role in the ζ-potential change.

Characterization of the covalent binding of cyanidin-3-glucoside to bovine serum albumin and its inhibition mechanism for advanced nonenzymatic glycosylation reactions.

Nonenzymatic glycosylation of proteins can generate advanced glycosylation end products, which are closely associated with the pathogenesis of certain chronic physiological diseases and aging. In this study, we characterized the covalent binding of cyanidin-3-glucoside (C3G) to bovine serum albumin (BSA) and investigated the mechanism by which this covalent binding inhibits the nonenzymatic glycosylation of BSA. The results indicated that the covalent interaction between C3G and BSA stabilized the protein's secondary structure. Through liquid chromatography-electrospray ionization tandem mass spectrometry analysis, we identified the covalent binding sites of C3G on BSA as lysine, arginine, asparagine, glutamine, and cysteine residues. This covalent interaction significantly suppressed the nonenzymatic glycosylation of BSA, consequently reducing the formation of nonenzymatic glycosylation products. C3G competitively binds to nonenzymatic glycosylation sites (e.g., lysine and arginine) on BSA, thereby impeding the glycosylation process and preventing the misfolding and structural alterations of BSA induced by fructose. Furthermore, the covalent attachment of C3G to BSA preserves the secondary structure of BSA and hinders subsequent nonenzymatic glycosylation events.