Quercetin Inhibited the Formation of Lipid Oxidation Products in Thermally Treated Soybean Oil by Trapping Intermediates

Effect and mechanism of polyphenols containing m-dihydroxyl structure on 2-amino-1-methyl-6-phenylimidazole [4, 5-b] pyridine (PhIP) formation in chemical models and roast pork patties

2-amino-1-methyl-6-phenylimidazole [4, 5-b] pyridine (PhIP) is a prevalent heterocyclic amine (HAA) found in heated processed meat. This study investigated the inhibitory impact of eight different types of polyphenols containing m-dihydroxyl structure on PhIP formation through a chemical model system. The structure-activity relationship and potential sites of action of polyphenols containing m-dihydroxyl structure were also analyzed. Then, the mechanism of inhibiting PhIP formation by kaempferol, naringenin and quercetin was speculated by UPLC-MS. Results showed that 8 kinds of polyphenols containing m-dihydroxyl structure had significant (P < 0.05) inhibition on the formation of PhIP in the chemical model system in a dose-dependent manner. In addition, PhIP was most significantly inhibited by naringenin at the same concentration, followed by kaempferol and quercetin (83.27%, 80.81% and 79.26%, respectively). UPLC-MS results speculated that kaempferol, naringenin, and quercetin formed a new admixture via an electrophilic aromatic substitution reaction with the intermediate product phenylacetaldehyde, preventing the formation of PhIP.

Combined dynamic transcriptome and flavonoid metabolome reveal the role of Mo nanoparticles in the nodulation process in soybean

Symbiotic nitrogen fixation can reduce the impact of agriculture on the environment by reducing fertilizer input. The rapid development of nanomaterials in agriculture provides a new prospect for us to improve the biological nitrogen fixation ability of leguminous crops. Molybdenum is an important component of nitrogenase, and the potential application of MoO3NPs in agriculture is largely unexplored. In this study, on the basis of verifying that MoO3NPs can improve the nitrogen fixation ability of soybean, the effects of MoO3NPs on the symbiotic nitrogen fixation process of soybean were investigated by using dynamic transcriptome and targeted metabolome techniques. Here we showed that compared with conventional molybdenum fertilizer, minute concentrations of MoO3NPs (0.01-0.1 mg kg-1) could promote soybean growth and nitrogen fixation efficiency. The nodules number, fresh nodule weight and nitrogenase activity of 0.1 mg kg-1 were increased by 17 %, 14 % and 27 %, and plant nitrogen accumulation increased by 17 %. Compared with conventional molybdenum fertilizer, MoO3NPs had a greater effect on apigenin, kaempferol and other flavonoid, and the expression of nodulation related genes such as ENOD93, F3'H. Based on WGCNA analysis, we identified a core gene GmCHS9 that was positively responsive to molybdenum and was highly expressed during MoO3NPs induced nodulation. MoO3NPs could improve the nitrogen fixation ability of soybean by promoting the secretion of flavonoids and the expression of key genes. This study provided a new perspective for the nano-strengthening strategy of nodules development and flavonoid biosynthesis by molybdenum.

Effect of deodorization conditions on fatty acid profile, oxidation products, and lipid-derived free radicals of soybean oil

Oxidative stability is a key quality characteristic of edible oils, and the oil's antioxidant capacity decreases during the deodorization stage. This study explores the changes in radical formation, molecular structure, oxidative characteristics, fatty acids, and main bioactive compounds in soybean oil during deodorization. The lag phase decreased, whereas the total amount of spins of free radicals increased as the deodorization time increased from 90 to 150 min. The total amount of spins and percentage of alkyl radicals varied dramatically under different times and temperatures (220 ∼ 260 ℃). Results showed that identifying and quantifying the formed radicals can provide useful information for monitoring and controlling oil oxidation in vegetable oil refining systems. Therefore, to control early oxidation events, maximize refined oil product yield, and reduce energy consumption in the refining plant, the priority should be to minimize temperature during the oil refining process and then shorten the deodorization time.

Senolytic combination of dasatinib and quercetin attenuates renal damage in diabetic kidney disease

BACKGROUND

Senolytic combination of dasatinib and quercetin (DQ) is the most studied senolytics drugs used to treat various age-related diseases. However, its protective activity against diabetic kidney disease (DKD) and underlying mechanisms are uncertain.

PURPOSE

To investigate the functions and potential mechanisms of the senolytics DQ on DKD.

METHODS

Diabetic db/db mice were administrated DQ or transfected with over-expressed PPARα or shPPARα vector. The positive control group was administered irbesartan. Renal function and fibrotic changes in kidney tissue were tested. Single-cell RNA-seq (scRNA-seq) was conducted to analyze the differential transcriptome between the diabetic and control mice. Molecular docking simulation was used to assess the combination of DQ and potential factors. Moreover, tubular epithelial cells under high-glucose (HG) conditions were incubated with DQ and transfected with or without over-expressed PPARα/siPPARα vector.

RESULTS

DQ significantly improved renal function, histopathological and fibrotic changes, alleviated lipid deposition, and increased ATP levels in mice with DKD. DQ reduced multiple fatty acid oxidation (FAO) pathway-related proteins and up-regulated PPARα in db/db mice. Overexpression of PPARα upregulated the expression of PPARα-targeting downstream FAO pathway-related proteins, restored renal function, and inhibited renal fibrosis in vitro and in vivo. Moreover, molecular docking and dynamics simulation analyses indicated the nephroprotective effect of DQ via binding to PPARα. Knockdown of PPARα reversed the effect of DQ on the FAO pathway and impaired the protective effect of DQ during DKD.

CONCLUSION

For the first time, DQ was found to exert a renal protective effect by binding to PPARα and attenuating renal damage through the promotion of FAO in DKD.

Unraveling the relationships between processing conditions and PhIP formation in chemical model system and roast pork patty via principal component analysis

2-amino-1-methyl-6-phenylimidazole [4,5-b] pyridine (PhIP) is one of the higher levels of HAAs produced in protein foods during heating. The effects of heating temperature, time, and concentration of precursors on PhIP and related substances in the chemical model system and roast pork patty were studied using HPLC-Q-Orbitrap-HRMS and GC-MS. Results showed that the heating temperature, time, and concentration of four precursors significantly affected PhIP and its related substances (P < 0.05) in the chemical model system. Among them, PhIP production was greatest when heating at 200 min with 220 °C, and the concentrations of phenylalanine, creatinine, glucose, and creatine added were 10, 20, 20, and 20 mmol/L, respectively. Moreover, as the fat proportion of roast pork patties increased, PhIP and its intermediate-phenylacetaldehyde concentrations increased substantially (P < 0.05). PCA results showed that the samples of PhIP and related substances gradually dispersed as the temperature and time increased, and there were obvious effects among them.

Layer-by-layer assembly of quercetin-loaded zein/γPGA/low-molecular-weight chitosan/fucoidan nanosystem for targeting inflamed blood vessels

Chitosan acts as a versatile carrier in polymeric nanoparticle (NP) for diverse drug administration routes. Delivery of antioxidants, such as quercetin (Qu) showcases potent antioxidant and anti-inflammatory properties for reduction of various cardiovascular diseases, but low water solubility limits uptake. To address this, we developed a novel layer-by-layer zein/gamma-polyglutamic acid (γPGA)/low-molecular-weight chitosan (LC)/fucoidan NP for encapsulating Qu and targeting inflamed vessel endothelial cells. We used zein (Z) and γPGA (r) to encapsulate Qu (Qu-Zr NP) exhibited notably higher encapsulation efficiency compared to zein alone. Qu-Zr NP coated with LC (Qu-ZrLC2 NP) shows a lower particle size (193.2 ± 2.9 nm), and a higher zeta potential value (35.2 ± 0.4 mV) by zeta potential and transmission electron microscopy analysis. After coating Qu-ZrLC2 NP with fucoidan, Qu-ZrLC2Fa NP presented particle size (225.16 ± 0.92 nm), zeta potential (-25.66 ± 0.51 mV) and maintained antioxidant activity. Further analysis revealed that Qu-ZrLC2Fa NP were targeted and taken up by HUVEC cells and EA.hy926 endothelial cells. Notably, we observed Qu-ZrLC2Fa NP targeting zebrafish vessels and isoproterenol-induced inflamed vessels of rat. Our layer-by-layer formulated zein/γPGA/LC/fucoidan NP show promise as a targeted delivery system for water-insoluble drugs. Qu-ZrLC2Fa NP exhibit potential as an anti-inflammatory therapeutic for blood vessels.

Ultrasonic-assisted extraction of grape seed procyanidins, preparation of liposomes, and evaluation of their antioxidant capacity

The residue remaining after oil extraction from grape seed contain abundant procyanidins. An ultrasonic-assisted enzyme method was performed to achieve a high extraction efficiency of procyanidins when the optimal extraction conditions were 8 U/g of cellulase, ultrasound power of 200 W, ultrasonic temperature of 50 ℃, and ultrasonic reaction time of 40 min. The effects of free procyanidins on both radical scavenging activity and thermal stability at 40, 60, and 80 ℃ of the procyanidins-loaded liposomal systems prepared by the ultrasonic-assisted method were discussed. The presence of procyanidins at concentrations ranging from 0.02 to 0.10 mg/mL was observed to be effective at inhibiting lipid oxidation by 15.15 % to 69.70 % in a linoleic acid model system during reaction for 168 h, as measured using the ferric thiocyanate method. The procyanidins-loaded liposomal systems prepared by the ultrasonic-assisted method were characterized by measuring the mean particle size and encapsulation efficiency. Moreover, the holographic plots showed that the effect-response points of procyanidins combined with α-tocopherol in liposomes were lower than the addition line and 95 % confidence interval limits. At the same time, there were significant differences between the theoretical IC50add value and the experimental IC50mix value. The interaction index (γ) of all combinations was observed to be less than 1. These results indicated that there was a synergistic antioxidant effect between procyanidins combined with α-tocopherol, which will show promising prospects in practical applications. In addition, particle size differentiation and morphology agglomeration were observed at different time points of antioxidant activity determination (0, 48, 96 h).

Scavenging Glyoxal and Methylglyoxal by Synephrine and Neohesperidin from Flowers of Citrus aurantium L. var. amara Engl. in Mice and Humans

There is considerable research evidence that α-dicarbonyl compounds, including glyoxal (GO) and methylglyoxal (MGO), are closely related to many chronic diseases. In this work, after comparison of the capture capacity, reaction pathway, and reaction rate of synephrine (SYN) and neohesperidin (NEO) on GO/MGO in vitro, experimental mice were administrated with SYN and NEO alone and in combination. Quantitative data from UHPLC-QQQ-MS/MS revealed that SYN/NEO/HES (hesperetin, the metabolite of NEO) could form the GO/MGO-adducts in mice (except SYN-MGO), and the levels of GO/MGO-adducts in mouse urine and fecal samples were dose-dependent. Moreover, SYN and NEO had a synergistic scavenging effect on GO in vivo by promoting each other to form more GO adducts, while SYN could promote NEO to form more MGO-adducts, although it could not form MGO-adducts. Additionally, human experiments showed that the GO/MGO-adducts of SYN/NEO/HES found in mice were also detected in human urine and fecal samples after drinking flowers of Citrus aurantium L. var. amara Engl. (FCAVA) tea using UHPLC-QTOF-MS/MS. These findings provide a novel strategy to reduce endogenous GO/MGO via the consumption of dietary FCAVA rich in SYN and NEO.

Glyoxal in Foods: Formation, Metabolism, Health Hazards, and Its Control Strategies

Glyoxal is a highly reactive aldehyde widely present in common diet and environment and inevitably generated through various metabolic pathways in vivo. Glyoxal is easily produced in diets high in carbohydrates and fats via the Maillard reaction, carbohydrate autoxidation, and lipid peroxidation, etc. This leads to dietary intake being a major source of exogenous exposure. Exposure to glyoxal has been positively associated with a number of metabolic diseases, such as diabetes mellitus, atherosclerosis, and Alzheimer's disease. It has been demonstrated that polyphenols, probiotics, hydrocolloids, and amino acids can reduce the content of glyoxal in foods via different mechanisms, thus reducing the risk of exogenous exposure to glyoxal and alleviating carbonyl stresses in the human body. This review discussed the formation and metabolism of glyoxal, its health hazards, and the strategies to reduce such health hazards. Future investigation of glyoxal from different perspectives is also discussed.

Compound Classification and Consideration of Correlation with Chemical Descriptors from Articles on Antioxidant Capacity Using Natural Language Processing

In recent times, there has been a substantial increase in the number of articles focusing on antioxidants. However, the development of a comprehensive estimator for antioxidant capacity remains elusive due to the challenge of integrating information from these articles. Furthermore, the complexity of the antioxidant mechanism, which involves a multitude of factors, makes it difficult to establish a simple equation or correlation. Hence, there is a pressing need for a model that can effectively interpret the collective knowledge from these articles, especially from a chemistry perspective. In this research, we employed natural language processing techniques, specifically Word2Vec, to analyze articles related to antioxidant capacity. We extracted representation vectors of compound names from these documents and organized them into 10 distinct clusters. In our investigation of two of these clusters, we unveiled that the majority of the compounds in question were flavonoids and flavonoid glycosides. To establish a link between the descriptors and clusters, we utilized kernel density estimation and generated scatter plots to visualize their similarity. These visualizations clearly indicated a strong relationship between the descriptors and clusters, affirming that a tangible connection exists between word vectors and compound descriptors through a document analysis conducted with natural language processing techniques. This study represents a pioneering approach that utilizes document analysis to shed light on the field of antioxidant capacity research, marking a significant advancement in this domain.

Introduction of chlorogenic acid into thermal processed starch- oleic acid system controls the ordered structure and inhibits oleic acid oxidation through molecular interactions

In this study, the effects of starch- oleic acid (OA)- chlorogenic acid (CA) molecular interaction on OA oxidation during thermal processing were investigated based on structural analysis, oxidation characteristics and quantum calculations. The results showed that in the ternary system, on the one hand, OA could enter the spiral cavity of starch through hydrophobic forces and form V-type crystalline structure, which delayed its oxidation. On the other hand, CA could further inhibit the oxidation of OA through free radical reaction and did not affect the molecular interactions between OA and starch due to the steric hindrance and hydrophily. Notably, starch-OA-CA interactions could effectively decrease total oxidation value (19.07), prolong the induction time of oxidation (114.6 min) and reduce the abundance of oxidation products through hydrogen atom transfer reactions with active phenolic hydroxyl to protect the α-methylene groups at C=C. Overall, these results provided insights into functional property regulation by the interaction of starch-based multi-component systems.

Effects of Stigmasterol on 3-Chloropropane-1,2-diol Fatty Acid Esters and Aldehydes Formation in Heated Soybean Oil

In this study, we investigated the inhibitory effects of three soybean isoflavones and two soybean phytosterols on the formation of 3-chloropropane-1,2-diol fatty acid esters (3-MCPDE) and aldehydes in heated soybean oil model. 0.4 mM of genistin, genistein, daidzein, stigmasterol, and β-sitosterol significantly reduced 3-MCPDE formation by 25.7, 51.4, 21.4, 61.6, and 55.7%, and total aldehydes formation by 42.03, 43.94, 28.36, 54.74, and 39.23%, respectively. Further study showed that stigmasterol reduced the content of glycidyl esters (GEs) and glycidol, two key intermediates of 3-MCPDE, and prevented fatty acids degradation in the oils. Moreover, the effects of continuous frying time on the content of stigmasterol and the migration of stigmasterol were evaluated in the fried dough sticks model system. The content of stigmasterol in soybean oil was found to be significantly decreased with prolonged heating time. The concentrations of stigmasterol in fried dough sticks and the migration rates of stigmasterol from soybean oil to fried dough sticks decreased with repeated frying sessions. In addition, stigmasterol undergoes oxidative changes during heat treatment, and the oxidation products including 5,6α-epoxystigmasterol, 5,6β-epoxystigmasterol, 7α-hydroxystigmasterol, 7β-hydroxystigmasterol, stigmasterlol-3β,5α,6β-triol, and 7-ketostigmasterol were identified in the frying oils but not in the fried dough sticks. Overall, stigmasterol could be added to soybean oil to reduce 3-MCPDE and aldehydes formation, and reacting with GEs/glycidol and protection of lipid acids from oxidation may be the mechanism of action of stigmasterol.

Effect of acrolein on the formation of harman and norharman in chemical models and roast beef patties

Harman and norharman were the most abundant β-carboline-type heterocyclic amines (HCAs) detected in various foodstuffs. Unsaturated fatty acids in foods may undergo rapid oxidative deterioration during transportation, storage and heat treatment, forming reactive carbonyl species (RCS). This work studied the effects of acrolein, a highly reactive RCS, on the formation of harman and norharman in the tryptophan model system. Results showed that 0.005, 0.01, 0.015, 0.02, 0.05, 0.1 and 0.2 mmol of acrolein led to harman production increased by 528 %, 752 %, 981 %, 1172 %, 1375 %, 1288 % and 768 % respectively, and led to norharman formation increased by 116 %, 129 %, 152 %, 169 %, and 197 %, 185 % and 157 %, respectively. Furthermore, acrolein addition reduced the residue of tryptophan (up to 63.19 %), but increased the level of the intermediates including formaldehyde (up to 352 %), acetaldehyde (up to 491 %), (1S,3S)-1-Methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (MTCA, up to 1936 %), and 1,2,3,4-tetrahydro-β-carboline-3-carboxylicacid (THCA, up to 2142 %) in the tryptophan model system. Acrolein might react with tryptophan, harman and norharman to eliminate them directly. These data suggested that acrolein may contribute to harman and norharman formation through participating in the above complex chemical reactions. In addition, the content of harman and norharman produced in roast beef patties made of minced beef oxidized for 2, 4, 6, 8, and 10 days increased by 118 %, 188 %, 267 %, 137 %, and 48 %, respectively, and led to norharman formation increased by 140 %, 132 %, 90 %, 86 %, and 74 %, respectively compared with those made of fresh minced beef, which further illustrated that lipid oxidation products potentially contributed to harman and norharman formation.

In vitro oxidation and digestibility profiles of iron-loaded whey protein isolate/gum Arabic complexes with different morphologies

This study was designed to investigate the promotion of oxidation of lipids in oil-in-water (o/w) emulsions and digestive properties of the bionic dynamic gastrointestinal system of whey protein isolate (WPI) and gum arabic (GA) complexes loaded with iron ions, which were fabricated previously and shown as WPI/GA_Fe³⁺ nanoparticles (WGS) and WPI/GA_Fe³⁺ fibers (WGF). Compared with emulsions containing Fe³⁺ and GA-loaded complex (GA_Fe³⁺), WGS and WGF greatly improved the oxidative stability of lipids along with the reduced lipid oxidation products and volatile compounds, attributed to the encapsulation of iron ions. During the bionic dynamic gastrointestinal digestion, the iron ion release of WGF was significantly higher than that of WGS, probably due to different assembled internal structures. Accordingly, two proposed WPI/GA_Fe³⁺ complexes with different morphologies are expected to be developed as novel stable iron fortifiers with delayed lipid oxidation and controlled iron-ion release in food emulsions.

Effects of quercetin on emissions of aldehydes from heated docosahexaenoic acid (DHA)-fortified soybean oil

Home cooking has been considered as an indoor pollution problem since cooking oil fumes contain various toxic chemicals such as aldehydes. Fortifying edible oils with docosahexaenoic acid (DHA) has been applied to enhance the nutritional value of oils. This study designed a frying simulation system and examined the effect of oil type, DHA fortification, heating time, and addition of natural antioxidant on the emissions of aldehydes from heated oils. Results showed that linseed oil had the highest total aldehyde emissions, followed by soybean oil, peanut oil, and palm oil. Fortifying soybean oil with DHA increased the toxic aldehydes emitted. Quercetin, a flavonoid, significantly reduced aldehydes emitted from DHA-fortified soybean oil (by up to 39.80%) to levels similar to those of normal soybean oil. Further analysis showed that DHA-fortified soybean oil with quercetin had a significantly higher DHA and unsaturated fatty acids (UFAs) content than the control oil at each heating time point. The result indicated that quercetin inhibited emissions of aldehydes, at least in part, by protecting UFAs from oxidation. Collectively, quercetin could be used as a natural additive in DHA-fortified and normal cooking oils to reduce aldehyde emissions, indoor air pollution, and preserve functional DHA and other UFAs.

Advanced glycation end products in diabetic retinopathy and phytochemical therapy

Advanced glycation end products (AGEs) are generated by the nonenzymatic glycation of proteins or lipids. Diabetic retinopathy (DR) is one common complication in patients with diabetes. The accumulation of AGEs in retinal cells is strongly associated with the development of DR. AGEs can induce the breakdown of redox balance and then cause oxidative stress in retinal cells, exerting cytopathic effects in the progression of DR. The interaction between AGEs and the receptor for AGE (RAGE) is involved in multiple cellular pathological alterations in the retina. This review is to elucidate the pathogenetic roles of AGEs in the progression of DR, including metabolic abnormalities, lipid peroxidation, structural and functional alterations, and neurodegeneration. In addition, disorders associated with AGEs can be used as potential therapeutic targets to explore effective and safe treatments for DR. In this review, we have also introduced antioxidant phytochemicals as potential therapeutic strategies for the treatment of DR.

Antibacterial Efficacy and Mechanisms of Curcumin-Based Photodynamic Treatment against Staphylococcus aureus and Its Application in Juices

Antimicrobial Photodynamic Treatment (aPDT) is a non-thermal sterilization technology, which can inactivate common foodborne pathogens. In the present study, photodynamic inactivation on Staphylococcus aureus (S. aureus) with different concentrations of curcumin and light dose was evaluated and the mechanisms were also investigated. The results showed that curcumin-based aPDT could inactivate S. aureus cells by 6.9 log CFU/mL in phosphate buffered saline (PBS). Moreover, the modified Gompertz model presented a good fit at the inactivation data of S. aureus. Photodynamic treatment caused cell membrane damage as revealed by analyzing scanning electron microscopy (SEM) images. Leakage of intracellular constituents further indicated that cell membrane permeability was changed. Flow cytometry with double staining demonstrated that cell membrane integrity and the activity of nonspecific esterase were destroyed. Compared with the control group, intracellular reactive oxygen species (ROS) levels caused by photodynamic treatment significantly increased. Furthermore, curcumin-based aPDT reduced S. aureus by 5 log CFU/mL in juices. The color of the juices was also tested using a Chromatic meter, and it was found that b* values were the most markedly influenced by photodynamic treatment. Overall, curcumin-based aPDT had strong antibacterial activity against S. aureus. This approach has the potential to remove foodborne pathogens from liquid food.

Response surface methodology-optimized extraction of flavonoids with antioxidant and antimicrobial activities from the exocarp of three genera of coconut and characterization by HPLC-IT-TOF-MS/MS

Response surface methodology optimization based on central composite design was applied to extract flavonoids from the exocarp of three coconut genera. The antioxidant and antimicrobial activities and structures of the flavonoids were determined. The results indicated that the optimal extraction conditions were ethanol concentration, 60%; temperature, 50 ℃; time, 90 min; liquid/material ratio, 40 mL/g; ultrasonic power, 150 W. Under these conditions, the yields of green, red and yellow coconut exocarp were 366.03 ± 7.57, 596.38 ± 10.32, and 403.78 ± 5.56 mg rutin/g powder, respectively. The flavonoids exhibited eminent DPPH and ABTS radical scavenging activities with IC₅₀ values of 0.01-0.02 mg/mL. At a concentration of 2 mg/mL, they exhibited antimicrobial activity against Vibrio parahaemolyticus, Listeria monocytogenes, Escherichia coli, Staphylococcus aureus, Salmonella and Pseudomonas aeruginosa. In total, 17 flavonoids and 5 phenolic acids were characterized by UPLC-IT-TOF-MS/MS; among them, catechin, kaempferol, and quercetin were abundant. Yellow coconut had a distinct flavonoid spectrogram from other genera and contained more methoxy flavonoids.

Apigenin and apigenin-7, 4'-O-dioctanoate protect against acrolein-aggravated inflammation via inhibiting the activation of NLRP3 inflammasome and HMGB1/MYD88/NF-κB signaling pathway in Human umbilical vein endothelial cells (HUVEC)

Exposure to acrolein, one environmental and dietary pollutant, has been shown to cause inflammation. Here, we reported for the first time that acrolein aggravated lipopolysaccharide (LPS)-induced inflammation in Human umbilical vein endothelial cells (HUVEC) as evidenced by the further increased mRNA expression of three pro-inflammatory cytokines, including interleukin 1β (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor-alpha (TNF-α). Acrolein also further increased the generation of reactive oxygen species (ROS) and decreased the activity of glutathione peroxidase (GSH-Px) in LPS-pretreated HUVEC. Moreover, acrolein treatment further increased the nucleotide oligomerization domain-like receptor protein 3 (NLRP3) and apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC) expression, caspase-1 cleavage, and downstream matures interleukin 18 (IL-18) and IL-1β level in LPS-pretreated HUVEC. Acrolein treatment also further increased the expressions of high-mobility group box 1 (HMGB1), toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), and phospho-NF-κB P65 (P-P65) in the LPS pre-treated HUVEC. Thus, acrolein aggravated LPS-induced HUVEC inflammation through induction of oxidative stress, and activation of NLRP3 inflammasome and HMGB1/MYD88/NF-κB signaling pathway. In addition, apigenin and apigenin-7, 4'-O-dioctanoate attenuated acrolein-aggravated inflammation by targeting the above signaling pathways. Our findings could help to develop potential therapeutic strategies against acrolein-enhanced inflammation.

Effect of acrolein, a lipid oxidation product, on the formation of the heterocyclic aromatic amine 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in model systems and roasted tilapia fish patties

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Acrolein was able to contribute to PhIP formation.

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Acrolein facilitated Strecker degradation of phenylalanine.

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Acrolein increased the formation of some key intermediates of PhIP.

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Acrolein reacted with phenylalanine, creatinine, and PhIP to form adducts.

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The oxidation of tilapia fish increased the PhIP formation in the roasted fish patties.

The effect of acrolein on the formation of the 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) was investigated in a chemical model. Acrolein was found to increase PhIP formation at each tested addition level. 0–0.2 mmol of acrolein increased PhIP formation dose-dependently, while high levels of acrolein (>0.2 mmol) did not further increase PhIP formation. Mechanistic study showed that acrolein addition decreased the residue of phenylalanine and creatinine, but increased the content of some key intermediates. Further analysis indicated that acrolein can react with phenylalanine, creatinine, and PhIP to form adducts. These results suggested that acrolein was able to contribute to PhIP formation as a consequence of its comprehensive ability to facilitate Strecker degradation of phenylalanine and react with phenylalanine, creatinine, and PhIP. In addition, oxidation of the tilapia fish increased the PhIP formation in the roasted fish patties, further supporting the potential contribution role of lipid oxidation products to the formation of PhIP.

Fat Oxidation of Fatty Fish vs. Meat Meal Diets Under in vitro Standardized Semi-Dynamic Gastric Digestion

Meat and fish are introduced into the diet as a source of protein, but these muscle foods present different fatty acid (FA) compositions and different lipid stabilities. Fatty fish is expected to oxidize due to its higher content of polyunsaturated FA (PUFA), whereas the higher heme-Fe content of red meat will also affect lipid stability. Combining other food ingredients within a meal also influences lipid oxidation, which will not stop after meals intake. This is due to the acidic environment of the stomach together with the presence of metallic ions, a process that is scarcely understood. The goal of this study was to evaluate the oxidation of fatty fish vs. meat meal diets under in vitro standardized semi-dynamic gastric conditions and FA release from the stomach to the duodenum. Meal diets composed by 25% beef meal (BM) or fatty fish meal (FM), 25% fried potatoes, and 50% sugar soft drink were prepared. Proximate composition, FA and amino acid profiles, and meals quality indices were evaluated. Their differences in composition led to different total gastric digestion time of 242.74 (BM) and 175.20 (FM) minutes. Using the INFOGEST semi-dynamic gastric model, 4 gastric emptying (GE) were simulated in both meals. In each GE, FA profile and lipid oxidation products (LOPs) formation were assessed. As a result, more than 50% FA release to the duodenum occurred in GE1, whose percentage decreased with the time of digestion. FM exhibited the highest LOPs formation, which corroborates the high peroxidizability index measured for this meal diet. Higher LOPs formation occurred in the later GEs, which released less FA. This suggests that higher times of residence in the stomach increase FA oxidation. This study shows a higher formation of LOPs during digestion of FM using a whole meal approach. These results relate to its richness in PUFAs compared to BM. Despite higher LOPs formation, FM digests that reached duodenum still contain higher content of unoxidized PUFAs compared with BM and a desirable ω3/ω6 PUFAs ratio of ~0.43. LOPs formation in PUFA-rich meals could be reduced if those meals have a low caloric value, avoiding large times of residence in the stomach and consequently high levels of oxidation.

Effect of Acrolein, a Lipid Oxidation Product, on the Formation of the Heterocyclic Aromatic Amine 2-Amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) in Model Systems and Roast Salmon Patties

The effect of acrolein, a lipid oxidation product, on the formation of the heterocyclic aromatic amine 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) was investigated in a chemical model containing glycine, creatinine, and glucose. Acrolein addition at 0.02-0.2 mmol increased MeIQx formation, while high levels of acrolein (>0.2 mmol) did not further increase MeIQx formation. Moreover, acrolein addition decreased the residue of glycine and creatinine but increased the residue of glucose; it also increased the formation of volatile intermediates in the MeIQx-producing chemical model. Further analysis indicated that acrolein can react with glycine, creatinine, and MeIQx to eliminate them. These results revealed that acrolein was able to contribute to MeIQx formation as a consequence of the comprehensive ability of acrolein to facilitate Strecker degradation of glycine, increase the formation of volatile intermediates, and react with glycine, creatinine, and MeIQx. In addition, the oxidation of minced salmon increased the content of MeIQx in the roasted salmon patties, further supporting the potential contribution role of lipid oxidation products in the formation of MeIQx.

Effect of Natural Antioxidants from Marigolds (Tagetes erecta L.) on the Oxidative Stability of Soybean Oil

In recent years, synthetic antioxidants that are widely used in foods have been shown to cause detrimental health effects, and there has been growing interest in antioxidants realised from natural plant extracts. In this study, we investigate the potential effects of natural antioxidant components extracted from the forage plant marigold on the oxidative stability of soybean oil. First, HPLC-Q-TOF-MS/MS was used with 1,1-diphenyl-2-picrylhydrazyl (DPPH) to screen and identify potential antioxidant components in marigold. Four main antioxidant components were identified, including quercetagetin-7-O-glucoside (1), quercetagetin (2), quercetin (3) and patuletin (4). Among them, quercetagetin (QG) exhibited the highest content and the strongest DPPH radical scavenging activity and effectively inhibited the production of oxidation products in soybean oil during accelerated oxidation, as indicated by reductions in the peroxide value (PV) and acid value (AV). Then, the fatty acids and volatile compounds of soybean oil were determined with gas chromatography–mass spectrometry (GC-MS) and headspace solid-phase microextraction–gas chromatography–mass spectrometry (HS-SPME-GC-MS). A total of 108 volatile components, including 16 alcohols, 23 aldehydes, 25 ketones, 4 acids, 15 esters, 18 hydrocarbons, and 7 other compounds, were identified. QG significantly reduced the content and number of aldehydes and ketones, whereas the formation of acids and hydrocarbons was completely prevented. In addition, the fatty acid analysis demonstrated that QG significantly inhibited oxidation of unsaturated fatty acids. Consequently, QG was identified as a potential, new natural antioxidant that is believed to be safe, effective and economical, and it may have potential for use in plant extracts feed additives.

Puerarin inhibited 3-chloropropane-1,2-diol fatty acid esters formation by reacting with glycidol and glycidyl esters

The inhibitory effects of seven polyphenols on 3-chloropropane-1,2-diol fatty acid esters (3-MCPDE) formation were investigated in palm oil models. Results showed that there was not a positive significant correlation between the free-radical scavenging activities of the tested compounds and their 3-MCPDE-formation inhibitory activities; puerarin, with weak antioxidant activity, showed the highest inhibitory capacity. Moreover, puerarin reduced the content of glycidol and glycidyl esters (GEs), two key intermediates of 3-MCPDE formation in the oil models; and a puerarin-adduct was discovered in the oil fortified with glycidol or GEs, with its structure elucidated by LC-MS/MS and comparison with newly synthesized ones. Based on its chemical structure, we proposed that puerarin, at least in part, reacted with glycidol and GEs to inhibit 3-MCPDE formation. In addition, the formed compound, puerarin-7-O-propanediol was identified in the potato chips frying system, further confirming reacting with glycidol/GEs as a key mechanism of puerarin to inhibit 3-MCPDE formation.