Chemistry and biology of ω-3 PUFA peroxidation-derived compounds

High use of non-hydrogenated plant source oils and mayonnaise sauce increase the risk of Parkinson disease

Objectives: This study aimed to assess the contribution of edible/cooking oils and mayonnaise sauce in the severity, motor and non-motor symptoms, and risk of Parkinson's disease (PD).Methods: In this study, 120 patients with PD and 50 healthy individuals participated. The frequency and quantity of edible/cooking oils including animal and plant source oils (hydrogenated and nonhydrogenated) and mayonnaise sauce used by participants were determined using a food frequency questionnaire. The severity of PD was determined by the Unified Parkinson's Disease Rating Scale (UPDRS).Results: Patients with PD had lower use of hydrogenated plant-based oil (HPO) (p < 0.001) and animal oils (p < 0.001) but had higher use of non-hydrogenated plant-based oil (NHPO) (p < 0.001), olive oil (p = 0.02), and mayonnaise sauce (p < 0.001) compared with the healthy subjects. Use of each unit HPO reduced 4% the odds of PD (p = 0.01). The odds of PD increased 20% by each unit increase in NHPO usage (p = 0.001), 49% by olive oil (p = 0.02), and 127% by mayonnaise sauce (p = 0.004) intake. According to receiver operator characteristics curve analysis, mayonnaise sauce and NHPO had the largest area under the curve in predicting PD. Intake of animal oil was positively correlated with total score of UPDRS (p = 0.05) and motor symptoms (p = 0.04). Intake of butter was positively correlated with total score of UPDRS (p = 0.047), nonmotor aspects of experiences of daily living (p = 0.02), and motor examination (p = 0.02).Discussion: The findings indicate that high intake of HPO reduces, while high intake of NHPO, olive oil, and mayonnaise sauce increases the odds of PD.

Use of olive and sunflower protein hydrolysates for the physical and oxidative stabilization of fish oil-in-water emulsions

BACKGROUND

Olive and sunflower seeds are by-products generated in large amounts by the plant oil industry. The technological and biological properties of plant-based substrates, especially protein hydrolysates, have increased their use as functional ingredients for food matrices. The present study evaluates the physical and oxidative stabilities of 50 g kg-1 fish oil-in-water emulsions where protein hydrolysates from olive and sunflower seeds were incorporated at 20 g kg-1 protein as natural emulsifiers. The goal was to investigate the effect of protein source (i.e. olive and sunflower seeds), enzyme (i.e. subtilisin and trypsin) and degree of hydrolysis (5%, 8% and 11%) on the ability of the hydrolysate to stabilize the emulsion and retard lipid oxidation over a 7-day storage period.

RESULTS

The plant protein hydrolysates displayed different emulsifying and antioxidant capacities when incorporated into the fish oil-in-water emulsions. The hydrolysates with degrees of hydrolysis (DH) of 5%, especially those from sunflower seed meal, provided higher physical stability, regardless of the enzymatic treatment. For example, the average D [2, 3] values for the emulsions containing sunflower subtilisin hydrolysates at DH 5% only slightly increased from 1.21 ± 0.02 μm (day 0) to 2.01 ± 0.04 μm (day 7). Moreover, the emulsions stabilized with sunflower or olive seed hydrolysates at DH 5% were stable against lipid oxidation throughout the storage experiment, with no significant variation in the oxidation indices between days 0 and 4.

CONCLUSION

The results of the present study support the use of sunflower seed hydrolysates at DH 5% as natural emulsifiers for fish oil-in-water emulsions, providing both physical and chemical stability against lipid oxidation. © 2024 Society of Chemical Industry.

Melatonin: a ferroptosis inhibitor with potential therapeutic efficacy for the post-COVID-19 trajectory of accelerated brain aging and neurodegeneration

The unprecedented pandemic of COVID-19 swept millions of lives in a short period, yet its menace continues among its survivors in the form of post-COVID syndrome. An exponentially growing number of COVID-19 survivors suffer from cognitive impairment, with compelling evidence of a trajectory of accelerated aging and neurodegeneration. The novel and enigmatic nature of this yet-to-unfold pathology demands extensive research seeking answers for both the molecular underpinnings and potential therapeutic targets. Ferroptosis, an iron-dependent cell death, is a strongly proposed underlying mechanism in post-COVID-19 aging and neurodegeneration discourse. COVID-19 incites neuroinflammation, iron dysregulation, reactive oxygen species (ROS) accumulation, antioxidant system repression, renin-angiotensin system (RAS) disruption, and clock gene alteration. These events pave the way for ferroptosis, which shows its signature in COVID-19, premature aging, and neurodegenerative disorders. In the search for a treatment, melatonin shines as a promising ferroptosis inhibitor with its repeatedly reported safety and tolerability. According to various studies, melatonin has proven efficacy in attenuating the severity of certain COVID-19 manifestations, validating its reputation as an anti-viral compound. Melatonin has well-documented anti-aging properties and combating neurodegenerative-related pathologies. Melatonin can block the leading events of ferroptosis since it is an efficient anti-inflammatory, iron chelator, antioxidant, angiotensin II antagonist, and clock gene regulator. Therefore, we propose ferroptosis as the culprit behind the post-COVID-19 trajectory of aging and neurodegeneration and melatonin, a well-fitting ferroptosis inhibitor, as a potential treatment.

Lipid Aldehydes 4-Hydroxynonenal and 4-Hydroxyhexenal Exposure Differentially Impact Lipogenic Pathways in Human Placenta

Long chain polyunsaturated fatty acids (LCPUFAs), such as the omega-6 (n-6) arachidonic acid (AA) and n-3 docosahexanoic acid (DHA), have a vital role in normal fetal development and placental function. Optimal supply of these LCPUFAs to the fetus is critical for improving birth outcomes and preventing programming of metabolic diseases in later life. Although not explicitly required/recommended, many pregnant women take n-3 LCPUFA supplements. Oxidative stress can cause these LCPUFAs to undergo lipid peroxidation, creating toxic compounds called lipid aldehydes. These by-products can lead to an inflammatory state and negatively impact tissue function, though little is known about their effects on the placenta. Placental exposure to two major lipid aldehydes, 4-hydroxynonenal (4-HNE) and 4-hydroxyhexenal (4-HHE), caused by peroxidation of the AA and DHA, respectively, was examined in the context of lipid metabolism. We assessed the impact of exposure to 25 μM, 50 μM and 100 μM of 4-HNE or 4-HHE on 40 lipid metabolism genes in full-term human placenta. 4-HNE increased gene expression associated with lipogenesis and lipid uptake (ACC, FASN, ACAT1, FATP4), and 4-HHE decreased gene expression associated with lipogenesis and lipid uptake (SREBP1, SREBP2, LDLR, SCD1, MFSD2a). These results demonstrate that these lipid aldehydes differentially affect expression of placental FA metabolism genes in the human placenta and may have implications for the impact of LCPUFA supplementation in environments of oxidative stress.

Oxidized PUFAs Increase Susceptibility of Mice to Salmonella Infection by Diminishing Host's Innate Immune Responses

Dietary ω-3 PUFAs are highly prone to oxidation, and this may potentially limit their application in the health-promoting field. Here, we sought to investigate whether and how oxidized PUFAs modulate the susceptibility of mice to Salmonella typhimurium (S. Tm) infection. Algae oil (AO) and oxidized algae oil (ox-AO) were administered to the C57BL/6 mice prior to S. Tm infection. Compared to the S. Tm group, ox-AO increased bacterial burden in systemic and intestinal tissues, downregulated host anti-infection responses, and developed worse colitis. In macrophages, ox-AO decreased both phagocytosis of S. Tm and clearance of intracellular bacteria and dampened the activation of mitogen-activated protein kinase (MAPK), NF-κB, and autophagy pathways. Furthermore, ox-AO diminished LPS-induced inflammatory cytokine production and S. Tm induced NLRC4 inflammasome activation. This study reveals that oxidized PUFAs may contribute to the development of enteric infections and regular monitoring of the oxidation status in commercial PUFA supplements to prevent their potential adverse impact on human health.

Incorporation of polyphenols in baked products

Bakery foods, including breads, cakes, cookies, muffins, rolls, buns, crumpets, pancakes, doughnuts, waffles, and bagels, etc., have been an important diet of humans for thousands of years. As the nutraceuticals with various biological activities, polyphenols, especially polyphenol-enriched products are widely used in bakery foods. The polyphenol-enriched products are mainly from fruits and vegetables, including fruits in whole, juice, puree, jam, and the powder of dried fruits, pomace, and peels. Incorporation of these products not only provide polyphenols, but also supply other nutrients, especially dietary fibers for bakery products. This chapter discussed the thermal stability of different types of polyphenols during baking, and the effect of polyphenols on the sensory attributes of baked foods. Moreover, their role in mitigation of reactive carbonyl species and the subsequent formation of advanced glycation end products, antioxidant and antimicrobial activities have been also discussed. Since polyphenols are subjected to high temperature for dozens of minutes during baking, future works need to focus on the chemical interactions of polyphenols and their oxidized products (quinones) with other food components, and the safety consequence of these interactions.

Characterization of Polysorbate 80 by Liquid Chromatography-Mass Spectrometry to Understand Its Susceptibility to Degradation and Its Oxidative Degradation Pathway

A liquid chromatography-mass spectrometry (LC-MS) method was developed to provide a fingerprint of polysorbate 80 (PS80) subspecies that enables identification of PS80 degradation pathway. The developed method demonstrates unique monoester peak profile of PS80 from different vendors, attributed by differences in relative abundance of the fatty acid monoesters. The LC-MS method was also applied to examine the susceptibility of PS80, at different grades, to auto-oxidation and hydrolysis. PS80 oxidative degradation induced by iron or occurred in open bottle without nitrogen overlay was found to follow the same pathway, but at a much faster rate in the former scenario. The oxidation preferentially occurs at the double bond of fatty acid chains, thus providing explanation on the faster degradation observed in PS80 at Chinese Pharmacopia (ChP) grade than at multi-compendial (MC) grade. In contrast, the difference in susceptibility of MC and ChP grade PS80 against esterase-induced hydrolysis in placebo was not pronounced. The method was also able to provide a fingerprint to identify both PS80 hydrolysis and oxidation in mAb drug product stability samples, but it required a solid phase extraction step to remove protein prior to the analysis.

The Effect of Carnosol, Carnosic Acid and Rosmarinic Acid on the Oxidative Stability of Fat-Filled Milk Powders throughout Accelerated Oxidation Storage

The in vitro antioxidant effects of the most potent antioxidants of rosemary, namely carnosol, carnosic acid and rosmarinic acid (c: ca: ra) were assessed in fat-filled milk powders (FFMPs) under accelerated conditions (40 °C and relative humidity (RH) 23%) over 90 days. Lipid oxidation was assessed in FFMPs by measuring peroxide values (PVs), thiobarbituric acid reactive substances (TBARS) and aroma volatiles using headspace (HS) solid-phase microextraction (SPME) coupled to gas-chromatography-mass spectrometry (GC-MS). The antioxidant potency of c: ca: ra exhibited a concentration-related effect (308 ppm > 200 ppm > 77 ppm), with the highest concentration being the most effective at controlling the formation of TBARS and PVs. At a concentration of 308 ppm c: ca: ra were particularly effective (p < 0.05) in inhibiting all the evaluated oxidation indices (primary and secondary) compared to the control samples, but in some cases less effectively (p < 0.05) than butylated hydroxyanisole: butylated hydroxytoluene (BHA: BHT) (200 ppm).

Impact of juçara (Euterpe edulis) fruit waste extracts on the quality of conventional and antibiotic-free broiler meat

Juçara (Euterpe edulis) is a native Brazilian palm tree from the Atlantic Forest, whose fruit-processing waste can present high concentration of antioxidant compounds. This research was assessed to determine the antioxidant potential of juçara waste extracts aiming to reduce the lipid and protein oxidation processes on conventional and antibiotic-free broiler meat throughout 9 d during refrigerated storage. The juçara waste extracts were obtained by microwave-assisted extraction. Two different extracts were tested based on the optimum point obtained when checking total phenolic (TPC) contents (Extract P) and antioxidant activity (Extract A) based on a previous study. The treatments using conventional and antibiotic-free broiler meat included: chicken patties without antioxidant addition (AFBNC and CBNC), with synthetic antioxidant (BHT) (AFBPC and CBPC), with Extract P (AFBEP and CBEP) and with Extract A (AFBEA and CBEA), totaling 8 treatments. Antioxidant activity of extracts along with TPC, flavonoid, anthocyanin, and tannin contents of extracts and patties were assessed. Proximate composition, fatty acid profile, lipid and protein oxidation process, and instrumental color were analyzed in patty treatments. Although both extracts had similar content of TPC and tannin, extract A presented the highest anthocyanin, while extract P exhibited the highest flavonoid. While extract A exhibited the highest antioxidant activity, extract P was highly influential in the stability of lipid oxidative degradation in both types of broiler meat (AFBEP and CBEP), and as successful as BHT (AFBPC and CBPC). In addition, extract P was also able to stabilize protein oxidation in conventional broiler meat (CBEP) from the third day, until the end of the storage period. Therefore, the fruit waste extract P of juçara can be a promising source of natural antioxidants to prevent the oxidative process in conventional and antibiotic-free broiler meat.

Polymer Conjugation of Docosahexaenoic Acid Potentiates Cardioprotective Therapy in Preclinical Models of Myocardial Ischemia/Reperfusion Injury

While coronary angioplasty represents an effective treatment option following acute myocardial infarction, the reperfusion of the occluded coronary artery can prompt ischemia-reperfusion (I/R) injury that significantly impacts patient outcomes. As ω-3 polyunsaturated fatty acids (PUFAs) have proven, yet limited cardioprotective abilities, an optimized polymer-conjugation approach is reported that improves PUFAs bioavailability to enhance cardioprotection and recovery in animal models of I/R-induced injury. Poly-l-glutamic acid (PGA) conjugation improves the solubility and stability of di-docosahexaenoic acid (diDHA) under physiological conditions and protects rat neonatal ventricular myocytes from I/R injury by reducing apoptosis, attenuating autophagy, inhibiting reactive oxygen species generation, and restoring mitochondrial membrane potential. Enhanced protective abilities are associated with optimized diDHA loading and evidence is provided for the inherent cardioprotective potential of PGA itself. Pretreatment with PGA-diDHA before reperfusion in a small animal I/R model provides for cardioprotection and limits area at risk (AAR). Furthermore, the preliminary findings suggest that PGA-diDHA administration in a swine I/R model may provide cardioprotection, limit edema and decrease AAR. Overall, the evaluation of PGA-diDHA in relevant preclinical models provides evidence for the potential of polymer-conjugated PUFAs in the mitigation of I/R injury associated with coronary angioplasty.

Pathophysiological relationship between hypoxia associated oxidative stress, Epithelial-mesenchymal transition, stemness acquisition and alteration of Shh/ Gli-1 axis during oral sub-mucous fibrosis and oral squamous cell carcinoma

Oral sub-mucous fibrosis (OSF) is a pathophysiological state of oral cavity or oropharynx having a high chance of conversion to oral squamous cell carcinoma (OSCC). It involves fibrotic transformation of sub-epithelial matrix along with epithelial abnormalities. The present work aims to unveil the mechanistic domain regarding OSF to OSCC conversion exploring the scenario of hypoxia associated oxidative stress, epithelial-mesenchymal transition (EMT), metastasis and stemness acquisition. The study involves histopathological analysis of the diseased condition along with the exploration of oxidative stress status, assessment of mitochondrial condition, immunohistochemical analysis of HIF-1α, E-cadherin, vimentin, ERK, ALDH-1, CD133, Shh, Gli-1 and survivin expressions in the oral epithelial region together with the quantitative approach towards collagen deposition in the sub-epithelial matrix. Oxidative stress was found to be associated with type-II EMT in case of OSF attributing the development of sub-epithelial fibrosis and type-III EMT in case of OSCC favoring malignancy associated metastasis. Moreover, the acquisition of stemness during OSCC can also be correlated with EMT. Alteration of Shh and Gli-1 expression pattern revealed the mechanistic association of hypoxia with the phenotypic plasticity and disease manifestation in case of OSF as well as OSCC. Shh/ Gli-1 signaling can also be correlated with survivin mediated cytoprotective phenomenon under oxidative stress. Overall, the study established the correlative network of hypoxia associated oxidative stress, EMT and manifestation of oral pre-cancerous and cancerous condition in a holistic approach that may throw rays of hope in the therapeutic domain of the concerned diseases.

How To Stabilize ω-3 Polyunsaturated Fatty Acids (PUFAs) in an Animal Feeding Study?-Effects of the Temperature, Oxygen Level, and Antioxidant on Oxidative Stability of ω-3 PUFAs in a Mouse Diet

Substantial studies have shown that ω-3 polyunsaturated fatty acids (PUFAs) have various health-promoting effects; however, there are inconsistent results from animal studies that showed that ω-3 PUFAs have no effects or even detrimental effects. Emerging research suggests that oxidized ω-3 PUFAs have different effects compared to unoxidized ω-3 PUFAs; therefore, lipid oxidation of dietary ω-3 PUFAs could contribute to the mixed results of ω-3 PUFAs in animal studies. Here, we prepared an AIN-93G-based, semi-purified, powder diet, which is one of the most commonly used rodent diets in animal studies, to study the oxidative stability of fortified ω-3 PUFAs in animal feed. We found that lowering the storage temperature or the addition of a certain antioxidant, notably tert-butylhydroquinone (TBHQ), helps to stabilize ω-3 PUFAs and suppress ω-3 oxidation in the animal diet, while reducing the level of oxygen in the storage atmosphere is not very effective. The addition of 50 ppm of TBHQ in the diet inhibited 99.5 ± 0.1% formation of primary oxidation products and inhibited 96.1 ± 0.7% formation of secondary oxidation products, after 10 days of storage of the prepared diet at a typical animal-feeding experiment condition. Overall, our results highlight that ω-3 PUFAs are highly prone to lipid oxidation in a typical animal-feeding experiment, emphasizing the critical importance to stabilize ω-3 PUFAs in animal studies.

ω-3 Polyunsaturated Fatty Acids on Colonic Inflammation and Colon Cancer: Roles of Lipid-Metabolizing Enzymes Involved

Substantial human and animal studies support the beneficial effects of ω-3 polyunsaturated fatty acids (PUFAs) on colonic inflammation and colorectal cancer (CRC). However, there are inconsistent results, which have shown that ω-3 PUFAs have no effect or even detrimental effects, making it difficult to effectively implement ω-3 PUFAs for disease prevention. A better understanding of the molecular mechanisms for the anti-inflammatory and anticancer effects of ω-3 PUFAs will help to clarify their potential health-promoting effects, provide a scientific base for cautions for their use, and establish dietary recommendations. In this review, we summarize recent studies of ω-3 PUFAs on colonic inflammation and CRC and discuss the potential roles of ω-3 PUFA-metabolizing enzymes, notably the cytochrome P450 monooxygenases, in mediating the actions of ω-3 PUFAs.

Screening of volatile decay markers of minced pork by headspace-solid phase microextraction-gas chromatography-mass spectrometry and chemometrics

Headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used to analyze the volatile compounds of minced pork meat during storage. The origin of aromatic hydrocarbons in pork was verified by migration test. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were applied to characterize the profile of volatile compounds in pork meat and identify the potential volatile markers associated with the spoilage of pork. A total of 41 compounds were identified. Migration test showed that the aromatic hydrocarbons in raw pork are from packaging. Three compounds: ethanol, 2,3-butanediol and 2-ethyl-1-hexanol were selected based on the loading plot and their variables importance in the projection (VIP) values, since they contribute mainly to the discrimination of pork with different storage times. These compounds can be used as additional indicators for quality control of pork.

The Anti-Inflammatory and Antioxidant Properties of n-3 PUFAs: Their Role in Cardiovascular Protection

Polyunsaturated fatty acids (n-3 PUFAs) are long-chain polyunsaturated fatty acids with 18, 20 or 22 carbon atoms, which have been found able to counteract cardiovascular diseases. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), in particular, have been found to produce both vaso- and cardio-protective response via modulation of membrane phospholipids thereby improving cardiac mitochondrial functions and energy production. However, antioxidant properties of n-3 PUFAs, along with their anti-inflammatory effect in both blood vessels and cardiac cells, seem to exert beneficial effects in cardiovascular impairment. In fact, dietary supplementation with n-3 PUFAs has been demonstrated to reduce oxidative stress-related mitochondrial dysfunction and endothelial cell apoptosis, an effect occurring via an increased activity of endogenous antioxidant enzymes. On the other hand, n-3 PUFAs have been shown to counteract the release of pro-inflammatory cytokines in both vascular tissues and in the myocardium, thereby restoring vascular reactivity and myocardial performance. Here we summarize the molecular mechanisms underlying the anti-oxidant and anti-inflammatory effect of n-3 PUFAs in vascular and cardiac tissues and their implication in the prevention and treatment of cardiovascular disease.

Isoprostanoid Profiling of Marine Microalgae

Algae result from a complex evolutionary history that shapes their metabolic network. For example, these organisms can synthesize different polyunsaturated fatty acids, such as those found in land plants and oily fish. Due to the presence of numerous double-bonds, such molecules can be oxidized nonenzymatically, and this results in the biosynthesis of high-value bioactive metabolites named isoprostanoids. So far, there have been only a few studies reporting isoprostanoid productions in algae. To fill this gap, the current investigation aimed at profiling isoprostanoids by liquid chromatography -mass spectrometry/mass spectrometry (LC-MS/MS) in four marine microalgae. A good correlation was observed between the most abundant polyunsaturated fatty acids (PUFAs) produced by the investigated microalgal species and their isoprostanoid profiles. No significant variations in the content of oxidized derivatives were observed for Rhodomonas salina and Chaetoceros gracilis under copper stress, whereas increases in the production of C18-, C20- and C22-derived isoprostanoids were monitored in Tisochrysis lutea and Phaeodactylum tricornutum. In the presence of hydrogen peroxide, no significant changes were observed for C. gracilis and for T. lutea, while variations were monitored for the other two algae. This study paves the way to further studying the physiological roles of isoprostanoids in marine microalgae and exploring these organisms as bioresources for isoprostanoid production.

Lipid Signaling in Ocular Neovascularization

Vasculogenesis and angiogenesis play a crucial role in embryonic development. Pathological neovascularization in ocular tissues can lead to vision-threatening vascular diseases, including proliferative diabetic retinopathy, retinal vein occlusion, retinopathy of prematurity, choroidal neovascularization, and corneal neovascularization. Neovascularization involves various cellular processes and signaling pathways and is regulated by angiogenic factors such as vascular endothelial growth factor (VEGF) and hypoxia-inducible factor (HIF). Modulating these circuits may represent a promising strategy to treat ocular neovascular diseases. Lipid mediators derived from membrane lipids are abundantly present in most tissues and exert a wide range of biological functions by regulating various signaling pathways. In particular, glycerophospholipids, sphingolipids, and polyunsaturated fatty acids exert potent pro-angiogenic or anti-angiogenic effects, according to the findings of numerous preclinical and clinical studies. In this review, we summarize the current knowledge regarding the regulation of ocular neovascularization by lipid mediators and their metabolites. A better understanding of the effects of lipid signaling in neovascularization may provide novel therapeutic strategies to treat ocular neovascular diseases and other human disorders.

DHA protects PC12 cells against oxidative stress and apoptotic signals through the activation of the NFE2L2/HO-1 axis

Docosahexaenoic acid (DHA) is an omega‑3 polyunsaturated fatty acid, derived mainly from fish oil. It is well known that DHA is present in high concentrations in nervous tissue and plays an important role in brain development and neuroprotection. However, the molecular mechanisms underlying its role remain to be fully elucidated. In this study, to enhance our understanding of the pathophysiological role of DHA, we investigated the possible neuroprotective mechanisms of action of DHA against hydrogen peroxide (H2O2)‑induced oxidative damage in a rat pheochromocytoma cell line (PC12). Specifically, we evaluated the viability, oxidation potential, and the expression and production of antioxidant/cytoprotective enzymes, and eventual apoptosis. We found that pre‑treatment with DHA (24 h) protected the cells from H2O2‑induced oxidative damage. In particular, pre‑treatment with DHA: i) Antagonized the consistent decrease in viability observed following exposure to H2O2 for 24 h; ii) reduced the high levels of intracellular reactive oxygen species (ROS) associated with H2O2‑induced oxidative stress; iii) increased the intracellular levels of enzymatic antioxidants [superoxide dismutase (SOD) and glutathione peroxidase (GSH‑Px)] both under basal conditions and following H2O2 exposure; iv) augmented the intracellular levels of reduced glutathione (GSH) and ascorbic acid, while it reduced the malondialdehyde (MDA) levels under conditions of oxidative stress; v) upregulated the expression of nuclear factor (erythroid‑derived 2)‑like 2 (NFE2L2) and its downstream target protein, heme‑oxygenase‑1 (HO‑1); and vi) induced an anti‑apoptotic effect by decreasing Bax and increasing Bcl2 expression. These findings provide evidence suggesting that DHA is able to prevent H2O2‑induced oxidative damage to PC12 cells, which is attributed to its antioxidant and anti‑apoptotic effects via the regulation NFE2L2/HO‑1 signaling. Therefore, DHA may play protective role in neurodegenerative diseases associated with oxidative stress.

Positive and negative effects of polyphenol incorporation in baked foods

Polyphenols are hot research topics worldwide owing to their physiological and pharmaceutical activities. Polyphenols and polyphenol-enriched by-products have been widely used in bakery foods because of their neutraceutical properties. This review summarizes the classification, biosynthesis, main source and analysis of polyphenols and intensively discusses the effects of their incorporation in baked foods. The positive effects of polyphenol incorporation include elevation of antioxidant activity of baked foods, scavenging of food-borne toxins produced during thermal processing and decreasing postprandial serum glucose level. Meanwhile, polyphenol incorporation negatively influences colour, texture and flavour of baked foods and bioavailability of the added polyphenols. Most polyphenols are thermally sensitive and reactive. Thus far, few studies have investigated on neoformed compounds from the reaction of polyphenols or their oxidised products (quinones) with other food components. Before launching polyphenol-incorporated bakery foods in the market, future work should focus on full toxicological evaluation of newly derived compounds from polyphenols.

Modulation of the endogenous omega-3 fatty acid and oxylipin profile in vivo-A comparison of the fat-1 transgenic mouse with C57BL/6 wildtype mice on an omega-3 fatty acid enriched diet

Dietary intervention and genetic fat-1 mice are two models for the investigation of effects associated with omega-3 polyunsaturated fatty acids (n3-PUFA). In order to assess their power to modulate the fatty acid and oxylipin pattern, we thoroughly compared fat-1 and wild-type C57BL/6 mice on a sunflower oil diet with wild-type mice on the same diet enriched with 1% EPA and 1% DHA for 0, 7, 14, 30 and 45 days. Feeding led after 14–30 days to a high steady state of n3-PUFA in all tissues at the expense of n6-PUFAs. Levels of n3-PUFA achieved by feeding were higher compared to fat-1 mice, particularly for EPA (max. 1.7% in whole blood of fat-1 vs. 7.8% following feeding). Changes in PUFAs were reflected in most oxylipins in plasma, brain and colon: Compared to wild-type mice on a standard diet, arachidonic acid metabolites were overall decreased while EPA and DHA oxylipins increased with feeding more than in fat-1 mice. In plasma of n3-PUFA fed animals, EPA and DHA metabolites from the lipoxygenase and cytochrome P450 pathways dominated over ARA derived counterparts.Fat-1 mice show n3-PUFA level which can be reached by dietary interventions, supporting the applicability of this model in n3-PUFA research. However, for specific questions, e.g. the role of EPA derived mediators or concentration dependent effects of (individual) PUFA, feeding studies are necessary.