The antioxidants in oils heated at frying temperature, whether natural or added, could protect against postprandial oxidative stress in obese people

The Stability of Refined Rapeseed Oil Fortified by Cold-Pressed and Essential Black Cumin Oils under a Heating Treatment

Polar compounds and polymers are regarded as the most reliable indicators of oil degradation during heating, and it is desirable to find methods to reduce these undesirable changes. The aim of this study was (1) to determine the effect of enrichment with black cumin cold-pressed oil (CP) or essential oil obtained from black cumin cold-pressed oil in an equivalent amount (ES) on limiting the polar compounds and polymers content in blends based on refined rapeseed oil during high-temperature heating in a thin layer; (2) to determine tocochromanol losses and their effect on the change content of the polar compounds and polymers. Four fortified oils were made from refined rapeseed oil and one of the four additives (10% CP, 20% CP, 0.1% ES, and 0.2% ES). All fortified oils and refined rapeseed oil as a control sample were heated at 170 and 200 °C on the pan in a thin layer and evaluated regarding loss of individual tocochromanol homologs by HPLC-FL, polar compounds content, oxidized triacylglycerols (TAG), and polymers content by HPSEC-ELSD. Additionally, the fatty acid profile in nonheated oil was investigated. Tocochromanol analysis showed loss in all the samples. At 170 °C polymers were not detected; no difference was noted for polar compounds and oxidized TAG content; only the 20% CP sample showed a higher level. At 200 °C the 10% CP sample exhibited a significant protective effect with the lowest content of polar compounds, oxidized TAG, and dimers.

An oleuropein rich-olive (Olea europaea L.) leaf extract reduces β-amyloid and tau proteotoxicity through regulation of oxidative- and heat shock-stress responses in Caenorhabditis elegans

Olive tree-derived products have been associated with numerous benefits for health. The aim of the present study was to characterize an olive leaf extract enriched in oleuropein (OLE) concerning phenolic content and profile as well as antioxidant capacity. Short-term and long-term toxicity, including oxidative stress, was in vivo evaluated in the experimental model Caenorhabditis elegans. Moreover, the potential therapeutic effect of the extract against Aβ induced- and tau protein induced-toxicity was also evaluated in C. elegans. OLE treatment did not exert toxicity. On the contrary, the extract was able to ameliorate oxidative stress and proteotoxicity related to Aβ and tau aggregation. The potential molecular mechanisms present behind the observed results explored by RNAi technology revealed that DAF-16/FOXO and SKN-1/NRF2, elements of the insulin insulin-like signalling pathway, as well as HSP-16.2 overexpression were involved.

Goji Berry (Lycium Barbarum L.) Carotenoids Enrichment through ‘Green’ Extraction Method Improves Oxidative Stability and Maintains Fatty Acids of Yak Ghee with Microwave Heating and Storage

As the oxidation of yak ghee is inevitable and as consumer demand for natural products continues to increase, this study aimed to enrich yak ghee with goji berry carotenoids by means of green solvent extraction and determined changes in the oxidative stability and fatty acid profiles of yak ghees during microwave heating (MW-heating) and accelerated storage. An enriched ghee (GG0) was prepared by high shear dispersion and ultrasound-assisted extraction, while a control ghee (FG0) was prepared by heating and filtration; both ghees were stored at 65 °C for 30 days and were microwave-heated (MW-heating) at 180 °C (15 and 30 min) and 200 °C for 30 min. The results showed that the carotenoid enrichment increased the oxidative stability of yak ghee during MW-heating and storage. The initial CLA and PUFA values of GG0 were not significantly different from those of FG0; SFA increased, and MUFA and TFA decreased. There was a faster rate of UFA loss and an increase in SFA and TFA in FG0 during MW-heating and storage. This indicated a protective effect of carotenoid enrichment on yak ghee. Therefore, the findings in this study support the use of goji berry carotenoids as a natural colorant and antioxidant in yak ghee. This study provides vital information for dairy processors and marketers.

Syringa microphylla Diels: A comprehensive review of its phytochemical, pharmacological, pharmacokinetic, and toxicological characteristics and an investigation into its potential health benefits

BACKGROUND

Syringa microphylla Diels is a plant in the family Syringa Linn. For hundreds of years, its flowers and leaves have been used as a folk medicine for the treatment of cough, inflammation, colds, sore throat, acute hepatitis, chronic hepatitis, early liver cirrhosis, fatty liver, and oesophageal cancer.

PURPOSE

For the first time, we have comprehensively reviewed information on Syringa microphylla Diels that is not included in the Pharmacopoeia, clarified the pharmacological mechanisms of Syringa microphylla Diels and its active ingredients from a molecular biology perspective, compiled in vivo and in vitro animal experimental data and clinical data, and summarized the toxicology and pharmacokinetics of Syringa microphylla Diels. The progress in toxicology research is expected to provide a theoretical basis for the development of new drugs from Syringa microphylla Diels, a natural source of compounds that are potentially beneficial to human health.

METHODS

The PubMed, Google Scholar, China National Knowledge Infrastructure, Web of Science, SciFinder Scholar and Thomson Reuters databases were utilized to conduct a comprehensive search of published literature as of July 2021 to find original literature related to Syringa microphylla Diels and its active ingredients.

RESULTS

To date, 72 compounds have been isolated and identified from Syringa microphylla Diels, and oleuropein, verbascoside, isoacteoside, echinacoside, forsythoside B, and eleutheroside B are the main active components. These compounds have antioxidant, antibacterial, anti-inflammatory, and neuroprotective effects, and their safety and effectiveness have been demonstrated in long-term traditional applications. Molecular pharmacology experiments have indicated that the active ingredients of Syringa microphylla Diels exert their pharmacological effects in various ways, primarily by reducing oxidative stress damage via Nrf2/ARE pathway regulation, regulating inflammatory factors and inducing apoptosis through the MAPK and NF-κB pathways.

CONCLUSION

This comprehensive review of Syringa microphylla Diels provides new insights into the correlations among molecular mechanisms, the importance of toxicology and pharmacokinetics, and potential ways to address the limitations of current research. As Syringa microphylla Diels is a natural low-toxicity botanical medicine, it is worthy of development and utilization and is an excellent choice for treating various diseases.

The effect of dietary phytochemicals on nuclear factor erythroid 2-related factor 2 (Nrf2) activation: a systematic review of human intervention trials

We conducted a systematic review of human trials examining the effects of dietary phytochemicals on Nrf2 activation. In accordance with the PRISMA guidelines, Medline, Embase and CAB abstracts were searched for articles from inception until March 2020. Studies in adult humans that measured Nrf2 activation (gene or protein expression changes) following ingestion of a phytochemical, either alone or in combination were included. The study was pre-registered on the Prospero database (Registration Number: CRD42020176121). Twenty-nine full-texts were retrieved and reviewed for analysis; of these, eighteen were included in the systematic review. Most of the included participants were healthy, obese or type 2 diabetics. Study quality was assessed using the Cochrane Collaboration Risk of Bias Assessment tool. Twelve different compounds were examined in the included studies: curcumin, resveratrol and sulforaphane were the most common (n = 3 each). Approximately half of the studies reported increases in Nrf2 activation (n = 10); however, many were of poor quality and had an unclear or high risk of bias. There is currently limited evidence that phytochemicals activate Nrf2 in humans. Well controlled human intervention trials are needed to corroborate the findings from in vitro and animal studies.

Effects of citrus leaf extract on aortic vascular reactivity in hypertensive rats fed repeatedly heated vegetable oil

The prolonged intake of diet containing repeatedly heated vegetable oil can cause hypertension in the long run. In this study, the effects of citrus leaf extract (CLE) supplementation on vascular reactivity, plasma nitrite, and aortic structure in hypertensive rats were investigated by the consumption of repeatedly heated vegetable oil [corrected]. Male Sprague Dawley rats (n = 56) were divided into 7 groups corresponding to the respective diets. For 16 weeks, 1 group was given standard rat chow (control) while other groups were given diets containing 15% w/w of palm oil, fresh palm oil (FPO), palm oil heated 5 times (5HPO), and palm oil heated 10 times (10HPO), with or without the incorporation of 0.15% w/w CLE (FPO+CLE, 5HPO+CLE, or 10HPO+CLE). Plasma nitrite levels were measured before and at 16 weeks of treatment. After 16 weeks, the rats were sacrificed and aortae were harvested for measuring vascular reactivity and for microscopic study. CLE supplementation had significantly reduced the loss of plasma nitrite and attenuated the vasoconstriction response to phenylephrine in the 5HPO group but not in the 10HPO group. However, CLE had no significant effect on the vasorelaxation response to acetylcholine and sodium nitroprusside. The elastic lamellae of tunica media in 5HPO, 10HPO, and 10HPO+CLE groups appeared disorganised and disrupted. Obtained findings suggested that CLE was able to enhance nitric oxide bioavailability that might dampen the vasoconstriction effect of phenylephrine.

Critical Evaluation of Gene Expression Changes in Human Tissues in Response to Supplementation with Dietary Bioactive Compounds: Moving Towards Better-Quality Studies

Pre-clinical cell and animal nutrigenomic studies have long suggested the modulation of the transcription of multiple gene targets in cells and tissues as a potential molecular mechanism of action underlying the beneficial effects attributed to plant-derived bioactive compounds. To try to demonstrate these molecular effects in humans, a considerable number of clinical trials have now explored the changes in the expression levels of selected genes in various human cell and tissue samples following intervention with different dietary sources of bioactive compounds. In this review, we have compiled a total of 75 human studies exploring gene expression changes using quantitative reverse transcription PCR (RT-qPCR). We have critically appraised the study design and methodology used as well as the gene expression results reported. We herein pinpoint some of the main drawbacks and gaps in the experimental strategies applied, as well as the high interindividual variability of the results and the limited evidence supporting some of the investigated genes as potential responsive targets. We reinforce the need to apply normalized procedures and follow well-established methodological guidelines in future studies in order to achieve improved and reliable results that would allow for more relevant and biologically meaningful results.

Changes in extra-virgin olive oil added with Lycium barbarum L. carotenoids during frying: Chemical analyses and metabolomic approach

In this work, an Italian extra-virgin olive oil (EVOO) sample and the same sample added with a carotenoid-rich nutraceutical extract from Lycium barbarum L. (EVOOCar) were subjected to a frying process to comparatively assess chemical and physical changes and heat stability. Oxidation progress was monitored by measuring oil quality changes such as peroxide value, free acidity, K232, K268, and fatty acid composition as well as minor compound content, phenols, α-tocopherol, and carotenoids. An UHPLC/QTOF-MS metabolomics approach discriminated the two oil samples based on their chemical changes during frying, identifying also the phenolic classes most exposed to statistically significant variations. Partial least square discriminant analysis and volcano analysis were applied together to identify the most significant markers allowing group separation. The decrease in total phenolic content was lower in EVOOCar than in EVOO during frying. Monounsaturated and polyunsaturated fatty acids showed a significant percentage loss, 3.7% and 17.2%, respectively, in EVOO after 180min frying at 180°C, while they remained constant or slightly changed in EVOOCar. Zeaxanthin added to the oil rapidly decreased during the frying process. These findings showed that the addition of a carotenoid extract from L. barbarum can help to improve the oxidative stability of extra-virgin olive oil.

The origin of aliphatic hydrocarbons in olive oil

BACKGROUND

There are many substances that can interfere with olive oil quality. Some of them are well characterized, but many others have an unknown origin. Saturated hydrocarbons make an extraordinary complex family of numerous molecules, some of them present naturally in vegetable oils. When major natural saturated hydrocarbons are analyzed by standard chromatographic methods, this complex mixture of saturated hydrocarbons appears as a hump in the chromatogram and is commonly named as unresolved complex mixture (UCM), whose origin remains unknown.

RESULTS

In this work we studied the occurrence and the origin of aliphatic saturated hydrocarbons in olive oil. Hydrocarbons were analyzed in olive oil and along the industrial process of oil extraction. We also analyzed n-alkanes and the UCM fraction of hydrocarbons in leaf, fruit and oil from different varieties and different locations, and we also analyzed the soils at these locations.

CONCLUSIONS

We conclude that the hydrocarbons present in olive oil do not necessarily have their origin in a contamination during olive oil elaboration; they seem to have a natural origin, as a result of olive tree metabolism and/or as the result of an intake and accumulation by the olive tree directly from the environment during its entire life cycle. © 2017 Society of Chemical Industry.

The Role of Food Antioxidants, Benefits of Functional Foods, and Influence of Feeding Habits on the Health of the Older Person: An Overview

This overview was directed towards understanding the relationship of brain functions with dietary choices mainly by older humans. This included food color, flavor, and aroma, as they relate to dietary sufficiency or the association of antioxidants with neurodegenerative diseases such as dementia and Alzheimer’s disease. Impairment of olfactory and gustatory function in relation to these diseases was also explored. The role of functional foods was considered as a potential treatment of dementia and Alzheimer’s disease through inhibition of acetylcholinesterase as well as similar treatments based on herbs, spices and antioxidants therein. The importance of antioxidants for maintaining the physiological functions of liver, kidney, digestive system, and prevention of cardiovascular diseases and cancer has also been highlighted. Detailed discussion was focused on health promotion of the older person through the frequency and patterns of dietary intake, and a human ecology framework to estimate adverse risk factors for health. Finally, the role of the food industry, mass media, and apps were explored for today’s new older person generation.

Effects of High Temperature Frying of Spinach Leaves in Sunflower Oil on Carotenoids, Chlorophylls, and Tocopherol Composition

Spinach is one of the highly consumed vegetable, with significant nutritional, and beneficial properties. This study revealed for the first time, the effects of high temperature frying on the carotenoids, chlorophylls, and tocopherol contents of spinach leaves. Spinach leaves were thermally processed in the sunflower oil for 15, 30, 45, and 60 min at 250°C. Reversed phase HPLC-DAD results revealed a total of eight carotenoids, four chlorophylls and α-tocopherol in the spinach leaves. Lutein, neoxanthin, violaxanthin, and β-carotene-5,6-epoxide were the major carotenoids, while chlorophyll a and b' were present in higher amounts. Frying of spinach leaves increased significantly the amount of α-tocopherol, β-carotene-5,6-epoxide, luteoxanthin, lutein, and its Z-isomers and chlorophyll b' isomer. There was significant decrease in the amounts of neoxanthin, violaxanthin, chlorophyll b, b' and chlorophyll a with increase of frying time. The increase of frying time increased the total phenolic contents in spinach leaves and fried sunflower oil samples. Chemical characteristics such as peroxide values, free fatty acids, conjugated dienes, conjugated trienes, and radical scavenging activity were significantly affected by frying, while spinach leaves increased the stability of the frying oil. This study can be used to improve the quality of fried vegetable leaves or their products at high temperature frying in food industries for increasing consumer acceptability.

Protective effect of gallic acid on the thermal oxidation of corn and soybean oils during high temperature heating

The comparative protective effects of gallic acid with well-known synthetic antioxidants (tert-butylhydroquinone, butylated hydroxylanisole, propylgallate) on the thermal oxidations of corn and soybean oils during heating for 8 h at 180°C were studied. The quantitative effects of gallic acid at three different concentrations on the time-course thermal oxidations in the two different vegetable oils were also studied for a prolonged heating of 6 days at 180°C. Gallic acid at 200 ppm exhibited higher protective activity than the synthetic antioxidants at the same concentration. Gallic acid also exhibited persistently strong protective activity, in a concentration dependent manner, on the changes in oxidation indices in corn and soybean oils throughout the prolonged heating period (6 days) at 180°C. The present results clearly suggested that gallic acid would be a potential natural substitute of synthetic antioxidants for the protection of vegetable oils during high temperature heating.

Cardiovascular risk protection from the Mediterranean diet and olive oil. A transcriptomic update in humans

This review highlights the human studies that explore the benefits of the Mediterranean diet and olive oil, based on gene expression analysis. We summarized consistent human transcriptomic studies on cardiovascular risk, based on TMD and olive oil interventions, with real life doses and conditions. A literature review was carried out leading up to February 2016. The results show that the TMD, specially supplemented with virgin olive oil, produces beneficial changes in the transcriptomic response of relevant genes in cardiovascular risk such as CAT, GPX1 and SIRT2. p65 and MCP-1, IL1B, IL6, CXCL1, INF-γ, ARHGAP15 and IL7R, which are involved in inflammation; and ABCA1, SR-B1, PPARBP, PPARα, PPARγ, PPARδ, CD-36 and COX-1, which play an important role in cholesterol efflux. The available data illustrate a transcriptomic effect on atherosclerosis, inflammation and oxidative stress pathways as well as the mentioned genes.

Ingestion of frying fat leads to activation of the endoplasmic reticulum stress-induced unfolded protein response in the duodenal mucosa of pigs

SCOPE

Ingestion of oxidized fats (OF) causes activation of stress signaling pathways such as nuclear factor-erythroid 2-related factor 2 (Nrf2) in the intestine. Activation of this pathway is mediated by ER stress-induced unfolded protein response (UPR). Herein, we hypothesized that ingestion of OF causes ER stress-induced UPR in duodenal mucosa of pigs.

METHODS AND RESULTS

Six-wk-old cross-bred pigs received either a control diet with fresh fat or a diet with OF for 29 days. Pigs fed OF exhibited increased phosphorylation of the ER stress downstream target eukaryotic translation initiation factor 2α and induction of several genes involved in ER stress-induced UPR and Nrf2 target genes in duodenal mucosa. No signs of an impaired intestinal barrier function or a systemic inflammatory response could be found in pigs fed OF.

CONCLUSION

Activation of ER stress-induced UPR by OF in the duodenal mucosa in pigs might be interpreted as a cytoprotective response to stress factors associated with ingestion of OF. Given the similarities between pigs and humans with respect to digestive physiology, it is possible that regular ingestion of fried foods containing OF activates the ER stress-induced UPR also in the intestinal mucosa of humans.

Alcoholic Liver Disease: Update on the Role of Dietary Fat

Alcoholic liver disease (ALD) spans a spectrum of liver pathology, including fatty liver, alcoholic steatohepatitis, and cirrhosis. Accumulating evidence suggests that dietary factors, including dietary fat, as well as alcohol, play critical roles in the pathogenesis of ALD. The protective effects of dietary saturated fat (SF) and deleterious effects of dietary unsaturated fat (USF) on alcohol-induced liver pathology are well recognized and documented in experimental animal models of ALD. Moreover, it has been demonstrated in an epidemiological study of alcoholic cirrhosis that dietary intake of SF was associated with a lower mortality rates, whereas dietary intake of USF was associated with a higher mortality. In addition, oxidized lipids (dietary and in vivo generated) may play a role in liver pathology. The understanding of how dietary fat contributes to the ALD pathogenesis will enhance our knowledge regarding the molecular mechanisms of ALD development and progression, and may result in the development of novel diet-based therapeutic strategies for ALD management. This review explores the relevant scientific literature and provides a current understanding of recent advances regarding the role of dietary lipids in ALD pathogenesis.

Does cooking with vegetable oils increase the risk of chronic diseases?: a systematic review

Overweight/obesity, CVD and type 2 diabetes are strongly associated with nutritional habits. High consumption of fried foods might increase the risk of these disorders. However, it is not clear whether the use of vegetables oils for cooking increases the risk of chronic diseases. We systematically searched for published studies that assessed the association between vegetable oil consumption including fried food consumption and the risk of overweight/obesity or weight gain, T2DM or the metabolic syndrome, and CVD or hypertension in the following databases: PubMed; Web of Science; Google Scholar. Keywords such as 'fried food' or 'vegetable oil' or 'frying' or 'frying oils' or 'dietary fats' and 'weight gain' or 'overweight' or 'obesity' or 'CHD' or 'CVD' or 'type 2 diabetes' or 'metabolic syndrome' were used in the primary search. Additional published reports were obtained through other sources. A total of twenty-three publications were included based on specific selection criteria. Based on the results of the studies included in the present systematic review, we conclude that (1) the myth that frying foods is generally associated with a higher risk of CVD is not supported by the available evidence; (2) virgin olive oil significantly reduces the risk of CVD clinical events, based on the results of a large randomised trial that included as part of the intervention the recommendation to use high amounts of virgin olive oil, also for frying foods; and (3) high consumption of fried foods is probably related to a higher risk of weight gain, though the type of oil may perhaps modify this association.

Virgin olive oil: a key food for cardiovascular risk protection

Olive oil is considered to be one of the most healthy dietary fats. However, several types of olive oils are present in the market. A key question for the consumer is: What of the olive oils is the best when concerning nutritional purposes? With the data available at present, the answer is: the Virgin Olive Oil (VOO), rich in phenolic compounds. On November 2011, the European Food Safety Authority released a claim concerning the benefits of daily ingestion of olive oil rich in phenolic compounds, such as VOO. In this review, we summarised the key work that has provided the evidence of the benefits of VOO consumption on other types of edible oils, even olive oils. We focused on data from randomised, controlled human studies, which are capable of providing the evidence of Level I that is required for performing nutritional recommendations at population level.

Peripheral blood mononuclear cells as in vivo model for dietary intervention induced systemic oxidative stress

Our aim was to assess the use of peripheral blood mononuclear cells (PBMC) as an in vivo cellular model to evaluate diet-induced changes in the oxidative stress status by analyzing the gene expression pattern of NADPH-oxidase subunits and antioxidant genes. A randomized, controlled trial assigned metabolic syndrome patients to 4 diets for 12 weeks each: (i) high-saturated fatty acid (HSFA), (ii) high-monounsaturated fatty acid, and (iii), (iv) two low-fat, high-complex carbohydrate diets supplemented with n-3 polyunsaturated fatty acids or placebo. A fat challenge reflecting the fatty acid composition as the original diets was conducted post-intervention. The mRNA levels of gp91(phox) (P<0.001), p22(phox) (P=0.005), p47(phox) (P=0.001) and p40(phox) (P<0.001) increased at 2h after the intake of the HSFA meal. The expression of SOD1, SOD2, GSR, GPx1, GPX4, TXN, TXNRD1 and Nrf2 increased after the HSFA meal (p<0.05). In contrast, the expression of these genes remained unaltered in response to the other dietary interventions. Our results suggest that the increased expression of antioxidant genes in PBMC seems to be due to the response to the postprandial oxidative stress generated mainly in adipose tissue after the consumption of an HSFA diet.

Extravirgin Olive Oil Consumption Reduces Risk of Atrial Fibrillation

Background—

The PREDIMED (Prevención con Dieta Mediterránea) primary prevention trial showed that a Mediterranean diet enriched with either extravirgin olive oil or mixed nuts reduces the incidence of stroke, myocardial infarction, and cardiovascular mortality. We assessed the effect of these diets on the incidence of atrial fibrillation in the PREDIMED trial.

Methods and Results—

Participants were randomly assigned to 1 of 3 diets: Mediterranean diet supplemented with extravirgin olive oil, Mediterranean diet supplemented with mixed nuts, or advice to follow a low-fat diet (control group). Some departures from individual randomization occurred in a subset of the trial because members of the same household and small clinics in one of the 11 recruiting centers were allocated by clusters instead of individually. Incident atrial fibrillation was adjudicated during follow-up by an events committee blinded to dietary group allocation. Among 6705 participants without prevalent atrial fibrillation at randomization, we observed 72 new cases of atrial fibrillation in the Mediterranean diet with extravirgin olive oil group, 92 in the Mediterranean diet with mixed nuts group, and 89 in the control group after median follow-up of 4.7 years. The Mediterranean diet with extravirgin olive oil significantly reduced the risk of atrial fibrillation (hazard ratio, 0.62; 95% confidence interval, 0.45–0.86 compared with the control group) after adjusting for propensity scores and using robust variance estimators to account for the intra-cluster correlations. No effect was found for the Mediterranean diet with nuts (hazard ratio, 0.86; 95% confidence interval, 0.63–1.16). In secondary analyses done after excluding all participants randomized in clusters, the results did not materially change.

Conclusions—

In the absence of proven interventions for the primary prevention of atrial fibrillation, this post hoc analysis of the PREDIMED trial suggests that a lower incidence of atrial fibrillation was found after an intervention with extravirgin olive oil in the context of a Mediterranean dietary pattern.

Clinical Trial Registration—

URL: http://www.controlled-trials.com . Unique identifier: ISRCTN35739639.

Combination of grape seed proanthocyanidin extract and docosahexaenoic acid-rich oil increases the hepatic detoxification by GST mediated GSH conjugation in a lipidic postprandial state

The ingestion of dietary lipids leads to oxidative stress. This postprandial oxidative stress may potentiate the adverse effects of postprandial hyperlipidaemia. Proanthocyanidins have been shown to alleviate oxidative stress and hypertriglyceridaemia associated with the postprandial state. Additionally, omega-3 polyunsaturated fatty acids (PUFAs) also have beneficial effects on lipoprotein metabolism and oxidative stress. The present study was designed to investigate the possible additive effects in liver of an acute dose of grape seed proanthocyanidins extract (GSPE) and oil rich in docosahexaenoic acid (DHA-OR) on lipidic postprandial oxidative stress in Wistar rats. GSPE+DHA-OR modifies the hepatic antioxidant enzymatic activities (GST and GPx), clearly showing that this combination increases the detoxification of postprandial xenobiotics via the GST action mediated hepatic GSH conjugation. In conclusion, this study provides evidence that the combination of GSPE and DHA-OR ameliorate the transient imbalance between the lipid hydroperoxide level and antioxidant status related to a lipidic postprandial state.

Protective effect of Xin Mai Jia ultrafiltration extract on human umbilical vein endothelial cell injury induced by hydrogen peroxide and the effect on the NO-cGMP signaling pathway

The aim of the present study was to evaluate the protective effect of the ultrafiltration extract of Xin Mai Jia (XMJ) on a human umbilical vein endothelial cell (HUVEC) injury model induced by hydrogen peroxide (H₂O₂), by providing experimental data to investigate the mechanism and efficacy underlying the therapeutic effects on atherosclerosis. HUVECs were first injured by H₂O₂ and then varying final concentrations of the Chinese herb extract were added. Effects of the XMJ extract on morphology, activity, monolayer permeability, biochemical indicators, cytokines, endothelial nitric oxide synthase (eNOS) protein content and eNOS gene expression in the HUVECs were analyzed. H₂O₂ significantly promoted HUVEC injury. The XMJ ultrafiltration extract significantly improved the morphological changes in the injured HUVECs. In addition, XMJ treatment increased cell activity and decreased monolayer permeability. The expression levels of intracellular adhesion molecule-1, vascular adhesion molecule-1, interleukin-1 and -6 and nuclear factor-κB decreased, while the expression levels of matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-2 increased with XMJ administration. Increased levels of nitric oxide (NO), eNOS protein and eNOS gene expression were also observed. Therefore, the XMJ ultrafiltration extract exhibits marked anti-inflammatory effects and antioxidant abilities. These properties significantly inhibited the H₂O₂-induced injury of HUVECs, which may be associated with the NO-cyclic guanosine monophosphate signaling pathway.

Heated vegetable oils and cardiovascular disease risk factors

Cardiovascular disease (CVD) is one of the leading major causes of morbidity and mortality worldwide. It may result from the interactions between multiple genetic and environmental factors including sedentary lifestyle and dietary habits. The quality of dietary oils and fats has been widely recognised to be inextricably linked to the pathogenesis of CVD. Vegetable oil is one of the essential dietary components in daily food consumption. However, the benefits of vegetable oil can be deteriorated by repeated heating that leads to lipid oxidation. The practice of using repeatedly heated cooking oil is not uncommon as it will reduce the cost of food preparation. Thermal oxidation yields new functional groups which may be potentially hazardous to cardiovascular health. Prolonged consumption of the repeatedly heated oil has been shown to increase blood pressure and total cholesterol, cause vascular inflammation as well as vascular changes which predispose to atherosclerosis. The harmful effect of heated oils is attributed to products generated from lipid oxidation during heating process. In view of the potential hazard of oxidation products, therefore this review article will provide an insight and awareness to the general public on the consumption of repeatedly heated oils which is detrimental to health.