Flaxseed Oil Containing α -Linolenic Acid Ester of Plant Sterol Improved Atherosclerosis in ApoE Deficient Mice

Anti-atherosclerotic effects of natural compounds targeting lipid metabolism and inflammation: Focus on PPARs, LXRs, and PCSK9

A large body of evidence has shown that modulation of the nuclear receptors peroxisome proliferator-activated receptors (PPARs), the liver X receptors (LXRs), the proprotein convertase subtilisin/kexin type 9 (PCSK9) and inflammatory processes by natural compounds has hypolipidemic and anti-atherosclerotic effects. These beneficial outcomes are certainly related to the crucial function of these targets in maintaining cholesterol homeostasis and regulating systemic inflammation. Currently, the therapeutic scenario for cardiovascular diseases (CVD) offers a plethora of widely validated and functional pharmacological treatments to improve the health status of patients. However, patients are increasingly sceptical of pharmacological treatments which are often associated with moderate to severe side effects. The aim of our review is to provide a collection of the most recent scientific evidence on the most common phytochemicals, used for centuries in the Mediterranean diet and traditional chinese medicine that act on these key regulators of cholesterol homeostasis and systemic inflammation, which could constitute important tools for CVD management.

Different Sources of Omega-3 Fatty Acid Supplementation vs. Blood Lipid Profiles-A Study on a Rat Model

Dyslipidemia is a serious condition affecting an increasing number of people, and thus, preventive measures, including supplementation, are being developed. We aimed to compare the effect of linseed oil, its ethyl esters and fish oil supplementation on the serum lipid profiles of rats fed a high-fat diet. Wistar rats were divided into nine groups. Four of them were fed a high-fat diet for the whole experiment, four groups were fed a high-fat diet before the supplementation period and then the control one with supplements, and one was fed a control diet without supplements. The whole experiment lasted 12 weeks. A significant reduction in blood triglycerides, total cholesterol and the LDL fraction was noted in supplemented groups compared to the controls, especially in groups supplemented with ethyl esters of linseed oil and linseed oil compared to fish oil groups. The results were also more beneficial in groups where, in addition to supplementation, there was also a diet change from a high-fat diet to a control diet during the supplementation period. We may conclude that supplementation with omega-3 fatty acids, combined with a healthy diet, may be a good way of preventing or alleviating dyslipidemia.

Flaxseed oil fraction reverses cardiac remodeling at a molecular level: improves cardiac function, decreases apoptosis, and suppresses miRNA-29b and miRNA 1 gene expression

Flaxseed is an ancient commercial oil that historically has been used as a functional food to lower cholesterol levels. However, despite its longstanding treatment, there is currently a lack of scientific evidence to support its role in the management of cardiac remodeling. This study aimed to address this gap in knowledge by examining the molecular mechanism of standardized flaxseed oil in restoring cardiac remodeling in the heart toxicity vivo model. The oil fraction was purified, and the major components were standardized by qualitative and quantitative analysis. In vivo experimental design was conducted using isoproterenol ISO (85 mg/kg) twice subcutaneously within 24 h between each dose. The rats were treated with flaxseed oil fraction (100 mg/kg orally) and the same dose was used for omega 3 supplement as a positive control group. The GC-MS analysis revealed that α-linolenic acid (24.6%), oleic acid (10.5%), glycerol oleate (9.0%) and 2,3-dihydroxypropyl elaidate (7%) are the major components of oil fraction. Physicochemical analysis indicated that the acidity percentage, saponification, peroxide, and iodine values were 0.43, 188.57, 1.22, and 122.34 respectively. As compared with healthy control, ISO group-induced changes in functional cardiac parameters. After 28-day pretreatment with flaxseed oil, the results indicated an improvement in cardiac function, a decrease in apoptosis, and simultaneous prevention of myocardial fibrosis. The plasma levels of BNP, NT-pro-BNP, endothelin-1, Lp-PLA2, and MMP2, and cTnI and cTn were significantly diminished, while a higher plasma level of Topo 2B was observed. Additionally, miRNA - 1 and 29b were significantly downregulated. These findings provide novel insight into the mechanism of flaxseed oil in restoring cardiac remodeling and support its future application as a cardioprotective against heart diseases.

The Chemical Composition and Health-Promoting Benefits of Vegetable Oils-A Review

With population and economic development increasing worldwide, the public is increasingly concerned with the health benefits and nutritional properties of vegetable oils (VOs). In this review, the chemical composition and health-promoting benefits of 39 kinds of VOs were selected and summarized using Web of Science TM as the main bibliographic databases. The characteristic chemical compositions were analyzed from fatty acid composition, tocols, phytosterols, squalene, carotenoids, phenolics, and phospholipids. Health benefits including antioxidant activity, prevention of cardiovascular disease (CVD), anti-inflammatory, anti-obesity, anti-cancer, diabetes treatment, and kidney and liver protection were examined according to the key components in representative VOs. Every type of vegetable oil has shown its own unique chemical composition with significant variation in each key component and thereby illustrated their own specific advantages and health effects. Therefore, different types of VOs can be selected to meet individual needs accordingly. For example, to prevent CVD, more unsaturated fatty acids and phytosterols should be supplied by consuming pomegranate seed oil, flaxseed oil, or rice bran oil, while coconut oil or perilla seed oil have higher contents of total phenolics and might be better choices for diabetics. Several oils such as olive oil, corn oil, cress oil, and rice bran oil were recommended for their abundant nutritional ingredients, but the intake of only one type of vegetable oil might have drawbacks. This review increases the comprehensive understanding of the correlation between health effects and the characteristic composition of VOs, and provides future trends towards their utilization for the general public's nutrition, balanced diet, and as a reference for disease prevention. Nevertheless, some VOs are in the early stages of research and lack enough reliable data and long-term or large consumption information of the effect on the human body, therefore further investigations will be needed for their health benefits.

The cardioprotective effects of secoisolariciresinol diglucoside (flaxseed lignan) against cafeteria diet-induced cardiac fibrosis and vascular injury in rats: an insight into apelin/AMPK/FOXO3a signaling pathways

Introduction: Fast food is a major risk factor for atherosclerosis, a leading cause of morbidity and mortality in the Western world. Apelin, the endogenous adipokine, can protect against cardiovascular disease via activating its receptor, APJ. Concurrently, secoisolariciresinol diglucoside (SDG), a flaxseed lignan extract (FLE), showed a therapeutic impact on atherosclerosis. The current study aimed to examine the effect of SDG on cafeteria diet (CAFD)-induced vascular injury and cardiac fibrosis via tracking the involvement of the apelin/APJ pathway. Methods: Thirty male rats were allocated into control, FLE-, CAFD-, CAFD/FLE-, and CAFD/FLE/F13A-treated rats, where F13A is an APJ blocker. All treatments lasted for 12 weeks. Results and discussion: The CAFD-induced cardiovascular injury was evidenced by histological distortions, dyslipidemia, elevated atherogenic indices, cardiac troponin I, collagen percentage, glycogen content, and apoptotic markers. CAFD increased both the gene and protein expression levels of cardiac APJ, apelin, and FOXO3a, in addition to increasing endothelin-1, VCAM1, and plasminogen activator inhibitor-1 serum levels and upregulating cardiac MMP-9 gene expression. Moreover, CAFD reduced serum paraoxonase 1 and nitric oxide levels, cardiac AMPK, and nuclear Nrf2 expression. FLE attenuated CAFD-induced cardiovascular injury. Such effect was reduced in rats receiving the APJ blocker, implicating the involvement of apelin/APJ in FLE protective mechanisms. Conclusion: FLE supplementation abrogated CAFD-induced cardiac injury and endothelial dysfunction in an apelin/APJ-dependent manner.

Beneficial Effects of Polyphenol-Rich Food Oils in Cardiovascular Health and Disease

A variety of vegetable and fruit derived food oils are considered beneficial for human health due to their content of functional components including their positive effects in cardiovascular system. In addition to the favorable ratio of unsaturated versus saturated fatty acids, some of these oils include also other health beneficial compounds such as vitamins, minerals, pigments, enzymes and phenolic compounds. Particularly polyphenols have been documented to exert numerous positive effects in cardiovascular system including their anti-hypertensive, anti-atherogenic as well as cardio- and vasculo- protective effects in subjects suffering from various cardiovascular and cardiometabolic diseases, likely via their antioxidant, anti-inflammatory, anti-coagulant, anti-proliferative and anti-diabetic properties. However, it has not been proven so far whether the positive cardiovascular effects of polyphenol-rich food oils are, and to what measure, attributed to their phenolic content. Thus, the current review aims to summarize the main cardiovascular effects of major polyphenol-rich food oils including olive, flaxseed, soybean, sesame and coconut oils, and to uncover the role of their phenolic compounds in these effects.

Hematological parameters, antioxidant status, and gene expression of γ-INF and IL-1β in vaccinated lambs fed different type of lipids

This study was aimed to evaluate the effects of vegetable oils as calcium salt on immune responses and the expression of immune-related genes in vaccinated lambs. Twenty-four lambs (35 kg body weight, 6 months old) were assigned to four treatments with six replicates in a completely randomized design for 40 days. Four concentrates were formulated in which the calcium salts of palm oil, canola oil, corn oil, and flaxseed oil were used. On day 30 of the experiment, lambs were vaccinated by a dose of foot-and-mouth disease virus. The blood samples were collected from jugular vein 10 days after vaccination. The level of malondialdehyde and the activity of liver enzymes were the highest in lambs receiving corn oil and the lowest in lambs receiving flaxseed oil. The highest lymphocytes and the lowest neutrophil percentages were observed in lambs receiving flaxseed oil. There was a significant difference among treatments for the relative genes expression. Flaxseed oil significantly upregulated interferon-γ and corn oil upregulated interleukin-1β. The highest titer against foot-and-mouth disease virus was related to lambs receiving flaxseed oil, and the lowest titer was related to lambs that received corn oil. Flaxseed oil had more beneficial effects on immune response than other oils.

Effects of Omega-3-Rich Pork Lard on Serum Lipid Profile and Gut Microbiome in C57BL/6NJ Mice

Background and Aims. Hyperlipidemia is a risk factor for cardiovascular diseases. This study is aimed at investigating the effects of consuming omega-3-rich pork lard on the serum lipid profile and gut microbiome of the mice model. Methods and Results. We divided 23 C57BL/6NJ males (16-week-old) into 3 groups, and each group received either a control diet, a high-fat diet of coconut oil (coconut oil), or a high-fat diet of omega-3-rich pork lard (omega lard) for 28 days. Thereafter, fasting serum lipids and fecal microbiomes were analyzed. The serum cholesterol, triglyceride, and LDL levels of the omega lard-treated group were significantly reduced compared to the coconut oil-treated group ( $P<0.05$ ). However, the microbiome analysis revealed a significant increase in the abundance of Lachnospiraceae in the omega lard-treated group compared to the coconut oil-treated group ( $P<0.05$ ). Furthermore, Spearman’s correlation analysis revealed that the increased serum lipid content was positively correlated with the abundance of Bacteroidaceae ( $P<0.05$ ) and negatively correlated with the abundance of Lachnospiraceae ( $P<0.05$ ). Conclusions. These findings suggested that omega-3-rich pork lard altered the serum lipid profile and gut microbiome in the mice model. Practical Application. The excellent protection offered by omega-3-rich pork lard against hyperlipidemia indicated that pork lard could be used as alternative cooking oil for health-conscious individuals. It could also be introduced as a functional ingredient for patients with hyperlipidemia.

Effect of dietary incorporation of peanut and linseed meals with or without enzyme mixture on physiological performance of broilers

The present study aimed to evaluate the impact of feeding peanut meal and linseed meal (LSM) with or without enzyme mixture on growth, plasma metabolites, muscle amino acid (AA) profile, nutrient digestibility, and expression of nutrient absorption-related genes in broilers. A total of 560 one-day-old Cobb-500 male broiler chicks were distributed into eight experimental treatments (7 replications of 10 chicks each) as follows: This study was designed by using 560 one-day-old Cobb-500 male broiler chicks were distributed into eight experimental groups (7 replications of 10 chicks each) to evaluate the differences in body weight, body weight gain, feed intake, feed conversion rate, carcass parts, blood biochemical and mRNA expression genes. Group 1 (C) control fed the basal diet without supplements, Group 2 (C + E) is control group fed on 350 g/ton enzyme mixture, Group 3 (C + PNM100) is control group fed 100 kg/ton peanut meal, Group 4 (C + E + PNM100) is a control group fed on 350 g/ton enzyme mixture and 100 kg/ton peanut meal, Group 5 (C + LSM100) is a control group fed on 100 kg/ton linseed meal, Group 6 (C + E + LSM100) is a control group fed on 350 g/ton enzyme mixture and 100 kg/ton linseed meal, Group 7 (C + PNM50 + LSM50) is control group fed on 50 kg/ton peanut meal and 50 kg/ton linseed meal. Group 8 (C + E + PNM50 + LSM50) is the control group fed on 50 kg/ton peanut meal and 50 kg/ton linseed meal. Each gram of the enzyme mixture contains 11,000 U Xylanase, 6000 U Cellulase, 700 U β-Mannanase, 1500 U Phytase, 5 mg α-Amylase, and 2 mg Protease. No differences in Bodyweight, Bodyweight gain, Feed intake, and carcass parts were noticed among experimental groups, while abdominal fat (%) and FCR were reduced (P < 0.05) in PNM50 + LSM50 + E and LSM100 groups. Plasma metabolites were not altered except total cholesterol, triglyceride, and LDL, reduced (P < 0.01) in treated birds. Dietary inclusion of 100 kg PNM or LSM reduced (P < 0.05) methionine concentration in muscle, while all remaining AA and ammonia concentrations were unaffected. Hepatic MDA contents were reduced (P < 0.001) in treated groups. Nutrient digestibility was not altered among groups except for protein digestibility, which was elevated (P < 0.05) in PNM50 + LSM50 + E, E, and PNM100 + E groups. The highest mRNA expressions of PepT1, APN, SGLT1, HMGCR, GHr, and IGF-1 genes were noticed in PNM50 + LSM50 + E. Conclusively, PNM and LSM can efficiently substitute corn and soybean meal in broiler diets, particularly when fortified with exogenous enzymes, without negative impacts on broiler performance.

Dietary α-Linolenic Acid-Rich Flaxseed Oil Ameliorates High-Fat Diet-Induced Atherosclerosis via Gut Microbiota-Inflammation-Artery Axis in ApoE−/− Mice

Atherosclerosis (AS) is closely associated with abnormally chronic low-grade inflammation and gut dysbiosis. Flaxseed oil (FO) rich in omega-3 polyunsaturated fatty acids (PUFAs), which are mainly composed of alpha-linolenic acid (ALA, 18:3 omega-3), has been demonstrated to exhibit pleiotropic benefits in chronic metabolic diseases. However, the impact of dietary ALA-rich FO on AS and its associated underlying mechanisms remain poorly understood. Thus, the present study was designed as two phases to investigate the effects in atherosclerotic Apolipoprotein E (ApoE)^−/− mice. In the initial portion, the ApoE^−/− mice were randomly allocated to three groups: control group (CON), model group (MOD), and FO-fed model group (MOD/FO) and were treated for 12 weeks. The second phase used antibiotic (AB)-treated ApoE^−/− mice were divided into two groups: AB-treated model group (AB/MOD) and FO-fed AB-treated model group (AB/FO). In the results, the dietary ALA-rich FO administration ameliorated atherosclerotic lesion, as well as the parameters of AS (body weights (BWs) and the total bile acids (TBA). Chronic systemic/vascular inflammatory cytokines and in situ macrophages (Mψs) were reduced with FO intervention. In addition, the FO improved the gut integrity and permeability by decreasing the plasma lipopolysaccharide (LPS). Moreover, gut dysbiosis and metabolites [short-chain fatty acids (SCFAs) and bile acids (BAs)] in AS were modulated after FO treatment. Intriguingly, during an AB-treated condition, a significantly weakened amelioration of FO-treated on AS proposed that the intestinal microbiota contributed to the FO effects. A correlation analysis showed close relationships among gut bacteria, metabolites, and inflammation. Collectively, these results suggested that the dietary ALA-rich FO ameliorated the AS in ApoE^−/− mice via the gut microbiota-inflammation-artery axis.

The review of alpha-linolenic acid: Sources, metabolism, and pharmacology

α-linolenic acid (ALA, 18:3n-3) is a carboxylic acid composed of 18 carbon atoms and three cis double bonds, and is an essential fatty acid indispensable to the human body. This study aims to systematically review related studies on the dietary sources, metabolism, and pharmacological effects of ALA. Information on ALA was collected from the internet database PubMed, Elsevier, ResearchGate, Web of Science, Wiley Online Library, and Europe PMC using a combination of keywords including "pharmacology," "metabolism," "sources." The following findings are mainly contained. (a) ALA can only be ingested from food and then converted into eicosapentaenoic acid and docosahexaenoic acid in the body. (b) This conversion process is relatively limited and affected by many factors such as dose, gender, and disease. (c) Pharmacological research shows that ALA has the anti-metabolic syndrome, anticancer, antiinflammatory, anti-oxidant, anti-obesity, neuroprotection, and regulation of the intestinal flora properties. (d) There are the most studies that prove ALA has anti-metabolic syndrome effects, including experimental studies and clinical trials. (e) The therapeutic effect of ALA will be affected by the dosage. In short, ALA is expected to treat many diseases, but further high quality studies are needed to firmly establish the clinical efficacy of ALA.

Flaxseed Oil Supplementation Augments Antioxidant Capacity and Alleviates Oxidative Stress: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objective

Studies have reported controversial findings regarding the flaxseed oil effect on antioxidant status biomarkers. The present meta-analysis aimed to determine the impact of flaxseed oil on the serum level of biomarkers of oxidative stress.

Methods

A systematic search was conducted up to November 2020 on PubMed, Embase, Web of Science, Scopus, and Cochrane Central Library. Random-effects model was employed to perform meta-analysis. Subgroup analysis was carried out to determine the effect across different ranges of dosages and durations.

Results

Eight trials were included with a total sample size of 429 individuals with a mean age range of 25 to 70 years. The results indicated that flaxseed oil supplementation led to a significant decrease in malondialdehyde (MDA) levels (SMD: −0.52 μmol/L; 95% CI: −0.89, −0.15; P=0.006, I² = 71.3, P < 0.001) and increase in total antioxidant capacity (TAC) levels (WMD: 82.84 mmol/L; 95% CI: 19.80, 145.87; P=0.006, I² = 92.7, P < 0.001). No significant effect was observed on glutathione (GSH).

Conclusion

Our findings revealed that flaxseed oil supplementation might play a beneficial role in the reinforcement of the antioxidant defense system and amelioration of oxidative stress in adults.

Physical Stability, Oxidative Stability, and Bioactivity of Nanoemulsion Delivery Systems Incorporating Lipophilic Ingredients: Impact of Oil Saturation Degree

There is great interest in the application of a lipid-based delivery system (like nanoemulsion) to improve the bioavailability of lipophilic components. Although emulsion characteristics are believed to be influenced by oil types, there is still a lack of systematic research concentrating on the effect of oil saturation degree on the nanoemulsion quality, especially for evaluation of the bioactivity. Here, we aimed to test the effect of oil saturation degree on the physical stability, oxidative stability, and bioactivity of the designed nanoemulision system. Our findings suggest that the oxidative stability and bioactivity of a nanoemulsion incorporating tocopherol and sesamol highly depend on the oil saturation. A nanoemulsion with an oil with a high degree of unsaturation was more susceptible to oxidation, and addition of tocopherol and sesamol could retard the lipid oxidation. Sesamol exhibited better bioactivity during the experiment compared with tocopherol in the Caenorhabditis elegans (C. elegans) model. The lipid-lowering effect of tocopherol and sesamol increased with lower saturation oil groups. The antioxidant activity of tocopherol and sesamol was higher in the high saturation oil groups. Overall, the obtained data is meaningful for applications using the designed systems to deliver lipophilic ingredients.

A review of dietary phytochemicals and their relation to oxidative stress and human diseases

Phytochemicals refer to active substances in plant-based diets. Phytochemicals found in for example fruits, vegetables, grains and seed oils are considered relatively safe for consumption due to mammal-plant co-evolution and adaptation. A number of human diseases are related to oxidative stress caused by for example chemical environmental contaminants in air, water and food; while also lifestyle including smoking and lack of exercise and dietary preferences are important factors for disease development in humans. Here we explore the dietary sources of antioxidant phytochemicals that have beneficial effects on oxidative stress, cardiovascular and neurological diseases as well as cancer. Plant-based diets usually contain phenolic acids, flavonoids and carotenoids, which have strong antioxidant properties, and therefore remove the excess of active oxygen in the body, and protect cells from damage, reducing the risk of cardiovascular and Alzheimer's disease. In most cases, obesity is related to diet and inactivity and plant-based diets change lipid composition and metabolism, which reduce obesity related hazards. Cruciferous and Allium vegetables are rich in organic sulphides that can act on the metabolism of carcinogens and therefore used as anti-cancer and suppressing agents while dietary fibres and plant sterols may improve intestinal health and prevent intestinal diseases. Thus, we recommend a diet rich in fruits, vegetables, and grains as its content of phytochemicals may have the potential to prevent or improve a broad sweep of various diseases.

Combined Effects of Plant Sterols with Low Ratio of n-6/n-3 Polyunsaturated Fatty Acids against Atherosclerosis in ApoE-/- Mice

The effects of low ratio of n-6/n-3 polyunsaturated fatty acids (PUFA) have been clarified against atherosclerosis. Increasing evidence indicated that plant sterols (PS) have a significant cholesterol-lowering effect. This study explored the effects of PS combined with n-6/n-3 (2:1) PUFA on atherosclerosis and investigated the possible mechanism. In ApoE^-/- mice, the milk fat in high fat diets was replaced with n-6/n-3 (2:1) PUFA alone or supplemented with 6% PS for 16 weeks. Results demonstrated that PS combined with PUFA exerted commentary and synergistic effects on ameliorating atherosclerosis, improving lipid metabolism and lipid deposition in liver, and alleviating inflammatory response. These changes were accompanied with decreased serum TC, TG, LDL-C and increased fecal cholesterol efflux, as well as the lower inflammatory cytokine CRP, IL-6, TNF-α. It is suggested that the underlying mechanism of PS combined with n-6/n-3 (2:1) PUFA promoting the fecal cholesterol efflux may be mediated by liver X receptor α/ATP-binding cassette transporter A1 pathway.

Cheese fortification through the incorporation of UFA-rich sources: A review of recent (2010-2020) evidence

Cheese is a widely consumed dairy product with high saturated fatty acids (SFA) content, and with other high nutritional quality components. Due to the link of SFA and different diseases, many studies have replaced the cheese fat content with unsaturated fatty acids (UFA) rich sources to improve its nutritional quality. The fat replacement has physicochemical, textural, and sensory effects on dairy matrix. To the food science is mandatory to know which technological strategies of milk processing improve the quality of the end products. The most relevant results reveal that fish oil (FO) and flaxseed oil (FSO) have been the most researched UFA-rich sources, microencapsulation has been the most studied incorporation technology because it allows the oil entrapment with minimal effects on the cheese quality, and non-thermal technologies allow greater UFA fortification in cheese, improving its nutritional quality. Finally, the development of fortified cheeses with UFA-rich sources has been found as an innovative strategy to obtain high quality products with functional potential.

Intake and adequacy of the vegan diet. A systematic review of the evidence

BACKGROUND

Vegan diets, where animal- and all their by-products are excluded from the diet, have gained popularity, especially in the last decade. However, the evaluation of this type of diet has not been well addressed in the scientific literature. This study aimed to investigate the adequacy of vegan diets in European populations and of their macro- and micronutrient intakes compared to World Health Organization recommendations.

METHODS

A systematic search in PubMed, Web of Science, IBSS, Cochrane library and Google Scholar was conducted and 48 studies (12 cohorts and 36 cross-sectional) were included.

RESULTS

Regarding macronutrients, vegan diets are lower in protein intake compared with all other diet types. Veganism is also associated with low intake of vitamins B₂, Niacin (B₃), B₁₂, D, iodine, zinc, calcium, potassium, selenium. Vitamin B₁₂ intake among vegans is significantly lower (0.24-0.49 μg, recommendations are 2.4 μg) and calcium intake in the majority of vegans was below recommendations (750 mg/d). No significant differences in fat intake were observed. Vegan diets are not related to deficiencies in vitamins A, B₁, Β₆, C, E, iron, phosphorus, magnesium, copper and folate and have a low glycemic load.

CONCLUSIONS

Following a vegan diet may result in deficiencies in micronutrients (vitamin B₁₂, zinc, calcium and selenium) which should not be disregarded. However, low micro- and macronutrient intakes are not always associated with health impairments. Individuals who consume a vegan diet should be aware of the risk of potential dietary deficiencies.

Medicinal plants and bioactive natural compounds as inhibitors of HMG-CoA reductase: A literature review

Cardiovascular diseases (CVDs) are one of the most important causes for mortality worldwide. Elevated levels of total cholesterol, and particularly LDL-cholesterol (LDL-C) are the main risk factor for acute myocardial infarction (AMI) and ischemic heart disease. The risk of CVDs could be reduced by decreasing the elevated cholesterol levels. β-hydroxy β-methylglutaryl-CoA reductase (HMGCoAR) is the primary and rate-limiting enzyme in the cholesterol biosynthesis pathway. Recently, the crucial role of nutraceuticals in maintaining normal physiological function was established. Nutraceuticals play an important role in preventing several non-communicable diseases such as obesity, CVDs, cancer, diabetes, and reducing hyperlipidemia. Although the effect of nutraceuticals and herbal medicine on CVDs and dyslipidemia was previously investigated thoroughly, the effect of these natural products on HMGCoAR as one of the important enzymes involved in CVDs etiopathogenesis has not yet been investigated. Therefore, the major aim of this paper was to review the effects of nutraceuticals and medicinal plants on HMGCoAR. Results indicate that different types of natural foods, isolated nutrients, herbal products, and dietary supplements as nutraceuticals decrease the expression and activity of HMGCoAR. This review shows that medicinal plants and nutraceuticals could be used to decrease HMGCoAR activity as accessible and convenient and economical natural compounds to prevent dyslipidemia and CVDs.

Improvement in serum lipids and liver morphology after supplementation of the diet with fish oil is more evident under regular feeding conditions than under high-fat or mixed diets in rats

BACKGROUND

Dietary n- 3 polyunsaturated fatty acids (PUFAs) have a role in preventing cardiovascular and hepatic diseases. However, their effects might differ significantly depending on individual dietary patterns. The aim of the present study was to evaluate the effects of dietary supplementation with ω-3 fatty acids (FA), administered in different schedules, on hepatic and aortic histological structure, lipid profile, and body weight (BW) in male Wistar rats under standard (SD), high-fat diet (HFD) and mixed feeding conditions.

METHODS

PUFA treatment consisted of the administration of 50 mg/kg fish oil (FO) daily by oral gavage. HFD was obtained by adding a suspension of 4% cholesterol, thiouracil and cholic acid to the animals' drinking water. The rats were maintained on the diets for 6 weeks, and different schedules of PUFA administration were used. At 14, 28, and 42 days, the morphology of liver and aortic samples and the levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), and triglycerides (TG) were assessed.

RESULTS

The HFD groups exhibited significant hyperlipidemia and aortic inflammation, with progression to atherogenesis after 6 weeks. Administration of PUFAs slightly attenuated the aortic changes in these groups and reduced the liver's tendency to steatosis. FO-induced metabolic improvement was more evident in SD than in HFD rats. For instance, after the first 2 weeks, SD animals that received PUFAs had significantly increased HDL levels vs. controls (62.375 ± 4.10 vs. 52.625 ± 8.38 mg/dL, P < 0.05), but HFD rats did not, and decreased TG levels were observed exclusively in the SD rats (57.6 ± 4.09 vs. 66 ± 4.69 mg/dL, P < 0.05). After 6 weeks of n- 3 PUFA administration, LDL was significantly lower in the SD rats than in controls (13.67 ± 4.13 vs. 30.83 ± 2.86 mg/dL, P < 0.001), but the decrease in the HFD rats, although significant (49.17 ± 5.85 mg/dL vs. 57.17 ± 4.96 g/dL, P < 0.05), was not as marked. In the mixed-diet groups, administration of 50 mg/kg/day FO for 14 days under SD conditions following 4 weeks of HFD slightly decreased TG (86.625 ± 11.67 vs. 73 ± 4.52 mg/dL, P < 0.05) and increased HDL (45.875 ± 5.28 vs. 56 ± 3.16 mg/dL). However, in these animals, n-3 PUFA administration had no effect on LDL or TC. Administration of half of the above dose failed to improve any biochemical parameters. FO protected against excessive weight gain mainly under SD conditions.

CONCLUSIONS

The results show that FO confers more protection against cardiovascular risk factors (increased LDL and TG, decreased HDL) and liver lipid accumulation when given to rats consuming regular diets than when given to rats consuming a high-fat diet. This argues that priority should be given to consumption of a healthy diet rather than to the use of supplements. The effectiveness of n-3 PUFAs might be reduced in the case of hyperlipidic intake or after consumption of a high-fat diet.

The effects of n-3 fatty acids from flaxseed oil on genetic and metabolic profiles in patients with gestational diabetes mellitus: a randomised, double-blind, placebo-controlled trial

The present study was performed to evaluate the effects of n-3 fatty acids from flaxseed oil on genetic and metabolic profiles in patients with gestational diabetes mellitus (GDM). This randomised, double-blind, placebo-controlled clinical trial was performed in sixty women with GDM. Participants were randomly divided into two groups to intake either 2 × 1000 mg/d n-3 fatty acids from flaxseed oil containing 400 mg α-linolenic acid in each capsule (n 30) or placebo (n 30) for 6 weeks. n-3 Fatty acid intake up-regulated PPAR-γ (P < 0·001) and LDL receptor (P = 0·004) and down-regulated gene expression of IL-1 (P = 0·002) and TNF-α (P = 0·001) in peripheral blood mononuclear cells of subjects with GDM. In addition, n-3 fatty acid supplementation reduced fasting plasma glucose (P = 0·001), insulin levels (P = 0·001) and insulin resistance (P < 0·001) and increased insulin sensitivity (P = 0·005) when compared with the placebo. Additionally, n-3 fatty acid supplementation was associated with a decrease in TAG (P < 0·001), VLDL-cholesterol (P < 0·001), total cholesterol (P = 0·01) and total cholesterol:HDL-cholesterol ratio (P = 0·01) when compared with placebo. n-3 Fatty acid administration was also associated with a significant reduction in high-sensitivity C-reactive protein (P = 0·006) and malondialdehyde (P < 0·001), and an increase in total nitrite (P < 0·001) and total glutathione levels (P = 0·006) when compared with the placebo. n-3 Fatty acid supplementation for 6 weeks to women with GDM had beneficial effects on gene expression related to insulin, lipid and inflammation, glycaemic control, lipids, inflammatory markers and oxidative stress.

Polyunsaturated Fatty Acids and Their Potential Therapeutic Role in Cardiovascular System Disorders-A Review

Cardiovascular diseases are described as the leading cause of morbidity and mortality in modern societies. Therefore, the importance of cardiovascular diseases prevention is widely reflected in the increasing number of reports on the topic among the key scientific research efforts of the recent period. The importance of essential fatty acids (EFAs) has been recognized in the fields of cardiac science and cardiac medicine, with the significant effects of various fatty acids having been confirmed by experimental studies. Polyunsaturated fatty acids are considered to be important versatile mediators for improving and maintaining human health over the entire lifespan, however, only the cardiac effect has been extensively documented. Recently, it has been shown that omega-3 fatty acids may play a beneficial role in several human pathologies, such as obesity and diabetes mellitus type 2, and are also associated with a reduced incidence of stroke and atherosclerosis, and decreased incidence of cardiovascular diseases. A reasonable diet and wise supplementation of omega-3 EFAs are essential in the prevention and treatment of cardiovascular diseases prevention and treatment.

Dietary Flaxseed Oil Prevents Western-Type Diet-Induced Nonalcoholic Fatty Liver Disease in Apolipoprotein-E Knockout Mice

The prevalence of nonalcoholic fatty liver disease (NAFLD) has dramatically increased globally during recent decades. Intake of n-3 polyunsaturated fatty acids (PUFAs), mainly eicosapentaenoic acid (EPA, C20:5n-3) and docosahexaenoic acid (DHA, C22:6n-3), is believed to be beneficial to the development of NAFLD. However, little information is available with regard to the effect of flaxseed oil rich in α-linolenic acid (ALA, C18:3n-3), a plant-derived n-3 PUFA, in improving NAFLD. This study was to gain the effect of flaxseed oil on NAFLD and further investigate the underlying mechanisms. Apolipoprotein-E knockout (apoE-KO) mice were given a normal chow diet, a western-type high-fat and high-cholesterol diet (WTD), or a WTD diet containing 10% flaxseed oil (WTD + FO) for 12 weeks. Our data showed that consumption of flaxseed oil significantly improved WTD-induced NAFLD, as well as ameliorated impaired lipid homeostasis, attenuated oxidative stress, and inhibited inflammation. These data were associated with the modification effects on expression levels of genes involved in de novo fat synthesis (SREBP-1c, ACC), triacylglycerol catabolism (PPARα, CPT1A, and ACOX1), inflammation (NF-κB, IL-6, TNF-α, and MCP-1), and oxidative stress (ROS, MDA, GSH, and SOD).