Article

Fish oil and argan oil intak differently modulate insulin resistance and glucose intolerance in a rat model of dietary induced obesity

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  • Centre intégré de santé et de services sociaux de Chaudière-Appalaches
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Abstract

We investigated the potential metabolic benefits of fish oil (FO) or vegetable argan oil (AO) intake in a dietary model of obesity-linked insulin resistance. Rats were fed a standard chow diet (controls), a high-fat/high-sucrose (HFHS) diet, or an HFHS diet in which 6% of the fat was replaced by either FO or AO feeding, respectively. The HFHS diet increased adipose tissue weight and insulin resistance as revealed by increased fasting glucose and exaggerated glycemic and insulin responses to a glucose tolerance test (intraperitoneal glucose tolerance test). Fish oil feeding prevented fat accretion, reduced fasting glycemia, and normalized glycemic or insulin responses to intraperitoneal glucose tolerance test as compared with HFHS diet. Unlike FO consumption, AO intake failed to prevent obesity, yet restored fasting glycemia back to chow-fed control values. Insulin-induced phosphorylation of Akt and Erk in adipose tissues, skeletal muscles, and liver was greatly attenuated in HFHS rats as compared with chow-fed controls. High-fat/high-sucrose diet-induced insulin resistance was also confirmed in isolated hepatocytes. Fish oil intake prevented insulin resistance by improving or fully restoring insulin signaling responses in all tissues and isolated hepatocytes. Argan oil intake also improved insulin-dependent phosphorylations of Akt and Erk; and in adipose tissue, these responses were increased even beyond values observed in chow-fed controls. Taken together, these results strongly support the beneficial action of FO on diet-induced insulin resistance and glucose intolerance, an effect likely explained by the ability of FO to prevent HFHS-induced adiposity. Our data also show for the first time that AO can improve some of the metabolic and insulin signaling abnormalities associated with HFHS feeding.

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... Studies relating effects on body weight and energy intake with n-3 PUFA supplementation are inconsistent; while some show either decreased [37,38] or increased energy intake [39], most show unchanged energy intake with the addition of n-3 PUFA or with varying n-3 PUFA doses [40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57]. Only one study performed with female mice reported decreased energy intake with no significant effect on body weight [38]. ...
... Thus far, most rodent studies have shown an antiobesity effect of n-3 PUFA, while fewer studies have found no change in body weight [37,[39][40][41][44][45][46]49,[51][52][53][54][55][56][57]59,61,62]. These studies do suggest that n-3 PUFA plays a role in reducing adipose tissue mass [40], particularly in the epididymal [39,42,43,46,49,52,53,56,57,[61][62][63][64] and retroperitoneal locations [37,39,41,46,49,57]. ...
... Thus far, most rodent studies have shown an antiobesity effect of n-3 PUFA, while fewer studies have found no change in body weight [37,[39][40][41][44][45][46]49,[51][52][53][54][55][56][57]59,61,62]. These studies do suggest that n-3 PUFA plays a role in reducing adipose tissue mass [40], particularly in the epididymal [39,42,43,46,49,52,53,56,57,[61][62][63][64] and retroperitoneal locations [37,39,41,46,49,57]. Differences in the outcomes of studies on the effects of n-3 PUFA on body weight could be due to differing animal models of obesity (genetic vs. dietinduced obesity), the content of the diet (HF vs. high sucrose), the n-3 PUFA (EPA or DHA) formulation, the form of n-3 PUFA (TG form or as ethyl ester) provided or various combinations of these factors. ...
Article
Strategies to reduce obesity have become public health priorities as the prevalence of obesity has risen in the United States and around the world. While the anti-inflammatory and hypotriglyceridemic properties of long-chain omega-3 polyunsaturated fatty acids (n-3 PUFAs) are well known, their antiobesity effects and efficacy against metabolic syndrome, especially in humans, are still under debate. In animal models, evidence consistently suggests a role for n-3 PUFAs in reducing fat mass, particularly in the retroperitoneal and epididymal regions. In humans, however, published research suggests that though n-3 PUFAs may not aid weight loss, they may attenuate further weight gain and could be useful in the diet or as a supplement to help maintain weight loss. Proposed mechanisms by which n-3 PUFAs may work to improve body composition and counteract obesity-related metabolic changes include modulating lipid metabolism; regulating adipokines, such as adiponectin and leptin; alleviating adipose tissue inflammation; promoting adipogenesis and altering epigenetic mechanisms.
... Insulin resistance related glucose abnormality constitutes a risk factor for CVD. 36 Findings from epidemiological 37 and animal studies 38,39 have been consistent, indicating that n-3 PUFA has the capacity to negatively regulate fasting glucose. Improvements of insulin signaling pathway and glucose transporter type 4 (GLUT4) content in insulin targeted tissues such as muscle and adipose tissue are supposed to be the mechanisms that link n-3PUFA to glycaemic control. ...
... Improvements of insulin signaling pathway and glucose transporter type 4 (GLUT4) content in insulin targeted tissues such as muscle and adipose tissue are supposed to be the mechanisms that link n-3PUFA to glycaemic control. [38][39][40] However, results of the hypoglycemic function of fish oil in available RCTs remain conflicting. 41,42 In the present study, fasting glucose exhibited a dose-response decrease in fish oil groups and the most obvious change was observed in the FO3 group (1.24 g d −1 of EPA and DHA). ...
Article
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n-3PUFA consumption has been widely accepted as a nutritional strategy for the secondary prevention of cardiovascular events in patients at high risk of cardiovascular disease (CVD), but little is known about the dose–response relationship between dietary n-3PUFA and serum biomarkers associated with cardiovascular health in the general population. The present study involved a 12-week double-blind, randomized controlled trial to explore the effects of fish oil with different doses (0.31, 0.62 and 1.24 g d⁻¹ of EPA and DHA) on serum fatty acids and cardio-metabolic biomarkers including adiponectin, inflammatory markers, lipid profiles and fasting glucose in healthy middle-aged and elderly Chinese people. 240 volunteers met our inclusion criteria. A total of 39 subjects dropped out and 201 finally completed the intervention. No significant differences in baseline characteristics and daily intakes of dietary nutrients were detected among all groups. After a 12-week intervention, fish oil dose-dependently enhanced serum EPA, DHA, n-3PUFA and adiponectin (except for 0.31 g d⁻¹), but decreased serum n-6/n-3PUFA, TG and fasting glucose. Changes in the above indicators from the baseline to week 12 in fish oil groups significantly differed from those in the control. Meanwhile, all the doses of EPA and DHA led to decreases in serum CRP; only 1.24 g d⁻¹ led to an increase in HDL-C with a concurrent decrease in TC/HDL-C even though these changes were not significantly different among all groups. All the findings suggested that fish oil dose-dependently regulated serum PUFA and cardio-metabolic biomarkers including adiponectin, CRP, lipid profiles and fasting glucose in healthy middle-aged and elderly Chinese people who consumed insufficient dietary n-3PUFA, and the most desirable changes were observed for 1.24 g d⁻¹.
... 16 Saturated fatty acids have been known to increase HDL, LDL and total cholesterol. 17 The increase of HDL in VCO group is suggested due to the high content of saturated fatty acids such as myristic acid and lauric acid in VCO 24 which is related to the increase of LCAT (Lecithin: Cholesteryl Acyltransferase) activity and apo-A1. 3,4,17 LCAT has been known as regulator of HDL. 4 HDL confers as a protective factor against atherosclerosis which may indicate obviously that low HDL is a potent risk factor for CVD. ...
... According to previous research, this showed the effect of CLO on increasing insulin sensitivity. 24 The short-term duration of this study may contribute to the non-significant statistical effect. ...
Article
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Virgin coconut oil (VCO) and Cod Liver Oil (CLO) are predominated by different fatty acids; VCO is dominated by medium-chain saturated fatty acids (MC-SFA) mainly lauric acids whereas CLO contains a lot of long-chain polyunsaturated fatty acids (LC-PUFA) such as EPA and DHA. Numerous previous studies were conducted for long duration of VCO and CLO treatment in mice and human. The objective of this study was to investigate the short-term effects of VCO and CLO consumption on the blood metabolite profile in mice. Twenty-four male strain ddY mice were divided into 3 groups of VCO, CLO and aquades-group (control). Oils or aquades were fed to mice at 5 µL/gBW once a day for two weeks and the blood sample was taken to analyze triglycerides, cholesterol, glucose, HDL, LDL, AST and ALT levels. Mice body weights were determined showing significantly elevated (p<0.05) in both VCO and CLO group. Results of this study showed that VCO-fed mice significantly increase (p<0.05) HDL and LDL levels compared to CLO and control group. Other metabolite profiles include triglycerides, cholesterol, glucose, ALT and AST had no significant changes after giving VCO and CLO. Those nonsignificant results may be caused by a short duration of treatment.
... Additionally, argan oil was found to lower BP and to improve endothelial dysfunction in SHR [20]. Furthermore, investigators have reported that argan oil prevents defects in insulin signaling in both fat and liver of obese insulin-resistant rats [21]. ...
... This is in agreement with previous studies [22] that have shown that argan oil decreased hyperglycemia and hyperinsulinemia in obese insulin-resistant rats. Moreover, another study reported that argan oil prevented the development of hyperglycemia and improved insulin sensitivity in fat and liver tissues of obese insulin-resistant rats [21]. In the present study, corn oil was found to attenuate hyperinsulinemia and IR in chronically glucose-fed rats. ...
Article
Objective: The aim of the present study was to investigate whether a 5-wk treatment with argan oil, which is known for its antioxidant properties, can reduce arterial hypertension, hyperglycemia, insulin resistance, and enhanced basal superoxide anion production and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity in the aorta of glucose-fed rats. Methods: Sprague-Dawley rats had free access to a drinking solution containing 10% D-glucose or tap water (control) for 5 wk. The effect of argan oil in glucose-fed rats was compared with that of corn oil given daily by gavage (5 mL/kg) over a 5-wk period. Oxidative stress was evaluated by measuring the superoxide anion production and the NADPH oxidase activity using the lucigenin method. Results: The 5-wk treatment with glucose led to increases in systolic blood pressure, plasma glucose, and insulin levels as well as an increase in the insulin resistance index in association with a rise in superoxide anion production and NADPH oxidase activity (sensitive to diphenyleneiodonium) in the aorta. The simultaneous treatment with argan oil prevented or significantly reduced all of these effects, yet the same treatment with corn oil had a positive effect only on hyperinsulinemia and insulin resistance. Conclusions: The findings from the present study demonstrated that argan oil treatment reduced elevation of blood pressure, hyperglycemia, and insulin resistance through its antioxidative properties in glucose-fed rats. Hence, argan oil, which is now available in the market as a consumable food, may be of potential therapeutic value in the treatment of arterial hypertension and insulin resistance.
... Additionally, argan oil was found to lower BP and to improve endothelial dysfunction in SHR [20]. Furthermore, investigators have reported that argan oil prevents defects in insulin signaling in both fat and liver of obese insulin-resistant rats [21]. ...
... This is in agreement with previous studies [22] that have shown that argan oil decreased hyperglycemia and hyperinsulinemia in obese insulin-resistant rats. Moreover, another study reported that argan oil prevented the development of hyperglycemia and improved insulin sensitivity in fat and liver tissues of obese insulin-resistant rats [21]. In the present study, corn oil was found to attenuate hyperinsulinemia and IR in chronically glucose-fed rats. ...
... The HFFD-fed rat form an excellent model to study obesity and insulin resistance as the diet simulates ''Western type'' highcalorie diet 28 . Consumption of high fat with high quantities of fructose promotes weight gain, obesity, insulin resistance and subsequently T2D 29 . HFFD feeding impairs insulin signaling and glucose uptake and utilization with 15 days of feeding 7 . ...
Article
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Dipeptidyl peptidase-IV (DPP-IV) inhibitors are incretin enhancers used in the treatment of diabetes. Due to their undesirable side effects, development of new agents preferably from natural sources with less adverse effects is needed. Apigenin (API), a well known insulin-secretagogue and insulin-mimetic agent is abundantly present in fruits, nuts and plant derived beverages. The present study investigates the DPP-IV inhibitory potential and antidiabetic effects of API using various approaches. Through in silico study, we showed that API has binding efficacy at Glu206 in the active site of DPP-IV. Plasma glucose and insulin levels were decreased when API (1.5 mg/kg b.w. for every alternate for last 30 days) was administered to high fat, high fructose diet (HFFD) fed rats. Further, the activity of DPP-IV in plasma and hippocampal homogenate was inhibited more in the API-treated group than in the sitagliptin (STG)-treated group. API has a strong inhibitory effect towards DPP-IV enzyme in vivo and in silico and therefore can be a promising compound for type 2 diabetes (T2D) treatment.
... The relationship between platelet aggregation and inflammation has been previously discussed [3]. Several studies have shown that animals fed high-fat diets are more likely to develop dyslipidemia [4], insulin resistance [5], hepatic steatosis [6], platelet aggregation [7], inflammation [8] and oxidative stress [9]. ...
Article
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Introduction A high-fat diet is one of the main dietary factors promoting platelet aggregation. The present study was conducted to elucidate the involvement of boswellic acid (BA) on the platelet hyperaggregability in HFD-fed rats. As platelet hyperaggregability in HFD rats is closely linked to inflammation and enhanced free radical production, the present study was extended to evaluate the anti-inflammatory and anti-oxidative effect of BA on HFD-promoted platelet aggregation. Material and methods Rats were assigned to normal, HFD-fed, aspirin-treated (30 mg/kg), and BA-treated (250 and 500 mg/kg) groups. Results Boswellic acid administration in a high dose was effective in attenuating the severity of hyperlipidemia and platelet aggregation, indicated by lower collagen/epinephrine-induced platelet aggregation, as evidenced by the significant increase (p < 0.05) in the circulating platelet count and reduction in the number of thrombi in the lungs. Moreover, it attenuated the oxidative stress and the intensity of inflammatory mediators associated with platelet hyperaggregability, as evidenced by the inhibitory effects on interlukin-1β, COX-2 and tumor necrosis factor-α, indicating that the antiplatelet activity of BA is likely a consequence of controlling oxidative stress and inflammation. Conclusions The present data suggest that BA shows a promising anti-aggregatory effect by attenuating the enhanced hyperlipidemia, oxidative stress and inflammation associated with HFD.
... The decreasing n-3:n-6 PUFA ratio in modern diets contributes to the development of obesity, diabetes and other metabolic syndromes (25,26) . Conversely, increasing the consumption of n-3 PUFA can decrease adiposity, hypertriacylglycerolaemia and fatty liver disease, and improve insulin sensibility and glucose homoeostasis in rodents (27)(28)(29)(30)(31) and humans (32) . 11β-HSD1, PPARγ and CCAAT/enhancer-binding protein α (C/EBPα) are involved in adipogenesis and lipogenesis and seem to be the key targets of n-3 PUFA (33)(34)(35) . ...
Article
Early life is considered a critical period for determining long-term metabolic health. Postnatal over-nutrition may alter glucocorticoid (GC) metabolism and increase the risk of developing obesity and metabolic disorders in adulthood. Our aim was to assess the effects of the dose and timing of a fish oil diet on obesity and the expression of GC-activated enzyme 11 β -hydroxysteroid dehydrogenase type 1 (HSD1) in postnatal overfed rats. Litter sizes were adjusted to three (small litter (SL)) or ten (normal litter) rats on postnatal day 3 to induce overfeeding or normal feeding. The SL rats were divided into three groups after weaning: high-dose fish oil (HFO), low-dose fish oil (LFO) and standard-diet groups. After 10 weeks, the HFO diet reduced body weight gain (16 %, P <0·05), improved glucose intolerance and decreased hyperlipaemia levels ( P< 0·05) in SL rats, but the LFO diet did not have any effect on the same rats. Moreover, we chose postnatal week 3 (W3), 6 (W6) and 8 (W8) as the intervention time points at which to begin the 10-week HFO diet, and found that the HFO diet improved glucose utilisation and lipid metabolism at all time points. However, body weight of SL rats was reversed to normal levels by the post-weaning intervention (461 ( sem 9·1) v . 450 ( sem 2·0)). 11 β -HSD1 mRNA expression in the adipose tissue (49 ( sem 7·5) v . 161 ( sem 18·3), P< 0·05) and hepatic tissue (11 ( sem 0·9) v . 16 ( sem 1·5), P< 0·05) was decreased by the HFO diet at W3, but not at W6 or W8 ( P >0·05). In conclusion, the post-weaning HFO diet could reverse adverse outcomes and decrease tissue GC activity in postnatal overfed rats.
... Recent meta-analysis and systematic reviews of RCTs as well as large observational studies show that EPA + DHA, common in fish oil preparations, does not affect adiposity (276)(277)(278)(279)(280). RCTs with purified EPA and DHA (1-4 g d −1 for 6-12 weeks) failed to show any reduction in adiposity (281)(282)(283). Studies with EPA + DHA (fish oil) supplementation suggest that marine n-3 PUFA reduces weight gain and adiposity in various animal models such as JCR:LA-cp rats (284), high-fat-diet rodent models (34,(285)(286)(287)(288), Dahl salt-sensitive rats fed a high-sucrose diet (289), castrated rabbits (290), female KK mice (291) and Zucker fatty rats (292). Our recent study in the high-carbohydrate, high-fat diet-induced obese model showed that both purified EPA and DHA at 3% in the food reduced abdominal adiposity and therefore the total body fat with more pronounced effect in the low-fat, high-carbohydrate diet-fed rats (274). ...
Article
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Obesity as part of metabolic syndrome is a major lifestyle disorder throughout the world. Current drug treatments for obesity produce small and usually unsustainable decreases in body weight with the risk of major adverse effects. Surgery has been the only treatment producing successful long-term weight loss. As a different but complementary approach, lifestyle modification including the use of functional foods could produce a reliable decrease in obesity with decreased comorbidities. Functional foods may include fruits such as berries, vegetables, fibre-enriched grains and beverages such as tea and coffee. Although health improvements continue to be reported for these functional foods in rodent studies, further evidence showing the translation of these results into humans is required. Thus, the concept that these fruits and vegetables will act as functional foods in humans to reduce obesity and thereby improve health remains intuitive and possible rather than proven.
... Trials were performed on rats to explore the antidiabetic activity of argan oil, the rats which were fed 6% of argan oil as part of a high-fat/high-sucrose diet showed a restoration of insulin signaling in fat and liver cells yet did not prevent weight gain (13). This shows that argan oil can improve some of the metabolic and insulin signaling abnormalities associated with high-fat/high-sucrose feeding. ...
... Evidence exists for the beneficial effects of omega-3 PUFA supplementation on the prevention and management of insulin resistance and glucose intolerance in humans and rodents (Lombardo & Chicco, 2006;Samane et al., 2009;Storlien et al., 1987). To our knowledge, only one study has examined the effects of omega-3 PUFA, DHA and EPA, on insulin sensitivity and glucose tolerance in healthy non-obese dogs (Irvine et al., 2002). ...
Article
The objective of this study was to determine the effect of feeding a fish oil (FO)-containing diet on lipid and protein metabolism, postprandial glycaemia and body weight (BW) of mature, overweight dogs. Seven female dogs were randomly assigned to one of two isonitrogenous and isocaloric diets, control (CO) or FO (FO), in a crossover design. Experimental periods were 69 day, separated by a washout period of 30 day. At the beginning of the experiment, and at 30 and 60 day of feeding the experimental diets, the dogs were infused with D-glucose (2 g/kg BW) through an intravenous catheter. Blood samples were collected for 3 hr to perform a glucose tolerance test. Nitrogen balance measurements began at 06:30 on d 63 of each experimental period and ended at 06:30 on d 69. On d 66 of each period, a single dose (7.5 mg/kg) of (15) N-glycine was administered orally for determination of protein turnover. Incremental area under the curve and glucose concentration at peak did not differ between treatments or among sampling days within treatment. Glucose half-life tended to decrease (p < .10) in the FO treatment on day 30 when compared to baseline (day 0). β-hydroxybutyrate, non-esterified fatty acid (NEFA) and triglycerides did not differ within or between treatments. Cholesterol decreased (p < .05) on the FO treatment on day 30, 60 and 69 when compared to day 0. High-density lipoprotein (HDL) decreased (p < .05) in the FO treatment on day 69 when compared to day 0. Body weight, food intake, faecal excretion, DM and N digestibilities, N balance and protein turnover were not different between diets. Overall, FO-containing diet decreases cholesterol in mature overweight dogs; however, further research is warranted to verify the effects of FO on glucose metabolism.
... Among the good examples are: (i) the red pepper decreases appetite [105], reduces fat intake [106] and increases satiety [107], (ii) oligofructose reduces hunger [108], (iii) dietary fiber potentiates weight regulation [109] and (iv) fenugreek fiber reduces energy intake and increases satiety [110]. In addition, the increased insulin resistance following the ingestion of a protein source mirroring western diet (compared to provision of casein) [111], prevention of obesity-related glucose intolerance by the salmon peptide fraction [112], the benefits of fish oil on diet-induced insulin resistance [113], the fish oil diet induced both reduction in body weight gain in ob/ob mice [114] and improvement of glucose intolerance in HFD-fed mice [115], the role of n-3 polyunsaturated fatty acid in insulin resistance prevention [116] that involve controlling adipose tissue inflammation in its mechanism [117], HFD effects on gut hormones production [118], the HFD-induced reduction of the sensitivity to satiety signals [119], blood lipid profile and body fat distribution improvement with fish oil [120], and appetite control [121] and food intake modification [122] of coffee/caffeine are also important illustrative properties mediated by diet and represent an indirect energy balance management. All these paths represent illustrations of how selecting diet can impact the energy balance and the metabolism beyond the simple caloric intake related to the diet ( Figure 2). ...
Article
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Obesity is a health problem with increasing impacts on public health, economy and even social life. In order to reestablish the energy balance, obesity management focuses mainly on two pillars; exercise and diet. Beyond the contribution to the caloric intake, the diet nutrients and composition govern a variety of properties. This includes the energy balance-independent properties and the indirect metabolic effects. Whereas the energy balance-independent properties are close to “pharmacological” effects and include effects such as antioxidant and anti-inflammatory, the indirect metabolic effects represent the contribution a diet can have on energy metabolism beyond the caloric contribution itself, which include the food intake control and metabolic changes. As an illustration, we also described the metabolic implication and hypothetical pathways of the high-fat diet induced gene Trefoil Factor Family 2. The properties the diet has can have a variety of applications mainly in pharmacology and nutrition and further explore the “pharmacologically” active food towards potential therapeutic applications.
... Some other recent preclinical reports in rat models have shown that argan oil prevented the body mass loss, induced a significant reduction of blood glucose and a significant increase of hepatic glycogen level as well as modulate insulin-resistance [97,98]. Argan oil intake reduced blood pressure, hyperglycemia and insulin resistance through its antioxidant properties as reflected by the normalization of the superoxide anion production and the NADPH oxidase activity at the vascular level in one nutritional hypertensive insulin-resistant rat model [99]. ...
Article
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This review summarizes available data on argan fruit botany, geographical distribution, traditional uses, environmental interest, socioeconomic role, phytochemistry, as well as health beneficial effects and examination of future prospects. In particular, ethnomedical uses of argan fruits are carried out throughout Morocco where it has been used against various diseases. Different classes of bioactive compounds have been characterized including essential oils, fatty acids, triacylglycerols, flavonoids and their newly reported acylglycosyl derivatives, monophenols, phenolic acids, cinnamic acids, saponins, triterpenes, phytosterols, ubiquinone, melatonin, new aminophenols along with vitamin E among other secondary metabolites. The latter have already shown a wide spectrum of in vitro, and ex vivo biologicalactivities including antioxidant, anti-inflammatory, anti-diabetic, antihypertensive, anti-hypercholesterolemia, analgesic, antimicrobial, molluscicidal anti-nociceptive and anticancer potential. Argan flesh (pulp) contains a broad spectrum of polyphenolic compounds which may have utility for incorporation into nutraceuticals and cosmeceuticals relevant to the food, cosmetic and health industries. Further research is recommended, especially on the health beneficial effects of the aminophenols.
... This is in accordance with a previous study [34], which has reported that four weeks of treatment with argan oil blunted hyperglycemia and hyperinsulinemia in obese insulin-resistant rats. Argan oil normalized blood glucose levels and improved insulin sensitivity in fat and liver tissues of obese insulin-resistant rats [43]. α-tocopherol, among the main compounds found in argan oil, improved insulin action and reduced plasma lipid peroxidation in obese insulin-resistant Zucker rats [16]. ...
Article
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The present study aims at examining the effects of argan oil on the three main cardiovascular risk factors associated with metabolic syndrome (hypertension, insulin resistance and obesity) and on one of its main complications, neuropathic pain. Male Sprague-Dawley rats had free access to a drinking solution containing 10% d-glucose or tap water for 12 weeks. The effect of argan oil was compared to that of corn oil given daily by gavage during 12 weeks in glucose-fed rats. Glucose-fed rats showed increases in systolic blood pressure, epididymal fat, plasma levels of triglycerides, leptin, glucose and insulin, insulin resistance, tactile and cold allodynia in association with a rise in superoxide anion production and NADPH oxidase activity in the thoracic aorta, epididymal fat and gastrocnemius muscle. Glucose-fed rats also showed rises in B1 receptor protein expression in aorta and gastrocnemius muscle. Argan oil prevented or significantly reduced all those anomalies with an induction in plasma adiponectin levels. In contrast, the same treatment with corn oil had a positive impact only on triglycerides, leptin, adiponectin and insulin resistance. These data are the first to suggest that argan oil is an effective nutri-therapeutic agent to prevent the cardiovascular risk factors and complications associated with metabolic syndrome.
... It also contains carotenes, phenols and squalene [10]. The benefit of argan oil in cosmetics and physiological disorders treatments were extensively studied while little information about antibacterial activity of argan oil gathered [11]. The antibacterial activity of argan oil was firstly studied against two perilous bacteria, Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa isolated from wounds infection [12,13]. ...
Article
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Objective: Tuberculosis (TB) is the threatful infectious disease that dwell about one third of worlds. Among Middle East, Iraq occupy the fifth order country endemic with TB. Methodology: Six mixtures of Argan oil: 1.5% H2O2 were prepared at different ratio: 1=0.75:9.25, 2=1:9, 3=1.5:8.5, 4=2:8, 5=2.5:7.5, 6=3:7 and mixed with Lowenstein-Jensen (L-J) medium. Seventeen Mycobacterium tuberculosis isolates got from the consultants clinic of respiratory and thoracic diseases in Hilla city-Iraq. All isolates cultured on LJ medium containing the mixture of Argan oil: 1.5% H2O2 in different ratio and control tube (LJ without mixture) also used. The growth monitored per a day and recorded at different interval and the inhibition (no growth) were recorded. Results: The effect of Argan oil: 1.5% H2O2 mixture on the Mycobacterium tuberculosis were investigated over three incubation intervals (14th -20th, 21st -28th and after 29th day). The results revealed the high Argan concentration mixture 2.5:7.5 and 3:7 give excellent inhibitory effect on Mycobacterium tuberculosis during full periods of incubation with inhibition percentage (64.71%-82.35%). Conclusion: The current study aims to investigate the effects of argan oil on Mycobacterium tuberculosis and conclude the anti-mycobacterial activity of argan oil as a safe medication for prophylaxis and treatment of TB.
... Feeding mice an obesogenic diet leads to impaired insulin signaling in adipose tissue, with a reduction of AKT phosphorylation [27], as we saw in our HF-L group. On the contrary, fish oil appears to improve AKT phosphorylation, enhancing insulin signaling [28]. In this context, AMPK is one of the best predictors of insulin sensitivity, and once activated, it enhances glucose homeostasis [29].The activation of AMPK in the HF-FO group probably contributed to the improvements in glucose tolerance and insulin signaling. ...
... Cependant, quelques études chez l'animal montrent que cette huile pourrait avoir un effet antidiabétique. Ces effets observés sont attribués à son profil en acides gras et sa haute teneur en tocophérols et en acide férulique qui améliorent le statut antioxydant au niveau des tissus (Samane et al., 2009;Samane et al., 2006). Une étude récente de Bellahcen et al. indique que l'administration de l'huile d'argan vierge à des rats n'a aucun effet sur le niveau de la glycémie à jeun. ...
Article
The objective of this thesis work was to explore the molecular basis of Argan Oil (AO) effects on the mitochondrial and peroxisomal lipid metabolism and to elucidate its anti-inflammatory potential. We thus showed, initially, that the artisanal method preparation preserved the antioxidant properties of AO preventing the oxidation of the ferulic acid, by contrast to AO of commercial origin. Then, the treatment by the AO or lipopolysaccharides (LPS) of human fibroblasts, the cellular model of pseudo-neonatal adrenoleukodystrophy (P-NALD), revealed for the AO that peroxisomes proliferation is independent from the activation of the nuclear receptor PPARα and the co-activator PGC-1α. On the other side, the induction of the proliferation of peroxisomes by LPS is accompanied by an activation of both PPARα and PGC-1α. At the same time, mice treatments by AO or by the LPS showed, for the first time, the hepatic antioxidant activity of AO through the induction of the activity of the peroxisomal catalase. In addition, we showed a hypolipidemic activity of AO, by the stimulation of dehydrogenase activities (ACADs) of the mitochondrial fatty acid b-oxidation. Moreover, the AO induces the transcription of genes involved in gluconeogenesis pathway (i.e. PEPCK and G6PH). We also revealed, for the first time, the preventive effect of AO against LPS repressions of mitochondrial and peroxisomal fatty acid degradation as well as on the gluconeogenic pathway. Furthermore, the AO anti-inflammatory potential has been shown, in mice treated by LPS, through the repression of the pro-inflammatory cytokines IL-6 and TNFα and by the induction of the anti-inflammatory cytokines IL10 and IL-4. All together, our results may indicate that the Argan oil, because of its composition rich in mono and polyunsaturated fatty acids and in antioxidants as well, has a hypolipidemic and an anti-inflammatory effects, which are revealed by the regulation of the expressions of nuclear receptors and their target genes including several cytokines
... As could be expected from its interesting composition, AO has demonstrated its pharmacologic effects in several studies. AO intake has been shown to decrease several CVD risk factors, such as atherogenic lipids [13], BP [14], and IR [15] in human and animal models. Haimeur et al. [16] recently demonstrated the antiplatelet and antioxidant effects of AO in dyslipidemic patients. ...
Article
Objectives: The aim of this study was to investigate the effects of two different sources of polyunsaturated fatty acid-fish oil (FO) and argan oil (AO)-on some risk factors for cardiovascular disease, such as platelet aggregation, dyslipidemia, and oxidative stress. Methods: To explore this, four groups of six male rats were fed with different diets: The first group received a standard diet (control); the second group received a high-fat diet; the third was fed with a high-fat diet supplemented with 5% FO, and the last group received a high-fat diet supplemented with 5% AO. Results: After 8 wk of the diet, AO showed a decrease in plasma lipids similar to that of FO. However, unlike FO, AO had no significant effect on hepatic lipid levels. On the other hand, supplementation with AO and FO similarly reduced platelet hyperactivity induced by high-fat diet. Concerning the results of oxidative stress, AO showed an antioxidant effect in the tissues and platelets greater than that observed in the high-fat FO group. Conclusions: For rats, the consumption of FO prevented the development of adiposity, restored insulin sensitivity, decreased plasma and liver lipid levels, and also prevented the prothrombotic effect. Intake of AO as a food supplement did not affect adiposity or liver lipid levels but decreased plasma lipid levels and improved oxidative status and platelet activity. FO and, to a lesser degree, AO thus represent promising nutritional tools in the prevention of cardiovascular disease.
... In addition, studies have been shown that n-6 PUFAs contribute to preadipocytes differentiation and replication, through peroxisome proliferator-activated receptor gamma (PPARγ), increasing adipose tissue accumulation (Boon Yin, Najimudin, & Muhammad, 2008;Costa et al., 2011). On the other hand, fish oil, an important source of n-3 PUFAs, has been associated with beneficial effects against obesity (Mori, Kondo, Hase, Tokimitsu, & Murase, 2007), insulin resistance and type 2 diabetes (Kalupahana et al., 2010;Neschen et al., 2007;Samane et al., 2009). The main anti-obesogenic effect of fish oil seems occur through modulation of genes involved in lipid oxidation and adipogenesis (Buckley & Howe, 2010;Flachs et al., 2005). ...
Article
Some oils considered healthy are commonly used, even in critical periods of life. We studied the effects of maternal supplementation with soybean, olive, fish and coconut oils during lactation on the male rat offspring metabolism. Dams and pups were divided: Soybean oil (control); Olive Oil (OO); Fish Oil (FO) and Coconut Oil (CO). Dams received the oils through gavage (0.5 g/kg BW) during lactation, as a supplement. At weaning, OO pups showed obesity. Milk from CO dams presented higher triglycerides. Milk from OO and CO dams presented more cholesterol and calories. At weaning, FO and CO pups presented hypotriglyceridemia. At PN180, OO and CO offspring showed obesity and hyperleptinemia. OO offspring had higher lean mass. CO offspring presented hyperphagia. OO, FO and CO offspring had higher T3. Oils used as supplement during lactation alter milk composition and induces short and long-term endocrine-metabolic dysfunctions in the progeny.
... In another work, it has been shown that argan oil significantly increases the cellular reactivity to insulin by activation (phosphorylation) of the two major pathways of insulin signalization, called AKT and Erk [16]. ...
Article
Many studies have demonstrated evidence of the health benefits of natural products. Plant extracts have been tested on a variety of physiological disorders, including diabetes mellitus. Studies have tested aqueous extracts, plant fractions extracts, families of active of compounds, and specific active compounds. In this review, we describe the antidiabetic effects of vegetable oils. Information was collected from ScienceDirect and PubMed databases using the following key words: Diabetes mellitus, Oils, Vegetable oils, Type 1 diabetes, type 2 diabetes, antidiabetic effect, antihyperglycemic, antidiabetic oil. We have compiled approximately ten vegetable oils with including experimental studies that have demonstrated benefits on diabetes mellitus. There are soybean, argan, olive, palm, walnut, black cumin, safflower, Colocynth, Black seed, Rice bran, Cinnamom, and Rocket oils. For each vegetable oil, we investigated on the plant's traditional uses, their pharmacological activities and their antidiabetic effects. It seems that many vegetable oils are really interesting and can be used in the improvement of human health, particularly, to prevent or to treat diabetes mellitus complications.
... IR and IRS-1 tyrosine phosphorylation insulin-dependently occurred in rat fed with n-3 PUFA at difference with rat fed with n-6 PUFA in whom insulin pathway was not activated [30]. Also, AKT and PI3K activities were improved after fish oil administration to rats fed with high sucrose diet [31]. On the other hand, it has been reported that n-3 PUFA is involved in gene expression changes related with insulin signaling, Glut-4 mRNA is recovered after fish oil supplementation in insulin resistance rats, but only in adipose tissue [32]. ...
... Further, ω-3FA reported to lower plasma LDL level in healthy human subjects 10 . Preclinical experimental studies demonstrated that dietary supplementation of ω-3FA can reduce the serum concentrations of triglycerides, total cholesterol and improves hepatic as well as peripheral insulin sensitivity 7,[11][12][13] . On contrary to these beneficial effects, fish oil containing ω-3FA are reported to reverse dyslipidemia but not insulin resistance in highfructose diet induced dyslipidemia, hepatic and adipose tissue insulin resistance in humans 14 . ...
... Insulin signaling molecules, IRS-1, PI3K, and Akt, which are known as critical mediators in the insulin signaling pathway, are involved in inducing the translocation of glucose transporter 4 from the cytosol to the cell membrane, resulting in increased glucose uptake into cells (White and Kahn 1994). A previous study reported that addition of 6% fish oil to rats improved the decreased phosphorylation of Akt in the liver, muscle and WAT induced by a high-fat/high-sucrose diet, which prevention both insulin resistance and glucose intolerance (Samane et al. 2009). In addition, DHA treatment enhances glucose uptake through an improvement in the insulin signaling pathway in skeletal muscle and adipocytes (Oliver et al. 2012). ...
Article
Fish oil containing omega-3 polyunsaturated fatty acids (PUFA) attenuates chronic inflammation found in obesity, leading to a reduction in insulin resistance. The effect of fish oils containing omega-3 PUFA in the lipophagy pathway is unknown. In the present study, we examined whether omega-3 PUFA affects anti-inflammatory or lipophagy pathways in high fat diet-induced obesity. There was a significant increase in body weight gain in mice fed a high fat diet (HFD) or HFD with fish oil (HFD-FO), but not in mice fed a normal diet (ND). Although there was no significant difference between body weight gain and plasma insulin levels in the HFD and HFD-FO mice, the intake of HFD-FO prevented glucose intolerance and peripheral insulin resistance induced by HFD. In addition, macrophage infiltration and cytokine levels in white adipose tissue (WAT) in HFD-FO mice were decreased, compared with HFD mice. There were no significant differences between lipophagy related proteins and their mRNA levels in the HFD-FO and HFD groups. These results suggest that supplementation with fish oil might be beneficial in preventing insulin resistance caused by a high fat diet through an anti-inflammatory effect, but not lipophagy activation.
... improve glycolipid metabolic disorders in high-fat diet-fed rats. 10 Additionally, a randomized clinical trial showed that DHA exhibited anti-inflammatory effects. 11,12 Thus, in this study, we aimed to examine the geneenvironment interactions between PPARγ2 Pro12Ala variant and DHA in 3T3-L1 preadipocytes. ...
Article
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Background: Peroxisome proliferator-activated receptor γ2 (PPARγ2) plays a critical role in the regulation of adipocyte differentiation and adipocytokine production. The Pro12Ala variant is the most common mutation in the PPARγ2 gene. Its effect appears to be sensitive to dietary factors, such as docosahexaenoic acid (DHA) level. The purpose of this study was to investigate the interaction effect between PPARγ2 Pro12Ala variant and DHA on the phenotypes of adipocytes. Methods: We generated stable 3T3-L1 cell lines expressing wild-type PPARγ2 or PPARγ2 Pro12Ala variant. These two cell lines were cultured with different concentrations of DHA (0, 50, 200 umol/L). Then Oil red O staining was used to observe cell differentiation and the degree of lipid accumulation, TUNNEL assay was used to detect cell apoptosis, and ELISA assays were used to detect the changes of TNF-α, resistin and adiponectin levels in cell culture supernatant. Results: PPARγ2 Pro12Ala variant reduced lipid droplet accumulation in 3T3-L1 preadipocytes treated with or without 50 μmol/L DHA, but not with 200 μmol/L DHA, compared to that of wild-type PPARγ2. PPARγ2 reduced resistin production and increased adiponectin production in 3T3-L1 adipocytes, whereas PPARγ2 Pro12Ala variant diminished these effects. However, the absence of DHA blocked PPARγ2 Ala12 variant-induced effects on adiponectin production. There was no significant difference in TNF-α secretion between wild-type PPARγ2 and PPARγ2 Pro12Ala cells whether with or without DHA. Conclusion: These results indicated that the effects of PPARγ2 Pro12Ala variant were dependent on DHA concentration.
... Cherng et al. [44] also showed that Chlorella pyrenoidosa has the ability to prevent dyslipidemia in rat and hamster models fed a high-fat diet containing 20% hydrogenated coconut oil (rich in saturated fatty acids). Several studies showed that animals fed high-fat diets are more likely to develop dyslipidemia and hyperglycemia [45], insulin resistance [46], hepatic steatosis [47], platelet aggregation [48], and oxidative stress [49]. Thus, a proper diet rich in PUFAs may ameliorate risk factors for these diseases. ...
Article
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Citation:Świderska-Kołacz, G.; Jefimow, M.; Klusek, J.; Rączka, N.; Zmorzyński, S.; Wojciechowska, A.; Stanisławska, I.; Łyp, M.; Czerwik-Marcinkowska, J. Influence of Algae Supplementation on the Concentration of Glutathione and the Activity of Glutathione Enzymes in the Mice Liver and Kidney. Nutrients 2021, 13, 1996. https://doi. Abstract: Algae are potential and natural source of long-chain polyunsaturated fatty acids like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The diatom Pinnularia borealis accumulates high levels of EPA and may be considered as a source for commercial production of dietary supplements. In this study we asked the question whether diet supplementation with P. borealis may augment antioxidant defense and ameliorate risk factors for cardiovascular diseases. We fed mice (Mus musculus) with lyophilized diatom solutions of different concentrations (1%, 3%, and 5%) for 7 days. Then we measured glutathione content and the activity of glutathione redox system enzymes, total cholesterol and triacylglycerol concentrations, and malondialdehyde concentration in the liver and kidney. We found that cholesterol and triacylglycerol concentrations in the liver and kidneys were the lowest in mice who were fed with the highest concentration of Pinnularia borealis, suggesting protective properties of algae. Additionally, the lowest concentration of Pinnularia borealis was sufficient to improve antioxidant capacity. Our results suggest that P. borealis may be used as a source for dietary supplements rich in EPA, but the amount supplied to the organism should be limited.
... lack of effects) is difficult to explain or to compare with other studies because of methodological differences. Many published studies have added omega-3 PUFAs to the diet (reducing saturated fat or even replacing it completely) (Samane et al. 2009;Cintra et al. 2012;Viggiano et al. 2016), whereas in this study, fish oil was administered via gavage without altering the diet. The only study we found that evaluated food/energy intake by obese animals after the administration of fish oil via gavage was published by Yook et al. (2015), which also showed that fish oil did not affect energy consumption. ...
Article
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This study evaluated the effects of omega-3 polyunsaturated fatty acids (PUFAs) on oxidative stress and energy metabolism parameters in the visceral fat of a high-fat-diet induced obesity model. Energy intake, body mass, and visceral fat mass were also evaluated. Male Swiss mice received either a control diet (control group) or a high-fat diet (obese group) for 6 weeks. After this period, the groups were divided into control + saline, control + omega-3, obese + saline, and obese + omega-3, and to these groups 400 mg·(kg body mass)-1·day-1 of fish oil (or saline) was administered orally, for 4 weeks. Energy intake and body mass were monitored throughout the experiment. In the 10th week, the animals were euthanized and the visceral fat (mesenteric) was removed. Treatment with omega-3 PUFAs did not affect energy intake or body mass, but it did reduced visceral fat mass. In visceral fat, omega-3 PUFAs reduced oxidative damage and alleviated changes to the antioxidant defense system and the Krebs cycle. The mitochondrial respiratory chain was neither altered by obesity nor by omega-3 PUFAs. In conclusion, omega-3 PUFAs have beneficial effects on the visceral fat of obese mice because they mitigate changes caused by the consumption of a high-fat diet.
... Indeed, linoleic acid contained in sunflower oil leads to the synthesis of dihomo-gamma-linolenic acid (DGLA) and arachidonic acid and its metabolite prostacyclin which act as activating ligands of nuclear receptors belonging to the family of peroxisome proliferator-activated receptors (PPARs). PPARs stimulate adipocyte differentiation and contribute to obesity [38], which in turn enhances epididymal and renal adiposity. This model of visceral obesity contributes to increased free fatty acids (FFA) levels which stimulate their accumulation in other tissues like testis. ...
Article
The purpose of the current study is to explore the prominent role of the fixed oil of Citrullus colocynthis seeds as a natural remedy to obesity. Wistar rats were subjected to different diets; one being an 8 week high-fat diet that was established to induce obesity in rats. The results from our experiment show a significant correction in body weight, blood parameters, and in particular, the total cholesterol, triglycerides, HDL-C (high-density lipoprotein cholesterol), and glycemia. There was also an improvement of the redox status shown by the significant increase in antioxidant vitamins levels and decrease in malondialdehyde contents as well as an increase in the hepatic enzymes activities in Citrullus colocynthis seeds oil treated rats compared to obese rats and olive oil treated rats. The results of this study demonstrated that Citrullus colocynthis seeds oil prompted a corrective effect in the antioxidant defense systems, restored insulin sensitivity, and improved lipid profile. To conclude, our study suggests that Citrullus colocynthis seeds oil is a promising natural tool to combat obesity and its associated complications.
... 29 Blocked transduction of the PI3K/AKT pathway has been described in various obese and diabetic models. 30,31 The insulin signaling pathway is triggered by the binding of insulin to the transmembrane insulin receptors, mainly INSR and IGFR. IRS-1 belongs to the IRS family of adaptor molecules and is the primary substrate for the receptors. ...
Article
Sandalwood (santalum spicatum) seed oil (SSO) is rich in ximenynic acid. The aim of the present study was to investigate the effect of SSO on high-fat/high-sucrose diet (HFHSD) induced insulin resistance (IR) compared with fish oil (FO), sunflower oil (SO) and linseed oil (LO). Fifty male Sprague-Dawley rats were randomly divided into five dietary groups: standard chow diet (controls), HFHSD plus 7% SSO, HFHSD plus 7% FO, HFHSD plus 7% SO and HFHSD plus 7% LO. After 12 weeks feeding, the rats were sacrificed, and the serum parameters, hepatic lipids and underlying molecular mechanisms were studied. SSO, FO or LO significantly prevented glucose intolerance, hyperglycaemia, obesity, hepatic lipids accumulation, and decreased the homeostasis model assessment of IR (HOMA-IR) and serum levels of pro-inflammatory factors (IL-6, IL-1β and TNF-α) compared with SO. In addition, SSO activated PI3K/AKT insulin signaling pathway and down-regulated JNK/NF-κB inflammatory signaling pathway in liver. In summary, our results proved the ameliorative effect of SSO on IR by regulating the hepatic inflammation related blockage of insulin signaling pathway in the rats.
... In addition, fish oil, a beneficial component in seafood, was expected to have a role in improving glucose metabolism. Various studies have revealed that fish oil ameliorated glucose disposal by improving the transduction of the PI3K/AKT pathway [30] , increasing the storage of glycogen [31] , inhibiting gluconeogenesis [32] , and increasing the expression of GLUT2 to promote glucose uptake [33] in insulin sensitive tissues. In this study, although the OGTT and hepatic glycogen did not improve significantly after fish oil intervention, the trend for improvement had already emerged. ...
Article
Scope: The maternal nutritional status during pregnancy and lactation was closely related to the growth and development of the fetus and infants, which had a profound impact on the health of the offspring. N-3 polyunsaturated fatty acid (PUFA) had been proved to have beneficial effects on glucolipid metabolism. However, the effects of dietary different n-3 PUFA levels for mother during pregnancy and lactation on susceptibility to high-fat-diet-induced metabolic syndrome for offspring in adulthood are still unclear. Methods and results: The maternal mice were fed with control, n-3 PUFA-deficient or fish oil-contained n-3 PUFA-rich diets during pregnancy and lactation, and the weaned offspring were fed with high-fat or low-fat diet for 13 weeks, then were subjected to oral glucose tolerance tests. The results showed that dietary n-3 PUFA-deficiency in early life could aggravate the high-fat diet-induced glucolipid metabolism disorders, including glucose intolerance, insulin resistance, obesity and dyslipidemia, thus increased the susceptibility to metabolic syndrome of adult mice. Notably, nutritional supplementation with n-3 PUFA in early life could significantly alleviate the glucose metabolism disorders by increasing insulin sensitivity, inhibiting gluconeogenesis and promoting glycogenesis. In addition, administration with n-3 PUFA in early life remarkably reduced serum and hepatic lipid profiles by mediating the expression of genes related to lipogenesis and β-oxidation of fatty acids. Conclusions: Dietary n-3 PUFA-deficiency in early life increases the susceptibility to metabolic syndrome of adult offspring, and nutritional supplementation with n-3 PUFA enhances the tolerance to a high-fat diet of adult offspring.
... Omega-3 polyunsaturated fatty acids (n-3 PUFAs), which are a highly abundant fatty acid type in fish oil (FO), are one of the distinct classes of fatty acids known to reduce lipid abundance and to protect against fat-induced defects in glucose metabolism and insulin action 9 . The partial or complete substitution of saturated, monounsaturated and omega-6 polyunsaturated fatty acids (n-6 PUFAs) in high-fat diets (the most common fatty acid types in western diets) by n-3 PUFAs has been reported to decrease adiposity and improve insulin sensitivity and glucose homeostasis in rodents 6,7,[10][11][12][13][14][15][16][17] . This is paralleled by the almost universal observation of reduced hepatic steatosis 11,14,[16][17][18][19][20][21] and decreased triacylglycerol (TAG) accumulation in skeletal muscle 5,19,22 . ...
Article
Full-text available
Excess dietary lipid generally leads to fat deposition and impaired glucose homeostasis, but consumption of fish oil (FO) alleviates many of these detrimental effects. The beneficial effects of FO are thought to be mediated largely via activation of the nuclear receptor peroxisomal-proliferator-activated receptor α (PPARα) by omega-3 polyunsaturated fatty acids and the resulting upregulation of lipid catabolism. However, pharmacological and genetic PPARα manipulations have yielded variable results. We have compared the metabolic effects of FO supplementation and the synthetic PPARα agonist Wy-14,643 (WY) in mice fed a lard-based high-fat diet. In contrast to FO, WY treatment resulted in little protection against diet-induced obesity and glucose intolerance, despite upregulating many lipid metabolic pathways. These differences were likely due to differential effects on hepatic lipid synthesis, with FO decreasing and WY amplifying hepatic lipid accumulation. Our results highlight that the beneficial metabolic effects of FO are likely mediated through multiple independent pathways.
... Many studies on Argan oil confirmed its activity as anti-sebum (Dobrev, 2007), antiproliferative Aactivity (Trichopoulou et al., 2000;Owen et al., 2000;, antioxidant and hypocholesterolemic effect (Drissi et al., 2004) and antidiabetic activity (Samane et al., 2009). According to our Knowledge, the antibacterial (antipseudomonal) activity of Argan oil was not investigated until yet and therefore the current study was suggested and designed to determine the effect of Argan oil on the Multidrugs resistant P. aeruginosa. ...
Article
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The burn and wound infection is considered one of the major health problems in the world, and one of the most frequent and severe complications in patients who have sustained burn. P. aeruginosa is a common cause of wound infections, especially of thermal burns, this is because burns have large exposed areas of dead tissue free of any defenses and, therefore, are ideal sites for infection by bacteria from the environment or normal microbiota. To assess Antibacterial effect Different concentrations of both Argan Oil (which was fetched from Maraco Kingdom) and Hydrogen Peroxide (H2O2). Bacterial isolates obtained from the Central Laboratory in Hilla City, Iraq. was preliminary diagnosed in this Lab. as Pseudomonas aeruginosa, the causative agents of skin and burns infections and the more resistant bacteria to antibiotics. Those isolates were reidentified in our Lab. for confirmation. The test bacterial isolates were treated with; H2O2 (1.5%) alone, Argan oil alone and with physiological saline as a control (by using the wells in agar method). No effect on bacterial activities and vitality were observed in this experiment. Argan oil and H2O2(1.5%) were combined together to form compounds in a rate of 1:1, 2:1 and 1:2 respectively. The results of this experiment revealed considerable effects on test organisms since the diameter of inhibition zones recorded as high as 23.82mm., 24.57mm. and 23.05mm. These effective of Argan oil Mixing with 1.5% H2O2 on P. aeruginosa burn isolates show remarkable results when compared to highly active antibiotics like Amikacin, Tobramycin, Ceftazidime, Aztreonam, Norfloxacin and Gentamycin.
Article
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This study was made to investigate the components of a new resource food in China, peony seed oil (PSO) by GC-MS (Gas chromatography–mass spectrometry), the inhibitory effects of peony seed oil on carbohydrate hydrolyzing enzymes in vitro and the anti-diabetic effects of peony seed oil on mice induced by streptozotocin(STZ). Results showed that peony seed oil showed weak anti-α-amylase activity; however, strong anti-α-glucosidase activity was noted. The GC-MS analysis of the oil showed 9 constituents of which α-linolenic was found the major component (38.66%), followed by linoleic acid (26.34%) and oleic acid (23.65%). The anti-diabetic potential of peony seed oil was tested in STZ induced diabetic mice. Administration of peony seed oil and glibenclamide reduced the blood glucose level and the area under curve (AUC) in STZ induced diabetic mice. There were significant increase in body weight, liver glycogen content, serum insulin level, high-density lipoprotein cholesterol (HDL-C) and decrease in glycosylated hemoglobin (HbA1C), total serum cholesterol (TC), and triglyceride (TG) in test groups as compared to untreated diabetic groups. In vivo antioxidant studies on STZ induced diabetic mice revealed the reduction of malondialdehyde (MDA) and increase of glutathione peroxides (GSH-px), superoxide dismutase (SOD), glutathione (GSH). The results provided a sound rationale for future clinical trials of oral administration of peony seed oil to alleviate postprandial hyperglycemia in streptozotocin-induced diabetic mice. Key words: peony seed oil; α-linolenic; antidiabetic; α-glucosidase; α-amylase
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Aceite de argán: usos tradicionales, aspectos fitoquímicos, nutricionales y farmacológicos Resumen Argania spinosa (L.) Skeels es un árbol originario del suroeste de Ma-rruecos de cuyo fruto se obtiene el aceite de argán, el cual ha sido uti-lizado tradicionalmente como alimento y como ingrediente cosmético. Los estudios referidos a los usos tradicionales muestran que este acei-te es conocido fundamentalmente por sus propiedades nutricionales y por los efectos beneficiosos en la hidratación de la piel, retrasando el envejecimiento y la aparición de arrugas y otros trastornos dermato-lógicos. Los estudios fitoquímicos y farmacológicos revelan que tiene actividades beneficiosas dentro del ámbito de la dermatología, diabetes , enfermedades cardiovasculares y trastornos hormonales, vali-dando de esta manera sus usos tradicionales y demostrando el gran potencial que tiene este aceite en salud humana. La presente revisión muestra investigaciones realizadas sobre el aceite de argán durante los últimos 15 años y que han sido recopiladas a través de las bases de datos Pubmed y Web of Science. Palabras clave Aceite de argán, Argania spinosa, dermatología, enfermedad cardio-vascular, antioxidante, cosmética.
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Trimethylamine N-oxide (TMAO), a component commonly present in seafood, has been found to have a harmful impact on glucose tolerance in high-fat diet (HFD)-fed mice. However, seafood also contains fish oil (FO), which has been shown to have beneficial effects on metabolism. Here, we investigated the effect of FO on TMAO-induced impaired glucose tolerance in HFD-fed mice. Male C57BL/6 mice were randomly assigned to the high fat (HF), TMAO, and fish oil groups. The HF group was fed a diet containing 25% fat, the TMAO group was fed the HFD plus 0.2% TMAO, and the FO group was fed the HFD plus 0.2% TMAO and 2% fish oil for 12 weeks. After 10 weeks of feeding, oral glucose tolerance tests were performed. Dietary FO improved the fasting glucose level, the fasting insulin level, HOMA-IR value, QUICKI score and ameliorated TMAO-induced exacerbated impaired glucose tolerance in HFD-fed mice. These effects were associated with the expression of genes related to the insulin signalling pathway, glycogen synthesis, gluconeogenesis, and glucose transport in peripheral tissues. Dietary fish oil also decreased TMAO-aggravated adipose tissue inflammation. Our results suggested that dietary FO ameliorated TMAO-induced impaired glucose tolerance, insulin signal transduction in peripheral tissue, and adipose tissue inflammation in HFD-fed mice.
Article
This study investigated the effect of yeast with bacteriocin (YB) on the homeostasis of lipid and glucose in diet-induced obese (DIO) mice. Seven-week-old C57BL/6 male mice were fed with a Western diet for 24 weeks to induce obesity. These DIO mice were randomly assigned to 2 groups: obese control (WS) and WYB [0.125 μg YB per g body weight (BW)]. YB was administered daily to the WYB mice in the last 4 weeks, while an equal volume of normal saline was administered to the WS mice. YB caused a significant reduction in BW, and in plasma levels of total cholesterol and glucose. Less hepatic lipid accumulation and smaller adipocytes were observed in WYB mice. WYB mice had higher lipid catabolism in liver and adipose tissue. Compared with WS mice, WYB mice had higher glycolysis in the liver and muscles. YB suppressed hepatic GLUT5 expression, altered the composition of cecal microbiota, and also caused more efficient carbohydrate utilization for energy expenditure. YB resulted in body weight loss, promoted lipid catabolism and carbohydrate utilization; it also modulated cecal microbiota, and therefore partially improved the health of obese mice.
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Obesity is a multi-factorial disorder which is of worldwide concern. In addition to calorie control, some specific dietary components might help resolving some of the complication of obesity, by providing antioxidant and anti-inflammatory activities. We investigated the effect of argan oil supplementation on plasma lipid profile and oxidant-antioxidant status of rats with high-fat diet (HFD)-induced obesity compared with rats fed a normal diet (ND). We used an animal model of high fat diet-induced obesity to study the metabolic effects of argan oil and we measured several markers lipid and redox statuses. Consumption of a high-fat diet led to an increase in serum total cholesterol (TC), LDL-cholesterol (LDL-C), and triacylglycerols (TAG) concentrations; however, argan oil blunted the increases of TC, LDL-C and TG, glucose, and insulin. Plasma total antioxidant capacity, erythrocyte catalase and superoxide dismutase activities were lower, whereas plasma hydroperoxide, thiobarbituric acid-reacting substances, and susceptibility of LDL to copper-induced oxidation were higher in obese rats compared with normal rats. Administration of argan oil ameliorated all these indices of redox status. Proper diet and lifestyle should be foremost implemented to reduce the lipoprotein metabolism and oxidant/antioxidant status alterations brought about by obesity. In addition, argan oil reduces the metabolic effects of obesity and its use might be promoted within the context of a balanced diet. Copyright © 2015 Elsevier B.V. All rights reserved.
Chapter
The therapeutic profits of argan oil have been increasingly sought after these days for its characteristic lipophilic antioxidant composition, majorly monounsaturated (up to 80%) and saturated (up to 20%) fatty acids, tocopherols, sterols, and polyphenols. These unique blend of lipophilic compounds, part from being safe, have been reported to be largely responsible especially for the prevention of noncommunicable diseases such as cardiovascular disease, hypercholesterolemia and obesity; and treatment for many dermatological disorders. Increasing interest in the nutricosmetics and cosmeceutical application of argan oil has led to more studies on the pharmacological benefits of the oil. So far, determination of active compounds in argan oil is abundant and extensive, which allows for the derivatization of several accurate analytical methods in the detection of adulteration and fraudulent in argan oil. However, clinical trials in substantiating various health-promoting bioactivities of the oil are relatively lacking. This chapter aims to present a review of proven biological properties specifically pharmaceutical, cosmeceutical, and nutraceutical of argan oil proven from the most recent clinical and preclinical (in vivo) data published. Although clinical data are increasingly available, this review shows that a lack of clinical pharmacokinetic and pharmacodynamic data as well as limited sample size constitutes a serious weakness in our knowledge about argan oil, therefore it is still in its infant stage to substantiate reported pharmacological activities to any potential clinical relevance.
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The impact of dietary soybean oil, lard and fish oil on physiological responses in middle age is little studied. In this study, we investigated the changes of oxidative stress, inflammatory cytokines, telomere length, and age-related gene expression in the liver of middle-aged rats in response to the above three fat diets. Male Sprague Dawley rats (12 months old) were fed AIN-93M diets for 3 months, in which soybean oil was equivalently replaced by lard or fish oil. As compared to the lard diet, intake of fish oil diet significantly decreased body weight gain, white blood cell count, and levels of hepatic triacylglycerol, total cholesterol, fat accumulation, low-density lipoprotein, oxidative stress and inflammatory cytokines (P < 0.05), but increased telomere length (P < 0.05). On the other hand, lard diet and soybean oil diet showed great similarity in the above variables. PCR array analysis further indicated that fish oil diet significantly down-regulated gene expression related to inflammatory response, apoptosis, DNA binding, proteostasis and telomere attrition. Differentially expressed genes were enriched in the complement and coagulation cascades pathways. Such physiological and molecular responses could be due to different fatty acid composition in fish oil, lard and soybean oil.
Article
The fruit of Argania spinosa (L.) Skeels, a tree native to southern Morocco, is used to obtain argan oil, which has been traditionally used as food as well as a cosmetic ingredient. Studies on its traditional uses show that this oil is mainly known by its nutritional properties and beneficial effects in skin hydration delaying ageing, the appearance of skin wrinkles and other skin disorders. Phytochemical and pharmacological reports have revealed that argan oil exerts interesting properties in the fields of dermatology, diabetes, metabolic, cardiovascular, and hormonal disorders, which support its traditional uses to a certain extent and demonstrate the potential of the oil in human health. This paper reviews the research of last 15 years on argan oil reported in the literature indexed in PubMed and Web of Science. © 2014, CITA Publicaciones y Documentacion. All rights reserved.
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The beneficial effects of fish oil consumption on glucose metabolism have been generally reported. However, the mechanism underlying the fish oil-induced protective effects against insulin resistance remains unclear. Endoplasmic reticulum (ER) stress is recognized as an important contributor to insulin resistance. The aim of this study is to evaluate whether fish oil supplementation reduces ER stress and ameliorates insulin resistance in diet-induced obese mice, and to investigate the molecular mechanism of fish oil-induced benefits on ER stress. C57BL/6J mice were fed one of the following diets for 12 weeks: the low-fat diet (LFD), the high-fat diet (HFD) or the fish oil-supplemented high-fat diet (FOD). Fish oil supplementation led to lower blood glucose, better glucose tolerance and improved insulin sensitivity in high-fat diet-induced obese mice. Importantly, fish oil administration inhibited high-fat feeding-induced ER stress and reduced adipose tissue dysfunction. The fish oil-induced improvements were accompanied by the elevation of phosphorylated AMP-activated protein kinase (AMPK) expression in white adipose tissue. Correspondingly, the results of in vitro experiments showed that docosahexaenoic acid (DHA), the main n-3 polyunsaturated fatty acid (PUFA) in the fish oil used in the study, led to a dose-dependent increase in AMPK phosphorylation and suppressed palmitic acid (PA)-triggered ER stress in differentiated 3T3-L1 adipocytes. Furthermore, AMPK inhibitor (compound C) treatment largely blocked the effects of DHA to inhibit PA-induced ER stress. Our data indicate that n-3 PUFAs suppress ER stress in adipocytes through AMPK activation, and may thereby exert protective effects against high-fat feeding-induced adipose tissue dysfunction and insulin resistance.
Thesis
L’objectif des travaux de cette thèse concerne la caractérisation du germoplasme marocain du cactus Opuntia. Les études réalisées pour atteindre cet objectif ont portées sur le comportement phénologique, les caractéristiques génétiques et la composition physicochimique du cactus, ainsi que sur les molécules à fort potentiel thérapeutique, susceptibles d’avoir des effets bénéfiques pour les cellules du système nerveux central, dans les extraits de cactus (fruit, fleur, graine, huile, raquette et épine) et ceci en comparaison avec l’huile d’Argan. Les travaux ont été réalisés dans quatre laboratoires partenaires partageant des compétences dans les domaines d’analyses agronomique, biochimique et moléculaire. Les résultats de nos travaux sont présentés dans trois volets : (i) la caractérisation agronomique du cactus, (ii) la purification et la caractérisation des extraits et des molécules naturelles et (iii) l’évaluation des effets biologiques de ces molécules sur un modèle cellulaire. L’étude phénologique sur des écotypes âgées de 4 ans, issus du site expérimental de l’INRA d’Ain Nezagh, nous a permis de les classer selon le taux de fructification ou la production de biomasse de manière à mieux orienter leur utilisation en fonction de l’origine géographique et de l’espèce. L’étude de la diversité génétique, basée sur les traits morphologiques et les marqueurs moléculaires, a permis d’identifier sur le site d’Ain Nezagh sept espèces de cactus dont deux n’avait jamais été décrites au Maroc, O. leucotricha et O. inermis. Les analyses morpho-anatomique et physico-chimique de la fleur, du jus, du fruit et de la raquette d’écotypes âgées de 10 ans provenant du site de l’INRA de Jemâat Riah ont démontré la présence de deux espèces différentes de cactus du genre Opuntia, comportant quatre variétés non identifiées auparavant sur ce site. Nos travaux montrent donc l’existence d’une grande diversité génétique intra-espèces (variétés) et inter-espèces chez le cactus au Maroc. Paralèllement à ces études, les compositions chimiques des huiles essentielles de raquette et de graine de cactus ainsi que celle d’huile d’argan ont été déterminées. A partir de ces analyses, nous avons choisi d’étudier les effets de deux stérols, le spinastérol et le schotténol, ainsi que d’extraits de stérols sur l’activation du récepteur nucléaire LXR (Liver X receptor, impliqué dans la régulation du métabolisme du cholestérol) dans les cellules cérébrales de la microglie (lignée murine BV-2). Nos résultats montrent que le spinastérol et le schotténol, sans être cytotoxiques, peuvent moduler les expressions des deux isoformes de LXR, LXR-α et LXR-β, ainsi que de leurs gènes cibles ABCA1 et ABCG1. De plus, le schotténol provoque une activation spécifique de LXR-β. Ces résultats suggèrent que ces deux phytostérols pourraient avoir un rôle protecteur dans la modulation du métabolisme du cholestérol dans la microglie.
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Gynostrmma pentaphyllum seed oil (GPSO), extracted from G. pentaphyllum seeds, is rich in conjugated linolenic acid, which is a special fatty acid consisting of cis-9, trans-11, trans-13 isomers. Type 2 diabetes mellitus (T2DM) is characterized by hyperglycemia resulting from insulin resistance, and is usually accompanied by hypertension, hyperlipidemia, atherosclerosis (i.e., the metabolic syndrome, or syndrome X), and polycystic ovarian disease. This study aimed to investigate the effect of GPSO on T2DM hepatic lipid metabolism and the underlying mechanism involving level of protein expression. In the experiment, the model of T2DM was established. Kunming male mice were fed with a high-fat diet and injected with streptozocin, in which the exploration of detailed mechanism in the therapy of T2DM was targeted. The results showed that the ability of oral glucose tolerance was improved in the GPSO group. Biochemical indices also revealed that GPSO had a positive effect on hypoglycemic activity, suggesting that GPSO could promote the expression of glucose transporter 4 in liver and skeletal muscle.
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The current paradigms of prevention and treatment are unable to curb obesity rates, which indicates the need to explore alternative therapeutic approaches. Obesity leads to several damages to the body and is an important risk factor for a number of other chronic diseases. Furthermore, despite the first alterations in obesity being observed and reported in peripheral tissues, studies indicate that obesity can also cause brain damage. Obesity leads to a chronic low-grade inflammatory state, and the therapeutic manipulation of inflammation can be explored. In this context, the use of n -3 PUFA (especially in the form of fish oil, rich in EPA and DHA) may be an interesting strategy, as this substance is known by its anti-inflammatory effect and numerous benefits to the body, such as reduction of TAG, cardiac arrhythmias, blood pressure and platelet aggregation, and has shown potential to help treat obesity. Thereby, the aim of this narrative review was to summarise the literature related to n -3 PUFA use in obesity treatment. First, the review provides a brief description of the obesity pathophysiology, including alterations that occur in peripheral tissues and at the central nervous system. In the sequence, we describe what are n -3 PUFA, their sources and their general effects. Finally, we explore the main topic linking obesity and n -3 PUFA. Animal and human studies were included and alterations on the whole organism were described (peripheral tissues and brain).
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We provide an overview of studies on seafood intake in relation to obesity, insulin resistance and type 2 diabetes. Overweight and obesity development is for most individuals the result of years of positive energy balance. Evidence from intervention trials and animal studies suggests that frequent intake of lean seafood, as compared with intake of terrestrial meats, reduces energy intake by 4–9 %, sufficient to prevent a positive energy balance and obesity. At equal energy intake, lean seafood reduces fasting and postprandial risk markers of insulin resistance, and improves insulin sensitivity in insulin-resistant adults. Energy restriction combined with intake of lean and fatty seafood seems to increase weight loss. Marine n -3 PUFA are probably of importance through n -3 PUFA-derived lipid mediators such as endocannabinoids and oxylipins, but other constituents of seafood such as the fish protein per se , trace elements or vitamins also seem to play a largely neglected role. A high intake of fatty seafood increases circulating levels of the insulin-sensitising hormone adiponectin. As compared with a high meat intake, high intake of seafood has been reported to reduce plasma levels of the hepatic acute-phase protein C-reactive protein level in some, but not all studies. More studies are needed to confirm the dietary effects on energy intake, obesity and insulin resistance. Future studies should be designed to elucidate the potential contribution of trace elements, vitamins and undesirables present in seafood, and we argue that stratification into responders and non-responders in randomised controlled trials may improve the understanding of health effects from intake of seafood.
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Nephron loss by uninephrectomy (UNX) as in renal donors is followed by structural and functional changes in the remaining kidney, and systemic metabolic changes. SIRT1, a NAD-dependent deacetylase, deficiency is implicated in renal fibrosis and dysfunction. We investigated the effects of resveratrol, a plant-derived poly-phenol antioxidant and SIRT1 inducer on renal SIRT1 expression and metabolic consequences post-ne-phrectomy. Adult male UNX rats were administered resveratrol 20 mg/kg/day starting 1-week post-ne-phrectomy till termination 3, 5 or 7 months later. UNX triggered renal hypertrophy and progressive glomerular fibrosis, with increased serum urea, creatinine and Na + , and proteinuria. The glucose tolerance and lipid profile deteriorated. Resveratrol upregulated renal SIRT1 expression, limited the renal hypertrophy and fibrotic changes, and markedly attenuated renal function and lipid peroxidation. With prolonged resveratrol administration , glucose tolerance and lipid profile were restored to control values. In conclusion, resveratrol may be potentially beneficial as adjuvant therapy in human kidney donors.
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L'épidémie d'obésité qui sévit à travers le monde, est liée à une augmentation de la prévalence des maladies métaboliques, telles que le diabète de type 2, les maladies cardiovasculaires ou encore la stéatose hépatique non alcoolique. Au cours des dernières décennies, la recherche s’est tournée vers l’analyse du microbiote intestinal et de nombreuses publications ont démontré un rôle important de la dysbiose microbienne dans le développement des maladies métaboliques. En effet, le tractus gastro-intestinal et le microbiote intestinal représentent une interface importante entre l'alimentation et l'organisme hôte. Dans ce contexte, l'utilisation de traitements d’origine alimentaire afin d’améliorer la santé gastro-intestinale pourrait prévenir le développement des désordres métaboliques liés à l'obésité.Dans une première étude, nous avons tenté de comprendre le rôle du microbiote intestinal dans les effets bénéfiques des acides gras oméga-3 sur la santé métabolique de l'hôte. Pour cela, nous avons réalisé un protocole animal afin de comparer les mécanismes d’action liés à la supplémentation orale d’huile de poisson riche en oméga-3, en contact direct avec le tractus-gastro-intestinal, avec les mécanismes qui ont été induits dans un modèle transgénique de souris capables de convertir les oméga-6 en oméga-3 de manière endogène. Nos résultats démontrent que les souris gavées avec l’huile de poisson, étaient totalement protégées contre le développement de la stéatose hépatique induite par la diète riche en gras. Au contraire, la résistance à l’insuline et l’intolérance au glucose ont été fortement diminuées chez les animaux transgéniques fat-1. Malgré des effets métaboliques différents, les deux modèles ont significativement réduit le taux de cholestérol circulant, ce qui pourrait être associé à l’augmentation importante du genre Allobaculum dans les fèces. Cependant, l’étude plus poussée du microbiote intestinal, ainsi que l’analyse prédictive de ses fonctions, démontrent des modulations bénéfiques plus importantes chez les souris gavées aux oméga-3. Cela suggère un rôle de l’axe-intestin foie dans les effets des oméga-3 contre le développement de la stéatose hépatique, qui pourraient notamment s’expliquer par l’augmentation de la production de propionate au niveau intestinal, pouvant être ensuite transporté jusqu’au foie par la veine porte.La seconde étude présentée en fait partie d’un vaste projet dont le but final est de sélectionner une nouvelle souche bactérienne présentant des propriétés anti-obésité, afin de l’incorporer dans des fromages et des yaourts, qui seront ensuite commercialisés. Les différents résultats obtenus démontrent que les souches Lb102, Bf141 et P35 ont significativement prévenu le gain de poids corporel induit par la diète riche en gras et en sucre, sans altérer la quantité de calories ingérées. Ces traitements ont également engendré une diminution de l’inflammation du tissu adipeux viscéral, de la résistance à l’insuline et/ou une augmentation de la tolérance au glucose. Malgré des effets métaboliques similaires et importants, l’analyse du microbiote intestinal et de l’expression des gènes du colon suggèrent des mécanismes d’action souche-dépendants. Il faut également noter que ces trois souches présentant un fort potentiel probiotique ont induit des effets métaboliques importants en affectant très peu la composition du microbiote intestinal. L’analyse du colon et du statut inflammatoire intestinal suggèrent des modulations de la fonction du microbiote, en particulier pour la souche P35, connue pour ses propriétés anti-inflammatoires, qui a démontré le plus d’améliorations au niveau intestinal.
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At the time of this writing, the COVID-19 pandemic will have infected more than 12 million people and taken the lives of nearly 600,000 individuals world-wide [1]. While containment and treatment strategies have focused primarily on social distancing, therapeutics, and vaccines, the pandemic has also revealed serious underlying vulnerabilities in individuals infected by the coronavirus, SARS-CoV-2. The vulnerable aspects include advanced age, obesity [and its comorbidities, diabetes and chronic heart diseases], systemic coagulopathy or thrombosis [2], acute respiratory failure (e.g., hypoxia), inflammation, immunodeficiency, and neuropathologies [3,4]. The evidence for vulnerable people is supported by early reports on the COVID-19 pandemic in the United States that revealed ethnic, racial, and socio-economic disparities that resulted in some sectors of the population being disproportionally affected by COVID-19. Some of the sectors showing disproportionate rates of infection and death included men, American Indians, Alaska Natives, Blacks, Latinos, older adults, recent immigrants, and individuals with low income [5,6]. What is largely missed by the public, researchers, and healthcare providers is how nutrition and food intersect with this multiplicity of COVID-19 symptoms and disparities, in different ways and to different degrees.
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Inflammation is a physiological response to injury, stimulating tissue repair and regeneration. However, the presence of peculiar individual conditions can negatively perturb the resolution phase eventually leading to a state of low-grade systemic chronic inflammation, characterized by tissue and organ damages and increased susceptibility to non-communicable disease. Marine n-3 polyunsaturated fatty acids (n-3 PUFAs), mainly eicosapentaenoic (EPA) and docosahexaenoic acid (DHA), are able to influence many aspects of this process. Experiments performed in various animal models of obesity, Alzheimer's disease and multiple sclerosis have demonstrated that n-3 PUFAs can modulate the basic mechanisms as well as the disease progression. This review describes the available data from experimental studies to the clinical trials.
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Fish oil (FO) contains omega-3 that inhibits inflammation and blood lipid metabolism, giving it a protective cardiovascular effect. Due to dietary habits, a majority of large-scale clinical trials examining FO and cardiovascular health have been conducted in the Caucasian populations. However, the effects of FO on cardiovascular inflammation indicators and blood lipid metabolism in the Chinese population remain unclear. This study aimed to perform a meta-analysis to elucidate the impact of FO on cardiovascular health in the Chinese population. Web searches were utilized to locate records of clinical trials related to cardiovascular health and consumption of FO capsules or fish containing omega-3 in several databases, including PubMed, Medline, Embase, Cochrane Library, CNKI, and ClinicalTrial.gov, etc. We obtained lipid metabolism and related proinflammatory markers as the study outcome. We used Review Manager 5.4 and Stata 16 for the statistical analysis. If the I2 ≥ 30%, a random effects model was used, and if the I2 < 30%, a fixed effects model was used. Twenty eligible trials were shortlisted from >1000 records. The meta-analysis revealed that supplementation with eicosapentaenoic acid and docosahexaenoic acid reduced systolic blood pressure by 1.88 mmHg (95% CI: −4.97 to −1.20, P = 0.23), diastolic blood pressure by 0.86 mmHg (95% CI: −1.79 to 0.06, P = 0.07), fasting blood glucose by 0.05 mmol/L (95% CI: −0.16 to 0.06, P = 0.40), and low-density lipoprotein-cholesterol by 0.12 mmol/L (95% CI: −0.23 to −0.01, P = 0.04), when compared to placebo. However, these supplements increased high-density lipoprotein-cholesterol by 0.03 mmol/L (95% CI: 0.01 to 0.05, P < 0.001), when compared to placebo. Dose subgroup analyses examining total cholesterol found that the low-dose group (mean difference = −0.44, 95% CI: −0.55 to −0.34, P < 0.001) demonstrated the best results. Further, results from dose subgroup analyses showed that the all-dose group demonstrated a decrease in tumor necrosis factor (TNF-α) levels among the study subjects, when compared to other groups. Consumption of FO containing omega-3 fatty acids in the Chinese population can improve lipid metabolism and reduce levels of proinflammatory markers. Therefore, it is necessary to vigorously promote the benefits of consuming FO to prevent cardiovascular diseases throughout China.
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Objective: To determine the prevalence of metabolic syndrome among Canadian amateur football players. Methods: University football players from Saskatchewan were invited to participate in this study. Each subject underwent screening for blood pressure using a BpTRU monitor, and serum cholesterol and fasting blood glucose using a Cholestech LDX analyzer. Waist circumference was recorded and body composition was measured by dual-energy x-ray absorptiometry. RESULTS were compared between linemen and non-linemen using independent sample t-tests for continuous data and chi-square for dichotomous variables. Results: Out of 39 players who consented to participate, 14% of linemen (3/21) and no non-linemen satisfied metabolic syndrome criteria. Compared to non-linemen, linemen had a higher waist circumference (108.0 vs. 82.9 cm; p<0.001), higher total body fat composition (26.4% vs. 11.2%; p<0.001), lower mean high-density lipoprotein cholesterol (0.93, vs. 1.12 mmol/L; p=0.021) and higher fasting blood glucose (5.22 vs. 4.77 mmol/L; p<0.001). Conclusion: Despite their young age and participation in an elite-level athletic program, many collegiate-level football linemen had features of metabolic syndrome. Although our study focused on a single team, we suspect these trends may be consistent across the country.
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Traditionally hand-pressed argan oil, obtained from Argania spinosa seeds, is eaten raw in south-west Morocco; its rich composition of tocopherols, MUFA and PUFA make a study of its actions on risk factors for CVD, such as hypertension, interesting. The effects of 7 weeks of treatment with argan oil (10ml/kg) on the blood pressure and endothelial function of spontaneously hypertensive rats (SHR) and normotensive Wistar–Kyoto rats were investigated. Systolic blood pressure and heart rate were measured every week by the tail-cuff method and endothelial function was assessed by carbachol (10−8 to 10−4m)-induced relaxations of aortic rings and small mesenteric arteries pre-contracted with phenylephrine. Argan-oil administration reduced the mean blood pressure of SHR after the fifth week of treatment (P<0·05) and increased (P<0·01) the endothelial responses of arteries from SHR. The NO synthase inhibitor, l-N-ω-nitroarginine (3×10−5m) revealed a greater participation of NO in the relaxant effect after the treatment. When cyclooxygenase (COX) was blocked with indomethacin (10−5m), an involvement of COX products in the endothelium-dependent response was characterized. Enzyme immunoassay of thromboxane B2 showed a significant decrease (P<0·05) in the release of thromboxane A2 in both aorta and small mesenteric artery after argan-oil treatment of SHR. Experiments in the presence of the thromboxane A2–prostaglandin H2 receptor antagonist ICI 192, 605 (10−5m) confirmed this result. Results after incubation with the antioxidants superoxide dismutase and catalase suggested that a decreased oxidative stress might contribute to explain the beneficial effects of argan-oil treatment.
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Alpha-linolenic acid (ALA) reduces cardiovascular disease (CVD) risk, possibly by favorably changing vascular inflammation and endothelial dysfunction. Inflammatory markers and lipids and lipoproteins were assessed in hypercholesterolemic subjects (n = 23) fed 2 diets low in saturated fat and cholesterol, and high in PUFA varying in ALA (ALA Diet) and linoleic acid (LA Diet) compared with an average American diet (AAD). The ALA Diet provided 17% energy from PUFA (10.5% LA; 6.5% ALA); the LA Diet provided 16.4% energy from PUFA (12.6% LA; 3.6% ALA); and the AAD provided 8.7% energy from PUFA (7.7% LA; 0.8% ALA). The ALA Diet decreased C-reactive protein (CRP, P < 0.01), whereas the LA Diet tended to decrease CRP (P = 0.08). Although the 2 high-PUFA diets similarly decreased intercellular cell adhesion molecule-1 vs. AAD (-19.1% by the ALA Diet, P < 0.01; -11.0% by the LA Diet, P < 0.01), the ALA Diet decreased vascular cell adhesion molecule-1 (VCAM-1, -15.6% vs. -3.1%, P < 0.01) and E-selectin (-14.6% vs. -8.1%, P < 0.01) more than the LA Diet. Changes in CRP and VCAM-1 were inversely associated with changes in serum eicosapentaenoic acid (EPA) (r = -0.496, P = 0.016; r = -0.418, P = 0.047), or EPA plus docosapentaenoic acid (r = -0.409, P = 0.053; r = -0.357, P = 0.091) after subjects consumed the ALA Diet. The 2 high-PUFA diets decreased serum total cholesterol, LDL cholesterol and triglycerides similarly (P < 0.05); the ALA Diet decreased HDL cholesterol and apolipoprotein AI compared with the AAD (P < 0.05). ALA appears to decrease CVD risk by inhibiting vascular inflammation and endothelial activation beyond its lipid-lowering effects.
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Dietary n-3 polyunsaturated fatty acids (n-3 PUFAs) limit abdominal fat depot hypertrophy. This could be due to regulation of the expression of proteins involved in adipose tissue metabolism. We investigated in vivo whether fatty acid synthase (FAS), hormone-sensitive lipase (HSL), lipoprotein lipase (LPL), phosphoenolpyruvate carboxykinase (PEPCK), CCAAT/enhancer binding protein alpha (C/EBP alpha), and leptin mRNA levels are affected in retroperitoneal (RP) and subcutaneous adipose tissues (SC) of rats fed n-3 PUFAs. For 4 weeks rats were fed high fat diets (20% fat) containing n-3 PUFAs given as eicosapentaenoic acid (EPA group), docosahexaenoic acid (DHA group), a mixture of these two fatty acids (MIX group), or native fish oil (FO group). A control group was fed with lard plus olive oil (LOO group). Final mean fat cell weight in RP ranged according to: LOO > or = EPA > or = DHA = FO = MIX. There was no difference in fat cell size of SC when comparing the LOO and MIX groups. The fatty acid compositions of RP and SC were similar and resemble that of dietary fat within each experimental group. In RP and compared to the LOO group, FAS, HSL, PEPCK, LPL, C/EBP alpha, and leptin mRNA levels decreased although not significantly in the EPA group, and were 40-75% lower in the DHA and MIX groups. mRNA levels were positively correlated to fat cell size in RP. In contrast, n-3 PUFAs had no effect on gene expression in SC. We conclude that n-3 PUFAs and mainly 22:6n-3 affect gene expression in a site-dependent manner in white adipose tissues via possible antiadipogenic effects.
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The mechanisms underlying the development of hypertension in obesity are not yet fully understood. We recently reported the development of hypertension in a rat model of diet-induced obesity. When Sprague-Dawley rats (n=60) are fed a moderately high fat diet (32 kcal% fat) for 10 to 16 weeks, approximately half of them develop obesity (obesity-prone [OP] group) and mild hypertension (158+/-3.4 mm Hg systolic pressure), whereas the other half (obesity-resistant [OR] group) maintains a body weight equivalent to that of a low fat control group and is normotensive (135.8+/-3.8 mm Hg). We examined the potential role of oxidative stress in the development of hypertension in this model. Lipid peroxides measured as thiobarbituric acid-reactive substances showed a significant increase in the LDL fraction of OP rats (2.8+/-0.32 nmol malondialdehyde/mg protein) compared with OR and control rats (0.9+/-0.3 nmol malondialdehyde/mg protein). Also, aortic and kidney thiobarbituric acid-reactive substances showed a significant (3- and 5- fold) increase in OP rats after 16 weeks of diet. In addition, superoxide generation by aortic rings, measured by lucigenin luminescence, showed a 2-fold increase in the OP group compared with both the OR and control groups. In addition, free isoprostane excretion and nitrotyrosine in the kidney showed an increase in OP rats only. The urine and plasma nitrate/nitrite measured by the LDH method showed a 1.8-fold decrease in OP rats compared with OR rats. However, endothelial NO synthase expression in the kidney cortex and medulla assessed by reverse transcriptase-polymerase chain reaction showed a strong increase in the OP rats versus OR and control rats (endothelial NO synthase/beta-actin ratio 1.3+/-0.04 in OP rats versus 0.44+/-0.02 in OR rats), suggesting a possible shift toward superoxide production by the enzyme. Collectively, the data show a decreased NO bioavailability in OP animals that is due in part to the increased oxidative stress.
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The effects of two monounsaturated fatty acid (MUFA)-rich diets, containing virgin olive oil (OO) and high-oleic-acid sunflower oil (HOSO), on development of vascular response from isolated thoracic rat aorta and lipid composition and fatty acid composition were studied and compared with samples from rats fed on a control diet. Dietary MUFA oils were fed for 6 weeks to spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats from 4 weeks of age. The maximum contraction of aortic ring preparations in response to phenylephrine (10(-6) m) was significantly decreased in SHR rats fed with OO (0.81 (sem 0.05) v. 1.18 (sem 0.09) g, and treatment with HOSO did not alter the phenylephrine-induced contractions. The relaxant responses to acetylcholine (10(-5) m) were significantly enhanced (30.03 (sem 0.70) v. 18.47 (sem 0.28) %, in the rings from SHR rats treated with OO, and were more pronounced than in WKY rats In the same way, OO attenuated the dose-response curves induced by phenylephrine (10(-8)-10(-5) m) from SHR rats, accompanied with a slower contraction. These results suggest that only the chronic feeding of OO diet was able to attenuate the vascular response of rat aorta. In addition, an increase in phospholipid content (186.7 (sd 3.2) v. 159.1 (sd 11.3) g/kg, and changes in the fatty acid composition of aorta (mainly a decrease in arachidonic acid) could contribute to improving endothelial function. Therefore, the effects can not be attributed exclusively to the content of MUFA (mainly oleic acid). Other components of OO, such as polyphenols, not present in HOSO, may help to explain the vascular protective effect of OO consumption.
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A high-fat diet containing polyunsaturated fatty acids (PUFA: n-3 or n-6) given for 4 wk to 5-wk-old male Wistar rats induced a clear hyperglycemia (10.4 +/- 0.001 mmol/l for n-6 rats and 10.1 +/- 0.001 for n-3 rats) and hyperinsulinemia (6.6 +/- 0.8 ng/ml for n-6 rats and 6.4 +/- 1.3 for n-3 rats), signs of insulin resistance. In liver, both diets (n-3 and n-6) significantly reduced insulin receptor (IR) number, IR and IR substrate (IRS)-1 tyrosine phosphorylation, and phosphatidylinositol (PI) 3'-kinase activity. In contrast, in leg muscle, IR density, as determined by Western blotting, was not affected, whereas IR and IRS-1 tyrosine phosphorylation in response to insulin treatment was restored in animals fed with n-3 PUFA to normal; in n-6 PUFA, the phosphorylation was depressed, as evidenced by Western blot analysis using specific antibodies. In addition, PI 3'-kinase activity and GLUT-4 content in muscle were maintained at normal levels in rats fed with n-3 PUFA compared with rats fed a normal diet. In rats fed with n-6 PUFA, both PI 3'-kinase activity and GLUT-4 content were reduced. Furthermore, in adipose tissue and using RT-PCR, we show that both n-3 and n-6 PUFA led to slight or strong reductions in p85 expression, respectively, whereas GLUT-4 and leptin expression was depressed in n-6 rats. The expression was not affected in n-3 rats compared with control rats. In conclusion, a high-fat diet enriched in n-3 fatty acids maintained IR, IRS-1 tyrosine phosphorylation, and PI 3'-kinase activity and total GLUT-44 content in muscle but not in liver. A high-fat diet (n-3) partially altered the expression of p85 but not that of GLUT-4 and leptin mRNAs in adipose tissue.
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Diet-induced obesity is known to cause peripheral insulin resistance in rodents. We have recently found that feeding cod protein to high-fat-fed rats prevents the development of insulin resistance in skeletal muscle. In the present study, we have further explored the cellular mechanisms behind this beneficial effect of cod protein on skeletal muscle insulin sensitivity. Rats were fed a standard chow diet or a high-fat diet in which the protein source was either casein, soy, or cod proteins for 4 weeks. Whole-body and muscle glucose disposal were reduced by approximately 50% in rats fed high-fat diets with casein or soy proteins, but these impairments were not observed in animals fed cod protein. Insulin-induced tyrosine phosphorylation of the insulin receptor and insulin receptor substrate (IRS) proteins were similar in muscle of chow- and high-fat-fed rats regardless of the dietary protein source. However, IRS-1-associated phosphatidylinositol (PI) 3-kinase activity was severely impaired (-60%) in muscle of high-fat-fed rats consuming casein or soy protein. In marked contrast, feeding rats with cod protein completely prevented the deleterious effect of fat feeding on insulin-stimulated PI 3-kinase activity. The activation of the downstream kinase Akt/PKB by insulin, assessed by in vitro kinase assay and phosphorylation of GSK-3beta, were also impaired in muscle of high-fat-fed rats consuming casein or soy protein, but these defects were also fully prevented by dietary cod protein. However, no effect of cod protein was observed on atypical protein kinase C activity. Normalization of PI 3-kinase/Akt activation by insulin in rats fed high-fat diets with cod protein was associated with improved translocation of GLUT4 to the T-tubules but not to the plasma membrane. Taken together, these results show that dietary cod protein is a natural insulin-sensitizing agent that appears to prevent obesity-linked muscle insulin resistance by normalizing insulin activation of the PI 3-kinase/Akt pathway and by selectively improving GLUT4 translocation to the T-tubules.
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Glucose transport across the cell surface is a key regulatory step for glucose metabolism in skeletal muscle. Both insulin and exercise increase glucose transport into myofibers through glucose transporter (GLUT) proteins. Skeletal muscle expresses several members of the GLUT family but the GLUT4 glucose transporter is considered the main "regulatable" isoform that is modulated by insulin and contraction. Glucose transport rate can be stimulated either by recruitment of GLUT4 units from intracellular storage vesicles or through activation of cell surface transporters. Insulin activates GLUT4 translocation through a complex signaling cascade involving both the lipid kinase phosphatidylinositol 3-kinase and the proto-oncoprotein c-Cbl. Contraction, on the other hand, appears to trigger GLUT4 translocation at least in part through activation of the metabolite-sensing 5'-AMP-activated protein kinase. Furthermore, recent studies suggest that p38 MAP kinase activation represents a point of convergence of the signaling pathways utilized by insulin and contraction to increase GLUT4 activation at the cell surface. This review will summarize our current knowledge of these alternative pathways of GLUT4 regulation in skeletal muscle.
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