Argan (Argania spinosa) oil lowers blood pressure and improves endothelial dysfunction in spontaneously hypertensive rats

Evaluation of Multivariate Filters on Vibrational Spectroscopic Fingerprints for the PLS-DA and SIMCA Classification of Argan Oils from Four Moroccan Regions

This study aimed to develop an analytical method to determine the geographical origin of Moroccan Argan oil through near-infrared (NIR) or mid-infrared (MIR) spectroscopic fingerprints. However, the classification may be problematic due to the spectral similarity of the components in the samples. Therefore, unsupervised and supervised classification methods-including principal component analysis (PCA), Partial Least Squares-Discriminant Analysis (PLS-DA) and Soft Independent Modeling of Class Analogy (SIMCA)-were evaluated to distinguish between Argan oils from four regions. The spectra of 93 samples were acquired and preprocessed using both standard preprocessing methods and multivariate filters, such as External Parameter Orthogonalization, Generalized Least Squares Weighting and Orthogonal Signal Correction, to improve the models. Their accuracy, precision, sensitivity, and selectivity were used to evaluate the performance of the models. SIMCA and PLS-DA models generated after standard preprocessing failed to correctly classify all samples. However, successful models were produced after using multivariate filters. The NIR and MIR classification models show an equivalent accuracy. The PLS-DA models outperformed the SIMCA with 100% accuracy, specificity, sensitivity and precision. In conclusion, the studied multivariate filters are applicable on the spectroscopic fingerprints to geographically identify the Argan oils in routine monitoring, significantly reducing analysis costs and time.

Quality Control and Authentication of Argan Oils: Application of Advanced Analytical Techniques

In addition to the nutritional and therapeutic benefits, Argan oil is praised for its unique bio-ecological and botanic interest. It has been used for centuries to treat cardiovascular issues, diabetes, and skin infections, as well as for its anti-inflammatory and antiproliferative properties. Argan oil is widely commercialized as a result of these characteristics. However, falsifiers deliberately blend Argan oil with cheaper vegetable oils to make economic profits. This reduces the quality and might result in health issues for consumers. Analytical techniques that are rapid, precise, and accurate are employed to monitor its quality, safety, and authenticity. This review provides a comprehensive overview of studies on the quality assessment of Moroccan Argan oil using both untargeted and targeted approaches. To extract relevant information on quality and adulteration, the analytical data are coupled with chemometric techniques.

Comparative study of three fingerprint analytical approaches based on spectroscopic sensors and chemometrics for the detection and quantification of argan oil adulteration

BACKGROUND

Argan oil is one of the purest and rarest oils in the world, so that the addition of any further product is strictly prohibited by international regulations. Consequently, it is necessary to establish reliable analytical methods to ensure its authenticity. In this study, three multivariate approaches have been developed and validated using fluorescence, UV-visible, and attenuated total reflectance Fourier transform mid-infrared (FT-MIR) spectroscopies.

RESULTS

The application of a partial least squares discriminant analysis model showed an accuracy of 100%. The quantification of adulteration have been evaluated using partial least squares (PLS) regression. The PLS model developed from fluorescence spectroscopy provided the best results for the calibration and cross-validation sets, as it showed the highest R² (0.99) and the lowest root mean square error of calibration and cross-validation (0.55, 0.79). The external validation of the three multivariate approaches by the accuracy profile shows that these approaches guarantee reliable and valid results of 0.5-32%, 7-32%, and 10-32% using fluorescence, FT-MIR and UV-visible spectroscopies respectively.

CONCLUSION

This study confirmed the feasibility of using spectroscopic sensors (routine technique) for rapid determination of argan oil falsification. © 2021 Society of Chemical Industry.

Animal Models of Early-Life Adversity

From the prenatal period throughout the first years of life, the brain undergoes its most rapid development, a period during which it is highly sensitive to external experiences. The timing of brain development differs from one region to another, as it also differs between substrates, neurotransmitter systems, and central endocrine circuitries. These discontinuities are part of the "critical periods of brain development." Early-life adversity (ELA), such as exposure to infection, maternal deprivation, and substance use, disrupts the programmed brain development, yielding a myriad of deviations in brain circuitry, stress responsivity, cognitive function, and general health. This is applicable to both humans and animal models.In our laboratory, several experimental animal designs have been developed that allow investigating the long-lasting consequences of ELA on brain function, cognitive and emotional development, and the risk to develop stress-related psychopathology later in adulthood. This book chapter will provide a review of such animal models, in particular, designs related to infections (LPS-induced), the quality of mother-infant relationship (maternal deprivation and separation), and substance use (ethanol intoxication). The behavior tests, biochemical, and immunohistochemistry assays applied after ELA will be explained. The behavioral tests encompass the open-field, elevated plus maze, forced swim, sucrose preference, Y-maze, object recognition, and Morris water maze tests. These experiments allow the assessment of several outcomes of interest, pertaining to locomotor activity, anxiety-like symptoms, depressive-like symptoms, working memory, recognition memory, spatial memory, and learning performance. The biochemical assays are employed to measure the level of oxidative stress and inflammation in brain areas after application of adversity. Immunohistochemistry puts into perspective the degree of immunoreactivity in the brain subjected to adversity. The findings from our laboratory indicate that the nature and timing of exposure play a critical role in sensitivity to develop neurodevelopmental disorders.

Co-administration of walnut (Juglans regia) prevents systemic hypertension induced by long-term use of dexamethasone: a promising strategy for steroid consumers

CONTEXT

The long-term consumption of glucocorticoids (GCs) may induce serious adverse effects such as hypertension. There is sufficient evidence related to the benefit of walnuts on the cardiovascular system.

OBJECTIVE

This study assesses the effect of methanol extract of walnut [Juglans regia L. (Juglandaceae)] on dexamethasone-induced hypertension and the possible mechanisms in Wistar rats.

MATERIAL AND METHODS

Animals were randomized into control, kernel extract (100 and 200 mg/kg/d, orally), dexamethasone (0.03 mg/kg/d, subcutaneously), dexamethasone + kernel (100 and 200 mg/kg/d, separately), and dexamethasone + captopril (25 mg/kg/d, orally) groups. Animals were treated with water, kernel extract or captopril by gavage 4 d before and during 11 d of saline or dexamethasone treatment. On the 16th day, blood pressure (BP) was recorded and blood samples were collected to measure nitric oxide (NO). Animal hearts were frozen for measurement of malondialdehyde (MDA) and glutathione peroxidase (GPX).

RESULTS

Dexamethasone increased the diastolic BP and MDA/GPX ratio in comparison with control group (128 ± 7 vs. 105 ± 3 mmHg, p < 0.05 and 0.2 ± 0.046 vs. 0.08 ± 0.02, p < 0.05). Combination of dexamethasone and walnut (200 mg/kg) prevented the dexamethasone-induced diastolic hypertension (109 ± 3 vs. 128 ± 7 mmHg; p < 0.05), increased the GPX level (14.8 ± 1.46 vs. 5.1 ± 0.64 unit/mg, p < 0.05), reduced the MDA/GPX ratio (0.16 ± 0.015 vs. 0.2 ± 0.046) and improved serum NO level.

CONCLUSION

Similar to captopril, walnut extract normalized dexamethasone-induced hypertension. A part of this beneficial effect apparently involves maintaining balance of the redox system and NO production.

Argan Oil as an Effective Nutri-Therapeutic Agent in Metabolic Syndrome: A Preclinical Study

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.

Ethnobotanic, Ethnopharmacologic Aspects and New Phytochemical Insights into Moroccan Argan Fruits

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.

Modulation of Systemic and Aortic Nitric Oxide by Melatonin and n-3 Polyunsaturated Fatty Acids in Isoproterenol Affected Spontaneously Hypertensive and Normotensive Wistar Rats

We aimed to explore the effects of melatonin and n-3 polyunsaturated fatty acids (PUFA) supplementation on plasma and aortic nitric oxide (NO) levels in isoproterenol (Iso) affected spontaneously hypertensive (SHR) and Wistar rats. Untreated control rats were compared with Iso injected (118 mg/kg, s.c.) rats, and Iso injected plus supplemented with melatonin (10 mg/kg, p.o.) or PUFA (1.68 g/kg, p.o.) for two months. Plasma and aortic basal, L-NAME inhibited, adrenaline and acetylcholine stimulated NO were determined using Griess method. Plasma NO levels were lower in SHR versus Wistar rats. Iso decreased NO in Wistar while not in SHR. PUFA but not melatonin intake of Iso treated SHR increased plasma NO along with a decrease in systolic blood pressure. Basal aortic NO level was higher in SHR than Wistar rats and not altered by Iso. Intake of melatonin increased but PUFA decreased basal NO levels in Wistar+Iso and did not affect in SHR+Iso rats. Acetylcholine and adrenaline induced aortic NO release was significantly increased in Wistar+Iso but not SHR+Iso group. Melatonin intake increased Ach induced aortic NO in Wistar+Iso and SHR+Iso groups, whereas there was no effect of PUFA intake. Findings suggest that PUFA modulates plasma and melatonin aortic NO levels of isoproterenol affected rats in a strain-dependent manner.

Anticonvulsant effect of argan oil on pilocarpine model induced status epilepticus in wistar rats

Argan oil (AO) is rich in oleic and linoleic acids, polyphenols, sterols, and tocopherols. This composition gives it numerous beneficial pharmacological effects such as hypolipemiant, hypotensive, and antiproliferative. Oxidative stress is a mechanism of cell death induced by seizures and status epilepticus (SE). This study aims at investigating AO effects on (i) latency to first seizure, seizure severity, weight loss, mortality rate, (ii) lipid peroxidation level, nitrite level, and catalase activity in the hippocampus after SE induced by pilocarpine (PC). Wistar rats (1-month old) were daily administered by oral gavage with AO (1 ml/100 g/day) or with NaCl 0.9% during 2 months before receiving PC (400 mg/kg). After the PC injection, all groups were observed for 24 h. The catalase activity, the lipid peroxidation, and nitrite concentrations were measured using spectrophotometric methods. AO pretreatment increased the latency to first seizures, decreased the weight loss, and reduced mortality rate after SE. AO pretreatment produces significant decrease of the lipid peroxidation and nitrite levels. On the contrary, AO increased the catalase activity in rat hippocampus after seizures. For the first time, our results suggest that AO pretreatment is capable of attenuating seizure severity and oxidative stress in the hippocampus of Wistar rats. This indicates that AO may exhibit a neuroprotection against the temporal lobe epilepsy. Further investigations are in progress to confirm this pharmacological property.

Argan oil prevents prothrombotic complications by lowering lipid levels and platelet aggregation, enhancing oxidative status in dyslipidemic patients from the area of Rabat (Morocco)

Background

It is now established that patients with hyperlipidemia have a high risk of atherosclerosis and thrombotic complications, which are two important events responsible for the onset and progression of cardiovascular disease. In the context of managing dyslipidemia by means of dietary advice based on the consumption of argan oil, we wanted to investigate the effect of virgin argan oil on plasma lipids, and for the first time, on the platelet hyperactivation and oxidative status associated with dyslipidemia. This study concerns patients recruited in the area of Rabat in Morocco.

Methods

39 dyslipidemic (79% women) patients were recruited for our study in the area of Rabat in Morocco. They were randomly assigned to the two following groups: the argan group, in which the subjects consumed 25 mL/day of argan oil at breakfast for 3 weeks, and the control group in which argan oil was replaced by butter.

Results

After a 3-week consumption period, blood total cholesterol was significantly lower in the argan oil group, as was LDL cholesterol (23.8% and 25.6% lower, respectively). However, the HDL cholesterol level had increased by 26% at the end of the intervention period compared to baseline. Interestingly, in the argan oil group thrombin-induced platelet aggregation was lower, and oxidative status was enhanced as a result of lower platelet MDA and higher GPx activity, respectively.

Conclusions

In conclusion, our results, even if it is not representative of the Moroccan population, show that argan oil can prevent the prothrombotic complications associated with dyslipidemia, which are a major risk factor for cardiovascular disease.

Antidiabetic and antihypertensive effect of Virgin Argan Oil in model of neonatal streptozotocin-induced diabetic and l-nitroarginine methylester (l-NAME) hypertensive rats

BACKGROUND

The goal of this study was to examine the effect of Virgin Argan Oil (VAO) obtained from the fruit of Argania spinosa in a model of type 2 diabetes and hypertensive rats. Neonatal diabetes was induced by a single i.p. injection of streptozotocin (90 mg/kg) 2 days after birth. To induce NO-deficient hypertension, the adult diabetic animals were treated with l-nitroarginine methylester (l-NAME) (30 mg/kg/day) given orally for 21 days.

METHODS

Following treatment with VAO (21 days), the hyperglycemia decreased to 1.3 ± 0.07 g/l compared with 1.92 ± 0.09 g/l (p < 0.01) in the untreated diabetic-hypertensive rats. The simultaneous administration of VAO with l-NAME prevented the increase in blood pressure during the 3 weeks of treatment. Blood pressure remained constant at 131 ± 1 mm Hg after 21 days - vs 157 ± 0.64 mm Hg in untreated animals (p < 0.001).

RESULTS

The treatment with VAO to diabetic-hypertensive rats caused a significant increase of hepatic glycogen levels (13.3 ± 1.8 vs 6.34 ± 0.75 mg/g tissue in untreated diabetic-hypertensive control group; p < 0.01).

CONCLUSIONS

In conclusion, the overall findings indicate that VAO possesses antidiabetic and antihypertensive activity in n-stz/l-NAME rats. This effect may be related to its high content of tocopherols, phenolic compounds, and unsaturated fatty acids.

Argan Oil and Postmenopausal Moroccan Women: Impact on the Vitamin E Profile

Vitamin E supplements could be beneficial for postmenopausal women. To evaluate the effect of edible argan oil consumption on the antioxidant status of postmenopausal women, the vitamin E serum level of 151 menopausal women consuming either olive or argan oil was determined. Serum level of vitamin E was increased in the argan oil consumer group. Therefore, an argan oil-enriched diet can be recommended to help prevent some postmenopausal disorders.

Argan oil improves surrogate markers of CVD in humans

Limited – though increasing – evidence suggests that argan oil might be endowed with potential healthful properties, mostly in the areas of CVD and prostate cancer. We sought to comprehensively determine the effects of argan oil supplementation on the plasma lipid profile and antioxidant status of a group of healthy Algerian subjects, compared with matched controls. A total of twenty healthy subjects consumed 15 g/d of argan oil – with toasted bread – for breakfast, during 4 weeks (intervention group), whereas twenty matched controls followed their habitual diet, but did not consume argan oil. The study lasted 30 d. At the end of the study, argan oil-supplemented subjects exhibited higher plasma vitamin E concentrations, lower total and LDL-cholesterol, lower TAG and improved plasma and cellular antioxidant profile, when compared with controls. In conclusion, we showed that Algerian argan oil is able to positively modulate some surrogate markers of CVD, through mechanisms which warrant further investigation.

Prevention of chemically induced diabetes mellitus in experimental animals by virgin argan oil

The argan tree plays an important socioeconomic and ecologic role in South Morocco. Moreover, there is much evidence for the beneficial effects of virgin argan oil (VAO) on human health. Thus, this study investigated whether administering VAO to rats can prevent the development of diabetes. VAO extracted by a traditional method from the almonds of Argania spinosa (2 mL/kg) was administered orally (for 7 consecutive days) to rats before and during intraperitoneal alloxan administration (75 mg/kg for 5 consecutive days). An alloxan diabetic-induced untreated group and treated by table oil were used as control groups. Body mass, blood glucose and hepatic glycogen were evaluated. In the present study, subchronic treatment with VAO at a dose of 2 mL/kg, before the experimental induction of diabetes, prevented the body mass loss, induced a significant reduction of blood glucose and a significant increase of hepatic glycogen level (p < 0.001) compared with the untreated diabetic group. In conclusion, the present study shows that argan oil should be further investigated in a human study to clarify its possible role in reducing weight loss in diabetics, and even in inhibiting the development or progression of diabetes. This antidiabetic effect could be due to the richness of VAO in tocopherols, phenolic compounds and unsaturated fatty acids.

Argan Oil Exerts an Antiatherogenic Effect by Improving Lipids and Susceptibility of LDL to Oxidation in Type 2 Diabetes Patients

In this study, we investigate the effect of argan oil consumption on serum lipids, apolipoproteins (AI and B), CRP, and LDL susceptibility to oxidation in type 2 diabetic patients which are known to have a high level of cardiovascular risk due to lipid abnormalities and lipid peroxidation. For that, 86 type 2 diabetic patients with dyslipidemia were randomized to one group consuming 25 mL/day of argan oil during 3 weeks and control group consuming 20 g/day of butter in breakfast. After argan oil intervention, serum triglycerides decreased by 11.84%, (P = 0.001), total chol by 9.13%, (P = 0.01), and LDL-chol by 11.81%, (P = 0.02). However, HDL-chol and Apo AI increased (10.51%, P = 0.01 and 9.40%,  P = 0.045, resp.). Susceptibility of LDL to lipid peroxidation was significantly reduced by increasing of 20.95%, (P = 0.038) in lag phase after argan oil consumption. In conclusion, we show for the first time that consumption of argan oil may have an antiatherogenic effect by improving lipids, and the susceptibility of LDL to oxidation in type 2 diabetes patients with dyslipidemia, and can therefore be recommended in the nutritional management of type 2 diabetes.

Therapeutic potential of argan oil: a review

Objectives

The therapeutic benefits of argan oil consumption have been claimed by natives of Morocco and explorers for more than eight centuries. However, argan oil has remained unresearched for a long time. Traditionally, argan oil has been well known for its cardioprotective properties and it is also used in the treatment of skin infections. Argan oil is principally composed of mono-unsaturated (up to 80%) and saturated (up to 20%) fatty acids. As minor components, it contains polyphenols, tocopherols, sterols, squalene, and triterpene alcohols. Together with the mono-unsaturated fatty acids, these minor components are likely to be responsible for its beneficial effects. This review aims to present an overview of the known pharmacological properties of argan oil.

Key findings

Antiproliferative, antidiabetic, and cardiovascular-protective effects of argan oil have been particularly actively evaluated over the last 5 years in order to build on phytochemical studies that indicate the presence of large amounts of possibly pharmacologically active compounds.

Summary

This review shows that a lack of clinical data constitutes a serious weakness in our knowledge about argan oil, therefore it is difficult to correlate the reported pharmacological activities to any potential clinical relevance.

Should the amazigh diet (regular and moderate argan-oil consumption) have a beneficial impact on human health?

Virgin argan oil, cosmetic or dietary grade, is prepared by cold-pressing the kernels of argan fruits. Both types of oil, traditionally used by the amazighs (the argan grove traditional dwellers), are now available on the shelves of the most-developed country stores. Argan oil contains a high level of oleic and linoleic acid and is also particularly rich in phenols. Since these metabolites are currently considered as essential to explain some of the protective effects against cancer and coronary heart disease attributed to other oils, similar effects can be expected from argan oil consumption as suggested by the amazigh medicine claims. Interestingly, argan oil content in gamma -tocopherol is much higher than that of any other oils. gamma -Tocopherol has recently been shown to possess strong chemopreventive and anti-inflammatory properties. This indicates that argan oil should readily find a place of choice amid the most profitable oils for human health. Because of its reduced geographical origin, the chemical composition (major as well as minor components) of argan oil is also highly reproducible. Therefore argan oil consumption should confer health benefits in a reliable and efficient manner.

Effects of chronic treatment with the CB1 antagonist, rimonabant on the blood pressure, and vascular reactivity of obese Zucker rats

Rimonabant (RM) is a cannabinoid CB1 receptor antagonist useful in the treatment of obesity associated cardiovascular risk factors. Since cannabinoids are vasoactive compounds, the aim of this study is to evaluate the effect of chronic treatment with RM on systolic blood pressure (SBP), and endothelial and vascular reactivity. Obese Zucker rats (OZRs) and their lean counterparts were orally treated during 20 weeks with either RM (10 mg/kg/day). Endothelial and vascular function was assessed in aorta and small mesenteric arteries (SMAs) by concentration response curves to acetylcholine (ACh) and phenylephrine (Phe), respectively. Participation of nitric oxide (NO) was evaluated by incubation with the NO synthase (NOS) inhibitor N(G)-nitro-l-arginine methyl ester (L-NAME) and cyclooxygenase (COX)-derived products involvement was analyzed by incubation with indomethacin (INDO). Plasma lipid profile, insulin and adiponectin were also analyzed. Sympathetic activity was evaluated by urinary excretion of noradrenaline. As expected, RM decreased body weight gain and enhanced adiponectin concentration. Insulin resistance and sympathetic activity were also decreased. The increase in SBP observed in OZRs was reduced by treatment with RM. Aortae and SMAs from OZRs exhibited lower contractile response to Phe, being this effect prevented by RM administration. Although ACh-induced response and NO participation remained unaltered with obesity, enhanced COX-derived constrictor products were found in OZRs. RM treatment neither altered endothelium-dependent relaxation nor L-NAME-sensitive component of the response. Nevertheless, it was able to regulate COX-derived vasoactive products participation. Those effects may contribute to explain some of the cardiovascular protective actions elicited by this drug.

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

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.

Protective effect of saponins from Argania spinosa against free radical-induced oxidative haemolysis

Saponins from Argania spinosa at a non-haemolytic concentration diminish by 53.2% erythrocyte haemolysis induced by free radicals. 2 mM aspirin and acetaminophen diminish by 75% and 68% , respectively, erythrocyte haemolysis induced by free radicals, while 0.3 microM vitamin E shows no significant antioxidant activity. Interestingly, a combination of 1 mg/l of A. spinosa saponins and vitamin E at 0.3 microM resulted in a 68% level of protection against free radical-induced erythrocyte haemolysis, which may suggest that A. spinosa saponins enhance the antioxidant effect of vitamin E. In contrast, no synergic effect was observed for acetaminophen (2 mM) when in combination with vitamin E (0.3 microM). These results demonstrate the antioxidant properties of saponins from A. spinosa and their ability to potentate the antioxidant effect of vitamin E.

Cedrelopsis grevei improves endothelial vasodilatation in aged rats through an increase of NO participation

Cedrelopsis grevei Baill. (Ptaeroxylaceae) trunk bark extract is empirically used in Madagascar against several pathologies, from persistent catarrh to hypertension. The effect C. grevei extract on age-related changes in systolic blood pressure (SBP) and endothelial function was investigated. Rats (90-100 week-old) received treatment either with C. grevei extract (80 mg kg(-1)) or vehicle for 8 weeks. SBP was evaluated by tail-cuff and vascular reactivity and endothelial vasodilatation of both aortae and small mesenteric arteries (SMA) were assessed by acetylcholine (ACh) in the presence or in the absence of either reactive oxygen species (ROS) scavengers superoxide dismutase (SOD) plus catalase or the nitric oxide synthase inhibitor, NG-L-arginine methyl ester (L-NAME). Plasma nitric oxide (NO) was evaluated by nitrite assay and expressions of eNOS, Cu/Zn-, Mn- and EC-SOD were determined by Western Blot. C. grevei administration prevented the increase of SBP and improved endothelium-dependent relaxations in aortae and SMA from aged rat via increased NO and decreased participation of ROS. Furthermore, C. grevei treatment enhanced plasma nitrite content but did not modify eNOS, Cu/Zn-, Mn- or EC-SOD expressions in the two arteries studied. These results suggest that C. grevei prevents both increased blood pressure and age-related endothelial dysfunction supporting the empirical use of C. grevei trunk bark extract against mild hypertension often associated with aging.

l-carnitine and its propionate: improvement of endothelial function in SHR through superoxide dismutase-dependent mechanisms

To clarify the mechanism underlying the antioxidant properties of l-carnitine (LC) and propionyl-l-carnitine (PLC) on spontaneously hypertensive (SHR) and normotensive WKY, animals were treated with either PLC or LC (200 mg kg(- 1)). Aorta was dissected and contraction to (R)-( - )-phenylephrine (Phe) and relaxation to carbachol (CCh) were assessed in the presence or not of the NO synthase (NOS) inhibitor, l-NAME. [image omitted] production was evaluated by lucigenin-enhanced chemiluminescence and its participation on relaxation was observed after incubation with superoxide dismutase (SOD) plus catalase. Protein expressions of eNOS, Cu/Zn-SOD and Mn-SOD were studied by western blot. Both LC and PLC treatments improved endothelial function of SHR through increasing NO participation and decreasing [image omitted] probably involving higher Cu/Zn-SOD expression. PLC treatment augmented eNOS expression in SHR. Surprisingly, LC increased [image omitted] produced by aorta from WKY and thus diminished NO and damaged endothelial function. Conversely, PLC did not affect CCh-induced relaxation in WKY. These results demonstrate that LC and PLC prevent endothelial dysfunction in SHR through an antioxidant effect.

Antiatherogenic activity of extracts of Argania spinosa L. pericarp: beneficial effects on lipid peroxidation and cholesterol homeostasisThis article is one of a selection of papers published in this special issue (part 1 of 2) on the Safety and Efficacy of Natural Health Products

Prevention of lipoprotein oxidation by natural compounds may prevent atherosclerosis via reducing early atherogenesis. In this study, we investigated for the first time the beneficial properties of methanolic extract of argania pericarp (MEAP) towards atherogenesis by protecting human low-density lipoprotein (LDL) against oxidation while promoting high-density lipoprotein (HDL)-mediated cholesterol efflux. By measuring the formation of malondialdehyde (MDA) and conjugated diene as well as the lag phase and the progression rate of lipid peroxidation, the MEAP was found to possess an inhibitory effect. In addition, MEAP reduced the rate of disappearance of α-tocopherol as well as the apoB electrophoretic mobility in a dose-dependent manner. These effects are related to the free radical scavenging and copper-chelating effects of MEAP. In terms of cell viability, MEAP has shown a cytotoxic effect (0–40 μg/mL). Incubation of3H-cholesterol-loaded J774 macrophages with HDL in the presence of increasing concentrations of MEAP enhanced HDL-mediated cholesterol efflux independently of ABCA1 receptor pathways. Our findings suggest that argania seed pericarp provides a source of natural antioxidants that inhibit LDL oxidation and enhance cholesterol efflux and thus can prevent development of cardiovascular diseases.

Effect of L-Carnitine and Propionyl-L-Carnitine on Endothelial Function of Small Mesenteric Arteries from SHR

BACKGROUND

The effect of treatment with either 200 mg x kg(-1) of L-carnitine (LC) or propionyl-L-carnitine (PLC) was studied on endothelial dysfunction of small mesenteric arteries (SMA) from spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats.

METHODS

Systolic blood pressure (SBP) was measured and endothelial and vascular functions were assessed by the effect of carbachol (CCh) and phenylephrine (Phe). O2- produced by SMA and eNOS expression were evaluated by chemiluminescence and Western blot, respectively.

RESULTS

Although SBP was not affected, endothelial relaxation increased in both LC- and PLC-treated SHR. Nevertheless, the CCh-induced contraction remained sensitive to indomethacin in these rats. On the contrary, NO participation was increased in all the groups except for LC-treated WKY. Furthermore, high concentrations of Phe produced NO-dependent relaxation of SMA from PLC-treated rats. Both compounds decreased basal and NADPH-stimulated O2- in SHR toward values observed in WKY. Only PLC increased eNOS protein expression in SHR. Neither LC nor PLC affected endothelium-derived hyperpolarizing factor-induced relaxation.

CONCLUSIONS

LC and its propionate improved endothelial responses of SMA from SHR by decreasing O2- production and thus increasing NO availability. PLC also increased NO synthesis by enhancing eNOS expression.

Effect of dietary argan oil on fatty acid composition, proliferation, and phospholipase D activity of rat thymocytes

OBJECTIVE

Argan oil is receiving increasing attention due to its potential health benefits in the prevention of cardiovascular risk, but no information to date is available about its possible effect on immune cells and functions.

METHODS

To address this issue male rats were fed one of five diets that contained fish oil, argan oil, olive oil, coconut oil, or sunflower oil for 4 wk. The fatty acid composition of plasma and thymocyte lipids was then analyzed in relation to the mitogen-induced proliferation and phospholipase D (PLD) activity of thymocytes.

RESULTS

The 18:2omega-6 proportion in thymocyte phospholipids from rats fed argan oil was significantly lower than that observed in phospholipids from rats fed sunflower oil and fish oil but higher than that found in the olive oil and coconut oil groups. Further, a significant positive linear relation was found between thymocyte proliferation and the 18:2omega-6 proportion in thymocyte phospholipids, whatever the diet. The proliferation response of thymocytes to mitogenic activation was also inversely correlated to PLD activity measured in intact thymocytes. Subsequent western blotting experiments indicated that the diet-induced variations in PLD activity mainly reflected variations in the expression of PLD2 protein.

CONCLUSIONS

On the whole, the present study shows that the effects of argan oil on immune cells are very similar to those of olive oil, and that, as a consequence, argan oil can be used as a balanced dietary supply without marked adverse effects on immune cell function.

Phenolic-extract from argan oil (Argania spinosa L.) inhibits human low-density lipoprotein (LDL) oxidation and enhances cholesterol efflux from human THP-1 macrophages

Argan oil is rich in unsaturated fatty acids, tocopherol and phenolic compounds. These protective molecules make further study of its cardiovascular diseases (CVDs) action interesting. Furthermore, no previous study has explored the antioxidant activity of argan oil in comparison with olive oil. The present study was conducted to evaluate the beneficial properties of Virgin argan oil phenolic extracts (VAO-PE) towards CVD by: (A) protecting human (low-density lipoprotein, LDL) against lipid peroxidation and (B) promoting high-density lipoprotein (HDL)-mediated cholesterol efflux. Human LDLs were oxidized by incubation with CuSO(4) in the presence of different concentrations of VAO-PE (0-320mug/ml). LDL lipid peroxidation was evaluated by conjugated diene and MDA formation as well as Vitamin E disappearance. Incubation of LDL with VAO-PE significantly prolonged the lag-phase and lowered the progression rate of lipid peroxidation (P<0.01) and reduced the disappearance of Vitamin E in a concentration-dependent manner. Incubation of HDL with VAO-PE significantly increased the fluidity of the HDL phospholipidic bilayer (P=0.0004) and HDL-mediated cholesterol efflux from THP-1 macrophages. These results suggest that Virgin argan oil provides a source of dietary phenolic antioxidants, which prevent cardiovascular diseases by inhibiting LDL-oxidation and enhancing reverse cholesterol transport. These properties increase the anti-atherogenic potential of HDL.