Longchain n-3 polyunsaturated fatty acids and microvascular reactivity: Observation in the hamster cheek pouch

Nutraceuticals in the prophylaxis of pediatric migraine: Evidence-based review and recommendations

Introduction

The literature on complementary and alternative medicine (CAM) is expanding. One of the most common conditions for which CAM is studied in the pediatric population is migraine. Nutraceuticals are a form of CAM that is being used for pediatric migraine prophylaxis.

Methods

A literature search was carried out in order to identify both observational studies and randomized controlled trials on the use of nutraceuticals for the prophylaxis of pediatric migraine. Adult studies on included nutraceuticals were also reviewed.

Review

Thirty studies were reviewed on six different nutraceuticals: butterbur, riboflavin, ginkgolide B, magnesium, coenzyme Q10 and polyunsaturated fatty acids.

Conclusion

Overall, the quality of the evidence for the use of nutraceuticals in pediatric migraine prophylaxis is poor. Further research needs to be done in order to study the efficacy of nutraceuticals for the prophylaxis of pediatric migraine.

Arteriolar diameter and spontaneous vasomotion: importance of potassium channels and nitric oxide

Arterioles display cyclic variations in diameter, termed vasomotion initiated by smooth muscle cells (SMCs), but the endothelium should also be evaluated due to its modulatory role on vessel tone. Since nitric oxide (NO) and prostacyclin (PGI2) regulate SMC tone and activate K(+) currents, we have investigated their role on vasomotion, by observing effects of topical application of N(ω)-nitro-l-arginine (L-NA, NO synthesis inhibitor), glibenclamide (KATP channel inhibitor), sodium nitroprusside (SNP, NO donor), iloprost (PGI2 analogue) and methylene blue (MB, cGMP production inhibitor) on the cheek pouch preparation of anesthetized male hamsters. L-NA (10(-10)-10(-6)M) induced vasoconstriction, reduction and abolition of vasomotion. MB (10(-7) to 10(-5)M) reduced mean arteriolar diameter with no changes on vasomotion. In the presence of 10(-6)M of MB, addition of 10(-6)L-NA totally abolished vasomotion without further constriction. Glibenclamide (10(-6)M) in the presence of L-NA at equimolar concentration restored both vasomotion frequency and amplitude. This effect was not observed in the presence of TEA 5mM. SNP (10(-10)-10(-6)M) induced a dose-dependent increase of arteriolar diameter and decreased vasomotion. Iloprost (10(-12)-10(-6)M) induced a concentration dependent increase of arteriolar diameter, reduced vasomotion frequency, but in lower concentrations (10(-12)-10(-10)M) increased its amplitude and in higher concentrations (10(-9)-10(-6)M) decreased it. SNP and iloprost inhibited vasomotion at 10(-7)M; however, at this concentration SNP and iloprost induced an increment of 35% and 50% of the initial arteriolar diameter, respectively. In the presence of L-NA (10(-6)M), vasomotion was restored by SNP at 10(-10)M and iloprost 10(-12)M, which corresponded to 80% of the initial diameter value. Around the initial (control) arteriolar diameter value, vasomotion presented its highest frequencies and amplitudes. Cessation of vasomotion occurred with L-NA (10(-6)M) in the presence of SNP (10(-6)M) and iloprost (10(-7)M) when arteriolar diameter reached 150% and 120% of its initial value, respectively. In conclusion, the present study strongly suggests that vasomotion (1) is not solely related to vascular tone, (2) needs an interplay between vascular tone and membrane currents and (3) could be modulated by NO (but not cGMP) and KATP channels. In addition, our results point to the existence of dissociation between vasomotion frequency and amplitude.

Effects of babassu nut oil on ischemia/reperfusion-induced leukocyte adhesion and macromolecular leakage in the microcirculation: observation in the hamster cheek pouch

Background

The babassu palm tree is native to Brazil and is most densely distributed in the Cocais region of the state of Maranhão, in northeastern Brazil. In addition to the industrial use of refined babassu oil, the milk, the unrefined oil and the nuts in natura are used by families from several communities of African descendants as one of the principal sources of food energy. The objective of this study was to evaluate the effects of babassu oil on microvascular permeability and leukocyte-endothelial interactions induced by ischemia/reperfusion using the hamster cheek pouch microcirculation as experimental model.

Methods

Twice a day for 14 days, male hamsters received unrefined babassu oil (0.02 ml/dose [BO-2 group], 0.06 ml/dose [BO-6 group], 0.18 ml/dose [BO-18 group]) or mineral oil (0.18 ml/dose [MO group]). Observations were made in the cheek pouch and macromolecular permeability increase induced by ischemia/reperfusion (I/R) or topical application of histamine, as well as leukocyte-endothelial interaction after I/R were evaluated.

Results

The mean value of I/R-induced microvascular leakage, determined during reperfusion, was significantly lower in the BO-6 and BO-18 groups than in the MO one (P < 0.001). In addition, histamine-induced increase of microvascular permeability was significantly less pronounced in BO groups compared to MO one. No significant differences among groups in terms of leukocyte adhesion, concentrations of tumor necrosis factor alpha, interleukin 1, and interleukin 6 were found.

Conclusions

Our findings suggest that unrefined babassu oil reduced microvascular leakage and protected against histamine-induced effects in postcapillary venules and highlights that these almost unexploited nut and its oil might be secure sources of food energy.

n-3 PUFA prevent metabolic disturbances associated with obesity and improve endothelial function in golden Syrian hamsters fed with a high-fat diet

Glucose intolerance and dyslipidaemia are independent risk factors for endothelium dysfunction and CVD. The aim of the present study was to analyse the preventive effect of n-3 PUFA (EPA and DHA) on lipid and carbohydrate disturbances and endothelial dysfunction. Three groups of adult hamsters were studied for 20 weeks: (1) control diet (Control); (2) high-fat diet (HF); (3) high-fat diet enriched with n-3 PUFA (HFn-3) groups. The increase in body weight and fat mass in the HF compared to the Control group (P < 0.05) was not found in the HFn-3 group. Muscle TAG content was similar in the Control and HF groups, but significantly lower in the HFn-3 group (P = 0.008). Glucose tolerance was impaired in the HF compared to the Control group, but this impairment was prevented by n-3 PUFA in the HFn-3 group (P < 0.001). Plasma TAG and cholesterol were higher in the HF group compared to the Control group (P < 0.001), but lower in the HFn-3 group compared to the HF group (P < 0.001). HDL-cholesterol was lower in the HFn-3 group compared to the Control and HF groups (P < 0.0005). Hepatic secretion of TAG was lower in the HFn-3 group compared to the HF group (P < 0.005), but did not differ from the Control group. Hepatic gene expression of sterol regulatory element-binding protein-1c, diacylglycerol O-acyltransferase 2 and stearyl CoA desaturase 1 was lower in the HFn-3 group, whereas carnitine palmitoyl transferase 1 and scavenger receptor class B type 1 expression was higher (P < 0.05). In adipocytes and adipose macrophages, PPARγ and TNFα expression was higher in the HF and HFn-3 groups compared to the Control group. Endothelium relaxation was higher in the HFn-3 (P < 0.001) than in the HF and Control groups, and was correlated with glucose intolerance (P = 0.03) and cholesterol (P = 0.0003). In conclusion, n-3 PUFA prevent some metabolic disturbances induced by high-fat diet and improve endothelial function in hamsters.

The differential effects of EPA and DHA on cardiovascular risk factors

Compelling evidence exists for the cardioprotective benefits resulting from consumption of fatty acids from fish oils, EPA (20:5n-3) and DHA (22:6n-3). EPA and DHA alter membrane fluidity, interact with transcription factors such as PPAR and sterol regulatory element binding protein, and are substrates for enzymes including cyclooxygenase, lipoxygenase and cytochrome P450. As a result, fish oils may improve cardiovascular health by altering lipid metabolism, inducing haemodynamic changes, decreasing arrhythmias, modulating platelet function, improving endothelial function and inhibiting inflammatory pathways. The independent effects of EPA and DHA are poorly understood. While both EPA and DHA decrease TAG levels, only DHA appears to increase HDL and LDL particle size. Evidence to date suggests that DHA is more efficient in decreasing blood pressure, heart rate and platelet aggregation compared to EPA. Fish oil consumption appears to improve arterial compliance and endothelial function; it is not yet clear as to whether differences exist between EPA and DHA in their vascular effects. In contrast, the beneficial effect of fish oils on inflammation and insulin sensitivity observed in vitro and in animal studies has not been confirmed in human subjects. Further investigation to clarify the relative effects of consuming EPA and DHA at a range of doses would enable elaboration of current understanding regarding cardioprotective effects of consuming oily fish and algal sources of long chain n-3 PUFA, and provide clearer evidence for the clinical therapeutic potential of consuming either EPA or DHA-rich oils.

Cardiovascular effects of edible oils: a comparison between four popular edible oils

Edible oils form an essential part of the modern diet. These oils play a role as an energy source, and provide the diet with many beneficial micronutrients. Although a popular conception may be that fat should be avoided, certain edible oils as a dietary supplement may play an important role in the improvement of cardiovascular health. CVD has become one of the leading causes of death worldwide. Dietary supplementation with different oils may have beneficial effects on cardiovascular health. While olive oil and sunflower-seed oil are known to reduce serum cholesterol, fish oil has become well known for reducing potentially fatal cardiac arrhythmias. Recently, red palm oil research has shown beneficial effects on cardiac recovery from ischaemia-reperfusion injury. It is clear that dietary supplementation with edible oils may play a vital role in reducing the mortality rate due to heart disease. The specific benefits and disadvantages of these oils should, however, be explored in greater depth. The present review will attempt to identify the benefits and shortcomings of four popular edible oils, namely olive oil, sunflower-seed oil, fish oil and palm oil. Additionally the present review will aim to reveal potential areas of research which could further enhance our understanding of the effects of edible oils on cardiovascular health.