Atherosclerosis is considered to be an inflammatory disease and the endothelium plays a key role in this process. It produces several vasoactive compounds like vasodilators [endothelium-derived relaxing factors (EDRFs)], such as nitric oxide (NO), prostacyclin and endothelium-derived hyperpolarizing factor (EDHF) and vasoconstricitors [endothelium-derived contracting factors (EDCFs)], such as angiotensin II, endothelin, and thromboxane A2/prostaglandin H2 and superoxide anions/isoprostane.
It has been shown that among the major known risk factors related to cardiovascular diseases, eating incorrectly has received special attention. A low fat, hight-fiber diet, rich in dietary antioxidants from fruits, vegetables and whole grains is recommended to help reduce cardiovascular risk in the general population. In this regard, the lipids are the most studied macronutrients concerning on the effects of dietary components on inflammation.
The oil extracted from the babassu nut is a complementary part of the diet of several indigenous and babassu-nut breakers communities and is one of the principal sources of food energy[10, 32].
In the present study, despite the presence of saturated fat acid, we have observed that treating male hamsters with unrefined babassu oil decreased ischemia-induced macromolecular leakage in postcapillary venules and protected against histamine-induced increase in microvascular permeability. However the degree of leukocyte adhesion was significantly lower only in the BO-2 group, compared to BO-18 one, data that need further investigations. It is important to emphasize that the histamine effect is not dependent on neutrophil inhibition[33, 34].
Unrefined babassu oil contains minor components such as sterols and tocopherols and oleic acid[7, 8] which have been investigated as responsibly for protective effect on the microcirculation.
Previous studies, comparing activities of α-tocopherol and shark cartilage given orally to hamsters have shown that both inhibited macromolecular permeability increase after ischemia/reperfusion but only α-tocopherol was effective in decreasing the macromolecular permeability increase induced by histamine.
Several different studies of I/R-induced plasma leakage in the hamster cheek pouch concluded that at least two reactive oxygen species are involved such as superoxide (O2) and nitric oxide (NO). Superoxide dismutase (EC-SOD and CuZn-SOD) inhibited I/R-induced plasma leakage and the nitric oxide synthetase inhibitor L-NA inhibited I/R-induced plasma leakage and leucocyte adherence to post capillary venules.
Vitamin E is considered the most important lipid-soluble antioxidant and lipid-rich plant products and vegetables are the main natural sources of it. Humans absorb all forms of vitamin E, but the body maintains only α-tocopherol, incorporated into cellular membranes in which it effectively inhibits lipid peroxidation.
Other compounds present in the babassu oil are phytosterols, related to cholesterol-lowering properties of some oils from natural plant sources, but the exact mechanisms is not fully understood.
The babassu nut is an important source of lauric acid but it has 17% of oleic acid. Baer and co-workers demonstrated that ingestion of 8% oleic acid could inhibit the inflammatory process. Whether or not the oleic acid plays a role in the protective effect observed in our experiments needs further investigation. Olive oil contains large amounts of oleic acid which is a ω-9 monounsaturated fatty acid converted to eicosatrienoic (ETA). ETA is converted to Leukotriene A3 (LTA3), which is a potent inhibitor of leukotriene B4 synthesis.
Given the limitations of our study and the fact that, to our knowledge, this is the first study to investigate effects of babassu oil in a model of ischemia-reperfusion injury, further studies will also be needed in order to corroborate our data and to justify the use of babassu oil as a source of food energy.