Antioxidants Compounds that prevent biologically active

Lipids play many essential roles in cell biology. They act as strnctnral materials or as cell signals, provide a barrier for ion separation, and prevent cells from pathogen invasion and water loss. Among many other fnnctions, they also act as temperatnre sensors and serve as a substrate for eicosanoids (Slabas et al., 2001). To fulfill these functions, n-6 and n-3 FA that cannot be synthesized by animal organisms need to be delivered in a diet. The majority of diet-snpplied lipids serve as a sonrce of energy and carriers of lipophilic, biologically active compounds, snch as vitamins and antioxidants. 

The growing interest in selenium speciation is due to its toxic and/or essential properties that depend on the actual physicochemical form of the element. Strong evidence exists on the adverse health effects related to selenium deficiency. It was also demonstrated that supplementation with different selenium forms might help to remove the symptoms of deficit. Selenium has been found in the active site of different antioxidant enzymes, protecting cells against the action of free radicals. The species-dependent cancer-preventive properties are well documented, yet the specific biological functions have not been ultimately elucidated. The list of small selenium compounds includes inorganic forms (two stable valence states), volatile alkylated species, and... 

Oleuropein appears to interfere with some biological processes such as lipoprotein oxidation, platelet aggregation, platelet and leukocyte eicosanoid production and cardiovascular control too. As previously described, oleuropein and hydroxy-tyrosol are characterised by a catechol moiety that appears to be needed for their scavenger and antioxidant activities. In fact, it was demonstrated that these compounds prevent thermally initiated autoxidation of methyl linoleate in homogenous solutions [56], protect LDL from oxidation [57] and inhibit production of... 

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