Eicosanoids are hormones that are made within the cell membrane of each and every cell--all 60 trillion cells in the human body. Eicosanoids are 20-carbon structures. Eicosanoids have autocrine, paracrine, and endocrine effects. That is, they affect the very cell that produces the eicosanoid (autocrine effect), as well as nearby cells (paracrine effect) and distant cells (endocrine effect). As with every aspect of biology, balance is a critical issue relating to good health as well as the development and progression of various diseases. Likewise, eicosanoid balance plays a central role that puts this desired biological endpoint at the hub of the integrative medicine wheel.
Eicosanoid synthesis involves the release of arachidonic acid (AA) from cell membrane phospholipids by an enzyme called phospholipase A2 (PLA2). AA then undergoes metabolism by cyclooxygenases (COXs) and lipoxygenases (LOXs). AA is an omega-6 fatty acid that is known to generate free radicals and is considered an unfavorable eicosanoid. Specific metabolites of AA, for example, PGE2 and 5-HETE, are created through the actions of the enzymes COX-2, 5-LOX, 12-LOX, and 15-LOX. These metabolites are examples of bad eicosanoids and have been implicated in prostate cancer (PC) growth and metastasis. In a study of human PC in which 5-LOX and its metabolite 5-HETE were evaluated in both malignant and benign prostate tissue within the same patient, both 5-LOX and 5-HETE were significantly over-expressed in the PC tissue. In other words, specific eicosanoids are modulators of tumor cell interactions with certain host components within the context of cancer growth, invasion, and spread.
The administration of PGE2 to prostate, breast, and colon cancer cells resulted in increased cellular proliferation. Some studies have shown that stimulation of PC growth is related more to COX-2 and a resultant increase in angiogenesis than to PGE2.
EPA, an omega-3 fatty acid, has been shown to suppress AA formation by inhibiting the enzyme delta-5-desaturase. Some epidemiologic studies have shown that high intakes of EPA and DHA lower prostate cancer risk substantially. Other studies have shown a reduction in PC risk only with a decrease in the ratio of AA to EPA (AA:EPA). A combination of GLA and EPA administered to humans was shown to strongly increase serum EPA and DGLA levels and to reduce AA formation and AA metabolites such as leukotrienes.
Foods rich in EPA include coldwater fish such as tuna, sardines, herring, swordfish, and salmon. Commercially available pharmaceutical-grade fish oils also contain large amounts of EPA and DHA.
Skin Care Sale
As you’d expect, Life Extension offers you healthy skin care and makeup that don’t just cover. They nourish and rejuvenate … with ingredients designed to complement your own good looks. With spring approaching, now is the time to stock up on your favorite skin care products. With the sunny days ahead, help nourish, protect and beautify your skin naturally, plus save 60% - 70% on breakthrough products. Try some of our exciting skin care products today while they’re on sale! But hurry, offer expires May 18, 2009.
Here is an example of the dramatic savings you can enjoy!