Interactions between α-tocopherol, polyunsaturated fatty acids, and lipoxygenases during embryogenesis.
α-Tocopherol is a lipid-soluble antioxidant that is specifically required for reproduction and embryogenesis. However, since its discovery, α-tocopherol's specific biologic functions, other than as an antioxidant, and the mechanism(s) mediating its requirement for embryogenesis remain unknown. As an antioxidant, α-tocopherol protects polyunsaturated fatty acids (PUFAs) from lipid peroxidation. α-Tocopherol is probably required during embryonic development to protect PUFAs that are crucial to development, specifically arachidonic (ARA) and docosahexaenoic (DHA) acids. Additionally, ARA and DHA are metabolized to bioactive lipid mediators via lipoxygenase enzymes, and α-tocopherol may directly protect, or it may mediate the production and/or actions of, these lipid mediators. In this review, we discuss how α-tocopherol (1) prevents the nonspecific, radical-mediated peroxidation of PUFAs, (2) functions within a greater antioxidant network to modulate the production and/or function of lipid mediators derived from 12- and 12/15-lipoxygenases, and (3) modulates 5-lipoxygenase activity. The application and implication of such interactions are discussed in the context of α-tocopherol requirements during embryogenesis.
Linus Pauling Institute, Oregon State University, Corvallis, OR, 97331, USA; School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, 97331, USA.
Katie M
KM
Lebold
Linus Pauling Institute, Oregon State University, Corvallis, OR, 97331, USA; School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, 97331, USA. Electronic address: maret.traber@oregonstate.edu.
Maret G
MG
Traber
D000022:Abortion, Spontaneous / Q000209:etiology; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D047108:Embryonic Development; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D005260:Female; D005609:Free Radicals; D006801:Humans; D050356:Lipid Metabolism; D015227:Lipid Peroxidation; D058945:Lipoxygenases / Q000378:metabolism*; D011247:Pregnancy; D014811:Vitamin E Deficiency / Q000150:complications; D024502:alpha-Tocopherol / Q000378:metabolism*
D000975:Antioxidants; D005231:Fatty Acids, Unsaturated; D005609:Free Radicals; D058945:Lipoxygenases; D024502:alpha-Tocopherol
12/15-LOX; 5-LOX; Arachidonic acid; Docosahexaenoic acid; Embryogenesis; Free radicals; Lipid peroxidation; Vitamin E