Free radical lipid peroxidation inhibits enzymatic conversion of beta-carotene into vitamin A.
Free radical oxidation of arachidonic acid with soybean lipoxygenase was accompanied by inhibition of retinal synthesis from beta-carotene catalyzed by enzyme preparation from rabbit intestinal mucosa. Lipoxygenase inhibitor salicylhydroxamic acid and antioxidants suppressing free radical reactions (ethyl gallate, alpha-tocopherol, astaxanthine, and quercetin) promoted conversion of beta-carotene into retinal catalyzed by beta-carotene-15,15'-dioxygenase. These results indicate that lipoperoxides and/or products of their homolysis attenuate enzymatic conversion of beta-carotene and confirm the important role of natural antioxidants in the maintenance of stable vitamin A content in mammals.
Gessler
N N
NN
Laboratory of Biochemistry and Biotechnology of Low-Molecular-Weight Natural Compounds, A. N. Bakh Institute of Biochemistry, Russian Academy of Sciences.
Gomboeva
S B
SB
Shumaev
K B
KB
Bykhovskii
V Y
VY
Lankin
V Z
VZ
D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005609:Free Radicals / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000378:metabolism; D015227:Lipid Peroxidation; D008084:Lipoxygenase / Q000378:metabolism; D018384:Oxidative Stress; D010105:Oxygenases / Q000494:pharmacology; D011817:Rabbits; D012172:Retinaldehyde / Q000096:biosynthesis; D013025:Glycine max / Q000201:enzymology; D014801:Vitamin A / Q000378:metabolism*; D019207:beta Carotene / Q000378:metabolism*; D050559:beta-Carotene 15,15'-Monooxygenase
D005609:Free Radicals; D019207:beta Carotene; D014801:Vitamin A; D016718:Arachidonic Acid; D010105:Oxygenases; D008084:Lipoxygenase; D050559:beta-Carotene 15,15'-Monooxygenase; D012172:Retinaldehyde