Hyperoxia-induced changes in antioxidant capacity and the effect of dietary antioxidants.
We investigated, by measuring oxygen radical absorbance capacity (ORAC), whether hyperoxia causes alterations in antioxidant status and whether these alterations could be modulated by dietary antioxidants. Rats were fed for 8 wk a control diet or a control diet supplemented with vitamin E (500 IU/kg) or with aqueous extracts (ORAC: 1.36 mmol Trolox equivalents/kg) from blueberries or spinach and then were exposed to air or >99% O2 for 48 h. Although the constituents of the extracts were not extensively characterized, HPLC indicated that blueberry extract was particularly rich in anthocyanins, and the spinach extract did not contain any anthocyanins. The ORAC was determined in samples without proteins [serum treated with perchloric acid (PCA); ORACPCA] and with proteins (ORACtot). Hyperoxia induced a decrease in serum protein concentration, an increase in serum ORACPCA, decreases in lung ORACPCA and ORACtot, and an equilibration of proteins and ORACPCA between serum and pleural effusion. These alterations suggested a redistribution of antioxidants between tissues and an increase in capillary permeability during hyperoxia. Only the blueberry extract was effective in alleviating the hyperoxia-induced redistribution of antioxidants between tissues.
Cao
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Jean Mayer Human Nutrition Research Center on Aging at Tufts University, Agriculture Research Service, United States Department of Agriculture, Boston, Massachusetts 02111, USA.
Shukitt-Hale
B
B
Bickford
P C
PC
Joseph
J A
JA
McEwen
J
J
Prior
R L
RL
D000818:Animals; D000872:Anthocyanins / Q000737:chemistry / Q000494:pharmacology; D000975:Antioxidants / Q000378:metabolism*; D001798:Blood Proteins / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D004032:Diet; D005609:Free Radicals / Q000378:metabolism; D018496:Hyperoxia / Q000097:blood / Q000378:metabolism*; D008297:Male; D010936:Plant Extracts / Q000494:pharmacology; D010944:Plants / Q000737:chemistry; D010996:Pleural Effusion / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D014810:Vitamin E / Q000494:pharmacology
D000872:Anthocyanins; D000975:Antioxidants; D001798:Blood Proteins; D005609:Free Radicals; D010936:Plant Extracts; D014810:Vitamin E