WHEY FROM CULTURED SKIM MILK DECREASES SERUM-CHOLESTEROL AND INCREASES ANTIOXIDANT ENZYMES IN LIVER AND RED-BLOOD-CELLS IN RATS

The study was carried out to examine the effect of whey from bovine sk im milk fermented with bifidobacteria and lactic acid bacteria on plas ma cholesterol and antioxidant enzymes in rats. Rats were maintained f or 6 wks on a purified diet (reference diet) and on the purified diet supplemented milk whey or whey from cultured skim milk with Bifidobact erium longum (B. longum), Lactobacillus acidophilus (L. acidophilus) o r Streptococcus salivarius subsp. thermophilus (S. thermophilus). Diet s containing the product with S. thermophilus resulted in the lowest c oncentration of plasma cholesterol. The activity of superoxide dismuta se (SOD) in red blood cells (RBC) and the activity of catalase in live r were elevated on cultured product-diets compared with the reference diet; in addition, the activity of glutathione peroxidase (GSHPx) in R BC was higher on the L. acidophilus diet compared with the reference d iet. Although there were no significant differences in the concentrati ons of thiobarbituric acid-reactive substances and alpha-tocopherol in plasma, plasma d<1.063 g/ml lipoprotein fractions prepared from rats fed on the B. longum- and L. acidophilus-diets were resistant to the o xidative stress induced by a transition metal ion when compared with t hose from rats fed on the reference diet. The non-fermented whey diet was not as effective in lowering plasma cholesterol and in increasing antioxidant enzymes as were the fermentation product diets. These resu lts therefore suggest that wheys from cultured milk may exert spesific effects on hypercholesterolemia and oxidative stress.