Effects of vitamin E and ascorbyl palmitate on cultured myocardial cells exposed to oxidized fats.

Primary cultures of rat heart cells were used as a model system to study the influence of two antioxidants, vitamin E and ascorbyl palmitate, on biological effects of thermally oxidized fat. The free fatty acid fraction of the distillable non-urea-adductable fraction of heated corn oil (HCO) was used as the test lipid; the free fatty acid fraction of fresh corn oil was the control. HCO (100 microgram/ml medium) depressed the mitotic index, induced excessive lipid accumulation, and increased the number of pyknotic nuclei in the cells. Addition of extra vitamin E (10 microgram/ml medium) reduced the toxicity of HCO by counteracting these changes. In comparison, ascorbyl palmitate (10 microgram/ml medium) in the presence of HCO was beneficial in that it produced only a slight increase in the mitotic index. HCO treatment also resulted in reduced levels of linoleic and arachidonic acids in the phospholipid fractions of the cells, and addition of vitamin E or ascorbyl palmitate increased the level of arachidonic acid. The triacylglycerol fraction of HCO-treated cells showed markedly reduced linoleic acid and increased arachidonic acid. These changes were unaffected by the antioxidant treatments. Vitamin E counteracted the adverse effects of HCO treatment on the rat heart cells. Ascorbyl palmitate only was as efficient as vitamin E in elevating the concentration of arachidonic acid at the membrane level in the presence of HCO.