Abstract

The effect of ingestion of thermoxidized sunflower oil (TOS) on fatty acids composition and histological alteration was investigated in rats. The animals were divided into 2 groups, the first group fed on fresh sunflower oil (FSO) diet and a second group fed on TOS diet during 9 weeks. This oil was heated at 99 ± 2°C with incorporation of 9 L of oxygen/second during 52 h continuously. Changes that occurred in oil fatty acid composition were similar to those found in tissues (liver and adipose tissue) of rat, nourished with oxidized oil. Indeed, our results showed a change in the tissues profile of the fatty-acids; the rates of saturated and monounsaturated fatty-acids increased with the detriment of the linoleic acid and its higher derivative, arachidonic acid. Thus, the total unsaturation of the tissues lipids decreased. In addition, unlike linoleic acid, the palmitic acid is converted into C16:1 n-7. Probably, this was due to the activation of Δ9-desaturase and the reduction of the Δ6- and Δ5-desaturases by the generated products in thermoxidized sunflower oil. Microscopic examination of the test group showed a significant histological change, when compared with the control, such as increase in cell size.

Key words: Thermoxidized sunflower oil, rat, fatty acid composition, histology, tissues.