Oxidative stability of sesame and flaxseed oils and their effects on morphometric and biochemical parameters in an animal model.

BACKGROUND: Sesame and flaxseed oils, which are rich in essential n-6 and n-3 polyunsaturated fatty acids, are widely consumed. We have determined the optical behavior with respect to the quality and identity of cold-pressed sesame and flaxseed oils. The effects of these oils and their combinations on metabolic parameters in animal models were also measured. RESULTS: Flaxseed oil emitted carotenoid fluorescence (500-650 nm), although it was more unstable than sesame oil, which had a larger induction period by the Rancimat method. The greater stability of sesame may be a result of the lower quantity of linolenic fatty acids. These oils were added to the feed of 56 rats, whereas animal fat was used for the control group. The sesame oil, flaxseed oil and sesame + flaxseed oils groups showed a significantly reduced adiposity index and blood glucose compared to the control group, whereas total cholesterol, high-density lipoprotein and triglycerides were lower in flaxseed oil and sesame + flaxseed oils (P < 0.05). Sesame + flaxseed oils had reduced levels of low-density lipoprotein and non-high-density lipoprotein (P < 0.05), indicating an anti-atherogenic effect in this group. CONCLUSION: Sesame oil was more stable than flaxseed oil. In an animal model, the diets with polyunsaturated fat sources proportions of 1:1 n-6:n-3 polyunsaturated fatty acids, improved the metabolic parameters, implying cardioprotective effects. © 2016 Society of Chemical Industry.

Individual in vitro effects of ochratoxin A, deoxynivalenol and zearalenone on oxidative stress and acetylcholinesterase in lymphocytes of broiler chickens.

The contamination of consumer food and animal feed with toxigenic fungi has resulted in economic losses worldwide in animal industries. Mycotoxins are highly biologically reactive secondary metabolites and can inhibit protein synthesis and cell multiplication. Considering the cytotoxicity of mycotoxins, this experiment was performed to determine the in vitro influence of ochratoxin A, deoxynivalenol and zearalenone on lipid peroxidation in lymphocytes of broiler chickens at different concentrations. This study has also evaluated whether the presence of these mycotoxins changes the acetylcholinesterase activity in lymphocytes, which is involved in the regulation of immune and inflammatory responses. Blood lymphocytes of broiler chickens were isolated through density gradient centrifugation and incubated with the respective mycotoxins at concentrations of 0.001, 0.01, 0.1 and 1 µg/mL. Lipid peroxidation, which was evaluated through the amount of malondialdehyde measured in a thiobarbituric acid-reactive species test, and the enzymatic activity were analyzed at 24, 48 and 72 h. Results of the lipid peroxidation evaluation showed an increasing cytotoxicity relation: ochratoxin A > deoxynivalenol > zearalenone. Conversely, cytotoxicity was valued as zearalenone > deoxynivalenol > ochratoxin A in relation to the acetylcholinesterase enzymatic activity. At a concentration of 1 µg/mL, ochratoxin A and deoxynivalenol induced the highest cellular oxidative stress levels and the highest enzymatic activity at the majority of time points. However, the same mycotoxins, except at 1 µg/mL concentration, induced a reduction of lymphocytic lipid peroxidation 72 h after incubation, suggesting the action of a compensatory mechanism in these cells.