Avaliação do estado oxidativo do fígado de ratos mantidos com dieta à base de óleo de coco

Abstract

Coconut oil has attracted the attention of the media and the world population, who associate its use with various health benefits. However, the high content of saturated fatty acids found in coconut oil may predispose to the development of chronic and/or degenerative diseases, such as cardiovascular, endocrine and oncological diseases. Thus, the present study aimed to evaluate the oxidative state of the liver of rats maintained on a coconut oil-based diet. Weanling male Wistar rats were randomly distributed into three groups: C, consisting of rats fed a control diet (AIN-93G); M, formed by rats fed a diet containing a mixture of soybean oil and coconut oil; and OC, composed of rats fed a diet containing coconut oil. Food consumption, fatty acid consumption profile and body weight were evaluated. The oxidative status of the liver was assessed by determining the expression of messenger RNA of the enzymes superoxide dismutase 1 and 2 (SOD1 and SOD2) and glutathione peroxidase (GPx), as well as by determining thiobarbituric acid reactive substances (TBARs). Initial and final body weights, weight gain and food intake during the growth phase after weaning did not differ between the studied groups. Rats maintained on the OC diet had a higher intake of short and medium chain fatty acids compared to those fed on the M diet, and in the latter group, the intake of these fatty acids was higher compared to the control group. On the other hand, the consumption of polyunsaturated fatty acids was lower in the OC group compared to the M and C groups. The expression of SOD1 messenger RNA was higher in the OC group compared to the M (p<0.0001) and C (p <0.0001), with no difference being observed between the last two groups. On the other hand, the expression of SOD2 messenger RNA was similar in groups M and OC and both groups showed lower expression of transcripts of this enzyme compared to group C (p<0.0877 and p<0.0004, respectively). No difference was observed between groups when evaluating GPx messenger RNA expression. Lipid peroxidation products were lower in the liver of rats from groups M and OC compared to group C (p<0.000179 and p<0.000178, respectively). Therefore, the coconut oil-based diet altered the oxidative state of the liver of rats, making animals fed with coconut oil-based diets more susceptible to liver damage.