Normal expression of these enzymes in VCO fed animals
clearly indicates that they are not under oxidative stress.
Even though fatty acid analysis of VCO and CO contains
same amount of saturated fatty acids the higher content
unsaponifiable components like vitamin E, polyphenols
may be contributing to this effect of VCO. Presence of high
amount of unsaturated fatty acids may be the reason for
the low antioxidant enzyme activities of GO fed animals
since polyunsaturated fatty acids (PUFA) deteriorates the
antioxidant status due to their liability to become highly
oxidized (Noguchi & Niki, 1999; Porter, Caldwell, & Mills,
1995). Feeding oils high in polyunsaturated fatty acids
(PUFA) results in their accumulation in cell membranes
and increase the oxidative stress since PUFA are highly
susceptible to peroxidation than monounsaturated and saturated
fatty acids (Beard, Barnard, Robbins, Ordovas, &
Schaefer, 1996; Hagve, Lie, & Gronn, 1993; Palozza
et al., 1996). VCO with its high saturated fat content and
high levels of vitamins and polyphenols may rectify these
problems.