The Effect of Fried Palm Oil Supplemented Diet on Enzymatic Antioxidant Status of Aging Mice

Abstract

There is increased evidence that reactive oxygen species (ROS) and their promoted oxidative damage are involved in a large number of pathologies, as well as in the aging process. ROS removal rate is mostly controlled by a variety of antioxidants. The extent of lipid peroxidation and antioxidants level, the way they are related to aging and whether they are affected by deep fried palm oil supplemented diet in aging mice was investigated. Standard laboratory methods were employed in the determination of Malondialdehyde (MDA), Catalase (CAT) and Superoxide Dismutase (SOD) activities in the plasma of the experimental animals. It was found that SOD activity in older mice not fed with fried palm oil supplemented diet was higher 24.75±1.96U/L than among younger mice 19.05±6.66 U/L; (P=0.091), and indication of increased production of superoxide radical with age. A significant (P=0.018) increase in SOD activity (43.05±14.91U/L) was observed in older mice fed with deep fried palm oil supplemented diet relative to 24.75±1.96U/L in older mice not fed with deep fried palm oil supplemented diet and 19.05±6.66U/L; (P=0.000) in younger mice, indicating a compensatory response to additional superoxide radical produced through the process of oxidative metabolism of deep fried palm oil supplemented diet. Expectedly, CAT activity increases with increased SOD activity in older mice not fed with deep fried palm oil supplemented diet 461.51±39.05U/L as against 440.10±29.20U/L in younger mice, although not to a statistically significant level (P=0.265). In contrast, a significant (P=0.008) decrease in CAT activity (366.29±63.56U/L) was observed in older mice fed with deep fried palm oil supplemented diet relative to older mice not fed with deep fried palm oil supplemented diet and younger mice (p=0.005). Increased MDA (102.53±1.02µM/L), a marker of lipid peroxidation due to free radicals was observed in older mice not fed with deep fried palm oil supplemented diet relative to 98.74±17.99µM/L in younger mice (p=0.652). However, the consequent increase in SOD activity in response to increased free radical production in older mice fed with deep fried palm oil supplemented diet helped modulate the extent of lipid peroxidation with consequent decrease (91.27±31.37µM/L; p=0.535) in MDA. Therefore, it can be concluded that consumption of deep fried palm oil supplemented diet increases superoxide radical formation, thus should be minimized, if possible avoided especially in ageing.