Red palm oil protects against the consequences of oxidative stress when supplemented with dislipidaemic diets.

Abstract

It is a well known fact that the modern diet contains either excess polyunsaturated fats or saturated fats, and rarely a balanced fat content. In recent research it was found that high concentrations of PUFAs in the diet may be detrimental to cardiovascular health by increasing oxidative stress. Previous studies showed that red palm oil (RPO) provided effective protection against ischaemia/reperfusion injury. In this study we developed an oxidative risk induced diet (ORD), which is rich in PUFAs and low in SFAs, and a high saturated fat diet (HFD), which is rich in SFAs and low in PUFAs. These diets were either supplemented with RPO (experimental groups) or not supplemented (control). Our aim was to investigate whether RPO could offer protection against ischaemia/reperfusion injury in these diets. Our results showed that RPO was able to protect against ischaemia/reperfusion injury in both an ORD and a HFD as indicated by an increased aortic output recovery (ORD+RPO: 83.63 ± 1.76 % versus 61.40 ± 3.76 %; HFD+RPO: 66.17 ± 2.85 % versus 50.00 ± 1.64 %, P<0.05). This increase in reperfusion function was accompanied by an increase in cGMP concentrations during ischaemia in both RPO supplemented groups, when compared to the unsupplemented groups (195.40 ± 18.26% versus 90.31 ± 12.78 % for the ORD groups and 132.98 ± 12.41 % versus 50.09 ± 10.42 % for the HFD groups, P<0.05). These results suggest that the NO-cGMP pathway may be stimulated by RPO during oxidative stress. This in turn would lead to elevation of cGMP during reperfusion, which is associated with protection.