The effect of dietary red palm oil on the functional recovery of the ischaemic/reperfused isolated rat heart : the involvement of the PI3-Kinase signaling pathway
Date
2009-05
Authors
Engelbrecht, Anna-Mart
Odendaal, Louise
Du Toit, Eugene F.
Kupai, Krisztina
Czont, Tamas
Ferdinandy, Peter
Van Rooyen, Jacques
Journal Title
Journal ISSN
Volume Title
Publisher
BioMed Central
Abstract
We have previously shown that dietary red palm oil (RPO) supplementation improves functional recovery in hearts subjected to ischaemia/reperfusion-induced injury. Unfortunately, the cellular and molecular mechanisms responsible for this phenomenon are still poorly understood and no knowledge exists regarding the effects of RPO supplementation on the phosphoinositide 3-kinase (PI3-K) signaling pathway and apoptosis during ischaemia/reperfusion injury. Therefore, the aims of the present study were three fold: (i) to establish the effect of RPO on the functional recovery of the heart after ischaemia/reperfuion injury; (ii) to determine the effect of the PI3-K pathway in RPO-induced protection with the aid of an inhibitor (wortmannin); and (iii) to evaluate apoptosis in our model. Wistar rats were fed a standard rat chow control diet or a control diet plus 7 g RPO/kg for six weeks. Hearts were excised and mounted on a Langendorff perfusion apparatus. Mechanical function was measured after a 25 min period of total global ischaemia followed by 30 minutes of reperfusion. Hearts subjected to the same conditions were freeze-clamped for biochemical analysis at 10 min during reperfusion to determine the involvement of the PI3-Kinase signaling pathway and apoptosis in our model. Dietary RPO supplementation significantly increased % rate pressure product recovery during reperfusion (71.0 ± 6.3% in control vs 92.36 ± 4.489% in RPO; p < 0.05). The % rate pressure product recovery was significantly reduced when wortmannin was added during perfusion (92.36 ± 4.489% in the RPO group vs 75.21 ± 5.26% in RPO + Wm). RPO + Wm also significantly attenuated PI3-K induction compared with the RPO group (59.2 ± 2.8 pixels in RPO vs 37.9 ± 3.4 pixels in RPO + Wm). We have also demonstrated that PI3-K inhibition induced PARP cleavage (marker of apoptosis) in the hearts during ischaemia/reperfusion injury and that RPO supplementation counteracted this effect.
Description
Includes bibliography
Keywords
Dietary red palm oil (RPO) supplementation, Ischaemia/reperfusion injury, Heart recovery, PI3-K pathway in RPO-induced protection, Apoptosis
Citation
Engelbrecht, A-M, Odendaal, L, Du Toit, EF, Kupai, K, Csont, T, Ferdinandy, P & Van Rooyen 2009, 'The effect of dietary red palm oil on the functional recovery of the ischaemic/reperfused isolated rat heart: the involvement of the PI3-Kinase signaling pathway', Lipids in Health and Disease, 29;8(1):18.