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This Article Full Text Full Text (PDF) All Versions of this Article: 294/2/H970    most recent 01200.2007v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Das, S. Articles by Das, D. K. PubMed PubMed Citation Articles by Das, S. Articles by Das, D. K.

Cardioprotection with palm oil tocotrienols: comparision of different isomers

¹Cardiovascular Research Center, University of Connecticut School of Medicine, Farmington, Connecticut; ²Department of Pharmacology, Faculty of Pharmacy, Health Science Center, University of Debrecen, Debrecen, Hungary; ³Malaysian Palm Oil Board, Kuala Lumpur, Malaysia; and ⁴Department of Medicine, The Feinstein Institute for Medical Research and Albert Einstein College of Medicine, New Hyde Park, New York

Submitted 15 October 2007 ; accepted in final form 10 December 2007

A recent study from our laboratory indicated the cardioprotective ability of the tocotrienol-rich fraction (TRF) from red palm oil. The present study compared cardioprotective abilities of different isomers of tocotrienol against TRF as recently tocotrienol has been found to function as a potent neuroprotective agent against stroke. Rats were randomly assigned to one of the following groups: animals were given, by gavage, either 0.35%, 1%, or 3.5% TRF for two different periods of time (2 or 4 wk) or 0.03, 0.3, and 3 mg/kg body wt of one of the isomers of tocotrienol (, , or ) for 4 wk; control animals were given, by gavage, vehicle only. After 2 or 4 wk, rats were killed, and their hearts were then subjected to 30 min of global ischemia followed by 2 h of reperfusion. Dose-response and time-response experiments revealed that the optimal concentration for TRF was 3.5% TRF and 0.3 mg/kg body wt of tocotrienol given for 4 wk. TRF as well as all the isomers of tocotrienol used in our study provided cardioprotection, as evidenced by their ability to improve postischemic ventricular function and reduce myocardial infarct size. The -isoform of tocotrienol was the most cardioprotective of all the isomers followed by the - and -isoforms. The molecular mechanisms of cardioprotection afforded by tocotrienol isoforms were probed by evaluating their respective abilities to stabilize the proteasome, allowing it to maintain a balance between prodeath and prosurvival signals. Our results demonstrated that tocotrienol isoforms reduced c-Src but increased the phosphorylation of Akt, thus generating a survival signal.

tocotrienol-rich fraction; -tocotrienol; -tocotrienol; -tocotrienol; c-Src; Akt