The alpha and gamma tocotrienol forms showed positive effects on cholesterol levels with rabbits fed a cholesterol diet for 60 days, supplemented with the different vitamin E forms for the last 30 days.
“The results of the present study demonstrate that the two isomers of tocotrienols [alpha and gamma], render the hypercholesterolemic hearts resistant to ischemic reperfusion injury by lowering several hypercholesterolemic proteins…” the researchers said.
They added: “Left ventricular function including aortic flow and developed pressure exhibited significantly improved recovery with tocotrienol [alpha and gamma], but not with tocotrienol [delta].”
The researchers detected a difference between female and male responses to the introduced vitamin E forms.
“The major findings of this study are that [alpha and [gamma] isomers, but not [delata] isomer improved the left ventricular function and reduced myocardial infarct size in the hearts of hypercholesteromic rabbits,” they said.
“Interestingly, the female rabbit hearts were more resistant to ischemic reperfusion injury compared to male hearts. Although tocotrienol isomers effectively reduced the serum cholesterol in the hypercholesteromic rabbits, there was no difference between the male and female rabbits. Expression of cholesterol-related protein profiles revealed differential effects of tocotrienol isomers.”
“More comprehensive analysis of the effects of [gamma] tocotrienol on cardiac gene expression in rats on a high cholesterol diet demonstrated significant changes in heat shock proteins, mitochondrial proteins, hFABP, antioxidants, and muscle proteins, all of which were increased.”
When consumers think of vitamin E, they are probably thinking of the tocopherol form. The vitamin comes in eight forms: Four tocopherols and four tocotrienols (alpha, beta, gamma, and delta-forms of each).
Molecular Cell Biology
‘Tocotrienols confer resistance to ischemia in hypercholesterolemic hearts: insight with genomics’
Authors: Somak Das et al