Gamma, alpha tocotrienols lower cholesterol

Gamma-tocotrienol and alpha-tocotrienol, but not delta-tocotrienol, reduced ischemia in hypercholesterolemic hearts in a recent study (Mol Cell Biochem. 2011 Sep 15). The gamma- and alpha- isomers of tocotrienols rendered rabbit hypercholesterolemic hearts resistant to ischemic reperfusion injury by lowering several hypercholesterolemic proteins including matrix metalloproteinase (MMP) 2 and MMP9 (cholesterol regulates MMP2 and MMP9 expression), ET-1(increased by hypercholesterolemia) and SPOT 14 (linked with hypercholesterolemia), and upregulating TGF- (cholesterol suppresses TGF-).

In the study from the University of Connecticut School of Medicine, rabbits were kept on cholesterol diet for 60 days supplemented with gamma-tocotrienol, alpha-tocotrienol and delta-tocotrienol for the last 30 days.

The serum cholesterol levels (in mmol/l) were 24.4 (alpha-tocotrienol), 34.9 (gamma-tocotrienol), 19.8 (delta-tocotrienol) versus. 39.7 (control). Blood cholesterol levels in the gamma- and alpha-tocotrienol supplemented groups were significantly lower (50% and 39% respectively) compared to the control group while the delta-tocotrienol supplemented group did not show any significant reduction.

Subsequently, the researchers compared left ventricular function and myocardial infarct size between control (hypercholesterolemic) and tocotrienol supplemented groups after induction of ischemia and reperfusion. Left ventricular function including aortic flow and developed pressure exhibited significantly improved recovery with gamma- and alpha-tocotrienol, but not with delta-tocotrienol. The myocardial infarct size showed a similar pattern: 33% (alpha-tocotrienol), 23% (gamma tocotrienol) and 47% (delta-tocotrienol). Gamma-tocotrienol reduced infarct size by a significant 50% to 60% compared to control. Again, delta-tocotrienol failed to improve cardiac function and infarct size. Analysis of the atherosclerotic lesions further confirmed that gamma-tocotrienol is the most effective in regression of atherosclerosis.

The researchers also examined several cholesterol-related proteins, and reported consistent with the cardioprotective effects of alpha- and gamma-tocotrienol, these two isomers reduced ET-1, decreased MMP2 and MM9, increased TGF-, and reduced SPOT 14, while delta-tocotrienol had no effects.

Each isomer in the tocotrienol family plays different roles in our health," said WH Leong, vice president, Carotech Inc., which produces a palm tocotrienol complex. "In terms of cardioprotection, this study once again proves gamma- and alpha-tocotrienol play an important part in lowering blood cholesterol and protecting the heart from injuries following a heart attack. Contrary to the misinformation that one can find on the Internet, delta-tocotrienol is the least effective. This study is consistent with the researchers earlier findings published in AJP-Heart and Circulatory Physiology, 2008."

Recently, another doubl -blind, placebo-controlled, parallel human study showed oral supplementation with Carotechs patented and bioenhanced Tocomin SupraBio® improved blood cholesterol levels in hypercholesterolemic individuals.

"Taken together, these studies underscore Carotechs Tocomin® / Tocomin SupraBio full-spectrum tocotrienol complex as the right choice of natural mixed tocotrienols in nutritional supplements to support heart health," Leong added.