Researchers from Ohio State University Medical Center decided to carry out a rat study following the successful results of an earlier trial, in which lead investigator Professor Chandan Sen demonstrated that unlike alpha-tocopherol (TCP), a better-known form of vitamin E, TCT blocks glutamate-induced cell death. Glutamate-induced toxicity is understood to contribute to pathological cell death in the nervous system.
In the new study, published in the October issue of the American Heart Association journal Stroke, Sen and his team studied the effects of low-dose TCT supplementation (Tocomin supplied by Carotech) on the brain tissue of spontaneously hypertensive rats after they experienced stroke. Hypertension is one of the main risk factors for stroke.
The supplemented rats were less susceptible to stroke-induced brain damage than unsupplemented control rats. The same low dose of TCP had no effect.
Vitamin E is a generic term for both tocopherol and tocotrienol derivatives. There are significant differences in their chemical structures which make them act very differently in humans. Of the two, tocopherol is the most commonly used, yet the antioxidant powers of tocotrienol have been proven to be much stronger than tocopherol.
The results were attributed to the suppression of c-Src, a molecular checkpoint associated with stroke. 12-Lox deficient mice were also seen to be more resistant to stroke-induced injury than wild-type controls, which led the researchers to believe that 12-lipoygenase is another TCT-sensitive checkpoint critical to neuron deaths.
"The natural vitamin E, TCT, acts on key molecular checkpoints to protect against glutamate- and stroke-induced neurodegeneration," they concluded.
"Eighty-three years after the discovery of vitamin E in 1922, it is long overdue to closely examine all naturally occurring forms of vitamin E side by side," said Professor Sen.
Sen was positive that the results of the new study and his previous investigations could prove useful in protecting against the debilitating effects of stroke, if TCT has the same protective effect on human brains:
"Attention to the naturally occurring tocotrienols, especially to their neuroprotective properties, could well provide us with a powerful tool to combat neurodegeneration especially stroke, by safe dietary means," he said.