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Alpha-tocotrienol protects against stroke damage
A series of experiments reported in the October 1 2005 issue of the American Heart Association journal Stroke found that the form of vitamin E known as alpha-tocotrienol helped protect against brain damage in an animal model of stroke. Vitamin E consists of alpha, beta, gamma and delta tocopherol as well as four tocotrienols which can be deficient among many individuals.
Based on their previous finding that alpha-tocotrienol blocked neuronal death induced by glutamate (which is released by injured cells following a stroke) researchers at Ohio State University administered glutamate to groups of neurons in which the cytoplasm of one cell had been injected with a nanomolar concentration of alpha-tocotrienol. Twenty-four hours after glutamate treatment, all cells except the one injected with tocotrienol had died in 90 percent of the cases among the experiments conducted.
The team discovered that the vitamin inhibits glutamate-induced 12-lipooxygenase (12-Lox) activation. In an in vivo experiment conducted by the researcher, mice bred to be deficient in 12-Lox in whom stroke was induced were found to possess a greater resistance to brain injury than normal mice.
In another experiment, 32 spontaneously hypertensive rats were placed on vitamin E deficient diets until the induction of experimental strokes at the age of twelve weeks. Rats given tocotrienols between the ages of eight to twelve weeks experienced a reduction in injured brain volume compared to that observed in rats who did not receive tocotrienols. Examination of the brains of the animals who received tocotrienols found a significantly higher level of the vitamin than that measured in the control rats. A second study which supplemented rats with alpha-tocotrienol for a longer period produced similar results.
The authors write that their “findings demonstrate that 12-Lox deficiency protects against stroke injury.” They conclude, “This study demonstrated that oral tocotrienol supplementation may protect against stroke in vivo.”