Tocotrienols Reduce Stroke Damage

COLUMBUS, OhioOral supplementation with tocotrienols, a natural form of vitamin E, reduced overall brain tissue damage, prevented loss of neural connections and helped sustain blood flow in the brains of dogs that had strokes, according to a new study (J Cereb Blood Flow Metab. 2011 Jun 15. DOI: 10.1038/jcbfm.2011.85). The study used tocotrienols supplied by Carotech, which offers the ingredient to the supplement industry.

Vitamin E consists of tocopherols and tocotrienols, in which alpha-tocotrienols are the most potent neuroprotective form that has been shown to be effective in protecting against stroke in rodents. Tocotrienols are not abundant in the American diet, but is available as a nutritional supplement. It is a common component of a typical Southeast Asian diet.

In this current study from the Ohio State University, dogs (mean weight=26.3±3.2 kg) were supplemented with tocotrienol-enriched supplements (200 mg b.i.d, n=11) or placebo (n=9) for 10 weeks before scientists induced stroke by blocking the middle cerebral artery in the animals brains for one hour while the animals were under anesthesia.

The researches found 24 hours after a stroke, lesions indicating brain tissue damage were about 80 percent smaller in dogs that received supplementation than were the lesions in dogs that received no intervention (P<0.005). Furthermore, tocotrienols prevented loss of white matter fiber tract connectivity after stroke. Imaging tests showed the treated animals brains had better blood flow at the stroke site as compared to untreated dogs brains (P<0.05), a difference attributed to tiny collateral blood vessels ability to improve circulation in the brain when blood flow stopped in more substantial vessels.

For the first time, in this pre-clinical large-animal model, we were able to see something that we were never able to see in the mouse or the rat: that if you had a stroke and you had prophylactically taken tocotrienol, the area of the brain affected by the stroke received blood flow from the collaterals," said Chandan Sen, professor and vice chair for research in Ohio States Department of Surgery and senior author of the study. These collaterals, which are an emergency response system, wake up when the blood circulation in the brain is challenged."

Additional examination of the affected brain tissue showed tocotrienol supplementation appeared to support arteriogenesis, a process by which collateral arteries remodel themselves into larger vessels so they can bypass the site of blockage. Genes associated with this process were more active in the affected brain tissue from treated animals than were those from untreated dogs.

The researchers noted the outcomes of the current preclinical trial set the stage for a clinical trial testing the effects of tocotrienol in patients who are at a high risk for stroke, have previously suffered a ministroke or had a temporary stoppage of blood flow in the brain. Of the almost 800,000 strokes in the United States each year, an estimated 25 percent are repeat events, according to the American Heart Association (AHA).

This work is supported by the National Institutes of Health, Ohio States Center for Clinical and Translational Science, and Carotech Inc.

Carotechs Tocomin® SupraBio, a patented and bioenhanced natural full-spectrum palm tocotrienol complex is currently being studied in a three-year randomized, double blind, placebo-controlled human clinical trial, specifically evaluating its neuroprotective and anti-atherogenic properties.