Green tea extract may help after stroke

SAN FRANCISCO, Dec. 29 (UPI) -- Administration of the green tea extract gallotannin, or GT, may protect against post-stroke brain damage, say researchers at San Francisco VA Medical Center.

In previous cell culture studies GT had been shown to inhibit the action of PARG, an enzyme that inhibits the repair of cell damage, leading to brain cell death, according to lead author Weihei Ying of the San Francisco VA Medical Center and the University of California-San Francisco.

Ying's study indicates that it does the same in rats, reducing brain cell death significantly when administered intranasally -- via the nose -- up to three hours after reperfusion -- reducing blood flow.

In the same study, Ying and his team also discovered that intranasal GT completely blocked a secondary post-ischemic effect associated with PARP-1 activation: the movement of the protein known as apoptosis inducing factor, or AIF, from where it resides in a dormant state in the mitochondria in the nucleus, where it becomes active and causes the cell to die.

Significantly, GT provided no protection at all against either PARG or AIF when administered intravenously.

The findings were presented at the annual meeting of the American Society for Neurosciences.