New York: A class of drug that inhibits production of the primary female sex hormone, estrogen, and is used to treat breast cancer has been found to quickly and effectively suppress dangerous brain seizures, a study says. "The effect was profound and very clear," said Catherine Woolley, senior author of the study from Northwestern University in Evanston, Illinois. The research was conducted in a rat model of status epilepticus, a condition characterised by a prolonged episode of seizure activity. "This shows that clinically available drugs could be effective therapies for suppressing seizures in humans," Woolley noted. The researchers also discovered, to their surprise, that seizures stimulate the production of estrogens in the brain of both males and females and that this plays a previously unknown role in the escalation of seizure activity. Estrogen synthesis during a seizure makes it worse, the study found. The findings suggest a new approach to treating seizures in humans -- shut down the brain's production of estrogen when a seizure first begins. Current seizure treatments are not targeted. They work by dampening neural activity generally and come with many side effects, such as drowsiness, dizziness or difficulty concentrating. In the study published in the journal eLife, the researchers found that inhibiting estrogen synthesis just after seizure onset strongly suppressed seizures in both sexes, without anti-seizure drugs or other interventions. The scientists injected male and female animals with either an inert substance or an aromatase inhibitor, either letrozole or fadrozole, just after the start of a chemically induced seizure. They studied the animals for up to six hours and found both fadrozole and letrozole strongly suppressed seizures in both sexes.