If a painting’s worth were measured by the money it fetched, van Gogh’s famous rendering of his friend and physician Dr. Gachet would be among the most valuable in all of art. “Portrait of Dr. Gachet”—which depicts a languid man holding a purple foxglove, the plant from which the drug digitalis is derived—was sold in 1990 for an astounding 82 million dollars. The great and famously tortured artist had his own reasons for valuing the portrait. He suffered from severe epilepsy and depended heavily on Gachet’s prescription of digitalis to treat his debilitating seizures.

The ranks of epilepsy medications have expanded considerably in the past hundred years, due mostly to the addition of pharmaceutically derived compounds. Still, people with epilepsy, who account for up to two percent of the population, may continue to suffer, either from seizures or from secondary effects associated with their medicines. “About two out of three people with epilepsy do not achieve the goal of therapy, which is seizure freedom without side effects,” said Steven Schachter, associate director of clinical research at the HMS Osher Institute and HMS professor of neurology and epileptologist at Beth Israel Deaconess Medical Center.

Part of the problem is that epilepsy is a brain disorder that has several underlying mechanisms. A drug that works in one patient may not work in another. Yet all epileptic seizures are characterized by uncontrolled electrical activity. One way to control them would be to block substances in the brain, such as glutamate, that cause neurons to fire. Pharmaceutical companies have been pressing to find glutamate-inhibiting compounds, with very limited success.

Schachter has hit upon a compound that does just that. And he has done so by drawing upon the same centuries-old botanical tradition that yielded the drug digitalis. Applying modern methods of drug discovery, he and colleagues have identified a compound derived from the spiky-looking Chinese club moss that when tested in rodents, had the power to prevent seizures. The seizures are considered to be representative of the highly debilitating grand mal, or tonic–clonic, episodes that many patients with epilepsy experience, and which are often refractory to treatment. In the fall, he hopes to launch a small clinical trial of the compound, huperzine A.