A memory-enhancing medicine derived from a Chinese plant has been reproduced in U.S. laboratories and holds promise for the senile and victims of Alzheimer's disease, scientists say.

"This is not a cure," cautioned Alan P. Kozikowski, professor of chemistry and behavioral neuroscience at the University of Pittsburgh."It's one hurdle in the path to trying to find something that can be used in treating this disease and helping to alleviate some of the symptoms."

For centuries, the Chinese have brewed tea from the leaves of the plant, Huperzia serrata, and served it to the elderly to improve their memory.