Ancient Chinese secret?

LONDON—In what is said to be the first large-scale screening of its kind, Dr. David Barlow and his colleagues Dr. Peter Hylands and Tom Ehrman in the Pharmacy Department at King's College London have used cutting-edge computing techniques to look for potential new drugs in Chinese herbal constituents, and have found a wealth of potential therapeutic value there.

To conduct the screening, the King's College team prepared a database of more 8,000 chemicals from the 240 most common Chinese herbs, and they found that more than 62 percent of the herbs contained what they call "candidate" drug compounds with the potential for use in treating a single disease. More than half of the compounds could potentially be used to treat two or more diseases.

Ginseng and rhubarb, for example, were found to have potential in treating inflammation, while ginkgo and mint offer prospects in the management of diabetes. Pomegranate and clove could turn out to be useful in treating HIV, the researchers note, because they contain a wide range of chemical classes, including lignans, carotenoids and phenolics, which could interfere with the way the virus invades and replicates within cells.

"Natural products are a significant resource for developing new medicines, but they are often underappreciated, particularly in an era dominated by combinatorial chemistry," notes Barlow, head of pharmaceutical chemistry at King's College. But drugs of plant or microbial origin count for more than 30 percent of worldwide sales, he points out, and natural products have been very successful in the past in providing new avenues for researching and manufacturing entirely new therapeutic classes.

Bringing together the high-powered punch of modern informatics with the "old world" of natural products is more than just a novel exercise, Barlow says, given the increasing need to quickly and flexibly respond to diseases in the modern world.

"Large-scale computer searches like this provide us with a quick and easy way to discover new drugs," Barlow says. "With the problems we're now having with MRSA and various other superbugs, any new leads we find will be invaluable."

Also, there is a growing trend toward reinvestigating the world of natural products among big pharma companies, and informatics searches like this may play a role in expanding that interest.

"There is this far-ranging and damaging perception that natural products are too complex to be used in a drug discovery setting despite their overwhelming track record in medicine," notes Phil Baran, a chemist with The Scripps Research Institute, who recently published a paper in Nature about new techniques that dramatically reduce the time, complexity and cost of synthesizing natural products with pharmaceutical potential.

But many pharmaceutical companies' potential drug pipelines are drying up, he says, and that suggests that interest in natural products—and tools to effectively study and produce them—should be renewed throughout the drug discovery world.