Tobacco leaves
Tobacco plants
Researchers at the University of Louisiana at Monroe have discovered anticancer compounds in the most unlikely of places - tobacco leaves.

Khalid El Sayed, an associate professor of medicinal chemistry at the ULM College of Pharmacy, and ULM colleagues Paul Sylvester and Girish Shah received a patent for their discovery of anti-cancer compounds in fresh tobacco leaves earlier this week from the U.S. Patent and Trademark Office.

"The leaf and flower of the tobacco plant contain high amounts of the key flavor ingredient called cembranoids, which shows promise as an anti-cancer agent," El Sayed said. "It was very exciting to discover the anti-cancer activities."

But this doesn't mean people will reap the same benefits by using commercial tobacco, he warned, adding that much of the anti-cancer compound is lost in the processing of commercial tobacco.

"This compound is not commonly found in commercial tobacco because commercial tobacco is largely degraded into smaller compounds for about a year to give it flavor during the processing and fermentation," he said.

The cembranoids are found in the waxy substance on fresh tobacco leaves and show potential for controlling metastic breast and prostate cancers. The plant produces them as a chemical defense to protect itself against insects and harmful microbial infections, El Sayed said.

El Sayed said the idea originated after examining soft-bodied corals, which also produce cembranoids to guard themselves against predators.

"We were collecting soft-bodied corals and found that it was using something to deter predators away, and these marine cembranoids are known for their anti-cancer activity," he said. "So then we became interested in isolating the same compound in tobacco leaves."

And sure enough, that's just what they did.

"This is a remarkable discovery," said Karen Briski, head of the department of basic pharmaceutical sciences. "It demonstrates that there is a helpful, healthy application for tobacco."

Shah, professor of pharmacology, said the discovery came as quite a shock. "I was tremendously surprised considering tobacco is a well-known carcinogen," he said. "This goes against the current dogma."

El Sayed said he hopes to sell the rights to the patent to a company that can support more pre-clinical and clinical testing of the compound so it can be used to develop beneficial applications.

El Sayed said his team also is working with other researchers to explore how the compounds can be used to protect neurological activity in addition to how they can be used to control tobacco addiction.

"Fresh tobacco is an important and relevant agricultural crop for many states in the U.S.," he said. "With this discovery, growers can now start producing tobacco for pharmaceutical use."