When cancer researcher Yung-Chi Cheng set out some 12 years ago to study a traditional Chinese medicine, the initialreaction from colleagues and other experts in the field was 'pretty bad,' he says.

Colleagues worried that Yale University's Dr. Cheng, a mainstream, respected professor of pharmacology, was taking a professional risk by delving into possible herbal treatments for cancer. It wasn't possible to get separate batches of herbs containing chemical compounds that were consistent, they told him. And there wasn't evidence to support the claim that the herbs had any benefit. 'It was rejectionist and narrow-minded,' Dr. Cheng says.

Born in Britain and raised in Taiwan, the 67-year-old Dr. Cheng mainly works at developing better cancer and antivirus compounds. He says he decided to move forward with the work on Chinese herbs on a part-time basis because he felt that whether the medical claims were true or not, they needed to be evaluated closely.

Over the years, the field's view of this type of work has changed, says Dr. Cheng. With clinical evidence and data showing that the herbal product can be made to be consistent, he has experienced more acceptance from colleagues in the U.S. and internationally. In 2003, he started a global consortium of researchers and pharmaceutical companies studying traditional Chinese medicine.

Dr. Cheng, who earned his doctorate in biochemical pharmacology from Brown University in Rhode Island, has also found it easier over time to get published and to receive funding for the work with herbs, including as a potentialtreatment for the side effects induced by cancer chemotherapy.

Anticipating the skepticism he might face in developing a plant-based drug, Dr. Cheng didn't publish his work in a journal until two years ago when he had consistent, clinical evidence and some understanding of the mechanism. 'I might as well wait until the whole comprehensive story develops,' says Dr. Cheng. 'Now I feel it's about time.'

Some herbs and plants with possible cancer-treatment benefits.

Boswellia serrata (frankincense)

Reduces inflammation

What it is being studied for: To reduce tumor growth and brain swelling in patients with gliomas

Nerium oleander (rose laurel)

Reduces inflammation and modulates the immune system

What it is being studied for: To use with chemotherapy drugs to treat advanced non-small-cell lung cancer

Valeriana officinalis (garden heliotrope)

Has sedating effects

What it is being studied for: To improve sleep in cancer patients undergoing treatment

Hypericum perforatum (St. John's sort)

Has analgesic, sedative and anti-depressant effects

What it is being studied for: To reduce hot flashes in postmenopausal women with breast cancer