Ginger Extract to Be Tested for Lung Cancer Prevention

Office of Cancer Complementary and Alternative Medicine
Division of Cancer Treatment and Diagnosis

Lung cancer currently causes the greatest number of cancer-related deaths in the United States, and no drugs are available to help prevent the disease. Shengmin Sang, Ph.D., assistant professor in the Human Nutrition Research Program at the North Carolina Central University, is studying whether several compounds isolated from the herb ginger could potentially be used to prevent the development of lung cancer.

“Ginger is currently one of the popular dietary supplements in the U.S. market, and it has recently started receiving attention from researchers due to its potential antioxidant, anti-inflammatory, and anti-cancer activity,” said Dr. Sang.

In earlier laboratory studies*, Dr. Sang and his colleagues showed that a compound isolated from dried ginger, 6-shogaol, inhibited the growth of human cancer cells and induced apoptosis (cell death) in a colorectal cancer cell line by destroying the mitochondria, the organelles that produce cellular energy.

Much of the previous work testing ginger as an anti-cancer agent has focused on compounds called gingerols, which are found in fresh ginger. Shogaols are formed when ginger is dehydrated. “In our studies, we have found that shogaols have much stronger anti-inflammatory and anti-carcinogenic activity than gingerols,” explained Dr. Sang.

One of the challenges for research using botanicals and dietary supplements, explained Dr. Sang, is that there are many compounds with biological activity in any one product. The levels of these compounds can also vary from batch-to-batch in commercial products. When Dr. Sang tested several ginger preparations purchased from a supermarket, the levels of shogaols and gingerols varied substantially among different products.

With funding from the NCI,** Dr. Sang’s laboratory is creating a standardized ginger extract high in shogaols. They plan to quantify the levels of shogaols and gingerols in the extract, identify any other bioactive compounds in the final product, and determine the bioavailability of any compounds with anti-cancer activity.

Once they have developed a standardized ginger extract, they will test it in a mouse model of lung carcinogenesis. In this model, mice will be exposed to a lung carcinogen called 4-(Methylnitrosamino-1-(3-pyridyl)1-butanone (called NNK), which is found in tobacco. Different groups of mice will receive either the standardized ginger extract or extract from fresh ginger before, or after, carcinogen exposure. A third group of mice will not receive ginger. Tumor development will be compared between mice that did or did not receive the ginger extracts.

“The development of a standardized and more-active ginger extract preparation will facilitate future pre-clinical and clinical studies on the health benefits of ginger,” said Dr. Sang. “If a standardized ginger extract can be developed into a lung cancer preventive agent, the public health benefit would be tremendous.”