Traditional Chinese Medicine Oil Studied Against Prostate Cancer

Division of Cancer Treatment and Diagnosis

Since prostate cancer is the third lead­ing cause of cancer death in U.S. males, an army of researchers is looking for answers. One of these researchers, Yongkui Jing, Ph.D., a biologist at the Mt. Sinai School of Medicine, is doing basic research, focusing on one of the pathways long known to be important to tumor growth in prostate, lung, and other cancers. This pathway is known by the name of one of it major components, the mammalian target of the drug rapamycin or mTOR.

Dr. Jing explained that mTOR seems to act as a switch for the growth and proliferation of tumor cells. The drug rapamycin – also known as siroli­mus – was originally discovered from bacteria found in the soil on Easter Island. It seems to have a lot of potential uses in cancer and other conditions and is a staple used to suppress the body’s immune system during organ transplants, he added. But rapamycin, like androgen treatments for prostate cancer, can have a lot of side effects, especially in the older patients, who make up the majority of prostate cancer cases, Dr. Jing noted.

Dr. Jing was originally trained in medicine in Beijing, China, and is very familiar with traditional Chinese medicine (TCM). His current NCI-funded work* is focused on a natural product mixture known as the essential oil of Wen Ezhu, which is derived from a tumeric-root tuber plant found throughout Asia called Curcuma wenyujin. He and others have found that Ezhu oil targets the mTOR pathway.

“It has been used to combat viruses for a long time,” explained Dr. Jing, “and for three or four decades researchers in China and the United States have been finding anti-cancer effects.” Though there may be as many as 30 active components in the Ezhu oil used in TCM, his lab is concentrating on the substance curcumol to see whether it is the primary active inhibitor of mTOR. They are testing human prostate cancer cells and mice with prostate cancer for the impact of the Ezhu oil in its natural form, as compared to curcumol. They are also looking at a separate drug designed along the lines of rapamycin, to see whether it adds to the impact on cancer cells when used in combination with the oil or curcumol.

“We really need to figure out if the combination has synergistic or enhanced effects,” Dr. Jing said. “Once we are confident we know which signaling pathways are involved, we might be able to use other drugs, less toxic than rapamycin, in combination with Ezhu oil.”

NCI Program Director Yali Fu, Ph.D., commented, “This work is a good example of tapping into traditional knowledge on natural medicines in use alone or in combination with modern cancer biology. Active components in Ezhu oil, such as curcumol, used alone or in combination with other mTOR-signaling pathway inhibitors, could potentially reduce toxicity and increase effectiveness of prostate cancer therapy.”