Most potent carcinogen found in herbal remedies

Duke-NUS members of the research team: (Clockwise from top right) Prof Teh, Dr Poon, Dr John McPherson, Assoc Prof Rozen and Prof Patrick Tan
Photo: The Straits Times © Singapore Press Holdings Ltd

The Aristolochia plant
Photo: Chang Gung Memorial Hospital

The research led by Professors Teh Bin Tean and Patrick Tan and Associate Professor Steven Rozen of the Duke-NUS Graduate Medical School Singapore (Duke-NUS), together with Professor See-Tong Pang from Chang Gung Memorial Hospital in Taiwan, was published online in Science Translational Medicine on 7 August 2013.

By means of advanced DNA sequencing technologies, the research team found that AA caused more DNA mutations than cigarette smoke or ultraviolet light. They also identified the “genetic fingerprint” of AA exposure that may pave the way to new approaches to detect AA presence in humans and the environment.

“AA’s contributions to kidney failure and cancer have been documented, but AA’s possible role in other cancer types was unknown. In this study, we found that the AA-related DNA fingerprint could be used to screen for the potential involvement of AA in other cancers such as liver cancer,” explained lead author Dr Poon Song Ling from Duke-NUS and the National Cancer Centre Singapore (NCCS).

“We have shown that AA causes 300 to 3000 gene mutations, creating a unique molecular fingerprint of this carcinogen,” said Prof Teh, who is also a Senior Principal Investigator at the Cancer Science Institute of Singapore (CSI), NUS and Principal Investigator at NCCS.

Cautioning the public, the researchers advised users to note the contents of herbal products prior to consumption. While AA had been banned officially in Europe, North America and Asia, some products containing AA are still allowed under supervision and easily available worldwide and over the Internet.

The one-and-half-year study was made possible by grants from the Singapore National Medical Research Council, the Singapore Millennium Foundation, the Lee Foundation, the National Cancer Centre Research Fund, The Verdant Foundation, Duke-NUS, CSI, the Chang Gung Memorial Hospital, LinKou, the Taiwan National Science Council, and the Wellcome Trust.

National University of Singapore.