Lab method identifies fake Chinese herbal medicine

A new method of identifying an ingredient commonly used in traditional Chinese medicine (TCM) could help avoid accidental or deliberate substitution, say researchers.

Immature bitter orange (Fructus aurantii) is used in TCM to relive gastrointestinal conditions but can sometimes be substituted in herbal preparations for other species - particularly the fruit of the trifoliate orange shrub (Ponicirus trifoliatae).

While the two plants have been used interchangeably in the distant past, recent studies have shown that they have different physiological effects in the body, say the scientists, who are from the US Department of Agriculture and China Medical University in Taiwan.

By the Ming and Qing dynasties of China, immature trifoliate orange fruit was "defined clearly as the counterfeit" of immature bitter orange and are still often misused either mistakenly or intentionally in counterfeit TCM preparations, they write in the Journal of Pharmaceutical and Biomedical Analysis (25 March 2015). 

Using a technique called flow-injection mass spectrometry, the researchers identified eight compounds that served as chemical markers to differentiate the two fruits using a simple and rapid laboratory analysis.

Other groups have tried to distinguish between the two ingredients using high performance liquid chromatography (HPLC) , but these methods " were time-consuming and labour-intensive," they report.


Image courtesy of Shutterstock / marilyn barbone