Scientists decode how traditional Chinese medicine kills cancer cells

Scientists have found how acomplex mix of plant compounds derived from ancient clinical practice in China - a traditional Chinese medicine - works to kill cancer cells.

Compound kushen injection (CKI) is approved for use in China to treat various cancer tumours, usually as an adjunct to western chemotherapy - but how it works has not been known.

The study, by researchers at University of Adelaide in Australia, is one of the first to characterise the molecular action of a traditional Chinese medicine rather than breaking it down to its constituent parts.

"Most Traditional Chinese Medicine are based on hundreds or thousands of years of experience with their use in China," said professor David Adelson, Director of the Zhendong Australia China Centre for the Molecular Basis of Traditional Chinese Medicine.

"There is often plenty of evidence that these medicines have a therapeutic benefit, but there isn't the understanding of how or why," said Adelson. "If we broke down and tested the components of many Traditional Chinese Medicines, we would find that individual compounds don't have much activity on their own," he said.

"It's the combination of compounds which can be effective, and potentially means few side-effects as well," he added. "This is one of the first studies to show the molecular
mode of action of a complex mixture of plant-based compounds - in this case extracts from the roots of two medicinal herbs, Kushen and Baituling - by applying what's known as a systems biology approach," Adelson said.

"This is a way of analysing complex biological systems that attempts to take into account all measurable aspects of the system rather than focussing on a single variable," he said.

The researchers used high-throughput next generation sequencing technologies to identify genes and biological pathways targeted by CKI when applied to breast cancer cells grown in the laboratory.

"We showed that the patterns of gene expression triggered by CKI affect the same pathways as western chemotherapy but by acting on different genes in the same pathways," said Adelson.

"These genes regulate the cell cycle of division and death, and it seems that CKI alters the way the cell cycle is regulated to push cancer cells down the cell death pathway, therefore killing the cells," he said.

Adelson said this technique could be used to analyse the molecular mechanisms of other traditional Chinese medicines, potentially opening their way for use in western medicine.

The study was published in the journal Oncotarget.