Plant metabolism steered to drug synthesis
making plant-derived compounds in cell cultures that should cut the
cost of manufacturing a raft of pharmaceuticals, including drugs
for cancer.
The scientists, from Finland's VTT Technical Research Centre and the Belgian VIB (Flander Interuniversity Institute for Biotechnology) have overcome one of the key obstacles to isolating compounds from plants, i.e. their extremely low concentrations.
A team led by VTT's chief research scientist, Kirsi-Marja Oksman-Caldentey, has developed a way of altering the metabolism of plant cells so that they are steered towards the production of the desired compound.
For example, Oksman-Caldentey et al recently reported in the Proceedings of the National Academy of Science (27 April issue) the genetic engineering of the plant henbane (Hyoscimus niger) so that it would produce the antimuscarinic drug scopolamine in root cultures used as a form of 'bioreactor'. The technique is suitable for commercial-scale production.
The key to the team's success has been to work out the secondary metabolic pathways in plant cells using functional genomics. "Despite the tremendous importance of secondary metabolites for humans and for the plant itself, plant secondary metabolism remains poorly characterised," according to the researchers.
Armed with this knowledge, they determined the entire chain of events leading to the creation of compounds, and developed a set of molecular tools to direct this to the biosynthesis of specific compounds.
"The biotechnical method developed by VTT and VIB offers a quick and efficient method for producing high-value medical compounds in cultivated cells," said Oksman-Caldentey. She added that it is also possible to use the new technology to produce totally new compounds.
Today, around one quarter of all pharmaceuticals are of plant origin, either used as a pure compound or chemically engineered to form appropriate derivatives. These include compounds such as morphine, codeine and several anticancer drugs.
VTT and VIB are now focusing on how to commercialise the method.
