Africa’s gift to the world

Scientists looking for potential new drugs in plants can take various routes along the path to drug discovery. All the plants in a specified region can be collected and their extracts tested – or screened – against various whole organisms, cells or purified proteins in the hope of finding new biologically active compounds, which might one day lead to new drugs. An alternative approach called ethnobotany, selects plants for screening based on their folkloric use in one or more traditional societies. Plants within the same species often contain similar compounds, and therefore another more targeted approach is to probe plants related to those already known to contain bioactive chemicals.

Regardless of how it is done, searching for new drugs in plants is tedious, time consuming and expensive. In a complete turnaround from 20 years ago, only a small number of pharmaceutical companies now continue with active research programmes in medicinal plant chemistry. But no matter which route in drug discovery is taken, serendipitous discoveries often play a part along the way.

Raymond Cooper and Jeffrey Deakin explain how the rosy periwinkle was discovered, and the chemistry behind its use in the fight against cancer.