Drug development from natural products: exploiting synergistic effects.

Drug development in phytomedicine has been focused in the past on the discovery and analysis of new structures from natural products. The search aimed at the determination of the single "active principle" in plants, based on the assumption that a plant has one or a few ingredients which determine its therapeutic effects. But traditional systems of medicines like Ayurveda, traditional Chinese medicine or the European phytotherapy generally assume that a synergy of all ingredients of the plants will bring about the maximum of therapeutic efficacy. This approach has for long been impossible to investigate since adequate methods to standardize complex plant mixtures as well as to rationalize complex mode of actions were lacking. The introduction of high throughput technologies provides the opportunity to determine profiles of plants and to systematically explore the mode of action of combinatory drug regimes. The present review highlights the concept of synergy and gives examples of synergistic effects of plant constituents. It elaborates on how the high throughput technologies can be used in drug development from natural products with the aim of creating evidence-based plant medications in prevention and treatment of different diseases in the form of new single treatments or new combinatory drug regimes while exploiting synergy-effects.