Bioprospecting of Artemisia genus: from artemisinin to other potentially bioactive compounds

The genus Artemisia is one of the largest and most widely distributed genera of the family Asteraceae. It consists of over 500 diverse species, including perennial, biennial and annual herbs or small shrubs, distributed mainly in the temperate zones of Europe, Asia and North America. The genus Artemisia has aroused great interests due to its chemical and biological diversity, which have led to an intensive use in perfumes, cosmetics, and traditional medicine. Among the various species, Artemisia annua is known for producing artemisinin, a sesquiterpene lactone that was isolated from the Chinese herbaceous plant in 1972. Artemisinin is considered as one of the most potent antimalarial drugs and artemisinin-based combination therapies have been recommended from WHO as treatments of malarial disease. Unfortunately, artemisinin yield from plants is rather low, ranging from 0,01% to 1,5% DW in the leaves. The constant and raising demand for artemisinin for medical purposes highlighted the necessity to find alternative natural resources and to develop new approaches to increase the production yields. In order to find out new sources for artemisinin and to identify new bioactive metabolites of interest, five different Artemisia species have been harvested from the wild mountain area around Verona. These species were chosen based on the ascribed medicinal properties and on their availability in the selected sampling region. Antioxidant, ant-inflammatory, and Monoamine Oxidase-B (MAO-B) inhibition potentials of the plant extracts have been evaluated and correlated with the corresponding metabolomes to identify new potential compounds of interest. Moreover, a metabolic engineering approach to boost artemisinin production is currently ongoing and it consists of transiently expressing genes involved in the biosynthetic pathway directly in Artemisia annua plants.