[Bryophytes, a potent source of drugs for tomorrow's medicine?]

Although secondary plant metabolites provided numerous leads for the development of a wide array of therapeutic drugs, the discovery of new drugs with novel structures has declined in the past few years. Indeed higher plants have a similar evolutionary history and so produce similar metabolites. Search for novel sources of new therapeutic compounds within unexplored parts of biodiversity is thus an attractive challenge. Bryophytes, a group of small terrestrial plants remain relatively untouched in the drug discovery process whereas some have been used as medicinal plants. Studies of their secondary metabolites are recent but reveal original compounds, some of which not synthesized by higher plants. However investigations often meet difficulties during harvest or isolation of active compounds. In consequence, small quantities of substances obtained may be the main reason for the lack of biological tests. Strategies to overcome those troubles may exist and then lead to innovative medicinal applications.