Medicines from the sea

Approximately 2 million species of marine organisms exist. They are complex and highly competitive, and are forced to share limited space and compete for habitats. A large number of species have adapted to these conditions by producing chemical compounds, often referred to as “bioactive compounds,” to defend themselves against predators and the excessive increase in numbers of competing species, or conversely, to subdue prey.

Bioactive compounds are complex molecules produced by a wide range of organisms which include bacteria, fungi, microalgae and complex organisms such as macroalgae, plants, and animals. These compounds are present in a wide range of molecules, including anticancer peptides, characterized by their cytotoxic and anti-tumor action against various types of cancer cells, antibacterial and antiviral secondary metabolites, toxins (and antitoxins), and even essential oils, which are thought to have curative and therapeutic properties within the realm of complementary medicine.

The bioactive potential of marine organisms can be classified into different types: Antibacterial, Antiviral, Antitumoral, Cytotoxic, Antifungal, Antioxidant, Anti-inflammatory and Anticoagulant.

Species with bioactive potential are a good source for developing new medicines.

The bioactive potential of Mediterranean animal species

Several animal species in the Mediterranean have bioactive potential. The majority are benthic organisms such as tunicates, sponges, bryozoans, and cnidarians. They produce a wide variety of chemical compounds that they use to defend themselves against predators, competing organisms, and parasites or invasive microorganisms.

Despite a growing interest in the bioactive potential of these marine animal species for discovering future compounds and drugs, human activities are affecting them, and some are even in danger of extinction. Marine pollution (e.g., from chemical compound spillage) damages populations of sponges and other slow growing organisms by limiting their filtering capacity, and recreational maritime activities can also have a negative impact. For example, anchors of moored boats damage algae and benthic organisms, and underwater fishing, swimming, and scuba diving can harm the sessile organisms that inhabit rocky sea beds. Sea warming caused by climate change can lead to large-scale mortality of species due to the proliferation of opportunistic pathogenic organisms which are thermophilic. Finally, some professional fishing methods, such as trawling, have a seriously detrimental impact on marine biota. To date, studies in this area have only been very general, and no comprehensive research has been carried out to examine the conservation status of species with bioactive potential in the Mediterranean. Further research is crucial in order to gain insights into how these species cope with the impact of human activity. In this context, one of the goals of the Oceans & Human Health Chair is to evaluate the bioactive potential of animal species inhabiting Mediterranean coastal waters, and link this to their conservation status.