Natural compounds from the red alga Asparagopsis: potential drugs against leishmaniasis

Marine macroalgae produce a wide variety of remarkable natural compounds, usually referred to as bioactive metabolites, in response to ecological pressure such as maintenance of unfouled surfaces or deterrence of predation. It was reported that marine algae exhibit antiviral, hypocholesterolemic, hypotensive, antibacterial, anticoagulant, anthelmintic, anticancer, cytotoxic and antifungal activities. In particular, the genus Asparagopsis (Rhodophyta) is responsible for the production of more than 100 halogenated compounds, which are active against several pathogens, particularly Leishmania spp. (Kinetoplastida, Euglenozoa). Protozoans belonging to the genus Leishmania are responsible of the anthropozoonosis known as Leishmaniasis. Leishmaniasis is a vector-borne disease caused by obligate intramacrophage protozoan parasite of the genus Leishmania and its incidence is increasing in non-endemic areas due to changing patterns of international travel and to population migration. It is a disease with a worldwide distribution, especially in many tropical and sub-tropical countries, affecting both humans and animals. Crude extracts of A. taxiformis from the Strait of Messina were tested against L. infantum (MHOM/IT/80/IPT1), the agent of Leishmaniasis in Europe. Preliminary results showed that extracts had remarkable antiprotozoal activity, revealing such algae as a great source of natural antiprotozoal products.