SCHISTOSOMIASIS Recent Progresses in Synthesis and Evaluation of Bioactive Compounds with Molluscicidal Activity - Molluscicidal Activity of Synthetic and Natural Products

Parasitic infections affect a vast number of people around the world. Schistosomiasis is a known example of tropical parasitic disease. Since the past decade, an increasing effort has been made towards its control. There are two main chemical interventions employed to cut off the schistosomiasis life-cycle. The first one consists of therapy, to treat infected individuals. The second uses molluscicidal compounds to control the population of the vector snails. This latter strategy has been considered as one of the best preventive actions, since it eliminates the parasites before they can reach human hosts. Towards this end, synthetic molluscicide, niclosamide, has proved to have efficient activity against schistosomiasis. Nevertheless, undesirable side effects associated with this compound, such as toxicity to non-target organisms in the aquatic environment, encouraged the search for new molluscicidal compounds. Although synthetic drugs often display higher molluscicidal activity than natural products, their lack of selectivity towards nocive snails, as well as difficult biodegradation, cause severe burdens on the environment. This problem has caused criticism on the use of the currently available synthetic molluscicides and turned the interest of a part of the scientific community to the investigation of new compounds, including natural substances. In fact, the dilemma between synthetic and natural products is not yet settled, and it still remains a challenge to find an effective and eco-friendly substance to combat the snails selectively. The focus of this chapter is to present an overview of recent studies on synthetic compounds and natural products with molluscicidal activity.

Keywords: Schistosomiasis, snail control, molluscicidal activity, synthetic compounds, natural products.