Effects of anti-Leishmania compounds in the behavior of the sand fly vector Lutzomyia longipalpis

BACKGROUND Leishmaniasis is an infectious parasitic disease caused by pathogens of the genus Leishmania transmitted through the bite of adult female sand flies. To reduce case numbers, it is necessary to combine different control approaches, especially those aimed at the sand fly vectors. Innovative forms of control with the use of attractive sugar baits explored the fact that adult sand flies need to feed on sugars of plant origin. Leishmania parasites develop in the gut of sand flies, interacting with the sugars in the diet of adults. Recent studies have shown that sugar baits containing plant-derived compounds can reduce sand fly survival, the number of parasites per gut, and the percentage of infected sand flies. Several synthetic compounds produced from naphthoquinones and pterocarpans have anti-parasitic activity on Leishmania amazonensis and/or Leishmania infantum in cell culture. This work aimed to assess the inclusion of these compounds in sugar baits for blocking transmission, targeting the development of the Leishmania parasite inside the sand fly vector. RESULTS We evaluated the attractant or repellent properties of these compounds, as well as of the reference compound N,N '-diethyl-m-toluamide (DEET), in sugar baits. We also observed changes in feeding preference caused by these compounds, looking for anti-feeding or stimulation of ingestion. Pterocarpanquinone L4 and pentamidine showed attractant and repellent properties, respectively. CONCLUSION Based on the effects in feeding preference and intake volume, pterocarpanquinone L6, and the pyrazole-derived compound P8 were chosen as the most promising compounds for the future development of anti-Leishmania sugar baits. (c) 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Automated summary

This study evaluated the effectiveness of adding synthetic compounds with anti-Leishmania activity to sugar baits and selected two promising compounds for future development. Pterocarpanquinone L6 and pyrazole-derived compound P8 showed attractive and repellent properties on sand flies, respectively.