Potential of the natural products against leishmaniasis in Old World - a review of in-vitro studies

ABSTRACT

Leishmaniasis is a vector-borne disease among the 10 most Neglected Tropical Diseases with diverse clinical manifestations caused by protozoan parasites of the Leishmania genus. Around 80% of leishmaniasis cases are found in the Old World affecting populations mainly in low and middle-income countries. Its control relies mostly on chemotherapy which still presents many drawbacks. Natural products may offer an inexhaustible source of chemical diversity with therapeutic potential. Despite the lack of knowledge on traditional products with activity against Leishmania parasites, many reports describe the search for natural extracts and compounds with antileishmanial properties against promastigote and amastigote parasite forms. This review summarizes the research of 74 publications of the last decade (2008–2018) focused on the identification of endemic plant-derived products that are active against Old World Leishmania parasites responsible for cutaneous and visceral leishmaniasis. The present review combines data on antileishmanial activity of 423 plants species, belonging to 94 different families, including a large range of crude extracts which lead to the isolation of 86 active compounds. Most studied plants came from Asia and most promising plant families for antileishmanial activity were Asteraceae and Lamiaceae. From the chemical point of view, terpenoids were the most frequently isolated natural products. These studies suggest that natural products isolated from Old World flora are a rich source of new chemical scaffolds for future leishmaniasis treatment as well as for other Neglected Tropical Diseases warranting further investigation.

KEYWORDS:

• Leishmaniasis
• plants
• natural compounds
• Old World Leishmania spp
• antileishmanial activity

Acknowledgments

The authors would like to thank Andreia Albuquerque-Wendt and Ciaran McCoi from Sir William Dunn School of Pathology, University of Oxford for the critical and English revision. We also thank Professor José Carlos Costa and Professor Raul Bruno de Sousa from the Instituto Superior de Agronomia of the University of Lisbon - Portugal for the revision of the botanic classification of the plants included in this review.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

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Additional information

Funding

This work was supported by the Fundação para a Ciência e a Tecnologia [UID/Multi/04413/2013 (GHTM)]; Fundação para a Ciência e a Tecnologia [SFRH/BD/78062/2011]; Fundação para a Ciência e a Tecnologia [IF/00743/2015]; CAPES [001]; CNPq [301357/2019-7]; FAPESP [18/07585-1].