AUTHOR=Pinheiro Liliane Sena , Andrade-Neto Valter Viana , Mantuano-Barradas Marcio , Pereira Elisa Cavalcante , Barbosa Rodrigo Cesar Fernandes , de Oliveira Marcia Cristina Campos , Menna-Barreto Rubem Figueiredo Sadok , Cunha-Júnior Edézio Ferreira , Torres-Santos Eduardo Caio 

TITLE=Biological effects of trans, trans-farnesol in Leishmania amazonensis

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=13

YEAR=2023

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2023.1221246

DOI=10.3389/fcimb.2023.1221246

ISSN=2235-2988

ABSTRACT=<sec><title>Introduction</title><p>Farnesol, derived from farnesyl pyrophosphate in the sterols biosynthetic pathway, is a molecule with three unsaturations and four possible isomers. <italic>Candida albicans</italic> predominantly secretes the <italic>trans</italic>, <italic>trans</italic>-farnesol (<italic>t</italic>, <italic>t</italic>-FOH) isomer, known for its role in regulating the virulence of various fungi species and modulating morphological transition processes. Notably, the evolutionary divergence in sterol biosynthesis between fungi, including <italic>Candida albicans</italic>, and trypanosomatids resulted in the synthesis of sterols with the ergostane skeleton, distinct from cholesterol. This study aims to assess the impact of exogenously added <italic>trans</italic>, <italic>trans</italic>-farnesol on the proliferative ability of <italic>Leishmania amazonensis</italic> and to identify its presence in the lipid secretome of the parasite.</p></sec><sec><title>Methods</title><p>The study involved the addition of exogenous <italic>trans</italic>, <italic>trans</italic>-farnesol to evaluate its interference with the proliferation of <italic>L. amazonensis</italic> promastigotes. Proliferation, cell cycle, DNA fragmentation, and mitochondrial functionality were assessed as indicators of the effects of <italic>trans</italic>, <italic>trans</italic>-farnesol. Additionally, lipid secretome analysis was conducted, focusing on the detection of <italic>trans</italic>, <italic>trans</italic>-farnesol and related products derived from the precursor, farnesyl pyrophosphate. <italic>In silico</italic> analysis was employed to identify the sequence for the farnesene synthase gene responsible for producing these isoprenoids in the <italic>Leishmania</italic> genome.</p></sec><sec><title>Results</title><p>Exogenously added <italic>trans</italic>, <italic>trans</italic>-farnesol was found to interfere with the proliferation of <italic>L. amazonensis</italic> promastigotes, inhibiting the cell cycle without causing DNA fragmentation or loss of mitochondrial functionality. Despite the absence of <italic>trans</italic>, <italic>trans</italic>-farnesol in the culture supernatant, other products derived from farnesyl pyrophosphate, specifically α-farnesene and β-farnesene, were detected starting on the fourth day of culture, continuing to increase until the tenth day. Furthermore, the identification of the farnesene synthase gene in the <italic>Leishmania</italic> genome through in silico analysis provided insights into the enzymatic basis of isoprenoid production.</p></sec><sec><title>Discussion</title><p>The findings collectively offer the first insights into the mechanism of action of farnesol on <italic>L. amazonensis</italic>. While <italic>trans</italic>, <italic>trans</italic>-farnesol was not detected in the lipid secretome, the presence of α-farnesene and β-farnesene suggests alternative pathways or modifications in the isoprenoid metabolism of the parasite. The inhibitory effects on proliferation and cell cycle without inducing DNA fragmentation or mitochondrial dysfunction raise questions about the specific targets and pathways affected by exogenous <italic>trans</italic>, <italic>trans</italic>-farnesol. The identification of the farnesene synthase gene provides a molecular basis for understanding the synthesis of related isoprenoids in <italic>Leishmania</italic>. Further exploration of these mechanisms may contribute to the development of novel therapeutic strategies against <italic>Leishmania</italic> infections.</p></sec>