Natural products as inhibitors of Leishmania major dihydroorotate dehydrogenase

Author(s)

Chibli, Lucas A. ^[1] ; Schmidt, Thomas J. ^[2] ; Cristina Nonato, M. ^[3] ; Calil, Felipe A. ^[3] ; Da Costa, Fernando B. ^[1]

Affiliation

^[1] Univ Sao Paulo, AsterBioChem Res Team, Sch Pharmaceut Sci Ribeirao Preto, Ave Cafe S-N, BR-14040903 Ribeirao Preto, SP - Brazil

^[2] Univ Munster, IPBP, PharmaCampus, Corrensstr 48, D-48149 Munster - Germany

^[3] Univ Sao Paulo, Lab Prot Crystallog, Sch Pharmaceut Sci Ribeirao Preto, Ave Cafe S-N, BR-14040903 Ribeirao Preto, SP - Brazil

• Document type: Journal article
• Source: EUROPEAN JOURNAL OF MEDICINAL CHEMISTRY; v. 157, p. 852-866, SEP 5 2018.
• Web of Science Citations: 3

Abstract

The flavoenzyme dihydroorotate dehydrogenase (DHODH) catalyzes the fourth reaction of the de novo pyrimidine biosynthetic pathway, which exerts vital functions in the cells, especially within DNA and RNA biosynthesis. Thus, this enzyme stands out as a new key molecular target for parasites causing Neglected Diseases (NDs). Focused on contributing to the development of new therapeutic alternatives for NDs, in this study, for the first time, a screening of 57 natural products for in vitro inhibition of Leishmania major DHODH (LmDHODH) was carried out, including cross validation against the human DHODH (HsDHODH). A subset of natural products consisting of 21 sesquiterpene lactones (STLs) was submitted to QSAR studies. Additionally, thermostability studies by differential scanning fluorimetry (DSF) were performed to determine whether the STLs are effectively or not binding to the enzyme. The IC50 values against LmDHODH varied from 27 to 1200 mu M; only irrelevant inhibition was obtained on HsDHODH. DSF assays confirmed binding of STLs to LmDHODH; moreover, it is suggested that such inhibitors might act in a different site other than the active site. A reliable QSAR model based on molecular descriptors was obtained (R-2: 0.83; Q(2)cv: 0.69 and Q(2)ExT/F2: 0.66) indicating that stronger inhibition requires a balanced distribution of the hydrophobic regions across the molecular surface, as well as higher width and lower hydrophobicity of the molecules. A pharmacophore-based 3D-QSAR approach also afforded a useful model (R-2: 0.72; Q(2)cv: 0.50 and Q(2)ExT/F2: 0.62), which confirmed the importance of proper orientation of the ligands, molecular surface features and shape for stronger inhibition, reflecting properties of a putative common binding site. These data indicated for the first time that natural products can actually inhibit LmDHODH and highlighted some metabolites as potentially interesting starting points for the discovery of more potent LmDHODH inhibitors, ultimately aiming at new effective therapeutic alternatives for leishmaniasis and, possibly, other NDs caused by trypanosomatids. (C) 2018 Elsevier Masson SAS. All rights reserved. (AU)

• FAPESP's process: 15/25099-5 - Antimalarial drug repositioning in the schistosomiasis treatment based on the selective inhibition of the enzyme dihydroorotate dehydrogenase
• Grantee: Felipe Antunes Calil
• Support type: Scholarships in Brazil - Doctorate
• FAPESP's process: 14/26866-7 - Metabolomics, enzymatic targets and in silico tools in the search of bioactive compounds from plants
• Grantee: Fernando Batista da Costa
• Support type: Regular Research Grants
• FAPESP's process: 14/01443-6 - Screening of inhibitors of trypanosomatides DHODHs enzymes in Asteraceae employing metabolomics combined with in silico methods
• Grantee: Lucas Apolinário Chibli
• Support type: Scholarships in Brazil - Doctorate
• FAPESP's process: 16/18579-3 - Chemoinformatic tools applied for the screening of inhibitors of the enzyme DHODH from Leishmania major
• Grantee: Lucas Apolinário Chibli
• Support type: Scholarships abroad - Research Internship - Doctorate