Antiprotozoal and Antibacterial Activity of Ravenelin, a Xanthone Isolated from the Endophytic Fungus Exserohilum rostratum

Author(s):Show less -

Pina, Jeferson Rodrigo Souza ^[1] ; Silva-Silva, Joao Victor ^[2] ; Carvalho, Josiwander Miranda ^[1] ; Bitencourt, Heriberto Rodrigues ^[1] ; Watanabe, Luciano Almeida ^[1] ; Fernandes, Juan Matheus Pereira ^[2] ; de Souza, Guilherme Eduardo ^[3] ; Aguiar, Anna Caroline Campos ^[3] ; Guido, Rafael Victorio Carvalho ^[3] ; Almeida-Souza, Fernando ^{[2, 4]} ; Calabrese, Katia da Silva ; Marinho, Patricia Santana Barbosa ^[1] ; Marinho, Andrey Moacir do Rosario ^[1]

Affiliation

^[1] Fed Univ Para, Postgrad Program Chem, BR-66075110 Belem, Para - Brazil

^[2] Fundacao Oswaldo Cruz, Inst Oswaldo Cruz, Lab Immunomodulat & Protozool, BR-21040360 Rio De Janeiro - Brazil

^[3] Univ Sao Paulo, Sao Carlos Inst Phys, BR-13566590 Sao Carlos, SP - Brazil

^[4] Univ Estadual Maranhao, Postgrad Program Anim Sci, BR-65055310 Sao Luis, Maranhao - Brazil

• Document type: Journal article
• Source: Molecules; v. 26, n. 11 JUN 2021.
• Web of Science Citations: 0

Abstract

The natural compound ravenelin was isolated from the biomass extracts of Exserohilum rostratum fungus, and its antimicrobial, antiplasmodial, and trypanocidal activities were evaluated. Ravenelin was isolated by column chromatography and HPLC and identified by NMR and MS. The susceptibility of Gram-positive and Gram-negative bacteria strains to ravenelin was determined by microbroth dilution assay. Cytotoxicity was evaluated in hepatocarcinoma cells (HepG2) and BALB/c peritoneal macrophages by using MTT. SYBR Green I-based assay was used in the asexual stages of Plasmodium falciparum. Trypanocidal activity was tested against the epimastigote and intracellular amastigote forms of Trypanosoma cruzi. Ravenelin was active against Gram-positive bacteria strains, with emphasis on Bacillus subtilis (MIC value of 7.5 mu M). Ravenelin's antiparasitic activities were assessed against both the epimastigote (IC50 value of 5 +/- 1 mu M) and the intracellular amastigote forms of T. cruzi (IC50 value of 9 +/- 2 mu M), as well as against P. falciparum (IC50 value of 3.4 +/- 0.4 mu M). Ravenelin showed low cytotoxic effects on both HepG2 (CC50 > 50 mu M) and peritoneal macrophage (CC50 = 185 +/- 1 mu M) cells with attractive selectivity for the parasites (SI values > 15). These findings indicate that ravenelin is a natural compound with both antibacterial and antiparasitic activities, and considerable selectivity indexes. Therefore, ravenelin is an attractive candidate for hit-to-lead development. (AU)

• FAPESP's process: 20/12904-5 - Discovery of Plasmodium falciparum inhibitors from Cerrado plants as lead compounds candidates for malaria: integrated studies of ultra-efficient chromatography, spectroscopy, and biological assays
• Grantee: Rafael Victorio Carvalho Guido
• Support Opportunities: BIOTA-FAPESP Program - Regular Research Grants
• FAPESP's process: 13/07600-3 - CIBFar - Center for Innovation in Biodiversity and Drug Discovery
• Grantee: Glaucius Oliva
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC