Antileishmanial Activity of Flavones-Rich Fraction From Arrabidaea chica Verlot (Bignoniaceae)

• Published in: Frontiers in pharmacology Vol. 12; p. 703985
• Main Authors: Silva-Silva, João Victor, Moragas-Tellis, Carla Junqueira, Chagas, Maria do Socorro dos Santos, Souza, Paulo Victor Ramos de, Souza, Celeste da Silva Freitas de, Hardoim, Daiana de Jesus, Taniwaki, Noemi Nosomi, Moreira, Davyson de Lima, Dutra Behrens, Maria, Calabrese, Kátia da Silva, Almeida-Souza, Fernando
• Format: Journal Article
• Language: English
• Published: Frontiers Media S.A 20-07-2021
• Subjects: Arrabidaea chica; flavonoids; L. amazonensis; macrophages; nitric oxide; Pharmacology; transmission electron microscopy
• ISSN: 1663-9812; 1663-9812
• DOI: 10.3389/fphar.2021.703985

Acknowledging the need of identifying new compounds for the treatment of leishmaniasis, this study aimed to evaluate, from
in vitro
trials, the activity of flavones from
Arrabidaea chica
against
L. amazonensis
. The chromatographic profiles of the hydroethanolic extract and a flavone-rich fraction (ACFF) from
A. chica
were determined by high-performance liquid chromatography coupled with a diode-array UV-Vis detector (HPLC-DAD-UV) and electrospray ionization mass spectrometry in tandem (LC-ESI-MS-MS). The flavones luteolin (
1
) and apigenin (
2
), isolated from chromatographic techniques and identified by Nuclear Magnetic Resonance of
1
H and
13
C, were also quantified in ACFF, showing 190.7 mg/g and apigenin 12.4 mg/g, respectively. The other flavones were identified by comparing their spectroscopic data with those of the literature. The
in vitro
activity was assayed against promastigotes and intramacrophagic amastigote forms of
L. amazonensis
. Cytotoxicity tests were performed with peritoneal macrophages of BALB/c mice. Nitrite quantification was performed with Griess reagent. Ultrastructural investigations were obtained by transmission electron microscopy. Anti-
Leishmania
assays indicated that the IC
50
values for ACFF, apigenin, and luteolin were obtained at 40.42 ± 0.10 and 31.51 ± 1.13 μg/mL against promastigotes, respectively. ACFF and luteolin have concentration-dependent cytotoxicity. ACFF and luteolin also inhibited the intra-macrophagic parasite (IC
50
3.575 ± 1.13 and 11.78 ± 1.24 μg/mL, respectively), with a selectivity index of 11.44 for ACFF. Promastigotes exposed to ACFF and luteolin exhibited ultrastructural changes, such as intense cytoplasm vacuolization and mitochondrial swelling. These findings data evidence the antileishmanial action of flavone-rich fractions of
A. chica
against
L. amazonensis
, encouraging further studies.