Schinus terebinthifolia leaf lectin (SteLL) has anti-infective action and modulates the response of Staphylococcus aureus-infected macrophages

Abstract

Staphylococcus aureus is recognized as an important pathogen causing a wide spectrum of diseases. Here we examined the antimicrobial effects of the lectin isolated from leaves of Schinus terebinthifolia Raddi (SteLL) against S. aureus using in vitro assays and an infection model based on Galleria mellonella larvae. The actions of SteLL on mice macrophages and S. aureus-infected macrophages were also evaluated. SteLL at 16 µg/mL (8 × MIC) increased cell mass and DNA content of S. aureus in relation to untreated bacteria, suggesting that SteLL impairs cell division. Unlike ciprofloxacin, SteLL did not induce the expression of recA, crucial for DNA repair through SOS response. The antimicrobial action of SteLL was partially inhibited by 50 mM N-acetylglucosamine. SteLL reduced staphyloxathin production and increased ciprofloxacin activity towards S. aureus. This lectin also improved the survival of G. mellonella larvae infected with S. aureus. Furthermore, SteLL induced the release of cytokines (IL-6, IL-10, IL-17A, and TNF-α), nitric oxide and superoxide anion by macrophagens. The lectin improved the bactericidal action of macrophages towards S. aureus; while the expression of IL-17A and IFN-γ was downregulated in infected macrophages. These evidences suggest SteLL as important lead molecule in the development of anti-infective agents against S. aureus.

Effects of Lectins from Alpinia purpurata Inflorescence (ApuL) and Schinus terebinthifolia Leaf (SteLL) on Human Leukemic Cell Lines and Mesenchymal Stem Cells

“…Brito et al [4] demonstrated the safety of ApuL with regards to human lymphocytes, while Santos et al [11] showed that SteLL (3.12-50 µg/mL) is not cytotoxic for mouse splenocytes. Additionally, the viability of macrophages isolated from mice was not affected by SteLL (2.0-16.0 µg/mL) [60].…”

“…In previous studies, SteLL (12.5 µg/mL) demonstrated the ability to stimulate the release of cytokines (IL-6, IL-10, IL-17A, TNF-α), NO, and superoxide anion in cultured macrophages isolated from mice. In addition, it stimulated the production of IL-17A, TNF-α, IFN-γ, IL-4, and IL-2 in cultured splenocytes isolated from mice [11,60]. It has already been shown that ApuL is capable of inducing lymphocytes isolated from humans to produce a Th17 response, producing IL-17 and IL-10, the latter with an immunoregulatory function [4].…”

Antivirulence activities of retinoic acids against Staphylococcus aureus

“…Staphylococcus aureus ATCC 6538 cells (~2 × 10 7 CFU/mL) were inoculated into LB medium (2 mL) in 14-mL tubes and incubated for 24 h at 37°C with 13- cis -retinoic acid (0, 10, 20, 50, or 100 μg/mL) with shaking at 250 rpm. Staphyloxanthin levels were assessed optically, as previously described ( De Souza Feitosa Lima et al, 2019 ; Kim et al, 2022a ).…”

Interplay between ESKAPE Pathogens and Immunity in Skin Infections: An Overview of the Major Determinants of Virulence and Antibiotic Resistance

“…These compounds act by interrupting the molecular synthesis and microbial cell cycle [ 205 , 206 , 207 ]. Several natural products are also reported to have promising in vivo antimicrobial activity against S. aureus , including in models of wound infections [ 208 , 209 , 210 , 211 ].…”