Evaluation of the Anti-Mycobacterial and Anti-Inflammatory Activities of the New Cardiotonic Steroid γ-Benzylidene Digoxin-15 in Macrophage Models of Infection

Author(s):Show less -

Magalhaes, Daniel Wilson A. ; Sidronio, Maria Gabriella S. ; Nogueira, Noemia N. A. ; Carvalho, Deyse Cristina Madruga ; de Freitas, Maria Eugenia G. ; Oliveira, Ericke Cardoso ; Lima, Gustavo F. de Frazao ; de Araujo, Demetrius A. M. ; Scavone, Cristoforo ; de Souza, Thalisson Amorim ; Villar, Jose Augusto F. P. ; Barbosa, Leandro A. ; Mendonca-Junior, Francisco Jaime Bezerra ; Rodrigues-Junior, Valnes S. ; Rodrigues-Mascarenhas, Sandra

• Document type: Journal article
• Source: MICROORGANISMS; v. 13, n. 2, p. 17-pg., 2025-02-01.

Abstract

Cardiotonic steroids modulate various aspects of the inflammatory response. The synthetic cardiotonic steroid gamma-benzylidene digoxin 15 (BD-15), a digoxin derivative, has emerged as a promising candidate with potential immunomodulatory effects. However, its biological activity remains largely unexplored. This study investigated the anti-mycobacterial and anti-inflammatory effects of BD-15 in an in vitro macrophage infection model with Mycobacterium spp. Unlike digoxin, which showed significant toxicity at higher concentrations, BD-15 exhibited no cytotoxicity in RAW 264.7 cells (a murine macrophage cell line). Both compounds were evaluated in Mycobacterium smegmatis-infected RAW 264.7 cells, reducing bacterial burden without direct bactericidal activity. Additionally, both modulated pro-inflammatory cytokine levels, notably by decreasing tumor necrosis factor alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) levels. BD-15 specifically reduced NOD-, LRR-, and pyrin-domain-containing protein 3 (NLRP3) inflammasome expression and increased interleukin-10 (IL-10) production. Notably, BD-15 reduced colony-forming unit (CFU) counts in Mycobacterium tuberculosis-infected RAW 264.7 cells. Toxicity assays in HepG2 cells (a human liver cancer cell line) showed that BD-15 had minimal hepatotoxicity compared to digoxin, and both demonstrated negligible acute toxicity in an Artemia salina bioassay. These findings revealed the immunomodulatory effects of cardiotonic steroids in a bacterial infection model and highlighted BD-15 as a safer alternative to digoxin for therapeutic applications. (AU)

• FAPESP's process: 21/06009-6 - Neuroplasticity -induced by challenge Na, K-ATPase, Klotho, glutamate, and neuroinflammation signaling cascades to reveal new therapeutic targets for aging and neurodegenerative diseases
• Grantee: Cristoforo Scavone
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 22/15745-0 - New Therapeutic Strategies Using Modified Digoxin Nanocompounds for Alternating Hemiplegia of Childhood (AHC)
• Grantee: Cristoforo Scavone
• Support Opportunities: Regular Research Grants