Anadenanthera colubrina (Vell.) Brenan as Inhibitor of HIV-1 BaL Infection

Objectives: Acquired Immunodeficiency Syndrome (AIDS), caused by the Human Immunodeficiency virus (HIV), is one of the principal causes of life lost worldwide. Natural compounds from plants represent an excellent source for new microbicides, which are anti-infective formulations prepared for vaginal or rectal use. Anadenanthera colubrina (Vell.) Brenan, popularly known as Angico, has been traditionally used due its promising therapeutic properties, such as antifungal and anti-inflammatory activities. In this regard, the aim of this study is to evaluate the in vitro anti-HIV-1 BaL activity and cytotoxicity of A. colubrina extract.
Methods: TZM-bl cells were cultured in DMEM (10% FBS, 1% Penicillin/Streptomycin), at 37°C in 5% CO₂. To evaluate the cytotoxicity and anti-HIV activity of A. colubrina extract, a TZM-bl cells (5 x 10⁴ cells/mL) were seeded into a 24-wells plate and exposed to concentrations of the extract (3.328 µg/mL – 0.3328 µg/mL) for 72 hours. Cell viability was determined by resazurin fluorometric method (Cell Titer Blue Viability Assay). Anti-HIV 1 Bal activity was determined by Luciferase assay method.

Results: Extract concentrations up to 33.28 mg/mL maintained the cell viability above 90% (LD₅₀ = 487.2 µg/mL) and reduced 87.6% of HIV-1 BaL infection, when compared to the infection control.

Conclusions: This is the first study presenting the anti-HIV effect of A. colubrina extract, also showing low cytotoxicity. This data suggests that A. colubrina may be a potential anti-HIV agent. Further studies should be performed to identify the action mechanism of the extract on HIV and the molecular targets activated, in order to provide solid scientific foundation for future researches.