Abstract
Arthrospira platensis, an ancient cyanobacterium, is rich in bioactive compounds with therapeutic potential, supporting its use in studies for various health conditions, including infectious and chronic diseases. This study aimed to evaluate the antiparasitic, cytotoxic, and immunomodulatory activities of A. platensis compounds against Trypanosoma cruzi. Peripheral Blood Mononuclear Cells (PBMC) and T. cruzi trypomastigotes were cultured for cytotoxic and antiparasitic analyses. Cytotoxicity was assessed in PBMC treated with different concentrations of crude extract, obtained by mechanical agitation in 0.1 M TRIS-HCl buffer (pH 7.2), and purified protein by DEAE-Sephadex A-50 chromatography and FPLC. Immune response was analyzed in infected and uninfected PBMC by measuring cytokines (IFN-γ, TNF, IL-2, IL-6, and IL-10) after treatment with purified protein and benznidazole. In vitro experiments showed that both crude extract and a 15 kDa purified protein were toxic to trypomastigotes in a dose-dependent manner, eliminating over 80% of the parasite at 1000 and 200 μg/mL, respectively. Both the extract and protein were nontoxic to PBMC, with the protein (SI: 20.7) being more selective than benznidazole (SI: 11.5). Results indicated that the purified protein modulated the immune response in T. cruzi-infected individuals, inducing a protective Th1 response while controlling an excessive inflammatory response with appropriate IL-10 levels. The anti-T. cruzi activity of this protein, alone or in combination with the commercial drug, suggests it could be a low-cost, safer, and more tolerable therapy for Chagas disease treatment.