The anti-infective and immunologic effect of babassu (Attalea speciosa, Mart. ex Spreng) reduces mortality induced by MRSA-Staphylococcus aureus.

Ethnopharmacological relevance: Babassu mesocarp, derived from the Attalea speciosa fruits, is used in folk medicine for infections, inflammatory diseases, and skin wounds. Aim of the study: To investigate the antimicrobial and immunological effect of babassu mesocarp aqueous extract (BAE) in Swiss mice lethally infected with methicillin-resistant Staphylococcus aureus (MRSA). Materials and methods: The animals (n = 14/group) received an overload of MRSA (3.0 x 108 CFU/mL, via intraperitoneal) and were treated 6 h later with the BAE (125 and 250 mg/kg, subcutaneously). Two experiments were performed with four groups each (Control, ATB, BAE125 and BAE 250). The first was to determine the survival (n = 7 animals/group). The second is to evaluate 24h after infection the number of Colony Forming Units (CFU) and cells in the blood, peritoneum and bronchoalveolar fluid. Cytometric Bead Assay - CBA quantified the cytokines and flow cytometry to determine the cellular distribution in the mesenteric lymph node. Results: Treatment with BAE improved the survival (60%) in all groups, reduced the number of colony-forming units in the peritoneum and blood, the number of peritoneal and bronchoalveolar cells, and the levels of proinflammatory IL-6, TNF-alpha, and IL-17 cytokines. Additionally, BAE increased: IL-10 and INF-gamma levels, nitric oxide release, CD4+ T helper cells, CD14+/IaIe + activated macrophages and Ly6G + neutrophils in the mesenteric lymph node. Conclusions: BAE can be used as a complementary treatment during infections due to its antimicrobial and immunomodulatory effect and the ability to protect animals from death after MRSA lethal infection.