Cytotoxic and inflammatory potential of a phospholipase A2 from Bothrops jararaca snake venom

BackgroundSnake venom phospholipases A(2) (PLA(2)s) have been reported to induce myotoxic, neurotoxic, hemolytic, edematogenic, cytotoxic and proinflammatory effects. This work aimed at the isolation and functional characterization of a PLA(2) isolated from Bothrops jararaca venom, named BJ-PLA(2)-I.Methods and ResultsFor its purification, three consecutive chromatographic steps were used (Sephacryl S-200, Source 15Q and Mono Q 5/50 GL). BJ-PLA(2)-I showed acidic characteristics, with pI4.4 and molecular mass of 14.2kDa. Sequencing resulted in 60 amino acid residues that showed high similarity to other Bothrops PLA(2)s, including 100% identity with BJ-PLA(2), an Asp49 PLA(2) previously isolated from B. jararaca venom. Being an Asp49 PLA(2), BJ-PLA(2)-I showed high catalytic activity, and also inhibitory effects on the ADP-induced platelet aggregation. Its inflammatory characterization showed that BJ-PLA(2)-I was able to promote leukocyte migration in mice at different concentrations (5, 10 and 20g/mL) and also at different response periods (2, 4 and 24h), mainly by stimulating neutrophil infiltration. Furthermore, increased levels of total proteins, IL-6, IL-1 and PGE(2) were observed in the inflammatory exudate induced by BJ-PLA(2)-I, while nitric oxide, TNF-, IL-10 and LTB4 levels were not significantly altered. This toxin was also evaluated for its cytotoxic potential on normal (PBMC) and tumor cell lines (HL-60 and HepG2). Overall, BJ-PLA(2)-I (2.5-160g/mL) promoted low cytotoxicity, with cell viabilities mostly varying between 70 and 80% and significant values obtained for HL-60 and PBMC only at the highest concentrations of the toxin evaluated.ConclusionsBJ-PLA(2)-I was characterized as an acidic Asp49 PLA(2) that induces acute local inflammation and low cytotoxicity. These results should contribute to elucidate the action mechanisms of snake venom PLA(2)s.