Local inflammatory mediators alterations induced by Daboia siamensis venom

The ability of Russell's viper (Daboia siamensis) venom (total RVV) and phospholipase A(2) (purified PLA(2)) to induce the local pathological effects were investigated by the local inflammatory events and the release of inflammatory mediators. Both 0.5 μg of total RVV/mouse and 0.15 μg of purified PLA(2)/mouse were administered via intra-peritoneal injection. After 30 min, 1 h, 2 h, and 4 h incubation time, the peritoneal cavity was flooded with normal saline and the total leukocytes were collected. The eicosanoids (lipid mediators) and the leukocyte expression of cyclooxygenase (COX-1 and COX-2) were investigated by ELISA assay and western blotting, respectively. The amounts of total leukocytes were increased from 30 min to 2 h, then decreased at 4 h, by both total RVV and purified PLA(2). Both treatments also induced the expression of COX-2 which was increased at 2 h and then decreased at 4 h, whereas only purified PLA(2) induced the expression level of a COX-1 protein which was increased at 30 min, then constantly expressed until 4 h. In addition, total RVV and purified PLA(2) caused the release of the eicosanoids; PGE(2), TXB(2), and LTB(4), which reached the peak after 2 h. The findings of this study indicate that purified PLA(2) has the potential effects to induce the local inflammation relating the amounts of leukocytes cells, lipid mediators and COX-2 more than the total RVV.