Local inflammatory mediators alterations induced by Daboia siamensis venom

Toxicon X. 2021 Oct 9:12:100085. doi: 10.1016/j.toxcx.2021.100085. eCollection 2021 Nov.

Abstract

The ability of Russell's viper (Daboia siamensis) venom (total RVV) and phospholipase A2 (purified PLA2) 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 PLA2/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 PLA2. Both treatments also induced the expression of COX-2 which was increased at 2 h and then decreased at 4 h, whereas only purified PLA2 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 PLA2 caused the release of the eicosanoids; PGE2, TXB2, and LTB4, which reached the peak after 2 h. The findings of this study indicate that purified PLA2 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.

Keywords: Cyclooxygenase; Daboia siamensis venom; Eicosanoids; Local inflammatory mediators.