Anti-Inflammatory Effect of Wasp Venom in BV-2 Microglial Cells in Comparison with Bee Venom

SIMPLE SUMMARY: As the population of the yellow-legged hornet (Vespa velutina) spreads, this study investigated ways to utilize this resource of abundant invasive wasp species. Hymenoptera venoms, including bee venom and wasp venom, have therapeutic potential. Although the venoms are toxic to humans, the elucidation of their composition and working mechanisms has led to discoveries about their potential applications in treatment modalities for a variety of disorders. Therefore, we examined the anti-inflammatory effect of wasp venom from V. velutina in comparison with that of bee venom from honey bee on BV-2 murine microglial cells. Treatment with wasp venom reduced the secretion of nitric oxide and pro-inflammatory cytokines, including interleukin-6 and tumor necrosis factor alpha, from BV-2 cells activated by lipopolysaccharide (LPS). Western blot analysis revealed that wasp venom and bee venom decreased the expression levels of inflammation markers, including inducible nitric oxide synthase and cyclooxygenase-2. In addition, wasp venom decreased the nuclear translocation of nuclear factor κB (NF-κB), which is a key transcription factor in the regulation of cellular inflammatory response. Overall, the findings demonstrated that wasp venom inhibited LPS-induced inflammation in microglial cells by suppressing the NF-κB-mediated signaling pathway, which warrants further studies to confirm its therapeutic potential for neurodegenerative diseases. ABSTRACT: The aim of this study was to compare the anti-inflammatory effect of wasp venom (WV) from the yellow-legged hornet (Vespa velutina) with that of bee venom (BV) on BV-2 murine microglial cells. WV was collected from the venom sac, freeze-dried, and used for in vitro examinations. WV and BV were non-toxic to BV-2 cells at concentrations of 160 and 12 µg/mL or lower, respectively. Treatment with WV reduced the secretion of nitric oxide and proinflammatory cytokines, including interleukin-6 and tumor necrosis factor alpha, from BV-2 cells activated by lipopolysaccharide (LPS). Western blot analysis revealed that WV and BV decreased the expression levels of inflammation markers, including inducible nitric oxide synthase and cyclooxygenase-2. In addition, WV decreased the nuclear translocation of nuclear factor κB (NF-κB), which is a key transcription factor in the regulation of cellular inflammatory response. Cumulatively, the results demonstrated that WV inhibited LPS-induced neuroinflammation in microglial cells by suppressing the NF-κB-mediated signaling pathway, which warrants further studies to confirm its therapeutic potential for neurodegenerative diseases.