Effect of Scorpion Venom on Nociceptive Response and Inflammatory Cytokines in Mice Using Experimental Hyperalgesia.

Scorpion envenomation is a public health issue in tropical and subtropical regions. Currently, there is limited data on the biological effects of scorpion venom (HjSV) in mammals. This study aims to analyze the effect of HjSV on lipopolysaccharide (LPS)-induced hyperalgesia in mice and its potential modulation of the immunological inflammatory response. Hyperalgesia is characterized by an increased response to pain, accompanied by heightened sensitivity that ranges from mild discomfort to intense pain. A series of tests were conducted, including heat resistance testing in BALB/c mice injected subcutaneously with LPS to induce hyperalgesia and intraperitoneally with HjSV. The hot plate test, used to assess pain endurance in mice, showed that LPS-injected mice, particularly females, exhibited heightened pain sensitivity. This suggests possible sex-based differences in pain perception. When HjSV was administered alone, a reduction in pain sensitivity was observed in both sexes. Additionally, ELISA tests were performed to assess changes in the secretion of inflammatory cytokines IL-4, IL-10, IL-6, IFN-γ, and TNF-α. A consistent increase in both pro- and anti-inflammatory cytokines was observed at early time points in females injected with HjSV alone. Moreover, the hyperalgesia induced by LPS was significantly reduced when HjSV was co-administered, indicating an anti-inflammatory effect at early stages. These findings suggest that HjSV has a significant immunomodulatory effect, potentially exerting anti-inflammatory action during acute inflammation. This effect appears to be time-dependent, diminishing as the immune response transitions toward its adaptive phase.