Moringa oleifera leaf fractions attenuated Naje haje venom-induced cellular dysfunctions via modulation of Nrf2 and inflammatory signalling pathways in rats

Varespladib attenuates Naja atra-induced acute liver injury via reversing Nrf2 signaling-mediated ferroptosis and mitochondrial dysfunction

Objective: To investigate the protective effects of varespladib against Naja atra-induced acute liver injury (ALI) and to elucidate the toxic mechanism of snake venom phospholipase A2 (SVPLA2)-induced hepatic oxidative stress, with a particular focus on the role of Nrf2 signaling and its downstream pathways.Methods: A combination of in vivo and in vitro models of N. atra envenomation was employed to assess liver injury, oxidative stress, and mitochondrial dysfunction. The interaction between SVPLA2 and Nrf2 was analyzed, and the effects of varespladib treatment on these processes were evaluated using histological analysis, biochemical assays, and molecular techniques targeting oxidative stress, ferroptosis, mitophagy, and apoptosis.Results: Varespladib significantly alleviated N. atra-induced ALI. SVPLA2 was found to directly bind to Nrf2, leading to severe oxidative stress. This oxidative stress initiated a cascade involving Nrf2-mediated ferroptosis, mitochondrial dysfunction, excessive mitophagy, and mitochondria-dependent apoptosis. Treatment with varespladib effectively reversed these pathological events by inhibiting SVPLA2 activity.Conclusion: Varespladib shows strong therapeutic potential for N. atra envenomation by targeting SVPLA2. Nrf2 was identified as a direct toxic target of SVPLA2, and Nrf2-mediated ferroptosis and mitochondrial dysfunction were key mechanisms underlying SVPLA2-induced hepatic injury.

Therapeutic potency of kaempferol against Naja haje venom induced neurotoxicity, inflammation, biological activities, and antioxidant system damage: a pre-clinical antivenom evaluation

Naja haje envenoming manifests organ system disorders leading to severe fatalities due to the venom's toxins. The neutralizing capacity of kaempferol has been reported against some medically significant snake venoms with exception of N. haje venom (NhV). This current study assessed the neutralizing profile of kaempferol against toxicities induced by NhV using in vitro and in vivo methods. In in vitro, NhV induced wide spectrum of toxic biological activities with substantial increase in hemorrhagic, anticoagulating, and hemolytic effects. Likewise in the in vivo study, the venom caused hematological disorders by inducing acute anemia, thrombocytopenia, and leucopenia in envenomed rats. Also, the venom caused detrimental effect on the antioxidant defense system of the brain through significant (P < 0.05) elevation of malondialdehyde (MDA), nitrite (NIT), and suppression of reduce glutathione (GSH) antioxidant, superoxide dismutase (SOD), catalase (CAT), and glutathione transferase (GST) enzymes. Additionally, the levels of neurotoxicity biomarkers, monoamine oxidase (MAO) and acetylcholinesterase (AChE), and pro-inflammatory cytokines, tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), were significantly (P < 0.0.5) enhanced by NhV in the brain of envenomed rats. Severe pathohistological effects were observed in brain tissues of the envenomed rats. However, kaempferol substantially (P < 0.05) inhibited the NhV-induced biological activities, normalized the hematological disorders, enhanced antioxidants system functions, and significantly (P < 0.05) suppressed the levels of neurotoxicity biomarkers and pro-inflammatory cytokines. Severe structural alterations observed in the brain tissues were ameliorated after kaempferol treatment. Further exploration of kaempferol could lead to the development of an alternative therapy for treatment of N. haje envenoming.