Fucoidan may treat jellyfish dermatitis by inhibiting the inflammatory effect of jellyfish venom

Baicalein antagonises Rhopilema esculentum toxin-induced oxidative stress and apoptosis by modulating ROS-MAPK-NF-κB and inhibiting PLA2 activity

The toxicity of jellyfish Rhopilema esculentum (R. esculentum), an edible jellyfish that releases venom, has been controversial. The aim of this comprehensive study was to investigate the toxic effects of jellyfish tentacle extract (TE), which was evaluated in vivo and in vitro using ICR mice and RAW264.7 cells respectively. A library of natural compounds was screened for their ability to antagonize phospholipase A2 (PLA2) activity to identify potential protective agents and mechanisms. Of the 20 natural compounds evaluated, baicalein was found to have the strongest PLA2 antagonistic and cytoprotective effects. In vivo, experiments showed that TE at a dose of 7.02 mg/kg only resulted in a 50% survival rate in mice. However, pretreatment with 30 mg/kg baicalein significantly increased the survival rate to 75%, while also attenuating TE-induced cardiac and hepatic injuries, and ameliorating TE-induced elevations in LDH, CK-MB, and AST levels. In vitro studies found that baicalein reduced cellular ROS and MDA levels, increased the expression of CAT, SOD, and GSH/GSSG to enhance cellular antioxidant defenses against TE-induced oxidative stress, and also inhibited TE-induced upregulation of TNF-α, IL-6, IL-1β, and CXCL10. Importantly, baicalein was found to modulate dysregulated MAPK and NF-κB signaling pathways disrupted by TE. Taken together, these findings suggest that baicalein can antagonize R. esculentum toxin-induced oxidative stress and apoptosis by modulating ROS/MAPK/NF-κB, which provides a viable therapeutic strategy to control the deleterious effects of jellyfish stings and associated inflammation.

Roles and mechanisms of fucoidan against dermatitis: A review

Fucoidan is a sulfate-containing polysaccharide derived from the cell walls of brown algae and marine invertebrates. Fucoidan is widely used for the treatment of various diseases owing to its various biological activities. Dermatitis is an inflammatory reaction that affects the skin. The primary clinical manifestations include atopic dermatitis (AD or eczema) and various subtypes of contact dermatitis. The treatment of dermatitis primarily improves symptoms and reduces inflammation. However, owing to individual variations, some patients have a poor prognosis or symptom recurrence after conventional treatment. Owing to the excellent anti-allergic and anti-inflammatory activities of the low cost nature compound fucoidan, its therapeutic effect in inflammatory diseases has recently attracted the attention of researchers. This article summarizes and analyzes the advantages and pharmacological mechanisms of fucoidan against dermatitis to provide a reference for the selection of drugs for the treatment of dermatitis.

Troxerutin suppress inflammation response and oxidative stress in jellyfish dermatitis by activating Nrf2/HO-1 signaling pathway

Background

Stomolophus meleagris envenomation causes severe cutaneous symptoms known as jellyfish dermatitis. The potential molecule mechanisms and treatment efficiency of dermatitis remain elusive because of the complicated venom components. The biological activity and molecular regulation mechanism of Troxerutin (TRX) was firstly examined as a potential treatment for jellyfish dermatitis.

Methods

We examined the inhibit effects of the TRX on tentacle extract (TE) obtained from S. meleagris in vivo and in vitro using the mice paw swelling models and corresponding assays for Enzyme-Linked Immunosorbent Assay (ELISA) Analysis, cell counting kit-8 assay, flow cytometry, respectively. The mechanism of TRX on HaCaT cells probed the altered activity of relevant signaling pathways by RNA sequencing and verified by RT-qPCR, Western blot to further confirm protective effects of TRX against the inflammation and oxidative damage caused by TE.

Results

TE significantly induced the mice paw skin toxicity and accumulation of inflammatory cytokines and reactive oxygen species in vivo and vitro. Moreover, a robust increase in the phosphorylation of mitogen-activated protein kinase (MAPKs) and nuclear factor-kappa B (NF-κB) signaling pathways was observed. While, the acute cutaneous inflammation and oxidative stress induced by TE were significantly ameliorated by TRX treatment. Notablly, TRX suppressed the phosphorylation of MAPK and NF-κB by initiating the nuclear factor erythroid 2-related factor 2 signaling pathway, which result in decreasing inflammatory cytokine release.

Conclusion

TRX inhibits the major signaling pathway responsible for inducing inflammatory and oxidative damage of jellyfish dermatitis, offering a novel therapy in clinical applications.

Effects of toxin metalloproteinases from jellyfish Nemopilema nomurai nematocyst on the dermal toxicity and potential treatment of jellyfish dermatitis

Jellyfish dermatitis is a common medical problem in many countries due to the jellyfish envenomation. However, there are no specific and targeted medications for their treatment. Here we investigated the possible therapeutic effects of metalloproteinase inhibitors on the dermal toxicity of Nemopilema nomurai nematocyst venom (NnNV), a giant venomous jellyfish from China, using the jellyfish dermatitis model, focusing on inflammatory effector molecules during jellyfish envenomation. Metalloproteinase may further stimulate inflammation by promoting oxidative stress in the organism and play key roles by activating MAPK and NF-κB, in the pathogenesis of jellyfish dermatitis. And the metalloproteinase inhibitors batimastat and EDTA disodium salt may treat the Jellyfish dermatitis by inhibiting the metalloproteinase activity in NnNV. These observations suggest that the metalloproteinase components of NnNV make a considerable contribution to dermal toxicity as the inflammation effect molecular, and metalloproteinase inhibitors can be regarded as novel therapeutic medicines in jellyfish envenomation. This study contributes to understanding the mechanism of jellyfish dermatitis and suggests new targets and ideas for the treatment of jellyfish envenomation.