Hemolytic, anticancer and antigiardial activity of Palythoa caribaeorum venom

Cnidarian venoms and extracts have shown a broad variety of biological activities including cytotoxic, antibacterial and antitumoral effects. Most of these studied extracts were obtained from sea anemones or jellyfish. The present study aimed to determine the toxic activity and assess the antitumor and antiparasitic potential of Palythoa caribaeorum venom by evaluating its in vitro toxicity on several models including human tumor cell lines and against the parasite Giardia intestinalis. Methods: The presence of cytolysins and vasoconstrictor activity of P. caribaeorum venom were determined by hemolysis, PLA2 and isolated rat aortic ring assays, respectively. The cytotoxic effect was tested on HCT-15 (human colorectal adenocarcinoma), MCF-7 (human mammary adenocarcinoma), K562 (human chronic myelogenous leukemia), U251 (human glyoblastoma), PC-3 (human prostatic adenocarcinoma) and SKLU-1 (human lung adenocarcinoma). An in vivo toxicity assay was performed with crickets and the antiparasitic assay was performed against G. intestinalis at 24 h of incubation. Results: P. caribaeorum venom produced hemolytic and PLA2 activity and showed specific cytotoxicity against U251 and SKLU-1 cell lines, with approximately 50% growing inhibition. The venom was toxic to insects and showed activity against G. intestinalis in a dose-dependent manner by possibly altering its membrane osmotic equilibrium. Conclusion: These results suggest that P. caribaeorum venom contains compounds with potential therapeutic value against microorganisms and cancer.(AU)

Dose and time dependence of box jellyfish antivenom

Background The effectiveness of the currently available box jellyfish (Chironex fleckeri) antivenom has been subject of debate for many years. To assess whether the box jellyfish antivenom has the ability to attenuate venom-induced damage at cellular level, the present study analyzed the dose and time dependence of the antivenom in a cell-based assay.Methods Different doses of antivenom were added to venom and subsequently administered to cells and the cell index was measured using xCelligence Technology (ACEA Biosciences). Similarly, antivenom and venom were incubated over different time periods and cell survival measured as stated above. For both experiments, the cell index was plotted as a measure of cell survival against the dose or incubation time and significance was determined with the use of a one-way ANOVA with a LSD post hoctest.Results Increasing concentrations of antivenom significantly augmented cell survival, with a concentration of approximately five times the currently recommended dose for human envenomation, causing the first significant increase in cell survival compared venom alone. Further, cell survival improved with increasing incubation time of venom and antivenom prior to addition to the cells, indicating that box jellyfish antivenom requires approximately 70 minutes to neutralize C. fleckeri venom.Conclusion The presented results suggest that the currently recommended dose of antivenom requires adjustment, and more importantly, a human trial to test the effects of higher concentrations is also necessary. Further, antivenom has delayed neutralizing effects (i.e. after 70 minutes) which underlines the eminence of immediate and prolonged cardiopulmonary resuscitation in victims suffering from a C. fleckerivenom-induced cardiovascular collapse.

Skin and systemic manifestations of jellyfish stings in Iraqi fishermen

Jellyfish stings are common worldwide with an estimated 150 million cases annually, and their stings cause a wide range of clinical manifestations from skin inflammation to cardiovascular and respiratory collapse. No studies on jellyfish stings have been carried out in Basra, Iraq. To describe the immediate and delayed skin reactions to White Jellyfish [Rhizostoma sp.] stings and the types of local treatment used by fishermen.] 150 fishermen were enrolled at three Marine stations in Basra, Iraq. Demographic data, types of skin reactions, systemic manifestations and kinds of treatments were collected. Overall, 79% of fishermen in all three Marine stations gave a history of having been stung. The common sites of sings were the hands and arms followed by the legs. Most fishermen claimed that stings led to skin reactions within 5 minutes. The presenting complaints were itching, burning sensation, and erythematic wheals. A few days after the sting, new groups of painless and itchy erythematous monomorphic papular rashes developed at the site of the sting in 62% of cases as a delayed type of skin reaction that resolved spontaneously. The local remedies commonly used by the fishermen were seawater, tap water and ice. A few fishermen considered stings as insignificant and did not think there was a need to seek medical help. We conclude that jellyfish causes many stings among fishermen in the Basra region. Their stings lead to immediate and delayed skin reactions. Self-treatment by topical remedies is common