Histopathological Changes Induced in Mice after Inramuscular and Intra Peritoneal Injections of Venom from Spine-bellied Sea Snake, Lapemis curtus (Shaw, 1802)

Distinctive Distribution of Secretory Phospholipases A₂ in the Venoms of Afro-Asian Cobras (Subgenus: Naja, Afronaja, Boulengerina and Uraeus)

The protein abundances of phospholipases A₂ in cobra venom proteomes appear to vary among cobra species. To determine the unique distribution of snake venom phospholipases A₂ (svPLA₂) in the cobras, the svPLA₂ activities for 15 cobra species were examined with an acidimetric and a colorimetric assay, using egg yolk suspension and 4-nitro-3-octanoyloxy benzoic acid (NOBA) as the substrate. The colorimetric assay showed significant correlation between svPLA₂ enzymatic activities with the svPLA₂ protein abundances in venoms. High svPLA₂ activities were observed in the venoms of Asiatic spitting cobras (Naja sputatrix, Naja sumatrana) and moderate activities in Asiatic non-spitters (Naja naja, Naja atra, Naja kaouthia), African spitters (subgenus Afronaja), and forest cobra (subgenus Boulengerina). African non-spitting cobras of subgenus Uraeus (Naja haje, Naja annulifera, Naja nivea, Naja senegalensis) showed exceptionally low svPLA₂ enzymatic activities. The negligible PLA₂ activity in Uraeus cobra venoms implies that PLA₂ may not be ubiquitous in all snake venoms. The svPLA₂ in cobra envenoming varies depending on the cobra species. This may potentially influence the efficacy of cobra antivenom in specific use for venom neutralization.

The Venom of the Spine-Bellied Sea Snake (Hydrophis curtus): Proteome, Toxin Diversity and Intraspecific Variation

The spine-bellied sea snake (Hydrophis curtus) is known to cause human deaths, yet its venom composition has not yet been proteomically characterised. An in-depth proteomic analysis was performed on H. curtus venom from two different seasons, January and June, corresponding to adults and subadults, respectively. Venoms from adult and subadult H. curtus individuals were compared using reversed-phase high-performance liquid chromatography (RP-HPLC), matrix-assisted laser desorption ionisation-time of flight (MALDI-TOF) mass spectrometry and liquid chromatography electrospray ionisation mass spectrometry (LC-ESI-MS) to detect intraspecific variation, and the molecular weight data obtained with ESI-MS were used to assess toxin diversity. RP-HPLC and LC-ESI-MS/MS were used to characterise the venom proteome and estimate the relative abundances of protein families present. The most abundant protein family in January and June venoms is phospholipase A₂ (PLA₂: January 66.7%; June 54.5%), followed by three-finger toxins (3FTx: January 30.4%; June 40.4%) and a minor component of cysteine-rich secretory proteins (CRISP: January 2.5%; June 5%). Trace amounts of snake venom metalloproteinases (SVMP), C-type lectins and housekeeping and regulatory proteins were also found. Although the complexity of the venom is low by number of families present, each family contained a more diverse set of isoforms than previously reported, a finding that may have implications for the development of next-generation sea snake antivenoms. Intraspecific variability was shown to be minor with one obvious exception of a 14,157-Da protein that was present in some January (adult) venoms, but not at all in June (subadult) venoms. There is also a greater abundance of short-chain neurotoxins in June (subadult) venom compared with January (adult) venom. These differences potentially indicate the presence of seasonal, ontogenetic or sexual variation in H. curtus venom.

Description of histopathological changes induced by the venom of the Persian Gulf Lionfish (Pterois russelli) in a mouse model of multiorgan toxicity

Pterois russelli is a venomous fish belongs to Scorpaenidae family. Envenomation by the Persian Gulf lionfish is associated with local pain, marked inflammation and local heat. The present study was aimed to document the histopathological changes in liver, heart, lung, kidney and alterations in release of critical enzymes such as LDH, CK. AST, ALT and ALP induced by the administration of various doses of P. russelli venom in a mouse model. LD50 of venom was determined by intravenous injection in Balb/c mice. Histopathological alterations of lung, liver, heart and kidney following injection of one LD50, 1/2 and 1/3 LD50 doses of the venom were evaluated. Simultaneously, release of LDH, CK, AST, ALT and ALP were measured in serum following administration of 1/2 and1/3 LD50 doses of the venom too. LD50 was calculated as 10.5 mg/kg. The level of all enzymes were increased after 3 h and significantly raised after 24 h and rapidly reduced after 48 h. Histological studies showed that one LD50 and 1/2 LD50 doses of the venom induced significant histological alterations in the lungs, liver, heart and kidneys including congestion, hemorrhage, necrosis, apoptosis, edema, and infiltration of inflammatory cells. The results indicate that the venom of P. russelli has nephrotoxic, hepatotoxic, cardiotoxic and pneumotoxic effects in mouse model. Among four examined vital organs, the highest critical events were seen in liver. The findings are useful to give new insight in the fish's venom studies. Gathering the data resulted from this study together will be directed us toward a good aspect concerning the toxicity of potential therapeutic molecules in the venom of lionfish.