Anticholinesterase-like activity by oriental hornet (Vespa orientalis) venom and venom sac extract

Hepatotoxicity induced by the Oriental hornet (Vespa orientalis) venom sac extract

Experiments were performed to investigate the nature of the in vitro and human liver damage exposed to hornets' acute or repeated stings. The hornet investigated is the one ubiquitous in Israel - Vespa orientalis. Experiments were performed in living cats and rats, after single or multiple exposures to venom-sac extracts (VSE) and in various doses. The injury was demonstrated by the increased levels of enzymes, bile acids and cholesterol in serum. Also measured was Beta-N-acetyl hexosaminidase (BNAH) which probably is the only biochemical indicator available of Kupffer-cell function. This, too, was found increased. Other experiments consisted of perfusion of the isolated, intact, rat liver in situ with measurements of enzyme leakage into perfusate and of bile flow. Another set of experiments involved the effects of VSE on in vitro monolayer tissue culture of rat embryos' livers. We examined damage to organelles and compared the damage produced by intact VSE with that produced by the venom sac extract after treatment by heat or dialysis. Light morphology, special stains, electron microscopy and morphometry were all performed. In the first set of experiments no shock was observed in cats and rats exposed to VSE. The increases in enzymes' activity in serum and liver perfusion fluid were significant. Histochemistry indicated decrease of hepatic glycogen and of cellular succinic dehydrogenase as well as hepatic fat infiltration and an increase of alkaline phosphatase activity in liver cells close to the bile capillaries.(ABSTRACT TRUNCATED AT 250 WORDS)

Multiple hornet (Vespa orientalis) stings with fatal outcome in a child

A case of multiple hornet stings is described with a rapidly fatal course due to the combination of massive haemolysis, coagulopathy, rhabdomyolysis, hyperkalaemia, acute renal failure, encephalopathy, hepatotoxicity and hyperglycaemia. These features of systemic envenomation can all be attributed to the toxic properties of Oriental hornet venom described in in vitro and in vivo experimental studies. Greater awareness of these features, aggressive treatment of hyperkalaemia and early institution of treatments such as peritoneal dialysis and plasma exchange may prevent fatalities in such cases.

Hepatotoxicity of hornet's venom sac extract in isolated perfused rat liver

The changes in the activity of some enzymes in parenchymal liver cells were measured in the perfusate of rat isolated liver after a single envenomation with two different doses of Hornet's (Vespa orientalis) venom sac extract (VSE). The maximal observed enzymatic changes were significant: twenty four fold rise of alkaline phosphatase E.C.3.1.3.1(ALP), six fold rise of alanine aminotransferase E.C.2.6.1.2. (ALT) and nine fold rise of aspartate aminotransferase E.C.2.6.1.1. (AST) activity. There were moderate changes (four fold) in lactic dehydrogenase activity E.C.1.1.1.2.7. (LDH) and a non-significant change in gamma-glutamyl-transferase E.C.2.3.2.1. (GGT) activity. These changes varied with the venom's dose. Also a decrease in the rate of effluent draining out via the hepatic vein was noted as an additional sign of liver damage. In light of the biochemical evidence presented here, as well as in previous work, it seems that no further biochemical proof is needed to establish the hepatotoxicity of VSE in rats, cats and probably humans too. It seems that VSE is a predictable hepatotoxin causing a pattern of enzyme changes of the cholangiocellular type.