Antidote Active Compound Against Snake Venom from Argusia argentea and Its Machanism of Action

Monpanoki (Argusia (or Messerschmidia or Tournefortia) argentea (Boraginaceae)) is locally used in Okinawa in Japan as an antidote for poisoning from snakes venoms, Trimeresurus flavoviridis (habu). A methanolic extract of the plant significantly inhibited hemorrhage induced by crude venom of Trimeresurus flavoviridis. The extract was then separated according to antivenom activity by using silica gel (ODS) column to afford rosmarinic acid (RA) (1) as an active principle. RA (1) significantly inhibited the hemorrhagic effect of crude venoms of T. flavoviridis, Crotalus atrox, Gloydius blomhoffii, Bitis arietans as well as snake venom metalloproteinases, HT-b (C. atrox), bilitoxin 2 (Agkistrodon bilineatus), HF (B. arietans), and Acl-proteinase (Deinagkistrodon acutus). This is the first report of the antihemorrhage activity of RA (1) and RA (1) greatly contributes to the antihemorrhagic efficiency of this plant against crude snake venoms and hemorrhagic toxins. Furthermore, mechanistic evidence of RA's neutralization of the hemorrhagic effects of snake venom was invesitigated. Inhibitions against fibrinogen hydreolytic and collagen hydrolytic activities of T. flavoviridis venom were examined by SDS-PAGE. Histopathological study was done by using microscope afer administration of venom with or without RA. RA was found to markedly neutralize venom-induced hemorrhage, fibrinogenolysis, cytotoxicity and digestion of type IV collagen activity. Moreover, both hemorrhage and neutrophil infiltrations were inhibited by RA, although both were observed in pathology sections administered only T. flavoviridis venom. These results demonstrate that RA inhibited most of the hemorrhage effects of venom. These findings indicate that rosmarinic acid can be expected to provide therapeutic benefits in neutralization of snake venom accompanied by heat stability.