Exploring the biochemical, haemostatic and toxinological aspects of mapanare dry-tail (Porthidium lansbergii rozei) snake´s venom causing human accidents in Eastern Venezuela

Abstract

Porthidium lansbergii rozei (P.l.rozei) is a snake species belonging to the Venezuelan ophidian-fauna causing relatively frequent human accidents. This study has been developed to enrich the medical information about this snake´s accident, which is often handled with difficulties due to the ignorance about its toxic activities. This work has studied the biochemical and toxinological characteristics of the P.l.rozei venom. The objective was to determine its biochemical characteristics, including protein content determination, electrophoretic and P.l.rozei chromatographic profile. The toxinological and enzymatic functions, comprised lethality (LD 50 ), haemorrhagic (MHD), myotoxic, coagulant, oedematising, proteolytic, fibrinogenolytic, fibrinolytic, anticoagulant, and phospholipase activities and crude venom recognition by the Venezuelan polyvalent antivenom (PAOS). The venom induced haemorrhagic, myotoxic, anticoagulant, fibrinolytic, fibrinogenolytic, and phospholipase A 2 activities in mice; the LD 50 was not established even though the doses tested expand the different lethal doses reported in previous studies. The venom induced a dose-dependent oedema up to the dose of 4 μg, corresponding to 27.91%. In conclusion, the studied venom presented a haemostatic, toxinological, and enzymatic biochemical profile similar to the one described for specimens of the Porthidium genus. However, there were evident quantitative variations in their different activities, offering new evidence of the intra-species variations that exists in the different snake families. These variations must be accounted for appropriate clinical management.

Variability in antivenom neutralization of Mexican viperid snake venoms

“…In the particular cases of A. bilineatus and C. basiliscus where EDTA treatment does not modify the proteolysis of fibrinogen, it can be concluded that SVMPs are not involved in the degradation of this protein, and it is suggested that SVSPs are responsible. A contrasting scenario occurs with the venoms of O. sphenophrys and P. yucatanicum, where the digestion of the α and β chains is catalyzed mainly by SVMPs, which agrees with what has been reported for the venom of P. lansbergii rozei [54]. It is also worth mentioning that the degradation of the γ chain caused by M. nummifer venom is caused by SVMPs since the presence of EDTA inhibited it (Table 5).…”

“…yucatanicum , where the digestion of the α and β chains is catalyzed mainly by SVMPs, which agrees with what has been reported for the venom of P . lansbergii rozei [ 54 ]. It is also worth mentioning that the degradation of the ɣ chain caused by M .…”

“…As for Porthidium, only the lethal activity of venom from organisms in Colombia, Venezuela, and Costa Rica has been evaluated. An interesting case is the venom of P. lansbergii rozei from Venezuela, which is not lethal even at a dose of 12.7 μg/g [33,53,54]. It is important to note that in all the studies cited in this paragraph the venom was administered intraperitoneally, which, combined with the species differences, makes direct comparisons challenging.…”