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African adders: partial characterization of snake venoms from three Bitis species of medical importance and their neutralization by experimental equine antivenoms.

Paixão-Cavalcante D, Kuniyoshi AK, Portaro FC, da Silva WD, Tambourgi DV - PLoS Negl Trop Dis (2015)

Bottom Line: The accidents are severe and the victims often have a poor prognosis due to the lack of effective specific therapies.Experimental antivenoms produced against B. arietans venom or Bitis g. rhinoceros plus B. nasicornis venoms cross-reacted with the venoms from the three species and blocked, in different degrees, all the enzymatic activities in which they were tested.We also demonstrated that horse antivenoms produced against B. arietans or B. g. rhinoceros plus B. nasicornis venoms can blocked some of the toxic activities of these venoms.

View Article: PubMed Central - PubMed

Affiliation: Immunochemistry Laboratory, Butantan Institute, São Paulo, São Paulo, Brazil.

ABSTRACT

Background: An alarming number of fatal accidents involving snakes are annually reported in Africa and most of the victims suffer from permanent local tissue damage and chronic disabilities. Envenomation by snakes belonging to the genus Bitis, Viperidae family, are common in Sub-Saharan Africa. The accidents are severe and the victims often have a poor prognosis due to the lack of effective specific therapies. In this study we have biochemically characterized venoms from three different species of Bitis, i.e., Bitis arietans, Bitis gabonica rhinoceros and Bitis nasicornis, involved in the majority of the human accidents in Africa, and analyzed the in vitro neutralizing ability of two experimental antivenoms.

Methodology/principal findings: The data indicate that all venoms presented phospholipase, hyaluronidase and fibrinogenolytic activities and cleaved efficiently the FRET substrate Abz-RPPGFSPFRQ-EDDnp and angiotensin I, generating angiotensin 1-7. Gelatinolytic activity was only observed in the venoms of B. arietans and B. nasicornis. The treatment of the venoms with protease inhibitors indicated that Bitis venoms possess metallo and serinoproteases enzymes, which may be involved in the different biological activities here evaluated. Experimental antivenoms produced against B. arietans venom or Bitis g. rhinoceros plus B. nasicornis venoms cross-reacted with the venoms from the three species and blocked, in different degrees, all the enzymatic activities in which they were tested.

Conclusion: These results suggest that the venoms of the three Bitis species, involved in accidents with humans in the Sub-Saharan Africa, contain a mixture of various enzymes that may act in the generation and development of some of the clinical manifestations of the envenomations. We also demonstrated that horse antivenoms produced against B. arietans or B. g. rhinoceros plus B. nasicornis venoms can blocked some of the toxic activities of these venoms.

No MeSH data available.


Related in: MedlinePlus

Inhibition of the proteolytic activity of Bitis ssp venoms by the experimental antivenoms.[A]Bitis spp venoms (20 μg) were pre-incubated (30’ at RT) with F(ab’)2 Ba (10 μL neat) or F(ab’)2 Br+ Bn (10 μL neat) antivenoms and ran under non-reducing conditions on a 10% polyacrylamide gel containing 1% gelatin type A. [B] One microgram of B. arietans, B. g. rhinoceros or B. nasicornis venoms were pre-incubated with 10 μL of neat sera prior incubation with 30 μg of human purified fibrinogen (Fn) then, ran under reducing condition in a 10% SDS-PAGE. The digestion of gelatin and the cleavage of fibrinogen were visualized by Coomassie Brilliant Blue staining.
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pntd.0003419.g007: Inhibition of the proteolytic activity of Bitis ssp venoms by the experimental antivenoms.[A]Bitis spp venoms (20 μg) were pre-incubated (30’ at RT) with F(ab’)2 Ba (10 μL neat) or F(ab’)2 Br+ Bn (10 μL neat) antivenoms and ran under non-reducing conditions on a 10% polyacrylamide gel containing 1% gelatin type A. [B] One microgram of B. arietans, B. g. rhinoceros or B. nasicornis venoms were pre-incubated with 10 μL of neat sera prior incubation with 30 μg of human purified fibrinogen (Fn) then, ran under reducing condition in a 10% SDS-PAGE. The digestion of gelatin and the cleavage of fibrinogen were visualized by Coomassie Brilliant Blue staining.

Mentions: α-Ba and α-Br + Bn antivenoms could also abolish the gelatinolytic activity of B. arietans and B. nasicornis venoms; the low molecular weight band of B. nasicornis was also strongly reduced, when incubated v:v for 30 min prior the zymography (Fig. 7A). α-Ba antivenom (10 μL neat) prevented the cleavage of the fibrinogen by all the Bitis venoms (1 μg per reaction); however, the α-Br +Bn antivenom (10 μL neat) only prevented the cleavage of fibrinogen by B. g. rhinoceros and B. nasicornis venoms, but not by B. arietans (Fig. 7B). Both antisera (10 μL neat) were also able to inhibit the cleavage of the FRET substrate, Abz-RPPGFSPFRQ-EDDnp (Fig. 8A). The cleavage of angiotensin I by B. g. rhinoceros and B. nasicornis venoms was strongly abolished when both antivenoms were used. Nevertheless, the angiotensin I hydrolysis by B. arietans was weakly blocked by α-Br+Bn antivenom and partially inhibited by α-Ba (Fig. 8B).


African adders: partial characterization of snake venoms from three Bitis species of medical importance and their neutralization by experimental equine antivenoms.

Paixão-Cavalcante D, Kuniyoshi AK, Portaro FC, da Silva WD, Tambourgi DV - PLoS Negl Trop Dis (2015)

Inhibition of the proteolytic activity of Bitis ssp venoms by the experimental antivenoms.[A]Bitis spp venoms (20 μg) were pre-incubated (30’ at RT) with F(ab’)2 Ba (10 μL neat) or F(ab’)2 Br+ Bn (10 μL neat) antivenoms and ran under non-reducing conditions on a 10% polyacrylamide gel containing 1% gelatin type A. [B] One microgram of B. arietans, B. g. rhinoceros or B. nasicornis venoms were pre-incubated with 10 μL of neat sera prior incubation with 30 μg of human purified fibrinogen (Fn) then, ran under reducing condition in a 10% SDS-PAGE. The digestion of gelatin and the cleavage of fibrinogen were visualized by Coomassie Brilliant Blue staining.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4340965&req=5

pntd.0003419.g007: Inhibition of the proteolytic activity of Bitis ssp venoms by the experimental antivenoms.[A]Bitis spp venoms (20 μg) were pre-incubated (30’ at RT) with F(ab’)2 Ba (10 μL neat) or F(ab’)2 Br+ Bn (10 μL neat) antivenoms and ran under non-reducing conditions on a 10% polyacrylamide gel containing 1% gelatin type A. [B] One microgram of B. arietans, B. g. rhinoceros or B. nasicornis venoms were pre-incubated with 10 μL of neat sera prior incubation with 30 μg of human purified fibrinogen (Fn) then, ran under reducing condition in a 10% SDS-PAGE. The digestion of gelatin and the cleavage of fibrinogen were visualized by Coomassie Brilliant Blue staining.
Mentions: α-Ba and α-Br + Bn antivenoms could also abolish the gelatinolytic activity of B. arietans and B. nasicornis venoms; the low molecular weight band of B. nasicornis was also strongly reduced, when incubated v:v for 30 min prior the zymography (Fig. 7A). α-Ba antivenom (10 μL neat) prevented the cleavage of the fibrinogen by all the Bitis venoms (1 μg per reaction); however, the α-Br +Bn antivenom (10 μL neat) only prevented the cleavage of fibrinogen by B. g. rhinoceros and B. nasicornis venoms, but not by B. arietans (Fig. 7B). Both antisera (10 μL neat) were also able to inhibit the cleavage of the FRET substrate, Abz-RPPGFSPFRQ-EDDnp (Fig. 8A). The cleavage of angiotensin I by B. g. rhinoceros and B. nasicornis venoms was strongly abolished when both antivenoms were used. Nevertheless, the angiotensin I hydrolysis by B. arietans was weakly blocked by α-Br+Bn antivenom and partially inhibited by α-Ba (Fig. 8B).

Bottom Line: The accidents are severe and the victims often have a poor prognosis due to the lack of effective specific therapies.Experimental antivenoms produced against B. arietans venom or Bitis g. rhinoceros plus B. nasicornis venoms cross-reacted with the venoms from the three species and blocked, in different degrees, all the enzymatic activities in which they were tested.We also demonstrated that horse antivenoms produced against B. arietans or B. g. rhinoceros plus B. nasicornis venoms can blocked some of the toxic activities of these venoms.

View Article: PubMed Central - PubMed

Affiliation: Immunochemistry Laboratory, Butantan Institute, São Paulo, São Paulo, Brazil.

ABSTRACT

Background: An alarming number of fatal accidents involving snakes are annually reported in Africa and most of the victims suffer from permanent local tissue damage and chronic disabilities. Envenomation by snakes belonging to the genus Bitis, Viperidae family, are common in Sub-Saharan Africa. The accidents are severe and the victims often have a poor prognosis due to the lack of effective specific therapies. In this study we have biochemically characterized venoms from three different species of Bitis, i.e., Bitis arietans, Bitis gabonica rhinoceros and Bitis nasicornis, involved in the majority of the human accidents in Africa, and analyzed the in vitro neutralizing ability of two experimental antivenoms.

Methodology/principal findings: The data indicate that all venoms presented phospholipase, hyaluronidase and fibrinogenolytic activities and cleaved efficiently the FRET substrate Abz-RPPGFSPFRQ-EDDnp and angiotensin I, generating angiotensin 1-7. Gelatinolytic activity was only observed in the venoms of B. arietans and B. nasicornis. The treatment of the venoms with protease inhibitors indicated that Bitis venoms possess metallo and serinoproteases enzymes, which may be involved in the different biological activities here evaluated. Experimental antivenoms produced against B. arietans venom or Bitis g. rhinoceros plus B. nasicornis venoms cross-reacted with the venoms from the three species and blocked, in different degrees, all the enzymatic activities in which they were tested.

Conclusion: These results suggest that the venoms of the three Bitis species, involved in accidents with humans in the Sub-Saharan Africa, contain a mixture of various enzymes that may act in the generation and development of some of the clinical manifestations of the envenomations. We also demonstrated that horse antivenoms produced against B. arietans or B. g. rhinoceros plus B. nasicornis venoms can blocked some of the toxic activities of these venoms.

No MeSH data available.


Related in: MedlinePlus