Volume 161, 23 February 2015, Pages 224–232
Research Paper
Plants used to treat snakebites in Santarém, western Pará, Brazil: An assessment of their effectiveness in inhibiting hemorrhagic activity induced by Bothrops jararaca venom
Abstract
Ethnopharmacological relevance
The
poor distribution and limited availability of antivenoms in Brazil have
led to greater use of plants to treat snakebites. Very often such
plants are the only alternative available to riverside communities.
Materials and methods
Direct
questionnaire-based interviews were conducted with members of the
Cucurunã, São Pedro and Alter do Chão communities in Santarém, Pará,
Brazil. For each of the 12 most frequently mentioned species aqueous
extracts were prepared and the phytochemical profiles determined by thin
layer chromatography. The concentrations of phenolic compounds (tannins
and flavonoids) in the aqueous extracts were determined by colorimetric
assays. To assess inhibition of the hemorrhagic activity of Bothrops jararaca
venom, solutions containing the venom mixed with aqueous extracts in
the ratios 1:12 and 1:48 were tested (w/w). SDS-PAGE and Western blot
were used to assess the action of the extracts on Bothrops jararaca venom.
Results
In
all, 24 plants belonging to 19 families were mentioned in the survey as
being used to treat snakebites. Leaves (84%), seeds (60.9%) and inner
bark (53%) were cited as the most frequently used parts in folk
remedies, which were usually prepared in the form of a decoction
(62.5%), tincture (45%) or maceration (22.5%). Hemorrhage induced by Bothrops jararaca venom was completely inhibited by aqueous extracts of Bellucia dichotoma, Connarus favosus, Plathymenia reticulata and Philodendron megalophyllum,
which had a high phenolic content and contained condensed and
hydrolyzable tannins. The results of SDS-PAGE showed that some venom
protein bands were not visible when the venom was preincubated with the
extracts that had completely inhibited hemorrhagic activity of the
venom. Western blot showed that the extracts did not have any enzymatic
action on the proteins in the venom as it failed to detect
low-molecular-weight bands, which are indicative of possible enzymatic
cleavage.
Conclusions
Traditional
use of plants to treat snakebites is a common practice in the western
region of Pará, Brazil. Our findings show that some plant extracts were
able to inhibit snake venom-induced hemorrhage in vitro. In vivo studies
are being carried out to validate the traditional use of these species
to treat snakebites.
Keywords
- Ethnobotany;
- Plant extracts;
- Snakebite envenomation;
- Anti-snakebite plants;
- Hemorrhage
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