Potencial antiofídico de taninos isolados de Plathymenia reticulata Benth. sobre as principais atividades enzimáticas e biológicas induzidas pela peçonha de Bothrops atrox

Abstract

Plathymenia reticulata Benth. (Fabaceae), popularly known as mahogany, is a specie of growing medical interest that presents popular usage, particularly in the treatment of inflammatory diseases, infections and bleeding. The various medicinal tasks of this plant awakens interest in investigating closely their chemical composition because their bark are widely used in traditional communities of the municipality of Santarém, Pará, Brazil, for the treatment of snakebites. Accidents caused by snakes, mainly of the genus Bothrops, results in a number of local and systemic actions on their victims. This study evaluated the potential of antivenin purified tannins from the aqueous extract of P. reticulata front of enzymatic and biological activities induced by the venom of Bothrops atrox. The phytochemical screening of the aqueous extract of P. reticulata ( EAPr ) was performed by thin layer chromatography (TLC ). The EAPr was purified by column chromatography using Sephadex LH20 gel, chromatographic process resulted in five major fractions labeled A, B, C, D and E, which were monitored by fofolipásic and hemorrhagic activities B. atrox venom. Then the EAPR and the fractions were subjected to colorimetric assays for determination of total phenol, total tannins and condensed tannins. The fraction E was defined as condensed tannins P. reticulata ( TCPr ) and chosen for continuity of pharmacological tests to be the most potent fraction in biomonitoring tests. The TCPr been reported in different experimental protocols in vivo and in vitro. In vivo: (1) pre -incubation (2) pretreatment (3) post- treatmentagainst hemorrhagic and edematous activities induced by the venom of B. atrox. In vitro, tested in the face of phospholipase A2 and coagulant protocol with pre-incubation. The TCPr significantly inhibited venom hemorrhagic activity induced when using the pre-incubation protocol and pre- treatment, however, no significant inhibition at the concentration tested in the post- treatment group. On the other hand, the edema induced by venom was significantly (p<0.05) in all protocols tested. The coagulant and phospholipase activities were completely inhibited when pre - incubated with the venom of B. atrox. The results indicate that the antivenom has TCPr front property venom of B. atrox, suggesting the need for in-depth studies to elucidate the chemistry of tannins isolated and the mechanism of action.