Banca de QUALIFICAÇÃO: JULIANA FELIX DA SILVA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : JULIANA FELIX DA SILVA
DATA : 27/07/2017
HORA: 08:00
LOCAL: Sala Carl Peter von Dietrich
TÍTULO:

Investigation of the toxicity of Bothrops erythromelas: a study of the pathogenesis and inhibitory efficacy of Jatropha gossypiifolia alone or in combination with antivenom therapy

PALAVRAS-CHAVES:

Bothrops erythromelas, snakes, antivenom, Jatropha gossypiifolia, “bellyache bush”, antiophidic activity, local effects, systemic effects

PÁGINAS: 237
GRANDE ÁREA: Ciências Biológicas
ÁREA: Bioquímica
RESUMO:

Bothrops snakes are responsible for about 90% of snakebites in Latin America. Antivenom serum therapy, however, still has low efficacy against local effects, hard access in some regions, in addition to high cost and potential risk of adverse reactions. In this context, the main objective of this work is to contribute with complementary alternatives to antivenom therapy, with emphasis on the species Bothrops erythromelas, which is a snake of epidemiologic relevance in Northeastern Brazil, but that, until this moment, still lacks further studies and that is not included in the antigenic mixture for production of Brazilian bothropic antivenom. For this, two main work fronts are being conducted: (1) characterization of the local and systemic toxic effects induced by this venom, in order to better understand its toxicity and thus to develop more effective strategies for its treatment; and (2) evaluation of the effectiveness of the plant species Jatropha gossypiifolia against the toxic effects of the venom under study, aiming at its use as raw material for future antiophidic herbal products, which may complement the efficacy of antivenom therapy. Through the experimental envenoming studies in mice, it was observed that B. erythromelas venom produced an intense local inflammatory picture, involving the direct participation of enzymatic components of the venom, as well as endogenous inflammatory mediators, which can be used as therapeutic targets for the treatment of local envenoming. In relation to systemic toxicity, venom produced in mice quite pronounced effects on hemostasis, in addition to systemic hemorrhage and a certain degree of renal and hepatic toxicity, which could be visualized by means of the alteration of several haematological, hemostatic and biochemical parameters. Through inhibition studies of these effects, it is observed that, in general, the tested antivenoms in fact have limited efficacy against the enzymatic activities in vitro and the local effects of the venom in vivo, despite the presence of immunological recognition, which indicates the presence of highly immunogenic but not toxicologically relevant components to the toxic action of the venom. Aqueous leaf extract of J. gossypiifolia, in turn, was able to significantly reduce the local and systemic effects of venom, which could be associated with its direct action on snake toxins, as well as an indirect action on the endogenous mediators. An herbal gel for use as a topical adjunct in the treatment of snake envenoming was developed and promising results were obtained when the association of this gel with antivenom was found to be able to significantly improve the effectiveness of the treatment of local tissue damage induced by B. erythromelas. Phytochemical analyzes indicate that flavonoids are the major compounds of the plant species, and may be, at least partially, the main class of substance responsible for the activities presented. In conclusion, the results obtained to date demonstrate the potential of the plant species J. gossypiifolia as an adjuvant in the treatment of bothropic envenoming, and could be the first step for the future development of herbal antiophidic products with genuinely Brazilian raw material for complementation of the current antivenom therapy in the treatment of bothropic accidents.

MEMBROS DA BANCA:
Presidente - 1549705 - ADRIANA FERREIRA UCHOA
Externo ao Programa - 1663052 - IVANISE MARINA MORETTI REBECCHI
Interno - 2275890 - MARCELO DE SOUSA DA SILVA