Banca de QUALIFICAÇÃO: SARAH DE SOUSA FERREIRA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : SARAH DE SOUSA FERREIRA
DATE: 16/11/2021
TIME: 09:00
LOCAL: Videoconferência
TITLE:

Evaluation of the antivenom potential of chlorogenic and rosmarinic acids and production of an antiserum against Bothrops brazili (Hoge, 1953) snake venom in chitosan nanoparticulate system

KEY WORDS:

Bothrops brazili. Chitosan. Nanotechnology. Ophidism. Phenolic compounds. Serum therapy.

PAGES: 136
BIG AREA: Ciências Biológicas
AREA: Bioquímica
SUMMARY:

Snakebite causes high mortality and morbidity in many regions of the world. Currently, the only treatment is serum therapy, which has some disadvantages, such as: high production cost, little efficacy in neutralizing local effects, low access in some regions and adverse reactions. Considering these factors, this study aims to present new alternatives to improve the treatment of snakebite. For this purpose, Bothrops brazili venom was used, this species is little studied and found mainly in the Amazon region. Thus, the present study has as general objective (1) to analyze the inhibitory potential of chlorogenic and rosmarinic acids against the local and systemic effects caused by the envenomation by B. brazili, (2) to obtain and characterize chitosan nanoparticles incorporated and adsorbed with the B. brazili venom and evaluate the immunoadjuvant potential of these nanoparticles for the production of a new serum. The evaluation of the antiophidic potential of chlorogenic and rosmarinic acids was carried out through in vivo and in vitro assays. In the in vitro assays, the acids were able to neutralize the activity of proteases and phospholipases in the venom, in addition to reducing the pro-coagulant effect in human plasma. In vivo, these compounds neutralized local effects such as edema, hemorrhage, increased myeloperoxidase enzyme and myotoxicity. Still, the acids mitigated the systemic effects resulting from envenomation by this species, which were: biochemical changes (kidney, liver and muscle damage), hemostatic changes (partially activated thromboplastin time, prothrombin time and platelet count), hematologic (white blood cells) and lipid peroxidation. For the production of chitosan nanoparticles, the ionic gelling technique was used. The nanoparticles had a size between 150 and 190 nm, a potential of approximately +30 mV and a polydispersion index of approximately 0.400. These parameters were evaluated using the Dynamic Light Scattering technique. The nanoparticles presented above 97% efficiency to incorporate and adsorb the venom and the analysis of Field Emission Gun Scanning Electronic Microscopy and Atomic Force Microscopy showed that they presented homogeneous shape and size. The Fourier Transform Infrared Spectroscopy analysis showed that the venom presented bands at 1543 cm^-1 and 1651 cm^-1 referring to amide groups and the nanoparticles presented bands at 916, 1087, 1259 and 1340 cm^-1 that underwent deviation after the incorporation and adsorption of the venom. Finally, the mice were immunized with the venom associated with chitosan nanoparticles or aluminum hydroxide and serum was obtained. In conclusion, these results demonstrate that chlorogenic and rosmarinic acids have the potential to neutralize the local and systemic effects caused by envenomation caused by B. brazili, and can be used as an alternative to complement serum therapy. Also, chitosan nanoparticles were efficient in incorporating and adsorbing the venom can be used as an adjuvant in the production of a new serum therapy.

BANKING MEMBERS:
Externa ao Programa - 2378605 - CRISTIANE FERNANDES DE ASSIS
Externo ao Programa - 2195251 - HUGO ALEXANDRE DE OLIVEIRA ROCHA
Externa à Instituição - JULIANA FÉLIX DA SILVA - UNIFACEX