Caracterização químico-estrutural e avaliação dos efeitos gastroprotetor e anti-inflamatório do polissacarídeo sulfatado da alga vermelha Pterocladiella beachiae Freshwater

• Ano de defesa: 2019
• Autor(a) principal: Lima, Glauber Cruz
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Macroalgas vermelhas; Polissacarídeo sulfatado; Pterocladiella beachiae; Gastroprotetor; Anti-inflamatório
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/50585

The red seaweeds (Rhodophyta) are sources of important bioactive molecules, among which the sulfated polysaccharides, in which the therapeutic activity is widely reported in scientific literature. Thus, this study aimed to characterize the chemical structure and determine the gastroprotective and anti-inflammatory potential of the sulfated polysaccharide extracted from the red seaweed Pterocladiella beachiae (SP-Pb). The SP-Pb was obtained through enzymatic extraction with papain and showed a degree of sulfonation of 0.32 with molar mass estimated at 2.33 x 105 g mol-1. The structural characterization was performed through Fourier transform infrared spectrometer (FTIR) and nuclear magnetic spectroscopy (NMR) and demonstrated that the SP-Pb as an agar-type sulfated polysaccharide and indicated the presence of xylose in its structure. The gastroprotective activity of SP-Pb was evaluated in an animal model of gastric ulcer induced by ethanol. The results showed that the SP-Pb (at the dose of 3 mg/kg) has a significant gastroprotective effect associated with reduction of oxidative damage and hemoglobin levels (indicative of hemorrhage) in the gastric mucosa. The SP-Pb also regulated the blood flow to the mucosal layer through modulations with the enzyme nitric oxide synthase (NOS) and the potassium channel sensitive to ATP (KATP). To assess the anti-inflammatory activity SP-Pb, the phlogistic agents carrageenan and dextran were used to induce edema in the paws of mice. The use of SP-Pb (at dose of 3 mg/kg) was effective in reducing the paw edema induced by both phlogistic agents. The anti-inflammatory activity of SP-Pb was related to its action in reducing the levels of reactive oxygen species (ROS) in carrageenan-induced peritonitis, and the immunoexpression of iNOS and TNF-α in edematous paw tissue. Thus, the SP-Pb is considered a promising candidate for the treatment of inflammatory and oxidative diseases.