Estudo dos efeitos de um polissacarídeo sulfatado isolado da alga marinha Solieria filiformis sobre os modelos de nocicepção e inflamação

• Ano de defesa: 2012
• Autor(a) principal: Araújo, Ianna Wivianne Fernandes de
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Química de macromoleculares; Algas marinhas; Carragenanas; Mediadores inflamatórios; Artrite; Hipernocicepção; Seaweeds; Carrageenans; Inflammatory mediators; Arthritis; Hypernociception; Mediadores da Inflamação; Alga marinha
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/16953

The sulfated polysaccharides (SP) of seaweed are recognized as biologically active molecules. This study aimed to evaluate the effects of a sulfated polysaccharide from red seaweed Solieria filiformis in classical models of nociception and acute inflammation in the experimental model of arthritis induced by zymosan in the temporomandibular joint of rats. In fractionation of the total SP by column of DEAE-cellulose were obtained two fractions of SP (F I-0.5 M and F II-0.75 M), in which the fraction F I presented the highest yield of SP. The analysis by gel permeation chromatography of the fractions (F I and F II) showed heterogeneous peaks with high molecular mass (1.12 x 105 and 2.95 x 105 g/mol, respectively). The fractions were structurally characterized by Fourier transformed infrared and identified as kappa - and iota- carrageenans, respectively. Male Swiss mice pretreated with F I (1; 3 or 9 mg/kg; i.v.) 30 min before receiving an injection of 0.8% acetic acid, 1% formalin or 30 min prior to a thermal stimulation showed antinociceptive response (p<0.05) in acetic acid-induced writhing and in the second phase of the formalin test, but did not increase the reaction time in the hot plate test, suggesting that antinociceptive effect occurs through a peripheral mechanism. F I (1; 3 or 9 mg/kg; sc) showed no significant anti-inflammatory effect when administered 1 hour before the flogistic agents carrageenan (500 µg/paw; 100 µL) or dextran (400 µg/paw; 100 µL) in male Wistar rats. In addition, the myeloperoxidase activity revealed a marked neutrophil accumulation in the paw in response to treatment with F I (1, 3 or 9 mg/kg, 100 µL/paw). In the assays of arthritis induced by Zy, the animals received F I (1; 3 or 9 mg/kg; s.c.) 1 hour before induction of arthritis (Zy 2 mg/joint; 40 uL) into the left temporomandibular joint (TMJ). As control groups, the animals received saline (40 µL; i.art.) or indomethacin (5 mg/kg; s.c.). Mechanical hypernociception in the TMJ was evaluated by von Frey electric apparatus in the basal time and 4 hours after induction of arthritis. At the 6th hour, the rats were euthanized and the TMJ cavity was washed to collect the synovial fluid and excised for histological analysis, and extraction of the mRNA from COX-2, TNF-α, IL-1β and HO-1. Pretreatment with F I (1, 3 or 9 mg/kg; s.c.) caused a reduction of facial hyperalgesia of 69, 66.6 and 78.08% respectively, compared to group Zy. However, F I (1; 3 or 9 mg/kg; s.c.) did not reduce the inflammation in the TMJ, increasing the relative expression of mRNA for COX-2, TNF-α, IL-1β and HO-1. Finally, F I (9 mg/kg; i.p.) did not show significant signs of toxicity when administrated in mice. Therefore, the F I of seaweed S. filiformis, showed to be an important biotechnological tool in the development of new pharmacological agents, without significant adverse effects in experimental models studied.