Polissacarídeo Modificado com Anidrido Propiônico Extraído da Macroalga Gracilaria Domingensis Possui Efeito Anti-inflamatório em Modelos Experimentais de Inflamação Geral em Camundongos

Abstract

In recent years, the search for new molecules from products of marine origin, specifically polysaccharides extracted from marine algae of the Filo Rodophyta (the genus Gracilaria being the best known) has gained a lot of attention in the face of numerous pharmacological activities, including antioxidant, anti-inflammatory and antinociceptive activity. Species of this genus, as well as Gracilaria domingensis are abundant throughout the northeastern coast, mainly in the range that extends from Piauí to Rio Grande do Norte, presenting great economic importance, because in addition to being appropriate for human consumption, they are also used in the cosmetic industry and by the food industry for gelatin production. Thus, one of the ways to improve the effects of some substances can be accomplished by modifying the surface of materials by changing the structural characteristics, without drastic changes in the properties of their volume, forming compounds with the intention of improving the compatibility of the polymer matrix. Therefore, the present work aimed to evaluate the anti-inflammatory action based on the polysaccharide of macroalgae G. domingensis modified with propionic anhydride in classical pharmacological models of acute inflammation (carrageenan-induced paw edema, histamine and serotonin) in mice. The research is experimental in nature and was approved by the ethics and animal experimentation committee (CEUA) under number 480/18. The experimental protocols followed the norms and guidelines of the Brazilian College of Animal Experimentation (COBEA). Swiss mice weighing between 25-30g were used, with 6 animals per group: Saline group 0.9%, indomethacin 10 mg/kg, and groups for the anti-iflamatory evaluation of PLS AP at doses of 2.5; 5.0 or 10 mg/kg intraperitoneally (i.p.) and subsequently submitted to carrageenan-induced paw edema (Cg) 500 μg per paw in order to choose a better dose with anti-inflammatory effect that would be used in the other tests. After Cg edema, the segments of the supplanting region of the animals' paws were removed and used for the evaluation of the enzyme myeloperoxidase (MPO). The animals also underwent paw edema by histamine vasoactive mediators (100 μg/paw) and serotonin (100 μg/paw), peritonitis was also induced with an injection of 250 μg of Cg (i.p.) in mice and peritoneal fluid was evaluated for leukocyte migration and glutathione (GSH) levels. The animals treated with PLS 2.5 mg/kg presented relevant and statistically significant results in the reduction of edema caused by Cg, as well as in the vascular response due to the decrease in vascular edema caused by histamine and serotonin. In addition, this compound showed efficacy in reducing MPO enzyme levels and migrating cells into the peritoneal cavity, as well as increasing GSH levels. The results obtained allow us to infer that PLS AP at a dose of 2.5 mg/kg has an anti-inflammatory effect and attenuates oxidative stress revealing a pharmacological potential of the compound as a promising anti-inflammatory agent.