Caracterização estrutural e atividade anti-inflamatória da lectina da alga marinha vermelha Bryothamnion triquetrum

Abstract

The great biodiversity of seaweeds and their occurrence in almost all environments on the planet demonstrate the importance of such beings to ecosystems. One example is the extraction of potentially active biomolecules such as lectins, which are proteins that have been subject of research worldwide. This is due to its impressive ability to bind specifically to carbohydrates or substances containing them, providing an immense field of biological application. This work purpose was to produce lectin from the red seaweed Bryothamnion triquetrum (Lec), evaluate its secondary structure using spectroscopic techniques, and investigate their anti-inflammatory properties in mice. Initially, the lectin was purified by precipitation with ammonium sulfate (0-60) and ion exchange chromatography, and obtained the first peak (PI). This peak was selected by hemagglutination activity thus obtaining pure lectin from Bryothamnion triquetrum, verified by SDS-PAGE. The secondary structure of lectin was analyzed by circular dichroism spectroscopic techniques, against to pH extremes (4.0 to 11.0), and compared to the spectrum of its native structure, and fluorescence against different temperatures, ranging from 25° to 75°, each 10° interval. In biological activities assessment, groups of animals were subjected to pretreatment with the lectin (1.5 and 10mg/kg, ip) and indomethacin (10mg/kg) 30 min before the inflammatory stimulus. The anti-inflammatory activity in mice was evaluated through the assays of peritonitis induced by carrageenan - Cg (500 μg / cav) and paw edema induced by Cg (500 μg / paw), and dextran (500 μg / paw). Extremes of pH (4.0 and 11.0) did not alter the protein secondary structure. Fluorescence data (280nm and 295nm) also showed stability, and aromatic amino acids presence in their structure. Lectin inhibited cell migration in the induced peritonitis by Cg and induced paw edema by Cg and dextran. Thus, it is concluded that the lectin obtained from the Bryothamnion triquetrum DEAE PI shows stable structure related to pH and temperature variation. Regarding biological properties tested, the lectin showed anti-inflammatory effects in models used, and it can be considered a molecule with potential for further studies of inflammation.