In vivo anti-inflammatory effect of a sulfated polysaccharide isolated from the marine brown algae Lobophora variegata

Context: Lobophora variegata J.V. Lamouroux (Dictyotaceae) is a brown marine alga widely encountered in the Brazilian sea coast that presents high content of fucans. Anti-inflammatory effects of fucans are reported mostly in models in vitro, but little is known about its effects in vivo. Objective: To investigate vascular and cellular effects of a sulfated polysaccharide from the brown marine algae L. variegata (SP-Lv) in acute inflammatory models. Materials and methods: SP-Lv was isolated by DEAE-cellulose and analyzed by agarose gel electrophoresis and evaluated for its inhibitory effect on paw edema, vascular permeability, leukocyte migration and peritoneal nitrite content induced by zymosan in Wistar rats. Anticoagulant activities and possible systemic toxicity were also evaluated. Results: SP-Lv inhibited the paw edema (120 min: 1.42 +/- 0.11 vs. 0.95 +/- 0.05 mL), plasma exudation (21.53 +/- 0.62 vs. 11.96 +/- 0.68 mu g/g), nitrite content (4.42 +/- 0.33 vs. 2.86 +/- 0.003 mu M) and leukocyte migration (5.15 +/- 1.21 vs. 1.99 +/- 0.16 cells/10(3) mL) induced by zymosan. SP-Lv and l-NAME reduced the paw edema (60-120 min) elicited by l-arginine. However, at 180 min SP-Lv effect was more accentuated and sustained until 240 min, while that of l-NAME was abolished. Similarly to indomethacin, SP-Lv inhibited the entire edema time-course induced by phospholipase A(2), except for the time of 60 min. Discussion and conclusion: The anti-edematogenic effect of SP-Lv seems to occur via inhibition of nitric oxide synthase and cyclooxygenase activities. These results suggest a potential applicability of polysaccharides from alga origin in acute inflammatory conditions.