Antinociceptive and anti-inflammatory activities of lectin from the marine green alga Caulerpa cupressoides.

The search for new compounds for controlling pain and inflammation, with minimal side effects has focused on marine algae. The aim of this work was to investigate the effect of the purified lectin from the green marine alga Caulerpa cupressoides (CcL) in classical models of nociception and inflammation. Male Swiss mice received i.v. CcL 30 min prior to receiving 0.8% acetic acid (10 ml/kg; i.p); 1% formalin (20 microl; s.c.) or were subjected to thermal stimuli. We observed that CcL (3, 9 or 27 mg/kg) significantly reduced the number of writhes induced by acetic acid by 37.2%; 53.5% and 86.0%, respectively. CcL (27 mg/kg) also reduced the second phase of the formalin test. However, CcL (27 mg/kg) did not present significant antinociceptive effects in the hot plate test, when compared to morphine, suggesting that its antinociceptive action occurs predominantly through a peripheral mechanism. The antinociceptive effects were abolished when CcL was pre-incubated with mucin (20mg/kg; i.v.). When CcL (9 mg/kg) was administered i.v. in Wistar rats 30 min before carrageenan administration, neutrophil counts were reduced by 65.9%. CcL also inhibited paw edema in all time intervals, especially at the third hour. Finally, CcL (9 mg/kg) administered i.v. in mice did not cause hepatic or renal alterations and did not affect body mass or macroscopy of the organs examined. In conclusion, CcL appears to have important antinociceptive and anti-inflammatory activities and could represent an important agent for future studies.

Antinociceptive and anti-inflammatory activities of lectin from marine red alga Pterocladiella capillacea.

Researchers see algae as a promising tool to discover both efficient and safe agents for pain therapy. We evaluated the antinociceptive and anti-inflammatory activities of lectin from the marine alga Pterocladiella capillacea lectin (PcL). PcL was purified and tested in classical models of nociception and inflammation. Male Swiss mice received PcL 30 min prior to receiving 0.8% acetic acid (10 microl/10 g, i.p.), 1% formalin (20 microl/intraplantar) or the hot plate test, and were compared to untreated animals or animals pretreated with indomethacin or morphine. PcL (0.9, 8.1 or 72.9 mg/kg, i.v.) significantly reduced the number of writhes (30%, 39%, and 52%, respectively). PcL (72.9 mg/kg, i.v.) also reduced (p<0.05) both the first and second phases of the formalin test by 58% and 87%, respectively. However, PcL (72.9 mg/kg) did not present significant antinociceptive effects in the hot plate test when compared to morphine, suggesting that its antinociceptive action occurs via peripheral rather than a central-acting mechanism. It was also observed that leukocyte migration was induced by carrageenan (500 microg/cavity) in male Wistar rats and that PcL (8.1 mg/kg, i.v.) significantly reduced neutrophil migration by 84%, as compared to untreated animals, suggesting inhibition of inflammatory mediators. The data indicated that PcL has peripheral actions with both anti-inflammatory and antinociceptive properties.

Purification of a lectin from the marine red alga Gracilaria ornata and its effect on the development of the cowpea weevil Callosobruchus maculatus (Coleoptera: Bruchidae).

A lectin from the marine red alga Gracilaria ornata (Gracilariaceae, Rodophyta) was purified and characterized. The purification procedure consisted of extracting soluble proteins in 0.025 M Tris-HCl buffer, pH 7.5, followed by ammonium sulfate precipitation (70% saturation), ion exchange chromatography on DEAE-cellulose and affinity chromatography on mucin-Sepharose 4B. The purified G. ornata lectin (GOL) showed a single protein band with an apparent molecular mass of 17 kDa when submitted to SDS-polyacrylamide gel electrophoresis under reducing conditions. The native molecular mass of GOL determined by gel filtration on a Sephadex G-100 column was 17.4 kDa and its carbohydrate content was estimated to be 2.9%. Therefore, GOL is a monomeric glycoprotein. The purified lectin agglutinated trypsin-treated erythrocytes from rabbit and chicken but not from human. Its activity was not inhibited by any of the mono- and disaccharides tested but by the complex glycoproteins porcine stomach mucin, lactotransferrin, asialofetuin and bovine and porcine thyroglobulins. Isoelectric focusing showed that GOL is an acidic protein with a pI of 5.4 with analysis of its amino acid composition revealing high contents of Asx, Glx, Ser, Glu, Ala and Cys. When incorporated in artificial seeds, GOL significantly affected the development of Callosobruchus maculatus larvae, indicating the possibility of using this lectin in a biotechnological strategy for insect management of stored cowpea seeds.