Purification of lectin from pleurotus eryngii var ferulae mushroom and investigation some of its biological properties

In this study the lectin from the crude extract of mushroom Pleurotus eryngyii var. ferulae (PEFL) was purified to homogeneity by 80 % ammonium sulfate fractional precipitation, DEAE Sepharose-4B anion exchange and Sephadex G-100 gel filtration chromatographies. The enzyme was obtained in 18.3 % yield. The specific activity of the purified enzyme was calculated as 5120 HB/mg protein, the molecule weight was found to be 43 kDa determined by SDS-PAGE under denaturing and reducing conditions. In this study we also evaluated the effect of PEFL on lypopolysaccaride (LPS)-induced levels of inducible nitric oxide synthase (iNOS) and cyclooxigenase-2 (COX-2) enzymes in RAW 264.7 macrophages and assessed the inhibitory effect of PEFL on the production of pro-inflammatory cytokines such as tumor necrose factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6) and interferon- (INF-) and anti-inflammatory cytokine IL-10 as well as prostaglandin E2 (PGE2) . We found that PEFL is a potent inhibitor of LPS-induced PGE2, TNF-α, IL-1β, IL-6 and INF-. In the LPS treated group PGE2, TNF-α, IL-1β and IL-6 levels were significantly (p < 0,05) higher than those of the control group. A significant (p < 0,05) reduction was observed in the LPS+PEFL treated groups (p < 0,05), compared with the only LPS treated group. In addition, a significant increase in the IL-10 levels was observed in the LPS+PEFL treated groups (p < 0,05), compared with the only LPS treated group. As determined by Western Blotting analysis, in the control groups, iNOS, and COX-2 protein levels were slightly detectable. However, in the LPS treated groups, iNOS and COX-2 were markedly expressed by LPS, whereas in the LPS+PEFL treated groups, PEFL significantly inhibit the expressions of these proteins in a concentration-dependent manner. These results suggest that the inhibitions of the iNOS and COX-2 expressions and PGE2 and cytokines production are responsible for the anti-inflammatory effects of PEFL. Keywords: Pleurotus eryngii var ferulae, Mushroom, Lectin, Lipopolysaccharide, RAW 264.7 Macrophage, Cytokines.