A New Ledin from the Pulp of Punica granatum: Isolation, Charactemation and Antiproliferative Activities

Abstract

A lectin (designated as PgL) was purified from the pulp of pomegranate (Punica granatum) by using Ion-exchange chromatography on DEAE cellulose column with the molecular mass of 28.0 ± 1.0 KDa as estimated by SOS-PAGE both in the presence and absence of ð€€‹- mercaptoethanol. The lectin agglutinated rat blood cells along with different groups of human blood cells. The hemmaglutination activity was inhibited by 4- nitrophenyl-a-D-manopyranoside and 2-nitrophenyl-ð€€‹-D-glucopyranoside. The lectin showed the maximum agglutination activity within the pH range of 6.0-8.0 and temperatures range of 30-80°C. PgL was glycoprotein in nature containing 40% neutral sugar. The lectin was a divalent ion-independent glycoprotein that lost 75% of its activity in the presence of 8M of urea. PgL exerted no toxic effect against brine shrimp nauplii and did not show any agglutination activity against five pathogenic bacteria (Escherichia coli, Listeria monocytogenes, Salmonella enteritidis, Bacillus subtilis and Salmonella typhi). MTT assay showed the growth of Ehrlich ascites carcinoma (EAC) cells to be inhibited upto 6.9-19.8% at a protein concentration of 12.5-100 µg/ml. PgL showed 18.0- 33.0% growth inhibition against Ehrlich ascites carcinoma (EAC) cells in vivo in mice when administered at 1.5-4.5 mg/kg/day (i.p.), respectively, for five consequent days. Keywords: lectin; anti tumor; fluorescence spectroscopy; MTT assay; agglutination; sugar inhibition