Extraction, purification des lectines à partir des plantes médicinales

Abstract

Lectins are ubiquitous proteins, non-immune origin, with several biological properties. The purpose of this work was to purify and characterize the lectin from Ruta montana roots and Peganum harmala seeds and to study their antiproliferative activity. Lectins from two plants were extracted by three different methods, distilled water at pH 4, sodium chloride (NaCl), phosphate buffered saline (PBS). Ruta montana lectin was purified by ultrafiltration and ammonium sulfate precipitation, followed by gel filtration chromatography. While Peganum harmala lectin was purified by ultrafiltartion and gel filtration chromatography. The characterization of Ruta montana lectin shows that it have a monomeric structure with a molecular weight of 28.8 kDa, it lost its activity at 70°C for 30 min and stable in neutral pH, and shows specificity to human erythrocytes type B, Its activity is inhibited by galactose and glucose. Peganum harmala lectin was composed of three identical subunits, each with a molecular mass of 70.53 kDa. The activity of this lectin was stable between pH 4.2 and pH 9, their incubation at 80°C for 10 min led to irreversible denaturation. It agglutinated all human erythrocyte ABO, its activity was not inhibited by the presence of monosaccharides, such as galactose, mannose, fructose, sucrose, and glucose. Ruta montana lectin has antiproliferative activity on Caco-2 cell lines and stimulates cell proliferation of THP-1 cell lines. Peganum harmala lectin has a dosedependently high inhibitory effect on Caco-2 cell lines and no effect on THP-1 cell lines.