title: First report of an anti-tumor, anti-fungal, anti-yeast and anti-bacterial hemolysin from Albizia lebbeck seeds.
abstract: A monomeric 5.5-kDa protein with hemolytic activity toward rabbit erythrocytes was isolated from seeds of Albizia lebbeck by using a protocol that involved ion-exchange chromatography on Q-Sepharose and SP-Sepharose, hydrophobic interaction chromatography on Phenyl-Sepharose, and gel filtration on Superdex 75. It was unadsorbed on both Q-Sepharose and SP-Sepharose, but adsorbed on Phenyl-Sepharose. Its hemolytic activity was fully preserved in the pH range 0-14 and in the temperature range 0-100 °C, and unaffected in the presence of a variety of metal ions and carbohydrates. The hemolysin reduced viability of murine splenocytes and inhibited proliferation of MCF-7 breast cancer cells and HepG2 hepatoma cells with an IC₅₀ of 0.21, 0.97, and 1.37 μM, respectively. It impeded mycelial growth in the fungi Rhizoctonia solani with an IC₅₀ of 39 μM but there was no effect on a variety of other filamentous fungi, including Fusarium oxysporum, Helminthosporium maydis, Valsa mali and Mycosphaerella arachidicola. Lebbeckalysin inhibited growth of Escherichia coli with an IC₅₀ of 0.52 μM.
authors.affiliation: School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China. lamszekwan@yahoo.com.hk
authors.forename: Sze Kwan
authors.initials: SK
authors.lastname: Lam
authors.forename: Tzi Bun
authors.initials: TB
authors.lastname: Ng
mesh_terms: D031289:Albizzia / Q000737:chemistry*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D000935:Antifungal Agents / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004926:Escherichia coli / Q000187:drug effects; D005658:Fungi / Q000187:drug effects; D006460:Hemolysin Proteins / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D020128:Inhibitory Concentration 50; D051379:Mice; D008810:Mice, Inbred C57BL; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology; D011817:Rabbits; D012639:Seeds / Q000737:chemistry; D013696:Temperature
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D006460:Hemolysin Proteins; D010936:Plant Extracts