title: Polyunsaturated fatty acids induce polarized submembranous F-actin aggregates and kill Entamoeba histolytica.
abstract: We have recently identified a novel galacto-glycerolipid (GGL) from the plant Oxalis corniculata that killed the human pathogen Entamoeba histolytica. In this study, we show that the anti-amoebic activity of GGL was due to the polyunsaturated fatty acid α-linolenic acid (C18:3 ) side chain. Treatment of α-linolenic acid to E. histolytica trophozoites disrupted the cytoskeletal network and led to polarization of F-actin at one end of the cells with prominent filopodial extensions. In addition, clustering of surface receptors and signaling molecules was also observed adjacent to the polarized actin similar to concanavalin-A-(Con-A) induced capping. But, in contrast to Con-A-induced capping, α-linolenic acid induced caps were not shed and showed accumulation of long and numerous filopodia at the cap site. We found that α-linolenic acid disrupts the actin cytoskeletal network, which led to the detachment of plasma membrane from the underlying cytoskeleton. A similar effect was observed with other dietary fatty acids such as linoleic acid (C18:2 ), arachidonic acid (C20:4 ), eicosapentaenoic acid (C20:5 ), and docosahexaenoic acid (C22:6 ). Our findings showed that dietary polyunsaturated fatty acids are powerful anti-amoebic agents that lead to disruption of the actin cytoskeleton.
authors.affiliation: Department of Biochemistry, Bose Institute, Kolkata, West Bengal, India.
authors.forename: Dipak
authors.initials: D
authors.lastname: Manna
authors.forename: Jaspreet Singh
authors.initials: JS
authors.lastname: Grewal
authors.forename: Bidyut
authors.initials: B
authors.lastname: Sarkar
authors.forename: Sudipta
authors.initials: S
authors.lastname: Maiti
authors.forename: Anuradha
authors.initials: A
authors.lastname: Lohia
mesh_terms: D000199:Actins / Q000378:metabolism*; D000563:Amebicides / Q000494:pharmacology*; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D004748:Entamoeba histolytica / Q000187:drug effects* / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology*; D006801:Humans
chemical_list: D000199:Actins; D000563:Amebicides; D005231:Fatty Acids, Unsaturated