title: Effects of L-canavanine on T cells may explain the induction of systemic lupus erythematosus by alfalfa.
abstract: Alfalfa sprouts can induce systemic lupus erythematosus (SLE) in monkeys. This property of alfalfa sprouts has been attributed to their non-protein amino acid constituent, L-canavanine. Occurrence of autoimmune hemolytic anemia and exacerbation of SLE have been linked to ingestion of alfalfa tablets containing L-canavanine. In this report we show that L-canavanine has dose-related effects in vitro on human immunoregulatory cells, which could explain its lupus-inducing potential. These effects include: 1) diminution of the mitogenic response to both phytohemagglutinin and concanavalin A but not to pokeweed mitogen, as determined in both thymidine incorporation and cell cycle studies, and 2) abrogation of concanavalin A-induced suppressor cell function, which results in increased release of both IgG and DNA binding activity into supernatants by cells from normal subjects and SLE patients. These immunoregulatory effects of L-canavanine may explain the induction or exacerbation of SLE by alfalfa.
authors.forename: J
authors.initials: J
authors.lastname: Alcocer-Varela
authors.forename: A
authors.initials: A
authors.lastname: Iglesias
authors.forename: L
authors.initials: L
authors.lastname: Llorente
authors.forename: D
authors.initials: D
authors.lastname: Alarcón-Segovia
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000032:analysis; D001402:B-Lymphocytes / Q000378:metabolism; D002172:Canavanine / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003208:Concanavalin A / Q000494:pharmacology; D004247:DNA / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis; D008180:Lupus Erythematosus, Systemic / Q000209:etiology*; D008213:Lymphocyte Activation / Q000187:drug effects; D000455:Medicago sativa / Q000009:adverse effects; D037121:Plant Lectins; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
chemical_list: D001323:Autoantibodies; D007074:Immunoglobulin G; D037121:Plant Lectins; D003208:Concanavalin A; D002172:Canavanine; D004247:DNA