Effects of L-canavanine on T cells may explain the induction of systemic lupus erythematosus by alfalfa

Arthritis Rheum. 1985 Jan;28(1):52-7. doi: 10.1002/art.1780280109.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Autoantibodies / analysis
  • B-Lymphocytes / metabolism
  • Canavanine / pharmacology*
  • Cell Cycle / drug effects
  • Cell Survival / drug effects
  • Concanavalin A / pharmacology
  • DNA / immunology
  • Humans
  • Immunoglobulin G / biosynthesis
  • Lupus Erythematosus, Systemic / etiology*
  • Lymphocyte Activation / drug effects
  • Medicago sativa* / adverse effects
  • Plant Lectins
  • T-Lymphocytes / drug effects*
  • T-Lymphocytes / immunology
  • T-Lymphocytes, Regulatory / immunology


  • Autoantibodies
  • Immunoglobulin G
  • Plant Lectins
  • Concanavalin A
  • Canavanine
  • DNA