Stimulation of IFN-γ production by garlic lectin in mouse spleen cells: involvement of IL-12 via activation of p38 MAPK and ERK in macrophages

Phytomedicine. 2011 Feb 15;18(4):309-16. doi: 10.1016/j.phymed.2010.06.008. Epub 2010 Aug 17.

Abstract

Several lectins, present in beans and edible plant products, have immuno-potentiating and anti-tumor activities. We here report the effects of garlic lectin purified from garlic bulbs on the production of cytokines such as interleukin-12 (IL-12) and interferon-γ (IFN-γ) in the mouse. Garlic lectin induced IFN-γ production in spleen cells in a bell-shaped time (24-60 h)- and concentration (0.25-2.0 mg/ml)-dependent manner. The maximal enhancement was observed at 36 h with 0.5 mg/ml of garlic lectin. The stimulatory effect of garlic lectin on IFN-γ production was completely inhibited by both actinomycin D and cycloheximide, an inhibitor of ribosomal protein synthesis and DNA-dependent RNA polymerase, respectively, and was associated with an increase in IFN-γ mRNA level. Garlic lectin also induced IL-12 production in mouse peritoneal macrophages in a concentration (0.25-1.0 mg/ml)- and bell-shaped time (3-24 h)-dependent manner. The lectin increased the phosphorylation of extracellular signal-regulated kinases (ERK) and p38 mitogen-activated protein kinase (p38 MAPK) in macrophages. Furthermore, specific pharmacological inhibitors of ERK kinase (U0126) and p38 MAPK (SB203580) also suppressed the production of IL-12 induced by garlic lectin. The present findings suggest that garlic lectin induces IL-12 production via activation of p38 MAPK and ERK in mouse macrophages, which, in turn, stimulates IFN-γ production through an increase in IFN-γ mRNA in the spleen cells.

MeSH terms

  • Animals
  • Cells, Cultured
  • Dose-Response Relationship, Drug
  • Extracellular Signal-Regulated MAP Kinases / drug effects
  • Extracellular Signal-Regulated MAP Kinases / metabolism*
  • Female
  • Garlic / chemistry*
  • Interferon-gamma / drug effects*
  • Interferon-gamma / genetics
  • Interferon-gamma / metabolism
  • Interleukin-12 / metabolism*
  • Macrophages, Peritoneal / drug effects
  • Macrophages, Peritoneal / immunology
  • Mice
  • Mice, Inbred C57BL
  • Phosphorylation / drug effects
  • Plant Extracts / isolation & purification
  • Plant Extracts / pharmacology
  • Plant Lectins / isolation & purification
  • Plant Lectins / pharmacology*
  • Plant Roots / chemistry
  • Spleen / cytology
  • Spleen / drug effects
  • Spleen / immunology
  • p38 Mitogen-Activated Protein Kinases / drug effects
  • p38 Mitogen-Activated Protein Kinases / metabolism*

Substances

  • Plant Extracts
  • Plant Lectins
  • Interleukin-12
  • Interferon-gamma
  • Extracellular Signal-Regulated MAP Kinases
  • p38 Mitogen-Activated Protein Kinases