Ethyl acetate extract of Psidium guajava inhibits IgE-mediated allergic responses by blocking FcεRI signaling

• Published in: Food and chemical toxicology Vol. 49; no. 1; pp. 100 - 108
• Main Authors: Han, Eun Hee, Hwang, Yong Pil, Kim, Hyung Gyun, Park, Jin Hee, Choi, Jae Ho, Im, Ji Hye, Khanal, Tilak, Park, Bong Hwan, Yang, Ji Hye, Choi, Jun Min, Chun, Sung-Sik, Seo, Jong Kwon, Chung, Young Chul, Jeong, Hye Gwang
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.01.2011; Elsevier
• Subjects: Acetates - chemistry; Animals; Anti-allergic activity; anti-inflammatory activity; antigens; antioxidants; Base Sequence; Biological and medical sciences; Cell Line; DNA Primers; ethyl acetate; food crops; gene expression; General pharmacology; histamine; Histamine Release - drug effects; Hypersensitivity - drug therapy; Hypersensitivity - immunology; IL-4; Immunoglobulin E - immunology; interleukin-4; Mast cells; Medical sciences; medicinal plants; messenger RNA; mitogen-activated protein kinase; NF-κB; Pharmacognosy. Homeopathy. Health food; Pharmacology. Drug treatments; Phosphorylation; Plant Extracts - pharmacology; Plant Extracts - therapeutic use; Polymerase Chain Reaction; protein synthesis; Psidium guajava; Rats; Reactive Oxygen Species; Receptors, IgE - metabolism; Signal Transduction - drug effects; Syk; toxicology; transcription factor NF-kappa B; tumor necrosis factor-alpha; IL-4; NF-κB; Mast cells; Anti-allergic activity; Syk; Psidium guajava; Allergy; B; Toxicity; IgE; Immunoglobulin receptor; Extract; Antiallergic; Medicinal plant; Signal transduction; Interleukin 4; Dicotyledones; Angiospermae; Myrtaceae; Tyrosine protein kinase Syk; Fruit tree; Transcription factor NFκB; Protein-tyrosine kinase; Organic compounds; Food; Immunopathology; Enzyme; Transferases; FcεRI receptor; Blocking; Acetate; Biological activity; Fruit crop; Plant origin; Carboxylate; NF; Spermatophyta; Inhibitor; Mast cell
• ISSN: 0278-6915; 1873-6351
• DOI: 10.1016/j.fct.2010.10.003

Psidium guajava (P. guajava) is an important food crop and medicinal plant with antioxidant, anti-inflammatory, and anti-allergic activities, supporting its traditional uses. However, its precise effects remain unknown. We investigated the effects of P. guajava ethyl acetate extract (PGEA) on IgE-mediated allergic responses in rat mast RBL-2H3 cells. PGEA reduced antigen (DNP–BSA)-induced release of β-hexosaminidase and histamine in IgE-sensitized RBL-2H3 cells. In addition, it inhibited antigen-induced IL-4 and TNF-α mRNA expression and protein production in IgE-sensitized RBL-2H3 cells. PGEA also suppressed antigen-induced COX-2 mRNA and protein expression in these cells, as well as antigen-induced activation of NFAT and reactive oxygen species. Moreover, it inhibited antigen-induced activation of NF-κB and degradation of IκB-α. To identify the mechanisms underpinning the inhibition of degranulation and cytokine production by PGEA, we examined the activation of intracellular FcεRI signaling molecules. PGEA suppressed antigen-induced phosphorylation of Syk, LAT, Gab2, and PLCγ2 but not Lyn, and inhibited antigen-induced phosphorylation of downstream signaling intermediates including MAP kinases and Akt. Collectively, the anti-allergic effects of PGEA in vitro suggest its possible therapeutic application to inflammatory allergic diseases, in which its inhibition of inflammatory cytokine production and FcεRI-dependent signaling events in mast cells may be hugely beneficial.