title: Astaxanthin, a Carotenoid, Stimulates Immune Responses by Enhancing IFN-γ and IL-2 Secretion in Primary Cultured Lymphocytes in Vitro and ex Vivo.
abstract: Astaxanthin, a potent antioxidant carotenoid, plays a major role in modulating the immune response. In this study, we examined the immunomodulatory effects of astaxanthin on cytokine production in primary cultured lymphocytes both in vitro and ex vivo. Direct administration of astaxanthin (70-300 nM) did not produce cytotoxicity in lipopolysaccharide (LPS, 100 µg/ mL)- or concanavalin A (Con A, 10 µg/ mL)-activated lymphocytes, whereas astaxanthin alone at 300 nM induced proliferation of splenic lymphocytes (p < 0.05) in vitro. Although astaxanthin, alone or with Con A, had no apparent effect on interferon (INF-γ) and interleukin (IL-2) production in primary cultured lymphocytes, it enhanced LPS-induced INF-γ production. In an ex vivo experiment, oral administration of astaxanthin (0.28, 1.4 and 7 mg/kg/day) for 14 days did not cause alterations in the body or spleen weights of mice and also was not toxic to lymphocyte cells derived from the mice. Moreover, treatment with astaxanthin significantly increased LPS-induced lymphocyte proliferation ex vivo but not Con A-stimulated lymphocyte proliferation ex vivo. Enzyme linked immunosorbent assay (ELISA) analysis revealed that administration of astaxanthin significantly enhanced INF-γ production in response to both LPS and Con A stimulation, whereas IL-2 production increased only in response to Con A stimulation. Also, astaxanthin treatment alone significantly increased IL-2 production in lymphocytes derived from mice, but did not significantly change production of INF-γ. These findings suggest that astaxanthin modulates lymphocytic immune responses in vitro, and that it partly exerts its ex vivo immunomodulatory effects by increasing INF-γ and IL-2 production without inducing cytotoxicity.
authors.affiliation: Department of Pharmacology and Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan. d102092002@tmu.edu.tw.|Central Laboratory, Shin Kong Wu Ho-Su Memorial Hospital, Taipei 111, Taiwan. d102092002@tmu.edu.tw.
authors.forename: Kuan-Hung
authors.initials: KH
authors.lastname: Lin
authors.affiliation: Department of Pharmacology and Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan. gaujang@mail2000.com.tw.|Department of Neurology, Chi Mei Medical Center, Tainan 710, Taiwan. gaujang@mail2000.com.tw.
authors.forename: Kao-Chang
authors.initials: KC
authors.lastname: Lin
authors.affiliation: Department of Pharmacology and Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan. d119096013@tmu.edu.tw.
authors.forename: Wan-Jung
authors.initials: WJ
authors.lastname: Lu
authors.affiliation: Department of Research and Development, Institute of Ophthalmology, Joseph Eye Hospital, Tiruchirappalli 620001, Tamil Nadu, India. thomasdiagnosticcentre@gmail.com.
authors.forename: Philip-Aloysius
authors.initials: PA
authors.lastname: Thomas
authors.affiliation: Department of Pharmacology and Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan. tjaya_2002@yahoo.co.in.
authors.forename: Thanasekaran
authors.initials: T
authors.lastname: Jayakumar
authors.affiliation: Department of Pharmacology and Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan. sheujr@tmu.edu.tw.
authors.forename: Joen-Rong
authors.initials: JR
authors.lastname: Sheu
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003208:Concanavalin A; D004797:Enzyme-Linked Immunosorbent Assay; D007107:Immune System / Q000187:drug effects; D007371:Interferon-gamma / Q000378:metabolism*; D007376:Interleukin-2 / Q000378:metabolism*; D008070:Lipopolysaccharides; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D008297:Male; D051379:Mice; D013154:Spleen; D024341:Xanthophylls / Q000276:immunology / Q000494:pharmacology
chemical_list: D007376:Interleukin-2; D008070:Lipopolysaccharides; D024341:Xanthophylls; D003208:Concanavalin A; D007371:Interferon-gamma; C005948:astaxanthine
keywords: Con A; IL-2; INF-γ; LPS; astaxanthin; immunomodulation; lymphocytes; mice