title: Effect of oral administration of kynurenic acid on the activity of the peripheral blood leukocytes in mice.
abstract: Kynurenic acid (KYNA), an endogenous tryptophan metabolite, is a selective ligand of the GPR35 receptor, expressed mainly on the immune cells. In inflammatory conditions, by affecting this receptor, KYNA inhibits the synthesis of pro-inflammatory cytokines and probably protects tissues from oxidative damage. However, we lack data regarding the effect of exogenous KYNA on the activity of immune cells in healthy individuals. The objective of this study has been to determine the influence of kynurenic acid administered to mice in different doses (2.5, 25 or 250 mg/l) and for different time periods (3, 7, 14, 28 days) in drinking water, on the activity of their peripheral blood leukocytes. The determinations comprised the proliferative activity of lymphocytes (MTT assay) and the phagocytic activity as well as the respiratory burst activity of granulocytes and monocytes (Phagotest, Phagoburst). It was only the lowest KYNA dose that influenced the mitogenic response of lymphocytes, namely by increasing the proliferation of T cells. The impact on the phagocytic activity was varied with KYNA dose and administration time. However, all the KYNA doses significantly lowered the activity of oxidative burst in phagocytes, which was probably associated with its antioxidant properties. In the light of the research results, kynurenic acid may find applications as an immuno-modulating agent able to correct an excessive or insufficient response of phagocytizing cells, protecting an organism from oxidative stress.
authors.affiliation: Department of Microbiology and Clinical Immunology, Faculty of Veterinary Medicine, University of Warmia and Mazury, Olsztyn, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Małaczewska
authors.affiliation: Department of Microbiology and Clinical Immunology, Faculty of Veterinary Medicine, University of Warmia and Mazury, Olsztyn, Poland.
authors.forename: Andrzej Krzysztof
authors.initials: AK
authors.lastname: Siwicki
authors.affiliation: Department of Microbiology and Clinical Immunology, Faculty of Veterinary Medicine, University of Warmia and Mazury, Olsztyn, Poland.
authors.forename: Roman Marcin
authors.initials: RM
authors.lastname: Wójcik
authors.affiliation: Department of Microbiology and Clinical Immunology, Faculty of Veterinary Medicine, University of Warmia and Mazury, Olsztyn, Poland.
authors.forename: Edyta
authors.initials: E
authors.lastname: Kaczorek
authors.affiliation: Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Poland.
authors.forename: Waldemar Andrzej
authors.initials: WA
authors.lastname: Turski
keywords: antioxidant properties; kynurenic acid; oxidative burst; phagocytic activity; proliferative response