Abstract
Certain strains of lactobacilli have been reported to exert favorable effects on atopic dermatitis (AD). Jeotgal, a traditional Korean food, is a salted fermented seafood known to harbor many lactic acid bacteria. In the present study, two novel lactobacillus strains were isolated from Jeotgal, and their anti-AD effects were investigated. Lactobacilli isolated from Jeotgal were identified, according to conjugated linoleic acid-producing activity, as Lactobacillus plantarum (JBCC105645 and JBCC105683). AD-like skin lesions were induced in BALB/c mice using dinitrofluorobenzene (DNFB). Ear swelling, histological analysis and serum immunoglobulin E (IgE) levels in mice were evaluated to investigate the anti-AD effects of lactobacilli. Cytokine production of ex vivo cluster of differentiation (CD)4+ T cells, and interleukin (IL)-12 production of in vitro macrophages were also evaluated to establish a putative mechanism of the action of lactobacilli. Administration of JBCC105645 or JBCC105683 suppressed ear swelling and serum IgE levels in DNFB-treated mice (P<0.05). Notably, JBCC105645 was more effective than JBCC105683 (P<0.05). Treatment with the lactobacilli also induced a significant decrease in IL-4 production with concomitant increase in interferon (IFN)-γ production in DNFB-exposed CD4+ T cells, and an increase in IL-12 production in macrophages (P<0.05). Taken together, the lactobacilli isolated from Jeotgal may suppress the development of AD-like skin inflammation in mice by modulating IL-4 and IFN-γ production in CD4+ T cells, presumably via enhancing IL-12 production by macrophages.