GOYANG, South Korea—Researchers at the Dongguk University Research Institute of Biotechnology, South Korea, found the production of Th2 cytokines, such as IL-4 and IL-5, was significantly decreased after in vitro administration of glucosamine, suggesting glucosamine as a useful immunomodulatory agent for the treatment of human atopic dermatitis (Scand J Immunol. 2011;73(6):536-45). Dysregulated Th subset responses, characterized by Th2-dominant allergic inflammation, are thought to be central to the pathogenesis of atopic dermatitis. Glucosamine has been shown to have immunosuppressive properties, but its effect on atopic dermatitis has not been examined. In this study, the immunoregulatory effects of glucosamine, using dermatophagoides farinae (Df)-induced atopic dermatitis-like skin lesions in NC/Nga mice, were investigated.
The clinical scores were reduced significantly by the treatment with glucosamine at 10 and 20 mg/d. Histological analysis of the skin also revealed treatment of glucosamine at 10 and 20 mg/d significantly reduced the inflammatory cellular infiltrate, including mast cells and eosinophils. The levels of serum IgE and Th2 cytokines in spleen cells were reduced, whereas no significant change was detected in IFN-gamma, a Th1 cytokine. To determine the mechanism associated with inhibition of the Th2 immune response, the effects of glucosamine on the selective differentiation pathway of the Th subset in vitro was examined in NC/Nga mice. The results showed glucosamine suppressed the differentiation of naïve CD4(+) T cells to Th2 cells in vitro. On the basis of in vivo and in vitro results of the NC/Nga mice, the immunobiological effects of glucosamine on peripheral blood mononuclear cells from patients with atopic dermatitis were examined, demonstrating a significant decrease in the production of Th2 cytokines after glucosamine administration.
