Dong-Hwa Shon

Oral Administration of Achyranthis radix Extract Prevents TMA-induced Allergic Contact Dermatitis by Regulating Th2 Cytokine and Chemokine Production in Vivo

Allergic contact dermatitis (ACD) remains a major skin disease in many countries, necessitating the discovery of novel and effective anti-ACD agents. In this study, we investigated the preventive effects of Achyranthis radix extract (AcRE) on trimellitic anhydride (TMA)-induced dermatitis and the potential mechanism of action involved. Oral administration of AcRE and prednisolone (PS) significantly suppressed TMA-induced increases in ear and epidermal thickness, and IgE expression. In addition, abnormal expression of IL-1β and TNF-α protein and mRNA was also significantly attenuated by oral administration of AcRE. Treatment with AcRE also significantly suppressed TMA-induced IL-4 and IL-13 cytokines and mRNA expression in vivo. Moreover, AcRE strongly suppressed TMA-induced IL-4 and IL-5 production in draining lymph nodes, as well as OVA-induced IL-4 and IL-5 expression in primary cultured splenocytes. Interestingly, AcRE suppressed IL-4-induced STAT6 phosphorylation in both primary cultured splenocytes and HaCaT cells, and TMA-induced GATA3 mRNA expression ex vivo. AcRE also suppressed TMA-mediated CCL11 and IL-4-induced CCL26 mRNA expression and infiltration of CCR3 positive cells. The major compounds from AcRE were identified as gentisic acid (0.64 ± 0.2 μg/g dry weight of AcRE), protocatechuic acid (2.69 ± 0.1 μg/g dry weight of AcRE), 4-hydroxybenzoic acid (5.59 ± 0.3 μg/g dry weight of AcRE), caffeic acid (4.21 ± 0.1 μg/g dry weight of AcRE), and ferulic acid (14.78 ± 0.4 ± 0.3 μg/g dry weight of AcRE). Taken together, these results suggest that AcRE has potential for development as an agent to prevent and treat allergic contact dermatitis.

Anti-allergic effects of Rosae multiflorae fructus via inhibition of T cell proliferation and the mast cell function

Anti-allergic effects of the hot water extract of Rosae multiflorae fructus (Rosae extract), which has long been used in oriental medicine for treatment of various diseases, were explored with a chicken ovalbumin (cOVA)-induced mouse model of food allergy. Compared to the sham mice to show severe allergic symptoms (i.e., anaphylaxis, diarrhea and decrease in the body temperature) following oral cOVA challenge, the Rosae extract-treated mice showed a marked improvement in those symptoms. Histology data demonstrated that Rosae extract treatment resulted in a amelioration in the intestinal inflammatory lesion and a reduction in the numbers of mast cells and eosinophils in the small intestine. Studies using DO11.10 TCR transgenic T cells indicated that Rosae extract had an activity to subdue the antigen-specific T cell activation/proliferation in vivo and thereby to lower the level of Th2 cytokine production by T cells during the antigen-specific immune response. Moreover, passive systemic anaphylaxis study showed that the extract also had an activity to inhibit the mast cells function in vivo, i.e., release of granules triggered by specific IgE-antigen interaction. Altogether, the results from this study not only imply a potential clinical application of Rosae extract in prevention and treatment of food allergy but also clearly elucidate the immunoregulatory mechanisms of Rosae extract underlying its anti-allergic effect.