Evaluation of the Anti-Atopic Dermatitis Effects of alpha-Boswellic Acid on Tnf-alpha/Ifn-gamma-Stimulated HaCat Cells and DNCB-Induced BALB/c Mice

Boswellic acids, triterpenoids derived from the genus Boswellia (Burseraceae), are known for their anti-inflammatory and anti-tumor efficacy. Atopic dermatitis is a chronic, non-infectious inflammatory skin disease. However, the effects of alpha-boswellic acid on atopic dermatitis have not been studied. Therefore, in this study we examined the expression level of pro-inflammatory cytokines, histopathological analysis, and physiological data from BALB/c mice with atopic-like dermatitis induced by 2,4-dinitrochlorobenzene and TNF-alpha/IFN-gamma-stimulated HaCaT cells to better understand the agent's anti-atopic dermatitis efficacy. First, we found that alpha-boswellic reduced the epidermal thickening, mast cell numbers, and dermal infiltration of 2,4-dinitrochlorobenzene-induced atopic-like dermatitis in BALB/c mice. Furthermore, we also found that alpha-boswellic acid can restore transepidermal water loss and skin reddening in mice. In human keratinocytes inflamed by TNF-alpha/IFN-gamma, alpha-boswellic acid inhibited MAP kinase activation and showed a reduction in NF-kappa B nuclear translocation. Finally, alpha-boswellic acid can reduce the expression level of cytokines (IL-1 beta, IL-6, and IL-8) following the stimulation of TNF-alpha/IFN-gamma in HaCaT cells. Taken together, our study suggests that alpha-boswellic acids are a potential component for the development of anti-atopic dermatitis drugs.