Atopic dermatitis (AD) is developed by complex interplay of various factors such as skin barrier
dysfunction, immunological derangement, and oxidative stress, so multipronged approaches are
needed to treat AD. Azulene (AZ), guaiazulene (GA), and sodium guaiazulene sulfonate (GAS-Na) are
known to have biological activities. This study aimed to evaluate the bioactivities of AZ, GA, GAS-Na from
the perspective of AD treatment. Anti-inflammatory properties were estimated by measuring inhibitory
effect on IL-6 and IL-8 production of TNF-α treated HaCaT cells via enzyme-linked immunosorbent assay
(ELISA). Antioxidant properties were estimated by measuring DPPH and ABTS+ radical scavenging activity.
Based on the experimental results that GA showed a wider range of anti-inflammatory and antioxidant
effects than AZ and GAS-Na, we concluded that GA is the most suitable for treating both immunological
derangement and oxidative stress. Furthermore, to overcome poor water solubility of GA hindering its
application to various cosmetic formulations, we developed 1% of GA loaded PEG-PCL micelles and
confirmed its stable characteristics via particle size, PDI, and zeta potential values. Through this study, we
suggest the widespread use of GA for the treatment of AD.