Hinokitiol as a modulator of TLR4 signaling and apoptotic pathways in atopic dermatitis

Atopic dermatitis (AD) poses a significant global health challenge, characterized by dysregulated inflammation and apoptotic processes. This study explores the therapeutic efficacy of hinokitiol, employing a comprehensive in vivo and in vitro approach. Assessment of inflammation-related markers in the animal model included observation of physical appearance, Western blotting, ELISA, and H&E staining. Additionally, the cell culture model enabled the evaluation of apoptosis and ROS levels using MTT assay, crystal violet staining, Western blot, and DCFDA assays. The results revealed hinokitiol's proficiency in ameliorating ear and skin morphology in the DNCB-induced AD model, mediated through the TLR4/MyD88 pathway. Notably, hinokitiol intervention led to a reduction in both M1 and M2 macrophage phenotypes. In vitro investigations demonstrated hinokitiol's ability to enhance cell viability and morphology under TNF-α and IFN-γ induction. Mechanistically, hinokitiol exhibited regulatory effects on apoptosis-related proteins, including Bax, Cytochrome c, Caspase-3, and PARP, thereby averting cellular damage. These findings suggest that hinokitiol is a promising natural compound with significant potential for alleviating inflammation and apoptosis in AD, indicating potential avenues for future therapeutic developments.