Abstract: Objective: Investigate the therapeutic effects of limonene on contact dermatitis in rats. Methods: Establish a rat model of contact dermatitis, 36 rats were randomly divided into 6 groups with 6 rats in each group: blank group, contact dermatitis model group, low-dose limonene group (100 mg/kg), the medium-dose limonene group (200 mg/kg), the high-dose limonene group (400 mg/kg), and the positive control dexamethasone group (0.41 mg/kg). All groups were treated continuously for 10 days. Before and after treatment, lesion scoring, histopathological examination, and detection of serum levels of IL-2, IL-4, IL-6 and IFN-γ were performed. Results: Compared with the model group, the limonene-treated groups showed significantly lower lesion scores, reduced epidermal hyperplasia, capillary dilation, inflammatory cell infiltration, as well as decreased serum levels of IL-2, IL-4, IL-6 and IFN-γ, with the high-dose limonene group exhibiting the most prominent effect. Moreover, the high-dose limonene group showed superior improvements in skin lesions and inflammatory indicators compared with the dexamethasone group (P＜0.05). Conclusion: Limonene can significantly ameliorate lesions of contact dermatitis and reduce the levels of inflammatory factors.

Key words: limonene, contact dermatitis, cytokine