Preparation and pharmacological study of Cnidium monnieri volatile oil cream

Eczema, a chronic inflammatory skin condition, causes persistent discomfort and impairs patients' quality of life. Cnidium monnieri has been traditionally used for its anti-inflammatory and antipruritic properties. The present study aimed to develop an optimized formulation of Cnidium monnieri volatile oil cream (CMVOC) and evaluate its anti-inflammatory effects in an eczema model. A single-factor and response surface optimization approach was used to determine the optimal cream formulation. The formulation was evaluated based on appearance, physical stability, particle size and moisturizing capacity. An eczema model was induced using 2,4-dinitrochlorobenzene (DNCB) in mice. Serum levels of IL-6 and IL-17 were measured by ELISA, skin pathology was assessed by hematoxylin and eosin and toluidine blue staining and JAK2/STAT3 expression was detected by immunohistochemistry to determine the activation status of the related signaling pathway. The optimized formulation contained 4.45 g octadecanol, 4 g Vaseline, 2.2 g liquid paraffin, 0.81 g isopropyl myristate Estergel^®, 1.6 g Cnidium monnieri volatile oil, 0.39 g sodium dodecyl sulfate, 1.16 g glycerol, 0.04 g nibergin ethyl ester and 25.35 g Distilled Water. In vivo, CMVOC markedly improved skin lesions in DNCB-induced mice, reduced serum IL-6 and IL-17 levels and alleviated epidermal thickening, edema and inflammatory infiltration. Immunohistochemistry further demonstrated suppressed activation of the JAK2-STAT3 signaling pathway. CMVOC effectively mitigated eczema-related inflammation by reducing pro-inflammatory cytokines and inhibiting JAK2-STAT3 pathway activation, providing experimental support for its potential as a topical therapy for eczema.