The Ethanol Extract of Caragana sinica Ameliorated Skin Lesions in Mice with Contact Dermatitis

ABSTRACT: Background: Caragana sinica (Buc’hoz) Rehd, which belongs to the legume family, is used to treat a variety of diseases such as gout, high blood pressure, neuralgia, arthritis, and eczema. Morden studies reveal that C. sinica has anti‑tumor, anti‑viral, anti‑hypertensive, immune‑stimulatory, immune‑suppressive and anti‑inflammatory activities. Aims: This study aims to confirm its therapeutic efficacy on contact dermatitis (CD) induced by harmful chemical. Materials and Methods: The dried roots of C. sinica were extracted using 70% ethanol, then the extract was condensed and lyophilized (ethanol extract of C. sinica, [EECS]). We investigated the effects of EECS on skin lesion severities, erythema and melanin indices, skin weights and thicknesses, histopathological changes and cytokine levels in mice with CD induced by 1‑fluoro‑2,4‑dinitrofluorobenzene. In addition, the effects on changes in body weight and spleen body weight ratios were also investigated. Results: EECS relieved skin lesions such as roughness, abrasions, scabs, erythema, and petechia, inhibited thickening of dorsal skin and lowered erythema and melanin indexes in the CD mice. Besides, EECS reduced epidermal hyperplasia and immune cell infiltration into inflamed tissues and reduced levels of Tumor necrosis factor‑α, interferon‑γ, interleukin‑6, and monocyte chemotactic protein-1 (MCP‑1) in inflamed tissues. Finally, body weight gains and spleen/weight ratios of CD mice were unaffected by EECS, unlike dexamethasone treatment. Conclusion: These results suggest that C. sinica has potential use as a therapeutic agent for CD and the therapeutic mechanism is different from that of corticosteroids.