Total flavonoids of sea buckthorn (Hippophae rhamnoides L.) improve MC903-induced atopic dermatitis-like lesions

Ethnopharmacological relevance: Sea buckthorn (Hippophae rhamnoides L.) is popularly used as a herbal medicine and food additive in the world. Total flavonoids of Hippophae rhamnoides (TFH) are reported to have anti-inflammatory and immunomodulatory activities. Aim: The effects of TFH on atopic dermatitis (AD)-like lesions induced by MC903 in mice was elucidated in the study.Methods: To induce AD-like lesions, MC903 was adopted to apply repeatedly on the left ear in C57BL/6 mice. After induction of AD-like lesions, 0.5% and 1% TFH cream was applied topically on ears of mice once a day for 8 days. The degree of skin lesions was evaluated by macroscopical and histological methods. Expressions of filaggrin (FLG) was evaluated by Western blotting. Real-time polymerase chain reaction (qPCR) was adopted to detect the mRNA expression of thymic stromal lymphopoietin (TSLP), interferon (IFN)-gamma, interleukin (IL-4), tumor necrosis factor (TNF)-alpha in skin lesions. In vitro, Cytokine Antibody Arrays were performed to measure production of cytokines in IFN-gamma/TNF-alpha-treated HaCaT cells, Western blotting was employed to detect the ex-pressions of p-NF-kappa B, p-ERK and p-P38. Results: Topical application of TFH significantly improved the severity of dermatitis by inhibiting the infiltration of mast cell, increasing expression of FLG, decreasing the expressions of TNF-alpha, IL-4, IFN-gamma and TSLP in skin lesions. TFH decreased the levels of IL-1 alpha, IL-1 beta, IL-6, monocyte chemoattractant protein (MCP)-1, MCP-3, macrophage-derived chemokine (MDC), platelet-derived growth factor (PDGF)-BB, thymus and activation regulated chemokine (TARC) in the supernatants of the HaCaT cells treated by IFN-gamma/TNF-alpha. Furthermore, ex-pressions of p-NF-kappa B, p-ERK and p-P38 were also decreased by TFH administration with dose dependent manner in HaCaT cells treated by IFN-gamma/TNF-alpha. Conclusions: Topical application of TFH improved AD-like lesions in mice induced by MC903. Which exerted the effects of anti-inflammation and repairing skin barrier by regulating Th1/Th2 balance. This finding indicates that TFH is a novel potential agent for the external treatment of AD.

Automated summary

The present study investigated the effects of total flavonoids of Hippophae rhamnoides (TFH) on MC903-induced atopic dermatitis (AD)-like lesions in mice. TFH showed anti-inflammatory and immunomodulatory effects by regulating Th1/Th2 balance, inhibiting mast cell infiltration, and promoting the expression of filaggrin (FLG). TFH also reduced the expressions of cytokines and signaling proteins related to inflammation and repaired the skin barrier. These findings suggest that TFH may have potential as an external treatment for AD.