Norisoboldine, an alkaloid from Radix linderae, inhibits NFAT activation and attenuates 2,4-dinitrofluorobenzene-induced dermatitis in mice

作者:Gao Shuang; Li Wencai; Lin Guochao; Liu Guangrong; Deng Wenjuan; Zhai Chuntao; Bian Chunliang; He Gaiying; Hu Zhenlin
来源:Immunopharmacology and Immunotoxicology, 2016, 38(5): 327-333.
DOI:10.1080/08923973.2016.1202961

摘要

CONTEXT: The nuclear factor of activated T-cells (NFAT) is a family of transcription factors, essential for T-cell activation. Norisoboldine (NOR), an isoquinoline alkaloid from Radix linderae, has been demonstrated to possess anti-inflammatory activity. OBJECTIVE: This study examines NOR's effect on NFAT activation and its therapeutic potential for atopic dermatitis (AD). MATERIALS AND METHODS: The transcriptional activity of NFAT was examined with luciferase reporter assay, using K562-luc cells, stimulated with 20 ng/mL PMA plus 1 muM ionomycin. NFAT dephosphorylation was examined by immuno-blotting in K562-luc cells and Jurkat cells. Interleukin-2 (IL-2) expression in Jurkat cells was examined by real-time PCR. A mouse model of dermatitis, induced by 2,4-dinitrochlorobenzene (DNCB), was used to test NOR's therapeutic potential for AD. RESULTS: NOR, dose-dependently, inhibited PMA and ionomycin-induced NFAT reporter gene expression in K562-luc cells in the range of 2-50 muM. NOR also inhibited PMA and ionomycin-induced NFAT dephosphorylation in K562-luc cells and Jurkat cells. Consequently, NOR suppressed PMA plus ionomycin-induced IL-2 expression in Jurkat cells. The administration of NOR (10 mg/kg, i.p.), alleviated DNCB-induced dermatitis in mice, by the reduction of ear swelling and attenuation of inflammatory infiltration into ear tissue. Moreover, mRNA levels of INF-gamma, TNF-alpha, IL-4 and IL-6 in ears of NOR-treated mice were reduced by 78.4, 77.8, 72.3 and 73.9%, respectively, compared with untreated controls. DISCUSSION AND CONCLUSION: This study demonstrates that NOR inhibits NFAT activation in T-cells and alleviates AD-like inflammatory reaction in a DNCB-induced dermatitis model, highlighting NOR as a potential therapeutic agent for AD.