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


METHODS
The transcriptional activity of NFAT was examined with luciferase reporter assay, using K562-luc cells, stimulated with 20 ng/mL PMA plus 1 μM 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 μM. 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-γ, TNF-α, 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.


CONCLUSIONS
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.
a Department of Biochemical Pharmacy, School of Pharmacy , Second Military Medical University , Shanghai , China ;
Shuang
S
Gao
a Department of Biochemical Pharmacy, School of Pharmacy , Second Military Medical University , Shanghai , China ;
Wencai
W
Li
a Department of Biochemical Pharmacy, School of Pharmacy , Second Military Medical University , Shanghai , China ;
Guochao
G
Lin
b Infinitus (China) Company Ltd , Guangzhou , China ;
Guangrong
G
Liu
b Infinitus (China) Company Ltd , Guangzhou , China ;
Wenjuan
W
Deng
c Shanghai LB Nature Co. Ltd , Shanghai , China.
Chuntao
C
Zhai
c Shanghai LB Nature Co. Ltd , Shanghai , China.
Chunliang
C
Bian
c Shanghai LB Nature Co. Ltd , Shanghai , China.
Gaiying
G
He
a Department of Biochemical Pharmacy, School of Pharmacy , Second Military Medical University , Shanghai , China ;
Zhenlin
Z
Hu
D000470:Alkaloids / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D003876:Dermatitis, Atopic / Q000139:chemically induced* / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D005260:Female; D006801:Humans; D020014:K562 Cells; D051379:Mice; D008807:Mice, Inbred BALB C; D050778:NFATC Transcription Factors / Q000276:immunology*; D009593:Nitroimidazoles / Q000633:toxicity*; D029626:Ranunculaceae / Q000737:chemistry*
D000470:Alkaloids; D050778:NFATC Transcription Factors; D009593:Nitroimidazoles; C464745:norisoboldine
Atopic dermatitis; T cells; calcineurin; cytokine; inflammation