Activity-guided isolation of NF-魏B inhibitors and PPAR纬 agonists from the root bark of Lycium chinense Miller

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• 作者：Lian-Wu Xie^a ; ^b ; ^e ; ¹ ; Atanas G. Atanasov^b ; ¹ ; De-An Guo^c ; Clemens Malainer^b ; Jing-Xian Zhang^c ; Martin Zehl^b ; Shu-Hong Guan^c ; Elke H. Heiss^b ; Ernst Urban^d ; Verena M. Dirsch^b ; Brigitte Kopp^b ; ^{brigitte.kopp@univie.ac.at" class="auth_mail}
• 关键词：1D NMR ; one-dimensional nuclear magnetic resonance spectroscopy ; 2D NMR ; two-dimensional nuclear magnetic resonance spectroscopy ; ANOVA ; analysis of variance ; AP-1 ; activator protein 1 ; CC ; column chromatography ; CDCl3 ; deuterated chloroform ; C/EBP ; CCAAT/enhancer binding protein ; CHCl3 ; chloroform ; COSY ; correlation spectroscopy in 2D NMR ; DCM ; dichloromethane ; EGFP ; enhanced green fluorescent protein ; ESI-MS ; electrospray ionization mass spectrometry ; DMEM ; Dulbecco壮s modified Eagle壮s medium
• 刊名：Journal of Ethnopharmacology
• 出版年：28 March, 2014
• 年：2014
• 卷：152
• 期：3
• 页码：470-477
• 全文大小：714 K

文摘

Ethnopharmacological relevance

The root bark of Lycium chinense Miller, Lycii Radicis Cortex, has been used in traditional Chinese medicine (TCM) to treat different inflammation-related symptoms, such as diabetes mellitus. The pro-inflammatory transcription factor nuclear factor kappa B (NF-魏B) is a key regulator of inflammation, while the transcription factor peroxisome proliferator-activated receptor gamma (PPAR纬) is a key modulator of genes involved in diabetes development. To identify putative active compound(s) from Lycii Radicis Cortex inhibiting NF-魏B or activating PPAR纬.

Material and methods

Using activity-guided fractionation, six extracts with different polarity, isolated fractions, and purified compounds from Lycii Radicis Cortex were tested for NF-魏B inhibition and PPAR纬 activation in vitro. The structure of the purified compounds was elucidated by NMR and MS techniques.

Results

The ethyl acetate extract and the methanol extract of Lycii Radicis Cortex suppressed tumor necrosis factor alpha (TNF-伪)-induced activation of NF-魏B, while the dichloromethane extract activated PPAR纬. Nine phenolic amide analogues, including trans-N-(p-coumaroyl)tyramine (1), trans-N-feruloyltyramine (2), trans-N-caffeoyltyramine (3), dihydro-N-caffeoyltyramine (4), three neolignanamides (5-7), and two lignanamide (8, 9), were isolated and their inhibitory potential on NF-魏B was determined (1-4 were also contained in water decoction). Two of the nine isolated phenolic amides inhibited TNF-伪-induced NF-魏B activation. Trans-N-caffeoyltyramine was verified as the key component responsible for the NF-魏B inhibition with an IC₅₀ of 18.4 渭M in our cell-based test system. Activation of PPAR纬 was attributed to a palmitic-acid enriched fraction which displayed concentration-dependent effect ablated upon co-treatment with the PPAR纬 antagonist T0070907.

Conclusions

Phenolic amides were confirmed as main components from Lycii Radicis Cortex responsible for NF-魏B inhibition. Fatty acids were identified as the major plant constituent responsible for the PPAR纬 activation. Structure-activity relationship analysis suggests that the NF-魏B inhibitory activity of trans-N-caffeoyltyramine may be attributed to its Michael acceptor-type structure (伪,尾-unsaturated carbonyl group). The data of this study contribute to a better understanding of the molecular mechanism of action of Lycii Radicis Cortex extracts in the context of inflammation.