title: Ethanol extract of Adiantum capillus-veneris L. suppresses the production of inflammatory mediators by inhibiting NF-κB activation.
abstract: BACKGROUND
  Adiantum capillus-veneris L. is a wildly distributed plant species and has been extensively used in south of China as traditional folk medicine for the treatment of inflammatory diseases.
  
  
  OBJECTIVE
  To investigate the anti-inflammatory effect of ethanolic extracts of Adiantum capillus-veneris L. and the involvement of NF-κB signaling in the regulation of inflammation.
  
  
  METHODS
  The plant ethanolic extracts were initially tested against lipopolysaccharide (LPS)-induced prostaglandin E2 (PGE2) production in RAW264.7 mouse macrophages, and interleukin 6 (IL-6) and tumor necrosis factor (TNF) production in human U937 monocytes. The effect of the plant extracts on the transcription factor nuclear factor kappa B (NF-κB) pathway was evaluated in TNF-α stimulated HepG2 cells by luciferase gene reporter assay and Western blotting at the transcriptional and translational levels. Subsequently, the inhibition of NF-κB downstream gene expression (IL-8 and ICAM-1) by the plant extracts was assessed via quantitative real time polymerase chain reaction (qPCR). Lastly, the anti-inflammatory activities of the plant extracts in vivo were evaluated by testing spleen index and NF-κB related protein expression in LPS-stimulated CD1 mice.
  
  
  RESULTS
  The plant ethanolic extracts effectively suppressed PGE2, IL-6 and TNF release with an IC50 less than 50 μg/ml. Moreover, luciferase expression could be specifically blocked in HepG2 cells, not in HEK293 cells, showing that the plant extracts displayed a cell-specific pattern on NF-κB gene transcription. The assayed biological activity also depended on the order of adding TNF-α and the plant extracts because the plant extracts could only block the NF-κB activation if added earlier but were unable to stop the signal when added after TNF-α. However, the plant extracts did not exert any effect on ubiquitination which regulates several steps in the NF-κB pathway. Additionally, the plant extracts down-regulated phosphorylation of IKKα/β at S176/180, p38 at T180/Y182 and p65 at S536, but not p65 at S276. This was confirmed by their ability to selectively abrogate the induction of IL-8 transcription, whereas the ICAM-1 gene, which is not transcribed selectively by an NF-κB complex containing a form of p65 phosphorylated on Ser536, did not change. Finally, the plant extracts at 200 μg/mg could normalize the LPS-induced elevation of spleen index as well as NF-κB and p38 activations in CD1 mice.
  
  
  CONCLUSIONS
  The present studies presents the potential utilization of this plant extracts, as a natural resources for the development of an anti-inflammatory medicine.
authors.affiliation: Key Laboratory of natural Medicinal Chemistry and Resources Evaluation of Hubei Province, School of Pharmacy, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Qianying
authors.initials: Q
authors.lastname: Yuan
authors.forename: Xuenong
authors.initials: X
authors.lastname: Zhang
authors.forename: Ziwei
authors.initials: Z
authors.lastname: Liu
authors.forename: Shanshan
authors.initials: S
authors.lastname: Song
authors.forename: Pinpin
authors.initials: P
authors.lastname: Xue
authors.forename: Jianping
authors.initials: J
authors.lastname: Wang
authors.forename: Jinlan
authors.initials: J
authors.lastname: Ruan
mesh_terms: D035681:Adiantum; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002460:Cell Line; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D015232:Dinoprostone / Q000378:metabolism; D000431:Ethanol / Q000737:chemistry; D006801:Humans; D007249:Inflammation / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D018836:Inflammation Mediators / Q000378:metabolism; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics; D008070:Lipopolysaccharides; D008099:Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D051379:Mice; D016328:NF-kappa B / Q000037:antagonists & inhibitors*; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D012997:Solvents / Q000737:chemistry; D013154:Spleen / Q000187:drug effects / Q000473:pathology
chemical_list: D000893:Anti-Inflammatory Agents; D016207:Cytokines; D018836:Inflammation Mediators; D008070:Lipopolysaccharides; D016328:NF-kappa B; D010936:Plant Extracts; D012997:Solvents; D018799:Intercellular Adhesion Molecule-1; D000431:Ethanol; D015232:Dinoprostone