Aspalathin and nothofagin from rooibos (Aspalathus linearis) inhibit endothelial protein C receptor shedding in vitro and in vivo.

Abstract

Aspalathin (Asp) and nothofagin (Not) are two major active dihydrochalcones found in green rooibos, which have been reported for their anti-oxidant activity. Increasing evidence has demonstrated that beyond its role in the activation of protein C, endothelial cell protein C receptor (EPCR) is also involved in vascular inflammation. EPCR activity is markedly changed by ectodomain cleavage and its release as the soluble EPCR. EPCR can be shed from the cell surface, which is mediated by tumor necrosis factor-α converting enzyme (TACE). However, little is known about the effects of Asp and Not on EPCR shedding. Our results demonstrated that Asp and Not induced potent inhibition of phorbol-12-myristate 13-acetate (PMA)-, tumor necrosis factor (TNF)-α-, interleukin (IL)-1β, and cecal ligation and puncture (CLP)-induced EPCR shedding. Asp and Not also inhibited the expression and activity of PMA-induced TACE in endothelial cells. Asp and Not also suppressed CLP-induced protein C decrease in mice and thrombin generation in HUVECs. In addition, treatment with Asp and Not resulted in reduced PMA-stimulated phosphorylation of p38, extracellular regulated kinase (ERK) 1/2, and c-Jun N-terminal kinase (JNK). These results demonstrate the potential of Asp and Not as an anti-sEPCR shedding reagent against PMA and CLP-mediated EPCR shedding.

• Authors: Soyoung Kwak, Min-Su Han, Jong-Sup Bae
• Journal: Fitoterapia (Fitoterapia) Vol. 100 Pg. 179-86 (Jan 2015) ISSN: 1873-6971 [Electronic] Netherlands
• PMID: 25510322 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014 Elsevier B.V. All rights reserved.

Chemical References

• Blood Coagulation Factors
• Chalcones
• Interleukin-1beta
• Receptors, Cell Surface
• Tumor Necrosis Factor-alpha
• activated protein C receptor
• aspalathin
• nothofagin
• JNK Mitogen-Activated Protein Kinases
• p38 Mitogen-Activated Protein Kinases
• ADAM Proteins
• ADAM17 Protein
• ADAM17 protein, human
• Adam17 protein, mouse
• Tetradecanoylphorbol Acetate

Topics

• ADAM Proteins (metabolism)
• ADAM17 Protein
• Animals
• Aspalathus
• Blood Coagulation Factors (metabolism)
• Chalcones (pharmacology)
• Human Umbilical Vein Endothelial Cells (drug effects)
• Humans
• Interleukin-1beta (metabolism)
• JNK Mitogen-Activated Protein Kinases (metabolism)
• Male
• Mice, Inbred C57BL
• Phosphorylation
• Receptors, Cell Surface (metabolism)
• Tetradecanoylphorbol Acetate (metabolism)
• Tumor Necrosis Factor-alpha (metabolism)
• p38 Mitogen-Activated Protein Kinases (metabolism)