Location: Diet, Genomics and Immunology LaboratoryTitle: Isolation and characterization of two flavonoids, engeletin and astilbin, from the leaves of Engelhardia roxburghiana, and their potential anti-inflammatory properties Author
|Wang, Thomas - Tom|
|Yu, Lu (lucy)|
Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/9/2011
Publication Date: 5/11/2011
Citation: Huang, H., Cheng, Z., Shi, H., Xin, W., Wang, T.T., Yu, L. 2011. Isolation and characterization of two flavonoids, engeletin and astilbin, from the leaves of Engelhardia roxburghiana, and their potential anti-inflammatory properties. Journal of Agricultural & Food Chemistry. 59(9):4562-9. Interpretive Summary: Phytochemicals are known to possess biological activity that may be beneficial to human health. Two novel phytochemicals that are flavanoids were isolated by USDA and University of Maryland scientists from the leaves of Engelhardia roxburghiana, a botanical found in Asia. The chemical structures of two flavanoids, engeletin and astilbin, were confirmed by spectra-photometric measurements, and their anti-inflammatory activities studied in special mouse cells involved in immune function. Bathing the cells with a compound called lipopolysaccharide (LPS) resulted in an inflammatory response in the cells and increased the formation of pro-inflammatory local compounds called cytokines. Engeletin and astilbin exhibited remarkable inhibitory effects on several of these pro-inflammatory cytokines and on other cellular proteins. The reduced amount of these proteins may contribute to a reduced immune response and inflammation, indicating that engeletin and astilbin may serve as potential anti-inflammatory agents. This work will benefit basic, as well as translational research science, and support the examination of dietary phytochemicals as substances that can regulate inflammation.
Technical Abstract: Engeletin, a flavonoid compound, was isolated from the leaves of Engelhardia roxburghiana for the first time, along with astilbin, another flavonoid. The chemical structures of engeletin and astilbin were confirmed by 1H and 13C nuclear magnetic resonance (NMR) and mass spectrometry (MS) spectra, and their anti-inflammatory activities were studied in lipopolysaccharide (LPS)-stimulated mouse J774A.1 macrophage cells. LPS induced the inflammatory state in macrophage cells and increased mRNA expressions of pro-inflammatory cytokines. Engeletin and astilbin exhibited remarkable inhibitory effects on interleukin (IL)-1ß and IL-6 mRNA expression. Significant inhibition of LPS-mediated mRNA expressions were also seen in LPS binding to toll-like receptor (TLR)-4, pro-inflammatory cytokine tumor necrosis factor (TNF)-alpha, IL-10, chemo-attractant monocyte chemotactic protein (MCP)-1, and cyclooxygenase (COX)-2 genes. The reduced expression of these cytokines may alleviate the immune response and reduce inflammatory activation, indicating that engeletin and astilbin may serve as potential anti-inflammatory agents.