NF-κB inhibitory activity of sucrose fatty acid esters and related constituents from Astragalus membranaceus

Twelve compounds, including six sucrose fatty acid esters (1-6), four galactosyl acylglycerols (7-10), and two sphingolipids (11 and 12), were isolated from the roots of Astragalus membranaceus. Their structures were identified on the basis of spectroscopic analysis. Among the isolated sucrose fatty acid esters, 6′-O-linoleyl sucrose (1) was identified as a new compound, and 6′-O-palmitoyl sucrose (2) and 6-O-palmitoyl sucrose (3) were isolated from nature for the first time. This is the first report on sucrose fatty acid ester components from A. membranaceus. The nuclear factor-κB (NF-κB) inhibitory activity of isolated compounds was measured in HepG2 cells stimulated with TNF-α using a luciferase reporter system. Among them, compounds 1-6 exhibited significant inhibition of NF-κB activation in a dose-dependent manner, with IC₅₀ values ranging from 4.4 to 24.7 μM. Compounds 1-6 also exhibited inhibition of TNF-α-induced expression of iNOS and ICAM-1 mRNA and dose-dependent inhibition of iNOS promoter activity, with IC₅₀ values ranging from 3.3 to 5.0 μM. These data demonstrate the potential of sucrose fatty acid esters from A. membranaceus to prevent and treat inflammatory diseases.