Abstract
The present study investigates the anti-skin-aging properties and bioactive compounds of the aerial parts of Astragalus membranaceus, which are typically discarded as agricultural waste. Liquid chromatography-mass spectrometry analysis identified flavonoid glycosides as the major constituents of the aerial parts of A. membranaceus extract. Two principal flavonoids, astraflavonoid A (1) and astraside C (2), were isolated using repetitive chromatography. Compounds 1 and 2 demonstrated antioxidative properties, reducing reactive oxygen species and matrix metalloproteinase-1 levels in human dermal fibroblasts upon stimulation with TNF-α. Specifically, astraside C (2) inhibited the expression of pro-inflammatory cytokines interleukin-6 and interleukin-8, whereas astraflavonoid A (1) did not affect their expression. Additionally, the expression of inflammatory mediators such as nuclear factor kappa B and cyclooxygenase-2 (COX-2) was increased by 1, whereas it was suppressed by 2. Furthermore, in silico molecular docking experiments confirmed that compound 2 effectively binds to COX-2. These findings suggest that the aerial parts of A. membranaceus contain bioactive flavonol glycosides with promising anti-skin-aging properties, offering valuable use as agricultural byproducts.