Effects of Astraflavonoid A and Astraside C from the Aerial Part of Astragalus membranaceus on TNF-α-Induced Human Dermal Fibroblasts

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.