Astragaloside IV ameliorates radiation-induced senescence via antioxidative mechanism

Abstract
Objectives Ageing is a universal and gradual process of organ deterioration. Radiation induces oxidative stress in cells, which leads to genetic damage and affects cell growth, differentiation and senescence. Astragaloside (AS)ā€IV has antioxidative, antiā€apoptotic and antiā€inflammatory properties. Methods To study the protective mechanism of ASā€IV on radiationā€induced brain cell senescence, we constructed a radiationā€induced brain cell ageing model, using biochemical indicators, senescenceā€associated galactosidase (SAā€Ī²ā€gal) senescence staining, flow cytometry and Western blotting to analyse the ASā€IV resistance mechanism to radiationā€induced brain cell senescence. Key findings Radiation reduced superoxide dismutase (SOD) activity and expressions of cyclinā€dependent kinase (CDK2), CDK4, cyclin E and transcription factor E2F1 proteins, and increased expressions of p21, p16, cyclin D and retinoblastoma (RB) proteins, malondialdehyde (MDA) activity, SAā€Ī²ā€galā€“positive cells and cells stagnating in G1 phase. After treatment with ASā€IV, the level of oxidative stress in cells significantly decreased and expression of proteins related to the cell cycle and ageing significantly changed. In addition, SAā€Ī²ā€galā€“positive cells and cells arrested in G1 phase were significantly reduced. Conclusions These data suggest that ASā€IV can antagonize radiationā€induced brain cells senescence; and its mechanism may be related to p53ā€p21 and p16ā€RB signalling pathways of ageing regulation.