Comparison of the inhibition of high phosphate-induced smooth muscle cell calcification by Porphyra yezoensis and Astragalus polysaccharides

[Display omitted] •The calcification inhibition of PYP and APS on A7r5 cells were investigated.•PYP and APS inhibited calcification by reducing high-Pi induced oxidative damage.•PYP exhibited better inhibitory effect on calcification of A7r5 cells.•The kinds of acid group and monosaccharide can affect calcification inhibition effect. This study aimed to investigate the inhibitory effects of Porphyra yezoensis polysaccharides (PYP) and Astragalus polysaccharides (APS) with similar molecular weight (approximately 4 KDa) on high phosphate (Pi)-induced vascular calcification (VC) in rat thoracic aortic smooth muscle cells (A7r5) and to develop drugs that can inhibit VC. After co-incubation with 3.0 mmol/L Pi and different concentrations of PYP or APS, calcium deposition and corresponding biochemical indicators of A7r5 cells were detected. PYP and APS remarkably restricted reactive oxygen species generation, restored mitochondrial membrane potential, reduced excessive apoptosis and autophagy, up-regulated expression of α-smooth muscle actin, suppressed alkaline phosphatase activity, and decreased calcium deposition on the surface of A7r5 cells. At the same concentration, PYP with stronger antioxidant capacity exhibited better inhibitory effect on calcification of A7r5 cells. These results suggest that polysaccharide can inhibit calcification by protecting A7r5 cells from high-Pi induced oxidative damage.