Astragalus Polysaccharide Injection Ameliorates the Apoptosis of Chondrocytes in the Ovariectomized Osteoporosis Mouse Model via Modulating Protein Kinase B/Glycogen Synthase Kinase 3 Beta Signal Transduction

Abstract

The Akt/GSK3 signal pathway exerts an impact on the apoptosis of chondrocytes. We planned to elucidate the role and mechanism of Akt/GSK3 signal transduction in ovariectomized osteoporosis. 50 female mice in SPF-graded and healthy condition were processed to establish the ovariectomized osteoporosis model, while 12 of the healthy mice were set as blank controls. The successfully established ovariectomized osteoporosis models were divided into model group (12 mice) and Astragalus group (12 mice). The following measurements were conducted: the bone mineral density in the left humerus, serum estrogen level and Cx43 protein level in osteoblasts, proportion of apoptotic cells, as well as the protein and mRNA levels of Akt and GSK3β in murine bone tissues via Western blotting and RT-PCR detection, respectively. The bone mineral density of mice in Astragalus group was the highest (0.174±0.04) g/cm2. The positive rate of Cx43 protein expression, apoptosis rate, as well as the protein and mRNA levels of Akt in osteocytes were significantly decreased (P < 0.05), but still significantly higher than model group. Estrogen level in Astragalus group was (87.52 ±8.69) pmol/L. The positive rate of Cx43 expression, apoptosis rate, as well as the protein and mRNA levels of GSK3β in osteocytes were decreased in comparison to model group (P < 0.05). Astragalus polysaccharide injection could ameliorate the apoptosis of chondrocytes and downregulate Cx43 protein via modulating Akt/GSK3β signal transduction, thereby exerting a therapeutic effect on ovariectomized osteoporosis.