Algal oligosaccharides ameliorate osteoporosis via up-regulation of parathyroid hormone 1-84 and vascular endothelial growth factor

ObjectiveTo determine whether algal oligosaccharide affects the levels of parathyroid hormone 1-84 (PTH1-84) and vascular endothelial growth factor (VEGF).MethodsAn osteoporosis rat model was established via bilateral ovariectomy. The model rats were fed algal oligosaccharides (molecular weights: 600-1, 200 Da) for 4 months. Bone mineral density (BMD) was then measured. MG-63 human osteoblastic cells were treated with algal oligosaccharides. The expression of PTH1-84 and VEGF was then examined. Oligosaccharide-treated cells were transfected with PTH1-84 short hairpin RNA (shRNA), VEGF shRNA, and PTH1-84-VEGF small interfering RNA (siRNA). The growth rates were then compared between transfected and non-transfected cells.ResultsAlgal oligosaccharides increased the BMD of the osteoporosis rat model compared with untreated controls (P < 0.05). When MG-63 cells were treated with algal oligosaccharides, the growth rate increased by 25% compared with the control group at day 3 (P < 0.05). In addition, the expression of PTH84 and VEGF was enhanced. Conversely, when the cells were transfected with PTH84 shRNA, VEGF shRNA, or PTH1-84-VEGF siRNA, the growth rate was decreased by 17%, 35% and 70%, respectively, compared with controls at day 3 (P < 0.05).ConclusionAlgal oligosaccharides ameliorate osteoporosis via up-regulation of PTH1-84 and VEGF. Algal oligosaccharides should be developed as a potential drug for osteoporosis treatment.