Beneficial contribution of a safflower (Carthamus tinctorius L.) polysaccharide on steroid-induced avascular necrosis of the femoral head in rats

A water-soluble polysaccharide (SPS) was purified from dried safflower (Carthamus tinctorius L.) and its structure was identified using a combination of chemical and instrumental analysis. SPS has a repeating backbone of 1,4,6-β-Glcp, which was attached with T-β-Glcp at its C6 position along the main chain in the molar ratio of 1:1. A steroid-induced avascular necrosis of the femoral head (SANFH) model was established in mice injected with dexamethasone (50 mg/kg) twice per week for 6 weeks. Following SPS treatment at 25 and 100 mg/kg for 60 days, the decreased bone mineral density, abnormal histopathological changes, the increased rate of empty lacunae and apoptosis rate of osteocytes of femoral head in mice induced by dexamethasone was significantly reversed. Meanwhile, increased serum hydroxyproline (HOP) and decreased serum hexosamine (HOM) concentration in mice were turned to the opposite trend with increasing dosage of SPS, thus leading to a high rate of HOM/HOP. In conclusion, SPS may serve as a potential agent for the treatment of SANFH.