Anti-osteoporosis Effect of Cynaropicrin against Ovariectomy-induced Osteoporosis in Rats

Abstract

Background Osteoporosis is a progressive bone disease, which is characterized by high bone resorption, and low bone density and mass. Osteoporosis elevates the risk of bone fragility and fracture, which leads to significant morbidity and poor life quality. Objectives The current study focuses to explore the anti-osteoporosis activity of cynaropicrin against the ovariectomized (OVX)-induced osteoporosis in rats. Materials and Methods The OVX method was performed on the female rats to induce osteoporosis and then treated with 10 and 20 mg/kg of cynaropicrin, respectively, for 16 weeks. The uterus and femur tissues were excised from rats after the sacrification. The biomechanical properties of femur bones were analyzed to detect the stiffness, maximum load, young modulus, and energy absorption. The levels of acid phosphatase (ACP), bone-gla-protein (BGP), and estradiol (E2) in the serum were analyzed. The status of TNF-α, IL-6, IL-1β, osteoprotegerin (OPG), and receptor activator of nuclear factor-κB ligand (RANKL) was analyzed in the serum samples of experimental rats. The femur tissues were examined by histopathological analysis. Results The cynaropicrin treatment effectively increased the uterine and femoral weight in the OVX rats. The stiffness, maximum load, young modulus, energy, and femoral length were effectively increased by the cynaropicrin treatment. Cynaropicrin decreased the levels of BGP and ACP and increased the E2 level. The Cr, Ca, and P levels were appreciably increased and TNF-α, IL-6 and IL-1β levels were decreased by cynaropicrin on the OVX rats. The cynaropicrin treatment also increased the OPG and reduced the RANKL in the OVX rats. The histological findings revealed that cynaropicrin improved the femur trabecular bone microarchitecture in the OVX rats. Conclusion Our findings revealed that cynaropicrin increased the femoral weight and length, restored bone turnover markers and mineral profiles, and decreased inflammatory markers.