Cosmos caudatus enhances fracture healing in ovariectomised rats: A preliminary biomechanical evaluation

Osteoporotic fractures occur in osteoporotic states and affect patients' quality of life. Cosmos caudatus (ulam raja) is a local plant known for its high calcium content and anti-oxidant properties. The present study aimed to investigate the fracture healing properties of C. caudatus water extract in ovariectomised rats by studying the biomechanical properties of tibia. Twenty-four female Sprague-Dawley rats were divided into 4 groups: (i) sham operated (ii) ovariectomised control (iii) ovariectomised + estrogen (100μg/kg/day) and (iv) ovariectomised + C. caudatus (500mg/kg). Following six weeks of sham operation or ovariectomy, the right tibia of the rats were fractured. Rats were then given their respective treatment for 8 weeks with body weight monitored weekly. Biomechanical analysis indicated that the maximum load, stress and Young's modulus of the ovariectomised control group (36.2 ± 4.7N, 10.01 ± 1.41MPa, 29.2 ± 9.39MPa respectively) were significantly lower compared to sham operated (150.32 ± 32. 6N, 36.75 ± 7.98MPa, 183 ± 53.2MPa respectively) and the C. caudatus treated group (136.86 ± 16.95N, 33.45 ± 4.14MPa, 155.13± 58.58MPa respectively). Therefore, C. caudatus extract improved the biomechanical property of the healed bone and may be beneficial for fracture healing in the estrogen deficient state. Industrial Relevance: Post-menopausal osteoporosis is a debilitating disease affecting women worldwide. Hormone replacement therapy (HRT), commonly used for the prevention and treatment of post-menopausal osteoporosis has been associated with several side effects. Thus, in finding alternatives in the treatment of osteoporosis, C. caudatus is a plant of interest. Previous study showed that C. caudatus improved bone histomorphometry in ovariectomized rats by increasing double-labeled surface (dLS/BS), mineral appositional rate (MAR), osteoid volume (OV/BV) and osteoblast surface (Ob.S/BS). Therefore, the present study aimed to assess the fracture healing properties of C. caudatus extract. The results of this study may offer a potential use of C. caudatus in the healing of fractures in the osteoporotic state.