Piper sarmentosum Improves Bone Structure and Biomechanical Strength of Rats Given Excess Glucocorticoid

Abstract

Aims: To determine the effect of Piper sarmentosum (Ps) leaf extract on biomechanical strength and trabecular structure of the bones of glucocorticoid-induced osteoporotic rats. Study Design: Administration of crude extract to rats with excessive glucocorticoids. Place and Duration of Study: Department of Anatomy and Pharmacology, National University of Malaysia, between September 2010 and December 2011. Methodology: Three-month old male Sprague-Dawley rats were adrenalectomized to remove the main source of circulating glucocorticoids. The animals were replaced with dexamethasone 120 µg/kg body weight/day. Treatment with P. sarmentosum 125 mg/kg body weight and glycirrhizic acid (GCA) 120 mg/kg body weight were given simultaneously for 2 months. After been sacrificed, a three-point bending configuration test for assessing the biomechanical properties of the right femoral bones was done using an Instron Universal testing machine equipped with Instron Bluehill software. The left undecalcified femoral bones were embedded in resin, sectioned and stained with Von Kossa for structural histomorphometric measurements. Results: P. sarmentosum extract had significantly increased the intrinsic parameter (flexure modulus) and extrinsic parameter (energy at break) of the biomechanical properties of the bone. It had also significantly improved the trabecular structure by increasing the BV/TV, Tb.Th, Tb.N and by reducing the Tb.Sp based on histomorphometric analysis. Conclusion: P. sarmentosum extract was able to protect bone biomechanical strength in glucocorticoid-induced osteoporotic bone, as confirmed by the structural histomorphometric finding. Therefore, Ps extract has the potential to be used as an agent to protect the bone strength and structure against osteoporosis due to chronic glucocorticoid treatment. These results however, need further study for better justification.