RESUMO
Long term glucocorticoids administration induces oxidative stress which leads to alteration of bone structure and strength. Palm oil is rich in tocotrienol, an antioxidant. It can be used for the prevention of oxidative stress related diseases. The main objective of this study was to determine the mechanism of palm tocotrienol in maintaining the bone structure and strength in glucocorticoid-induced osteoporosis. Thirty two adult male Sprague-Dawley rats, aged 3 months, weighing 300-320 g rats were used in this study. Sixteen rats undergone adrenalectomy and were administered with 120μg/kg/day intramuscular injection of dexamethasone. Eight rats were supplemented with oral palm tocotrienol 60 mg/kg/day (Adrx+Dex+PTT) and the other eight rats were given oral vehicle palm olein 0.1 ml/kg/day (Adrx+Dex). Eight rats underwent sham procedure and were given vehicle palm olein 0.05 ml/kg/day by intramuscularly and oral 0.1 ml/kg/day (Sham). The rats were euthanized after two months of treatments. Eight rats were euthanized after acclimatic action without receiving any treatment (Baseline). The right femurs were used for bone biomechanical strength and histomorphometry analysis while the left for gene expression and oxidative stress enzymes activities. The results indicated that long-term glucocorticoid treatment significantly increased bone resorption marker, CTX (6060.7 ± 410 pg/ml) and decreased bone structure and strength. Osteoblast and osteoclast related genes expressions indicated an increase in bone turnover. Supplementation of palm tocotrienol had maintained serum resorption (2619.4 + 209 pg/ml) marker level and preserved bone structure and strength. Gene expression analysis showed decrease in bone resorption. The findings suggested that palm tocotrienol has potential benefits against glucocorticoid-induced osteoporosis by regulating osteoblast and osteoclast related gene expression
RESUMO
Long term glucocorticoids administration induces oxidative stress which leads to alteration of bone structure and strength. Palm oil is rich in tocotrienol, an antioxidant. It can be used for the prevention of oxidative stress related diseases. The main objective of this study was to determine the mechanism of palm tocotrienol in maintaining the bone structure and strength in glucocorticoid-induced osteoporosis. Thirty two adult male Sprague-Dawley rats, aged 3 months, weighing 300-320 g rats were used in this study. Sixteen rats undergone adrenalectomy and were administered with 120μg/kg/day intramuscular injection of dexamethasone. Eight rats were supplemented with oral palm tocotrienol 60 mg/kg/day (Adrx+Dex+PTT) and the other eight rats were given oral vehicle palm olein 0.1 ml/kg/day (Adrx+Dex). Eight rats underwent sham procedure and were given vehicle palm olein 0.05 ml/kg/day by intramuscularly and oral 0.1 ml/kg/day (Sham). The rats were euthanized after two months of treatments. Eight rats were euthanized after acclimatic action without receiving any treatment (Baseline). The right femurs were used for bone biomechanical strength and histomorphometry analysis while the left for gene expression and oxidative stress enzymes activities. The results indicated that long-term glucocorticoid treatment significantly increased bone resorption marker, CTX (6060.7 ± 410 pg/ml) and decreased bone structure and strength. Osteoblast and osteoclast related genes expressions indicated an increase in bone turnover. Supplementation of palm tocotrienol had maintained serum resorption (2619.4 + 209 pg/ml) marker level and preserved bone structure and strength. Gene expression analysis showed decrease in bone resorption. The findings suggested that palm tocotrienol has potential benefits against glucocorticoid-induced osteoporosis by regulating osteoblast and osteoclast related gene expression
RESUMO
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.