Drinking orange juice or grapefruit juice may affect bone homeostasis in ovariectomized rats.

摘要

Osteoporosis is a condition of decreased bone density among old age people and postmenopausal women. This is characterized by the increased resorption and degeneration of bone tissue. Major factors responsible for this disease are aging and oxidative stress. Oxidative stress is caused by accumulation of free radicals like superoxide anion and hydrogen peroxide which in turn cause damage to the cell components and result in cell death. Loss of bone density leads to increased occurrence of fractures and joint pains in elderly and post-menopausal women. These free radicals are neutralized or removed by antioxidants. Thus antioxidants are supposed to provide protection to bone cells and decrease bone resorption. Fruits and vegetables are rich in antioxidants and increased consumption of these may prevent or delay osteoporosis along with other chronic diseases. Among fruits, citrus fruits are considered to be good source of vitamin c and other antioxidant compounds like limonoids and flavanoids. So, to improve bone health among those who suffer from osteoporosis, dietary supplementation of antioxidants to prevent bone loss is important along with weight bearing exercises that help in strengthening the bone iv tissue. In the present study, fifty six rats were treated for 120 days. On arrival, all the rats were subjected to surgery, in which 14 rats were subjected to sham surgery for control and others were ovariectomized. For initial sixty days all the rats were fed with sham (control) diet to ensure to bone loss has occurred in ovariectomized rats and for next sixty days these rats are divided into four groups. Sham (control) group, ovariectomized (OVX) rats, OVX rats drinking either freshly squeezed orange juice or Grapefruit juice. All rats consumed a common control diet. At the end of the study all the rats were euthanized and their blood was collected to measure plasma antioxidant capacity. Also, 5th lumbar vertebrae and femurs were collected to determine their strength and density. Antioxidant status significantly (P<0.05) increased to the level of the sham with drinking orange juice or grapefruit juice. In the present study, 5th lumbar density improved with drinking either orange juice (P=0.06) or grapefruit juice (P<0.05) compared to ovariectomized rats. Compared to sham group, despite numerical changes, rats drinking grapefruit juice had similar 5 th lumbar density (P=0.06) while there was a significant difference (P<0.05) in 5th lumbar density between rats drinking orange juice and the sham group. The 5th lumbar strength significantly improved (P<0.05) in rats drinking orange juice or grapefruit juice compared to the OVX group. However, the improvement in 5th lumbar quality was still significantly (P0.1) were not significantly different between those drinking citrus juice compared to OVX group. In conclusion, the increased 5th lumbar quality with drinking citrus juice most likely is related to increased bone metabolic activity and improved antioxidant status may have contributed to the 5 th lumbar quality.