Aging and Chronic Disease
Objectives : Osteoporosis may result in fracture with dire consequences. For instance, 40% of people with their second hip fracture die within two years. Aside from pharmaceutical interventions, that are not free of side effects, identifying edible and safe foods to prevent bone loss is of importance. We and others have shown that dried plum (DP) prevents loss of bone both in ovariectomized (Ovx) rat models as well as postmenopausal women. Hence, the purpose of this study was to examine the bone protective mechanism of action of DP, a rich source of phenolic and flavonoid compounds, in preventing bone loss using a rat model of ovarian hormone deficiency.
Methods : Forty-eight 90-day old female Sprague-Dawley rats were divided into four groups: sham-operated (Sham), Ovx, Ovx + 5% DP (low-dose, LD), and Ovx + 25% DP (high-dose, HD). Treatments started immediately after surgery and continued for 45 days. Animals were either fed a semi-purified diet, or a similar diet in which 5% or 25% of the diet (w/w) consisted of DP. All diets were made isocaloric and isonitrogenous containing 0.4% calcium and 0.3% phosphorus. Food intake, bone mineral density, bone mineral content, body/organ weight, blood biomarkers of bone metabolism, and static bone histomorphometry were assessed.
Results : The right femoral and the 4th lumbar vertebrae density were significantly (P< 0.05) lower in the Ovx control rats compared to Sham. The loss of density in both bones were completely prevented by HD-DP (P< 0.05). The HD-DP increased insulin-like growth factor-1 (IGF-1) significantly (P< 0.05) from 110±4 ηmol/L to 135±4 ηmol/L. In terms of bone histomorphometry, % bone area was significantly (P< 0.05) decreased as a result of Ovx and HD-DP nearly prevented this decrease (P >0.05). Although the endosteal perimeter (mm2) was not statistically different from other groups, the endosteal perimeter of the HD-DP group was 13.6% lower than that of the Ovx group.
Conclusions : The bone protective effects of DP may, in part, be explained by an increase in IGF-1, which is strongly correlated with bone formation, and a decrease in the endosteal perimeter, which is increased in ovarian hormone deficiency and postmenopausal women. Future studies should examine radiolabeling compounds in DP to see how they contribute to its bone protective effects.
Funding Sources : There have been no funding sources.