Effect of diets fortified with Nigella sativa, sesame seeds and high calcium on osteoporosis in ovariectomized rats

The study was carried out to assess the effect of diets fortified with Nigella sativa (NS), sesame (SS) seeds and high calcium (Ca) on osteoporosis in ovariectomized (OVX) rats. Fifty six rats were randomized into 8 equal groups (n= 7) and housed individually in metal metabolic cages. Under ether anesthesia, group (1) was SHAM-operated and fed on basal diet, while the other 7 groups were bilaterally OVX-operated. Three weeks after ovariectomy, group (2) was fed on basal diet, while groups (3), (4), (5), (6) and (7) were fed on experimental diets fortified with the following: 10% NS; 10% SS; 2% Ca; 10% NS+2% Ca and 10% SS+2°/0 Ca, respectively for 6 weeks. Group (8) was fed on basal diet and given orally Alendronate (anti-osteoporotic drug) in a daily dose of 3 mg/kg for 6 weeks. During feeding period, initial and final body weights of rats were recorded. At the end of the experiment, the last 24 hr urine samples were collected for estimating Ca, P, pyridinoline (PD) and deoxypyridinoline (DPD) concentrations. Rats were then euthanized by prolonged exposure to anesthetic ether. Blood samples were collected for estimating serum calcium (Ca), phosphorous (P), bone-specific alkaline phosphatase (b-ALP) and osteocalcin (OC) levels. The uteri were dissected out and weighed. Femur bones also were dissected out and used for measurement and analysis of bone ash. The results showed that diets fortified with NS and SS and high calcium prevented the increase in body weight gain and the decrease in uterine weight induced by ovariectomy. These experimental diets normalized serum Ca, P, b-ALP and OC levels and decreased urinary excretion of Ca, P, PD and DPD. There were also significant increases in femur bone mineral density (BMD) and calcium content in bone ash. In conclusion, diets fortified with NS, SS and high calcium have a promising anti-osteoporotic effect in OVX rats. The study recommends enrichment of the bakeries and food stuff with Nigella sativa and sesame seeds and eating meals rich in calcium such as dairy products (milk and yoghurt) may be beneficial for the treatment of postmenopausal osteoporosis in women.