A Comparative Study of the Ameliorative Effects of Skimmed Milk and Tuna Fish in the Dietary Management of Dexamethasone Sodium Phosphate Induced Osteoporotic Female Wistar Rats

Objective: This investigation was carried out to compare the moderating effects of skimmed milk and whole dried Tuna fish in osteoporotic female rats.

Methods: Sixty female albino Wistar rats were divided into two main groups. The first group (ten rats) fed basal diet and was maintained as negative control group. The second main group (fifty rats) was injected with 2 mg dexamethasone sodium phosphate daily (a synthetic corticosteroid) for 5 weeks after which the second main group was divided into five groups. Group 1 osteoporotic group fed basal diet, while groups from 2 to 5 osteoporotic rats fed basal diet supplemented with 5% and 10% skimmed milk, 5% and 10% Tuna fish powder respectively.

Results: The results indicated that the injection with cortisone caused osteoporosis of rats. Induced osteoporosis caused decreases in body weight gain (BWG), serum osteocalcin, Estradiol (E2), calcium (Ca) and phosphorous (P) concentration in serum and femur bone, Bone mineral density (BMD), Bone mineral concentration (BMC) and increases in weight of liver and Parathyroid hormone (PTH) compared to negative control group (healthy rat). However, supplementation diet of osteoporotic rat with 5% and 10% skimmed milk and 5% and 10% dried whole dried Tuna fish respectively led to increases in body weight gain, serum osteocalcin, E2, Ca, P in serum and femur, BMD, BMC and decreases in weight of liver and PTH. Positive control group (osteoporotic rats) resulted to changes in the histological structure of bone compared to negative control group. The best results were observed in rats fed diet supplemented with 10% skimmed milk.

Conclusion: Administration of diet supplemented with 10% skimmed milk is more effective in the dietary management of dexamethasone induced osteoporosis in female rats than when supplemented with 5% or 10% powdered Tuna fish as a supplemental source of calcium.