Background: Glucocorticoid is the most common cause of medication-induced osteoporosis.
Aim of the work: Comparing the role of Nigella sativa (NS) versus calcium and vitamin D (Ca+Vit D) in the protection from Glucocorticoid-induced osteoporosis in a rat model. Material and Methods: Fifty-one male albino rats weighing 120-150 gm were divided into 4 groups: Group I (Control), Group II (dexamethasone group), Group III (dexamethasone plus Ca+Vit D), and Group IV (dexamethasone plus NS oil). Results: Rats of group II revealed erosion cavities in compact bone with eroded surface and widened Haversian canal and osteocyte lacunae. The cancellous bone showed thin disconnected bone trabeculae containing empty lacunae with wide bone marrow spaces. Areas of faintly stained bone matrix and minor fractures could be detected. These results were confirmed by a significant decrease in the thickness and number of lacunae containing osteocytes in cortical and cancellous bone. Also, there was an apparent decrease in osteopontin and an increase in caspase-3immune reaction. Moreover, a significant increase in alkaline phosphatase and IL6 was detected. Groups III and IV showed improvement in cortical and trabecular bone structure. The expression of osteopontin, caspase-3, alkaline phosphatase, and IL6 was also improved. Conclusion: This study demonstrated that supplementation of NS oil was better than calcium and vitamin D in osteoporotic lesions of rat femur due to its effect on bone remodeling. It acts as a calcium source and has antioxidant effects. So, it is recommended to use NS in the protection of glucocorticoid-induced osteoporosis.