Vertebral histomorphometry in a child with glucocorticoid-induced osteoporosis

Grapefruit juice exerts anti-osteoporotic activities in a prednisolone-induced osteoporosis rat femoral fracture model, possibly via the RANKL/OPG axis

This study aimed to shed light on the protective and therapeutic anti-osteoporotic effects and mechanisms of action of grapefruit juice (GFJ) on prednisolone-induced osteoporosis a rat femoral fracture model. We found that treating rats with GFJ before and/or after prednisolone-induced osteoporosis resulted in increased bone density, total mineral content, and calcium content to counteract the osteoporotic effects of prednisolone. In parallel, the histological and ultrastructural results of the GFJ-treated groups correlated well with enhanced breaking strength of femurs subjected to a constant load. Furthermore, GFJ treatment before and after prednisolone-induced osteoporosis decreased plasma alkaline phosphatase and tartrate-resistant acid phosphatase activities and increased the level of insulin-like growth factor 1. Mechanistically, our immunohistochemistry study showed that GFJ ameliorated prednisolone-induced osteocalcin depletion, decreased receptor activator of nuclear factor kappa-B ligand (RANKL) expression, and increased osteoprotegerin (OPG) expression. GFJ showed a beneficial anti-osteoporotic effect against prednisolone-induced osteoporosis in rats, possibly via the RANKL/OPG axis, suggesting that GFJ might be a good candidate for developing anti-osteoporotic drugs.

Effects of short-term glucocorticoid administration on bone mineral density, biomechanics and microstructure in rats’ femur

The effects of short-term use of oral glucocorticoid (GC) on the skeleton are not well defined. To address this gap, the influences of 7 days, 21 days of GC administration on femurs of intact rats were investigated. Forty 4-month-old female Sprague–Dawley rats were randomly divided into control group (Cont) and prednisone-treated group (Pre) and administered either distilled water or prednisone acetate at doses of 3.5 mg/kg/day for 0, 7 and 21 days, respectively. All the femurs were harvested for dual-energy X-ray absorptiometry scan, biomechanical testing and micro computed tomography scan. The whole body weight, femur bone mineral density (BMD), all three-point bending test parameters, microstructural parameters increased or improved significantly in Cont at day 21 when compared to day 0. The whole body weight, distal femur BMD, Young’s modulus, bending stiffness, density of tissue volume and trabecular thickness (Tb.Th) decreased, while structure model index and trabecular separation (Tb.Sp) increased significantly in Pre at day 21 when compared to age-matched control but had no significant differences between day 7 and day 21. Our data demonstrate that 7-day use of prednisone does not influence on rats’ femur, and 21-day use of prednisone slows in rate of whole body weight gain, decreases femur metaphysis BMD and bone stiffness which mainly due to the deteriorated bone microstructure.