Histological, Immunohistochemical and Ultrastructural Studies on a Glucocorticoid-Induced Osteoporosis Model and The Probable Curing or Protective Role of Certain Anabolic or Antiresorptive Natural Products

Abstract

Glucocorticoids are widely usedin the treatment ofautoimmune diseasesandinflammatory diseases owing to their immunosuppressive and anti-inflammatory properties. Glucocorticoids are alsoconsidered one of the desired therapiesinthe treatment of cancer, especially malignantsolid tumours. However, thecontinuous useofglucocorticoidsfor long periodsoftencause seriousside effectsas osteoporosisaccompanied bybonepainandoftenend up infracturing of the bone.Therefore,thisstudy aimedto establish a model for osteoporosis in white male albino rats(Rattus norvegicus) using one of the glucocorticoids, the prednisolone which was orally administrated dailyat a dose of 4.05 mg/ kg b. wt. for two months.This study explored which mechanism stands mainly behind osteoporosis,i.e. which was the leading cause of the glucocorticoid-induced osteoporosis,the increase in the rate of bone resorption or the imperfection in bone formation, or both occurring parallel to each other. In addition, this study evaluated the probable curing and protective effectsof lovastatin as an anabolic agentfor bones ─ a secondary metabolite produced by Aspergillus terreus ─at a dose of 3.60 mg/kg b. wt. 3 times/week for 1 month as a curing agent, or for 3 months as a protective agent.Also, the study evaluatedthe probable curing and protective effects of grapefruit juice as an antiresorptive agent for bonesat a dose of 250 mg/kg b. wt.3 times/ week for 1 month as a curing agent or for 3 months as a protective agent, against this model of osteoporosis.This aims to evaluate the effectiveness ofthe therapeutic and protectiveregimesforosteoporosisviainhibitionofbone resorption or activation of bone formation.