Steroid-induced osteonecrosis (ON) of the femoral head represents one of the most significant complications of long-term high-dose steroid use. [1] Steroids are commonly used in the treatment of chronic autoimmune diseases such as systemic lupus erythematosus, nephrotic syndrome, asthma, after the organ transplantation, and in the patients hospitalized due to novel coronavirus disease-2019 (COVID-19). [2] The early diagnosis of ON of the femoral head (ONFH) is critical, since it mainly influences the young and middle-aged population, and progression of the disease to collapse of the femoral head occurs in most patients, if untreated.Although it has been argued that steroid-induced ON develops due to an ischemia in the bone, Objectives: In this study, we aimed to evaluate the antioxidant, antiapoptotic, osteoblastic and hypolipidemic effects of thymoquinone (TQ) treatment on the steroid-induced osteonecrosis of femoral head (ONFH) model in rats.
Materials and methods:A total of 24 rats were randomly divided into four groups: the control group administered saline; the TQ group administered 10 mg/kg/day TQ orally; lipopolysaccharide/ methylprednisolone (LPS/MPS) group administered 20 µg/kg intraperitoneally LPS and 40 mg/kg intramuscularly MPS to establish ONFH model; and the LPS/MPS+TQ group administered both LPS/MPS and, then, TQ once daily for four weeks. All rats were sacrificed after intracardiac blood collection and their right femurs were removed.Results: Micro-computed tomography showed a higher bone mineral density and lower porosity, Tr.Sp and Tr.Sep data were detected in the LPS/MPS+TQ group. In histopathology, osteonecrosis increased significantly in the LPS/MPS group and osteonecrosis decreased in the LPS/MPS+TQ group compared to the LPS/MPS group (p=0.0077). Histomorphometric examination revealed that the percentage of BV/TV in the LPS/MPS group was significantly lower compared to control and other groups (p<0.01 and p<0.05, respectively), while it reached normal rates in the LPS/MPS+TQ group. Immunohistochemically, antioxidant, anti-apoptotic, and angiogenesis indicators , malondialdehyde [MDA], B-cell lymphoma [Bcl-2], caspase-3, vascular endothelial growth factor [VEGF]) were significantly improved in tissue and serum with TQ. Furthermore, TQ significantly reduced low-and high-density lipoprotein cholesterol ratio and carboxy-terminal type 1 collagen crosslink (CTX) in serum.
Conclusion:Vascular and hematopoietic cell damages that occur due to steroid-induced deoxyribonucleic acid (DNA) oxidative and lipid peroxidative damages in an ONFH model can be successfully ameliorated by TQ administration. This antioxidant and antiapoptotic effects of TQ may be a promising treatment option for early stage of osteonecrosis.