Steroid-induced avascular necrosis of femoral head（SANFH） is a bone and joint disease caused by prolonged and excessive steroid use. Its typical pathological features involve progressive circulatory disorders in the blood supply system of femoral head， leading to osteocyte apoptosis and bone tissue necrosis. As the disease progresses， it ultimately results in structural collapse and necrotic lesions of the femoral head， severely affecting patients' limb function and quality of life. Glucocorticoids mediate pathological damage through dual mechanisms， on the one hand， they disrupt the dynamic equilibrium between bone formation and resorption by suppressing osteoblast differentiation activity and activating osteoclastogenesis， on the other hand， they induce lipid metabolism disorders， inhibit angiogenesis， and impair endothelial cell function， thereby triggering microcirculatory disorders. Epimedii Folium and its active components exhibit multidimensional regulatory effects in SANFH prevention and treatment. Literature review reveals that it is rich in multiple active ingredients， primarily including total flavonoids of Epimedii Folium， icaritin， icariin， kaempferol， icariside Ⅱ， etc. These compounds exert multiple pharmacological effects（regulating bone metabolic homeostasis， modulating angiogenesis， correcting lipid metabolism disorders， and controlling cellular autophagy processes） through multiple signaling pathways， including Wnt/β-catenin， transforming growth factor（TGF）-β/bone morphogenetic protein（BMP）/Smad， mitogen-activated protein kinase（MAPK）， phosphoinositide 3-kinase/protein kinase B（PI3K/Akt）， osteoprotegerin/receptor activator of nuclear transcription factor-κB ligand/receptor activator of nuclear transcription factor-κB（OPG/RANKL/RANK）， etc. Based on existing research findings， this paper systematically elucidates the intervention mechanisms of active components in Epimedii Folium on key pathological processes of SANFH through the above pathways. It also deeply analyzes their regulatory roles in key nodes of different signaling pathways， aiming to provide valuable references for future clinical treatment and experimental research.

OBJECTIVE1-Bromo-3-chloro-5,5-dimethylhydantoin (BCDMH) is a solid oxidizing biocide for water disinfection. The objective of this study was to investigate the toxic effect of BCDMH on zebrafish.

METHODSThe developmental toxicity of BCDMH on zebrafish embryos and the dose-effect relationship was determined. The effect of BCDMH exposure on histopathology and tissue antioxidant activity of adult zebrafish were observed over time.

RESULTSExposure to 4 mg/L BCDMH post-fertilization was sufficient to induce a number of developmental malformations, such as edema, axial malformations, and reductions in heart rate and hatching rate. The no observable effects concentration of BCDMH on zebrafish embryo was 0.5 mg/L. After 96 h exposure, the 50% lethal concentration (95% confidence interval (CI)) of BCDMH on zebrafish embryo was 8.10 mg/L (6.15-11.16 mg/L). The 50% inhibitory concentration (95% CI) of BCDMH on hatching rate was 7.37 mg/L (6.33-8.35 mg/L). Histopathology showed two types of responses induced by BCDMH, defensive and compensatory. The extreme responses were marked hyperplasia of the gill epithelium with lamellar fusion and epidermal peeling. The histopathologic changes in the gills after 10 days exposure were accompanied by significantly higher catalase activity and lipid peroxidation.

CONCLUSIONThese results have important implications for studies on the toxicity and use of BCDMH and its analogs.

Animals ; Antioxidants ; metabolism ; Disinfectants ; toxicity ; Dose-Response Relationship, Drug ; Embryo, Nonmammalian ; drug effects ; Hydantoins ; toxicity ; Time Factors ; Water ; chemistry ; Water Pollutants, Chemical ; toxicity ; Zebrafish