Inhibition of the RANK RANK-L OPG/Cathepsin-K pathway on osteoclast activity by a treadmill in the osteoporosis induced by D-gal in the male rats

Osteoporosis is bone loss density and deterioration of bone tissues; osteoclasts are generally regarded as the only cells capable of resorbing to bone physical exercise by Treadmill, which has positive preventive and therapeutic effects on osteoclast activity. The experiment employed 24 male rats, randomly divided equally into three groups: the first group was the control group, and the second group of rats was given daily 200 mg/kg BW D-gal injected intraperitoneally for sixty days. The third group, the rats, were given 200mg/kg BW D galactose daily using a treadmill at 25 m/min for five days weekly for 60 days. Serum blood was drawn for biochemical analysis to evaluate the bone densitometry by measuring bone resorption and formation biomarkers represented by receptor activator of nuclear factor kappa-B (RANK), receptor activator of nuclear factor kappa-B ligand (RANK-L), cathepsin, and osteoprotegerin (OPG). Femur bone tissues were removed and processed for light and electron microscopy inspection for light and electron microscopy inspection. The results investigate a significant increase in serum RANK, RANK-L, and cathepsin-K levels in osteoporotic rats treated with D-gal. At the same time, OPG analysis revealed a substantial decline in these groups. The impact of the treadmill showed a significant decrease in serum levels, RANK, RANKL, and cathepsin K compared with the D-gal group. The femur rats' histological examination of the osteoporotic group showed resorption and marked trabecular thinning with numerous osteoclasts. In contrast, using an electron microscope, the D-gal treadmill group showed a newly added lamellar structure and several healthy osteocytes with fewer cavities in the bony plates and reduced micro-fissures in femur compact bone.