HPBzyme delays the progression of osteoarthritis in vivo. (a-h) Effect of HPBzyme on the BAX, iNOS, caspase 3, MMP13, COL2, Rac1, p-p65, and t-p65 protein levels as determined by Western blotting analyses in vivo. Protein levels were normalized to that of GAPDH. (i) The effects of HPBzymes on ROS levels were determined by flow cytometer analysis in vivo. Data are means ± SD, n = 3. *P < 0.05 vs. sham group (rat knee joint without HPBzyme and meniscectomy), #P < 0.05 vs. OA group (rat knee joint with only meniscectomy).