Low-dose captopril inhibits wear debris-induced inflammatory osteolysis

The role of captopril in titanium alloy particle-induced inflammatory osteolysis was investigated. BALB/c mice (n = 32) were divided into four groups, an untreated control group and three treatment groups given 12.5, 25 or 50 mg/kg per day captopril. Intraperitoneal injections of either 0.9% saline (control) or captopril began 2 days before the introduction of titanium alloy particles and calvaria bone from a syngeneic mouse into established air pouches. Mice were sacrificed 10 days after bone/titanium alloy implantation, and pouch membranes and implants were collected for histological and molecular analysis. Low-dose captopril (12.5 mg/kg per day) was found to inhibit titanium particle-induced tissue inflammation and inflammatory osteolysis. Pouch membrane thickness and inflammatory cellular infiltration were significantly reduced relative to controls. Captopril also inhibited production of the inflammatory cytokines tumour necrosis factor-α, interleukin-1β and receptor activator of nuclear factor-κB ligand compared with controls. This study provides evidence that a low-dose of captopril can inhibit titanium particle-induced inflammatory osteolysis.