Effect of nebivolol on fracture healing: An experimental rat model

Background. Bone metabolism is a complex system, and fracture healing is one of its most important functions. Many circumstances can influence this process. Chronic drug use in elderly populations can affect bone healing, and inadequate tissue perfusion, increased free radicals and adverse drug effects can negatively influence fracture healing. Nebivolol, an anti-hypertensive drug that selectively blocks beta 1 receptors, effectively reduces blood pressure by inducing peripheral vasodilation. Nebivolol also exerts anti-oxidant effects by stimulating nitric oxide (NO) synthesis. Many studies show that NO protects the vascular endothelium and improves fracture healing. Objectives. In this study, the histological and radiological effects of intraperitoneally administered nebivolol on fracture healing were evaluated. Material and methods. Twenty-one Sprague Dawley rats were divided into 3 (nebivolol 1, 2 and control) groups. Sterile nebivolol solution (1 mL = 0.017 mg nebivolol) was given to the rats in group 1 every day for 4 weeks, while the rats in nebivolol group 2 were given 2 mL per day, beginning after the production of an open, displaced unilateral femur fracture. Radiographic and histological studies were used to evaluate fracture healing. Results. Histological and immunohistochemical analysis showed osseous healing with woven bone at the fracture site and only minimal amounts of cartilage in nebivolol 1 and 2 groups. Radiological grading was not different between the control and the nebivolol groups. Conclusions. This study suggests that nebivolol, a selective beta blocker, has positive effects on fracture healing through anti-oxidative effects via the NO pathway and direct vasodilator effects.