Cerebrolysin dose-dependently improves neurological outcome in rats after acute stroke: A prospective, randomized, blinded, and placebo-controlled study

Background Cerebrolysin is a mixture of neuropeptides and free amino acids that is clinically used for the treatment of stroke. To further standardize treatment schemes, we assessed the dose response of Cerebrolysin on sensorimotor outcome in a rat model of ischemic stroke. Methods This study was a prospective, blinded, placebo-controlled, preclinical experiment. Male and female Wistar rats, subjected to embolic middle cerebral artery occlusion, were randomly treated with Cerebrolysin doses of 0.8, 2.5, 5.0, 7.5 ml/kg or placebo, 4 h after middle cerebral artery occlusion for a total of 10 consecutive days. Results The primary outcome was neurologic improvement at day 28, lesion volume, mortality, and animal weight were secondary and safety outcomes, respectively. There was a significant ( p < 0.001) dose effect of Cerebrolysin on neurological outcome. Cerebrolysin at a dose of ≥ 2.5 ml/kg significantly ( p < 0.001) improved neurological outcome (Mean Estimate (95% CL): 0.8 ml/kg: 6.2 (–6.0/18.4), 2.5 ml/kg: −28.9 (−41.6/−16.2), 5.0 ml/kg: −33.4 (−45.0/−21.7), 7.5 ml/kg: −36.3 (−48.2/−24.4). Higher doses (≥2.5 ml/kg) resulted in better recovery; however, differences between effective doses were not significant. Treatment with 5 ml/kg reduced lesion volume ( p = 0.016). No treatment gender interactions were found and there were no differences in death or weight loss. Conclusion Collectively, these data on Cerebrolysin efficacy demonstrate the feasibility of a preclinical study setup following a randomized, placebo-controlled, and blinded design with a clinical relevant treatment scheme. Cerebrolysin at doses of ≥ 2.5 ml/kg improved functional outcome and at a dose of 5 ml/kg reduced infarct volume.