Synergistic effects of a combination of low-dose basic fibroblast growth factor and citicoline after temporary experimental focal ischemia

Abstract

BACKGROUND AND PURPOSE: Basic fibroblast growth factor (bFGF) and citicoline (cytidine 5'-diphosphate choline, an endogenous compound that stabilizes membrane function) have demonstrated neuroprotective effects after focal cerebral ischemia. Both agents are candidates for future stroke therapy in humans. For evaluation of synergistic effects of bFGF and citicoline, a low-dose combination of both compounds was tested against each compound alone and placebo. METHODS: Four groups of Sprague-Dawley rats (n=12 per group) underwent 90 minutes of focal cerebral ischemia with the use of the suture model of middle cerebral artery occlusion. Animals were randomly and blindly assigned to one of the following treatment groups: placebo, low-dose citicoline (250 mg/kg IP daily for 4 days), low-dose bFGF (10 microg/kg per hour IV for 3 hours), and the combination of both (250 mg/kg citicoline and 10 microg/kg per hour bFGF). Triphenyltetrazolium chloride staining was used after 4 days to determine postmortem infarction. Neurological scores were assessed on a daily basis. RESULTS: The premature mortality rate was 41.7% in the placebo and citicoline groups, 33.3% in the bFGF group, and 25% (P=NS) in the combination group. The mean neurological score on day 4 was 3.1+/-1.6 (placebo), 3.1+/-1.6 (citicoline), 2.9+/-1.5 (bFGF), and 2.4+/-1.4 (combination) (P=NS). The mean volume of infarction was significantly reduced in the combination group (136. 5+/-25.4 mm3) versus placebo (172.6+/-48.9 mm3; P=0.036, Fisher test), versus citicoline alone (186.0+/-35.7 mm3; P=0.005, Fisher test), and versus bFGF alone (176.0+/-49.2 mm3; P=0.023, Fisher test). CONCLUSIONS: These results demonstrate synergistic effects of a low-dose combination of the growth factor bFGF and citicoline after temporary experimental focal cerebral ischemia and furthermore support the effectiveness of a combination treatment regimen for the management of acute stroke.