Salvianolic acid B improves motor function after cerebral ischemia in rats.

In a previous short-term study, salvianolic acid B was reported to have a protective effect on cerebral ischemia. Here, we investigated whether salvianolic acid B improves the recovery of motor function after cerebral ischemia in a 14-day investigation. Cerebral ischemia was induced by middle cerebral artery occlusion in rats. Motor function was evaluated with beam-walking performance. Neural cell injury in both the sensorimotor cortex and CA1 of the hippocampus ipsilateral to ischemia was studied by Nissl stain with methylene blue. The integrity of cerebral microvessels was monitored by immunoglobulin extravasations. Neurogenesis in the subgranular zone in the dentate gyrus of the hippocampus was detected with 5'-bromo-2'-deoxyuridine incorporation. Animals receiving salvianolic acid B at a dose of 10 mg/kg had a more rapid recovery of beam-walking performance than vehicle-treated ischemia animals, and the improvement became significant at 10 and 14 days after ischemia (P<0.05). Treatment with salvianolic acid B at a dose of 10 mg/kg also significantly prevented neural cell loss in CA1 of the hippocampus. Neural cells in the sensorimotor cortex were also preserved in animals that received salvianolic acid B at a high dose of 10 mg/kg. Salvianolic acid B (10 mg/kg) also improved the integrity of microvessels after ischemia. We observed a slight increase in 5'-bromo-2'-deoxyuridine-positive cells in the subgranular zone of the hippocampus in the animals treated with salvianolic acid B at a dose of 10 mg/kg. These data indicate that salvianolic acid B could improve the recovery of motor function after cerebral ischemia in rats.