Scutellarin Blocks Sodium Current in Freshly Isolated Mouse Hippocampal CA1 Neurons

Scutellarin (Scu), the main bioactive component of Erilgeron breviscapus, protects the brain against ischemic damages. To explore the therapeutic mechanism of Scu, we investigated the impact of Scu on sodium current (INa) of freshly isolated mouse hippocampal CA1 neurons using the whole-cell patch clamp technique. Results showed that Scu inhibited INa in concentration- and holding potential-dependent manners. At 50 μM, Scu markedly shifted the steady state inactivation curve of INa towards a more negative potential, slowed down the recovery of INa from inactivation state, and elicited a frequency-dependent block of INa. The shape of the current–voltage (I–V) curve and the steady state activation curve of INa were unaffected by Scu treatment. These findings suggest that Scu is capable of inhibiting INa in neurons through predominantly affecting the inactivated state of INa. Inhibition of Na+ channels provides a novel pharmacological basis for the anti-ischemic application of Scu.