Treatment of Brain Edema by Wogonoside Is Associated with Inhibition of Neuronal Apoptosis and SIRT1 Activation in Rats

BACKGROUND: Brain edema and neuronal apoptosis are closely associated with loss of neurological function and death in rats with subarachnoid hemorrhage (SAH). The present study investigated the effect of wogonoside on brain edema induced by SAH in rats and studied the mechanism involved. MATERIAL/METHODS: The rats were intra-gastrically administered 10, 20, 50, 100, 150 and 200 mg/kg doses of wogonoside 24 h prior to SAH induction. Western blotting was used to assess levels of pro-apoptotic protein, SIRT1, ZO-1, and p53 protein expression. Apoptotic nuclei were detected using immunofluorescence and TUNEL staining. RESULTS: Wogonoside treatment significantly suppressed edema formation in SAH-induced rats. Pre-treatment with wogonoside exhibited an inhibitory effect on SAH-induced extravascular Evans blue staining in rats. The expression of ZO-1, Occludin, and Claudin-5 proteins was increased by wogonoside in the SAH-induced rats. The inhibitory effect of SAH was completely reversed in the rats treated with the 200 mg/kg dose of wogonoside. The expression of SIRT1 protein was upregulated, and p53 and AC-p53 were downregulated by wogonoside in SAH rats. Wogonoside treatment significantly reduced SAH-mediated promotion of Bax, Puma, Noxa, Bid, and cleaved Caspase-3 expression. In the SAH-induced rats, pre-treatment with wogonoside reduced the TUNEL-positive cell count. CONCLUSIONS: The present study demonstrated that wogonoside prevents brain edema development and apoptosis of neurons in rats by promoting SIRT1 expression and suppression of p53 activation. Therefore, wogonoside has therapeutic potential for the treatment of edema and needs to be investigated further to completely define the mechanism involved.