Curcuma longa Linn extract suppresses neuronal apoptosis induction by sevoflurane via activation of the ERK1/2 pathway

Purpose: To investigate Curcuma longa Linn against neuronal damage induced by exposure to sevoflurane during surgical procedures. Methods: A sealed box made of transparent glass was used for anaesthetic exposure of neurons. The neurons were exposed to Curcuma longa Linn at doses of 1.5, 3, 6 and 12 mu M prior to viability assessment using MTT assay. The effect of Curcuma longa Linn treatment on protein expression was determined using western blotting. Results: Sevoflurane exposure led to significant and time-dependent reductions in neuronal proliferation, when compared to unexposed cells (p < 0.05). Curcuma longa Linn at doses of 1.5, 3, 6 and 12 mu M significantly decreased sevoflurane-mediated neuronal apoptosis. It reduced cleaved caspase-3 and Bax levels in neurons. However, the Curcuma longa Linn-mediated inhibition of sevoflurane-induced neuronal apoptosis was significantly suppressed by VPC23019 (p < 0.05). The p-ERK1/2 level was dose-dependently up-regulated in neurons exposed to sevoflurane on treatment with Curcuma longa Linn. Moreover, VPC23019 reversed the upregulatory effect of Curcuma longa Linn on p-ERK1/2 expression in sevoflurane-exposed neurons (p < 0.05). Conclusion: Curcuma longa Linn reversed sevoflurane-induced neuronal apoptosis by elevating p-ERK1/2 expression. Therefore, Curcuma longa Linn exerts inhibitory effect on anaesthesia-induced apoptosis in neurons, and may be useful for the treatment of this condition.