Curcumin Attenuated Bupivacaine-Induced Neurotoxicity in SH-SY5Y Cells Via Activation of the Akt Signaling Pathway.

Bupivacaine is widely used for regional anesthesia, spinal anesthesia, and pain management. However, bupivacaine could cause neuronal injury. Curcumin, a low molecular weight polyphenol, has a variety of bioactivities and may exert neuroprotective effects against damage induced by some stimuli. In the present study, we tested whether curcumin could attenuate bupivacaine-induced neurotoxicity in SH-SY5Y cells. Cell injury was evaluated by examining cell viability, mitochondrial damage and apoptosis. We also investigated the levels of activation of the Akt signaling pathway and the effect of Akt inhibition by triciribine on cell injury following bupivacaine and curcumin treatment. Our findings showed that the bupivacaine treatment could induce neurotoxicity. Pretreatment of the SH-SY5Y cells with curcumin significantly attenuated bupivacaine-induced neurotoxicity. Interestingly, the curcumin treatment increased the levels of Akt phosphorylation. More significantly, the pharmacological inhibition of Akt abolished the cytoprotective effect of curcumin against bupivacaine-induced cell injury. Our data suggest that pretreating SH-SY5Y cells with curcumin provides a protective effect on bupivacaine-induced neuronal injury via activation of the Akt signaling pathway.

Cardioprotection of sevoflurane postconditioning by activating extracellular signal-regulated kinase 1/2 in isolated rat hearts.

AIM: The activation of extracellular signal-regulated kinase (ERK)1/2 protects against ischemic-reperfusion injury. Whether ERK1/2 mediates the cardioprotection of sevoflurane postconditioning is unknown. We tested whether sevoflurane postconditioning produces cardioprotection via an ERK1/2-dependent mechanism. METHODS: In protocol 1, Langendorff-perfused Sprague-Dawley rat hearts (n=84, 12 per group), with the exception of the Sham group, were subjected to 30 min ischemia followed by 90 min reperfusion and were assigned to the untreated (control) group, followed by 4 cycles of ischemic postconditioning (25 s of each), 3% (v/v) sevoflurane postconditioning (for 5 min and 10 min of washout), and the PD98059 solvent DMSO (<0.2%), ERK1/2 inhibitor PD98059 (20 micromol/L), and Sevo+PD administration. Left ventricular hemodynamics and coronary flow at 30 min of equilibrium were recorded at 30, 60, and 90 min of reperfusion, respectively. Acute infarct size was measured by triphenyltetrazolium chloride staining. The configuration of mitochondria was observed by an electron microscope. Western blot analysis was used to determine the contents of cytosolic and mitochondrial cytochrome c at the end of reperfusion. In protocol 2, after 15 min of reperfusion, the expression of total and phosphorylated forms of ERK1/2 and its downstream target p70S6K was determined by Western blotting. RESULTS: No differences in baseline hemodynamics were observed among the experimental groups (P>0.05). After reperfusion, compared with the control group, sevoflurane postconditioning and ischemic postconditioning significantly(P<0.05) improved functional recovery and largely (P<0.05) decreased myocardial infarct size (22.9%+/-4.6% and 21.2%+/-3.8%, vs 39.4%+/- 5.7%, both P<0.05). Sevoflurane-mediated protection was abolished by PD98059. CONCLUSION: Anesthetic postconditioning by sevoflurane effectively protects against reperfusion damage by activating ERK1/2 in vitro.

Anesthetic agent etiomidate induces apoptosis in N2a brain tumor cell line.

The present study identified the cytotoxic effects of etomidate on the N2a neuroblastoma cell line. Etomidate induced apoptosis in N2a cells in a concentration­dependent manner, which was confirmed by western blotting and flow cytometry. Phase contrast microscopy was used to analyze the effect of etomidate on morphological characteristics. The number of the apoptotic cells was increased and confirmed by DAPI and PI staining, which served as a characteristic hallmark of apoptosis. Additionally, etomidate led to loss of mitochondrial membrane potential and resulted in the generation of reactive oxygen species in N2a cells. The western blot analysis revealed that N2a cells treated with etomidate had a significant modulation of pro­apoptotic proteins, includingpoly ADP­ribose polymerase (PARP), cleaved PARP, caspase­9 and procaspase­3. In conclusion, the present study determined that etomidate induced cytotoxic and apoptotic effects in N2a brain tumor cells in vitro.