Alpha-lipoic acid prevents bupivacaine-induced neuron injury in vitro through a PI3K/Akt-dependent mechanism.
BACKGROUND
Bupivacaine is an amide type local anesthetic which is widely used for epidural anesthesia and nerve blockade in patients. However, local administration of bupivacaine could cause neuron injury showing transient neurologic symptoms. alpha-Lipoic acid (LA) was shown to protect nerve cells from substance-induced injury. We hypothesized that LA administration could attenuate bupivacaine-induced neurotoxicity.


METHODS
To evaluate our hypothesis, we treated mouse neuroblastoma N2a cells with LA 30 min before the cells were exposed to bupivacaine. We evaluated cellular injury by examination of cell viability, morphology changes, nuclear condensation, and Annexin V staining. We also examined the levels of intracellular reactive oxygen species (ROS) and activation of PI3K/Akt signaling pathway. In a separate experiment, we determined the effect of Akt inhibition on cell viability in the presence of LA and bupivacaine.


RESULTS
Bupivacaine treatment significantly induced cell injury as evidenced by decreased cell viability, increased nuclear condensation and Annexin V staining. Administration of LA significantly attenuated bupivacaine-induced cell injury. In addition, LA treatment increased the levels of phospho-Akt and phospho-GSK3beta and attenuated bupivacaine decreased the levels of ROS. More significantly, pharmacological inhibition of Akt abolished the LA-induced protection from bupivacaine-caused cell injury.


CONCLUSIONS
Our findings suggest that pretreatment of neuroblastoma cells with LA protected neural cells from bupivacaine-induced injury. The mechanisms involve activation of the PI3K/Akt signaling pathway.
Wang
Xiaohui
X
Department of Anesthesiology, First Affiliated Hospital with Nanjing Medical University, Nanjing, China.
Zhang
Xiaojin
X
Cheng
Yunlin
Y
Li
Chuanfu
C
Zhang
Wenbo
W
Liu
Li
L
Ding
Zhengnian
Z
D000779:Anesthetics, Local / Q000494:pharmacology*; D000818:Animals; D000831:Animals, Newborn; D017304:Annexin A5 / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects; D002045:Bupivacaine / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006624:Hippocampus / Q000166:cytology; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D009447:Neuroblastoma / Q000473:pathology; D009474:Neurons / Q000187:drug effects*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013778:Tetrazolium Salts; D013844:Thiazoles; D008063:Thioctic Acid / Q000494:pharmacology*; D013997:Time Factors; D014803:Vitamin B Complex / Q000494:pharmacology*
D000779:Anesthetics, Local; D017304:Annexin A5; D004791:Enzyme Inhibitors; D017382:Reactive Oxygen Species; D013778:Tetrazolium Salts; D013844:Thiazoles; D014803:Vitamin B Complex; D008063:Thioctic Acid; D007770:L-Lactate Dehydrogenase; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; C022616:thiazolyl blue; D002045:Bupivacaine