Inhibitory effects of salvianolic acid B on apoptosis of Schwann cells and its mechanism induced by intermittent high glucose.
OBJECTIVE
To investigate protective effects of Salvianolic acid B (Sal B) on the intermittent high glucose (IHG)-induced oxidative stress, mitochondrial pathway activation and Schwann cell (SC) apoptosis in vitro.


METHODS
SCs were primarily cultured and exposed to the different conditions. Apoptosis was confirmed by the Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) method and concentration of 8-hydroxy-2-deoxy Guanosine (8-OHdG) was detected by Elisa. Intracellular ROS generation and mitochondrial transmembrane potential (ΔΨm) were detected by flow cytometry analysis. Quantitative real-time reverse transcriptase PCR was performed to analyze the expression levels of Bax and BcL-2. Western blot was performed to analyze the expression levels of some important transcription factors and proteins.


RESULTS
Treatment with Sal B inhibited the IHG-induced oxidative stress by reducing ROS production and 8-OHdG levels, mitochondrial depolarization and apoptosis in SCs in a dose-dependent manner. Furthermore, treatment with Sal B down-regulated the IHG-induced release of cytochrome c, AIF nuclear translocation and Bax expression, but mitigated the IHG-mediated down-regulation of BcL-2 expression in SCs. In addition, treatment with Sal B attenuated the IHG-induced activation of caspase-9 and caspase-3 and minimized the cleavage of PARP in SCs.


CONCLUSIONS
Our results indicated that IHG induced SC apoptosis in both caspase-dependent and caspase-independent pathways by activating the mitochondrial pathway. Sal B inhibited the IHG-induced oxidative stress, activation of the mitochondrial pathway and apoptosis in SCs.
Department of Endocrinology, Chinese PLA General Hospital, 28 Fu Xing Road, Beijing 100853, China.
Lian-Qing
LQ
Sun
Bing
B
Xue
Xiao-Jin
XJ
Li
Xuan
X
Wang
Ling
L
Qu
Ting-Ting
TT
Zhang
Jue
J
Zhao
Bao-An
BA
Wang
Xiao-Man
XM
Zou
Yi-Ming
YM
Mu
Ju-Ming
JM
Lu
D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology*; D001572:Benzofurans / Q000494:pharmacology*; D002478:Cells, Cultured; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D005947:Glucose / Q000008:administration & dosage*; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012583:Schwann Cells / Q000187:drug effects / Q000378:metabolism*; D053630:Depsides
D001572:Benzofurans; D004365:Drugs, Chinese Herbal; D005947:Glucose; C076944:salvianolic acid B; D053630:Depsides