Tetramethylpyrazine protects rat astrocytes against H2O2-induced oxidative stress injury

Abstract

Objective To investigate the protective effect of tetramethylprazine (TMP) on oxidative stress injury induced by hydrogen peroxide (H2O2) in rat astrocytes. Methods Astrocytes were isolated from SD newborn rats (24~48 h old) and cultured, and then the cells were randomly divided into control group (cultured with normal culture medium), model group (100 μmol·L-1 H2O2 for 24 h), TMP groups (pretreatment of 25, 50, 100 μmol·L-1 TMP for 48 h, and then H2O2 was added for 24 h). CCK-8 assay was used to detect cell survival rate, GFAP staining to observe cell morphology, flow cytometry to detect cell apoptosis, corresponding reagent test kits to detect the lactate dehydrogenase (LDH) content and superoxide dismutase (SOD) activity, real-time fluorescent quantitative PCR to measure the detect the mRNA expression of PI3K, AKT, Bcl-2, Bax and Caspase-3, and Western blotting to test the protein expression levels of PI3K, AKT, p-AKT, Bcl-2, Bax and Caspase-3 in each group of cells. Results The model group had significantly reduced cell survival rate (P < 0.05), increased apoptotic rate (P < 0.05), elevated LDH content (P < 0.05), decreased SOD activity (P < 0.05); down-regulated PI3K, AKT, Bcl-2 mRNA and protein levels, and up-regulated the expression levels of Bax and Caspase-3 mRNA and protein levels (P < 0.05). Compared with the model group, TMP pretreatment resulted in significantly increased cell survival rate (P < 0.05), lowest apoptotic rate (P < 0.05) and LDH content (P < 0.05), enhanced SOD activity (P < 0.05), up-regulation of PI3K, AKT, and Bcl-2 at mRNA and protein levels, and down-regulation of Bax and Caspase-3 at mRNA and protein levels (P < 0.05). Conclusion TMP exerts protective effects on oxidative stress injury of rat astrocytes induced by H2O2, and improves cell morphology and inhibits cell apoptosis after injury, and this effect may be related to the regulation of PI3K and p-AKT activation.

Keywords

• tetramethylprazine
• astrocyte
• oxidative stress
• apoptosis