Total flavones of Dracocephalum moldavica L. protect astrocytes against H2O2-induced apoptosis through a mitochondria-dependent pathway

Rui-Fang Zheng,Yan-Wen Du,Jian-Guo Xing,Ming Xu,Cheng Zeng,Hui-Fang Wang

doi:10.1186/s12906-020-2846-4

Abstract

BackgroundThe active components of Dracocephalum moldavica L. (TFDM) can inhibit myocardial ischemia by inhibiting oxidative stress. However, the effects of TFDM on astrocytes have not been investigated in vitro. The current study aimed to explore whether TFDM protects astrocytes against H2O2-induced apoptosis through a mitochondria-dependent pathway.MethodsThe human glioma cell line U87 was used to investigate the ability of TFDM to protect astrocytes against H2O2-induced apoptosis. The cell counting kit-8 assay and flow cytometry were used to detect cell viability, apoptosis, MMP, Ca2+ influx and reactive oxygen species (ROS). Lactate dehydrogenase (LDH) and malonic dialdehyde (MDA) levels were measured by ELISA. In addition, protein and mRNA expression changes were detected by Western blotting and qRT-PCR.ResultsTFDM (0.78~200 μg/ml) had limited cytotoxic effects on the viability of U87 cells. Compared with the model group (treated with H2O2 only), cells treated with medium- and high-dose TFDM exhibited reduced MDA concentrations (P < 0.05) and ROS production (P < 0.05) and decreased MMP (P < 0.05) and reduced apoptosis (P < 0.05). The percentage of annexin V-FITC-stained cells was markedly suppressed by TFDM, confirming its anti-apoptotic properties. WB results showed that protein expression of Bcl-2-associated X protein (BAX), Caspase-3, Caspase-9, Caspase-12, and B-cell leukemia/lymphoma 2 (Bcl2) was reduced in the TFDM group compared with that in the model group (P < 0.05) and that expression of these proteins was normalized by TFDM treatment in a dose-dependent manner. According to RT-qPCR results, TFDM pretreatment resulted in reduced mRNA expression of BAX, Caspase-9, Caspase-12, p38MAPK, and CaMKII and increased mRNA expression of mTOR compared with the model group.ConclusionsThe current study revealed the protective effects of TFDM on U87 cells under oxidative stress conditions through the inhibition of a mitochondria-dependent pathway that is associated with the CaMKII/P38MAPK/ERK1/2 and PI3K/AKT/mTOR pathways.

Highlights

The active components of Dracocephalum moldavica L. (TFDM) can inhibit myocardial ischemia by inhibiting oxidative stress
The current study explored whether TFDM protects astrocytes against oxidative stress-induced apoptosis by attenuating a CaMKIIdependent mitochondria pathway
TFDM protected U87 cells against H2O2 injury Based on CCK-8 and Lactate dehydrogenase (LDH) kit results, TFDM treatment for 24 h had no significant effect on the viability of U87 cells (Fig. 1a)

Summary

Introduction

The active components of Dracocephalum moldavica L. (TFDM) can inhibit myocardial ischemia by inhibiting oxidative stress. The active components of Dracocephalum moldavica L. The effects of TFDM on astrocytes have not been investigated in vitro. The active components of D. moldavica L. TFDM contains the main active components of D. moldavica L., accounting for 53.06% of the total activity. Our previous studies found that TFDM can inhibit myocardial ischemia and stroke through the inhibition of oxygen free radical production [17,18,19,20], and recent evidence confirms that TFDM functions as an effective and stable free radical scavenger [21]. The purpose of this study was to investigate the role of TFDM in astrocytes, which are the most abundant cells in the central system and comprise approximately 20% of the total brain cells in mammals

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