Tiao Geng decoction inhibits tributyltin chloride-induced GT1-7 neuronal apoptosis through ASK1/MKK7/JNK signaling pathway. (6th April 2021)

• Record Type: Journal Article
• Authors: Li, Shengnan; Cong, Chao; Liu, Yang; Liu, Xiaofei; Liu, Huicong; Zhao, Li; Gao, Xianwei; Gui, Wenjia; Xu, Lianwei
• Is Part Of: Journal of ethnopharmacology. Volume 269(2021)
• Publication Date: 2021-04-06
• Subjects: Aging -- Apoptosis -- JNK signal Pathway -- TG decoction -- Traditional Chinese medicine; ASK1 Apoptosis signal-regulating kinase 1 -- p-ASK1 Phospho-Apoptosis signal-regulating kinase 1 -- AP-1 Activating protein 1 -- Casp3 caspase-3 -- Cl-Casp3 cleaved-caspase-3 -- Bcl-2 B-cell lymphoma 2 -- ER Estrogen Receptor -- ERK Extracellular signal-regulated kinase -- MAPK Mitogen-activated protein kinase -- MKK7 Mitogen-activated protein kinase kinase 7 -- p-MKK7 Phospho-Mitogen-activated protein kinase kinase 7 -- JNK c-Jun N-terminal kinase -- p-JNK Phospho-c-Jun N-terminal kinase -- TNF tumor necrosis factor -- ROS reactive oxygen species -- VMS Vasomotor symptoms -- GSM genitourinary syndrome of menopause -- MS Menopause syndrome -- GSH-Px Glutathione peroxidase -- LPO Lipid peroxide; Ethnopharmacology -- Periodicals; Pharmacognosy -- Periodicals; Herbs -- Periodicals; Herbs -- Periodicals; Pharmacognosy -- Periodicals; Pharmacognosie -- Périodiques; Herbes -- Périodiques; 615.1
• DOI: 10.1016/j.jep.2020.113669
• Languages: English
• ISSNs: 0378-8741

Abstract

Abstract: Ethnopharmacological relevance: Tiao Geng (TG) decoction is a Chinese herbal medicine extract that has been utilized for the treatment of menopausal symptoms for a history of over 30 years. In our previous study, we suggest that TG decoction possibly exerts an anti-apoptotic effect on hypothalamic neurons of ovariectomized rats via the ASK1/MKK7/JNK pathway. Tributyltin chloride (TBTC) causes oxidative damage and induces apoptosis of primary hypothalamic neurons in rats. Aim of the study: The present work aimed to explore the inhibition of TG decoction on TBTC-induced GT1-7 cell apoptosis and its possible molecular mechanism. Materials and methods: The GT1-7 cell line was exposed to TG decoction at diverse doses (31.25, 62.5, 125 μg/mL) for 24 h and later with TBTC (1 mg/L) for 1 h, with 17β-E2 (100 nM) treatment being the positive control. Then, CCK8 assay was conducted to evaluate cell viability, while flow cytometric analysis was conducted to examine the apoptosis level. Related pathways and differentially expressed proteins were identified by tandem mass tag (TMT)-based quantitative phosphoproteomics. qRT-PCR was carried out to examine mRNA levels of Bax and B-cell lymphoma-2 (Bcl-2). Western blotting was performed to detect the levels of Bax, Bcl-2, c-Jun, c-Jun N-terminal kinase (JNK), Caspase-3 (Casp3), Mitogen-activated protein kinase kinase 7 (MKK7), and apoptosis signal-regulating kinase 1 (ASK1) . Finally, cells were pretreated with SP600125, an inhibitor of JNK, later the expression of JNK and Casp3 was measured. Results: Application of TG decoction mitigated the GT1-7 cell apoptosis and injury caused by TBTC; besides, it inhibited the activation of the ASK1/MKK7/JNK pathway. Moreover, Bcl-2/Bax ratio became higher, and the MKK7, ASK1, Casp3 and c-Jun levels were inhibited. Besides, TG decoction combined with SP600125 (the JNK inhibitor) more significantly inhibited GT1-7 cell apoptosis caused by TBTC. Conclusion: As discovered from the experiment in this study, TG decoction has a neuroprotective effect, which is achieved through inhibiting the ASK1/MKK7/JNK signal transduction pathway to reduce GT1-7 cell apoptosis. Graphical abstract: Image 1 The ASK1/MKK7/JNK signal transduction pathway plays an important part in the TG decoction mechanism of action. Highlights: Tiao Geng (TG) decoction has been shown to alleviate menopausal symptoms. Tributyltin chloride induces oxidative damage and apoptosis of neuronal cells. TG decoction reduced apoptosis and increased viability of damaged GT1-7 cells. The activated ASK1/MKK7/JNK signaling pathway in damaged cells was inhibited. TG decoction exerted a protective effect on GT1-7 cells against oxidative damage.