Attenuation of Glutamate-Induced Excitotoxicity by Withanolide-A in Neuron-Like Cells: Role for PI3K/Akt/MAPK Signaling Pathway
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Glutamate-induced excitotoxicity is one of the major underlying mechanisms for neurodegenerative diseases. Efforts are being made to treat such conditions with an array of natural compounds that can modulate the release of glutamate or the underlying mechanisms associated with it. Withania somnifera extract has potent pharmacologic activity similar to that of Korean Ginseng tea and is used to treat several neuronal disorders. However, to date, little efforts have been made to evaluate individual constituents of this plant for neurodegenerative disorders. Present study was carried out to investigate withanolide-A, one of the active constituents of Withania somnifera against glutamate-induced excitotoxicity in retinoic acid differentiated Neuro2a neuroblastoma cells. The results indicated that glutamate treatment for 2 h induced death in cells that was significantly attenuated by pre-treatment with MK-801 (specific NMDA receptor antagonist) and different concentrations of withanolide-A. Withanolide-A abated the glutamate-induced influx of intracellular calcium and excessive ROS production significantly. Further on, glutamate treatment resulted in increased levels of pro-apoptotic and decreased levels of anti-apoptotic proteins, and these protein levels were normalized by various doses of withanolide-A. All of these protective effects were partly due to inhibition of MAPK family proteins and activation of PI3K/Akt signaling. Thus, our results suggest that withanolide-A may serve as potential neuroprotective agent.
KeywordsWithanolide-A Withania somnifera Glutamate ROS Intracellular calcium NMDA MAPK and PI3K/Akt
Reactive oxygen species
Horse reddish peroxidase
Dulbecco’s Modified Eagle Medium
Dr. Ahmad’s work was supported by Ramalingaswamy Fellowship of Department of Biotechnology and financial assistance (MLP6009) as well as logistic support from Council for Scientific and Industrial Research. Dr. Hamid’s research is supported by Department of Biotechnology (BT/PR/3140/PBD/17/656/2009). Additionally, research in both labs is supported by BSC-0108. Mr. Dar is thankful to University Grants Commission, India for Ph.D. research fellowship. Authors are thankful to director of the institute, Dr. Ram Vishwakarma for facilitating the work. Institutional Publication number of this manuscript is IIIM/2019/2017.
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no conflict of interest.
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