Naringenin, a dietary flavanone, enhances insulin-like growth factor 1 receptor-mediated antioxidant defense and attenuates methylglyoxal-induced neurite damage and apoptotic death. (2nd January 2021)

• Record Type: Journal Article
• Authors: Tseng, Yu-Ting; Hsu, Hung-Te; Lee, Tzu-Ying; Chang, Wan-Hsuan; Lo, Yi-Ching
• Is Part Of: Nutritional neuroscience. Volume 24:Number 1(2021)
• Page Start: 71
• Page End: 81
• Publication Date: 2021-01-02
• Subjects: Naringenin -- insulin-like growth factor 1 -- methylglyoxal -- glucose neurotoxicity -- antioxidant defense -- anti-apoptosis -- motor neurons; Neuropharmacology -- Periodicals; Diet -- Periodicals; Diet therapy -- Periodicals; Nutrition -- Periodicals; 615.78
• DOI: 10.1080/1028415X.2019.1594554
• Languages: English
• ISSNs: 1028-415X

Abstract

ABSTRACT: Objectives: Recent studies revealed the neuroprotective effects of naringenin (NGEN), a common dietary bioflavonoid contained in citrus fruits. However, there are limited data on its protection against methylglyoxal (MG), the most potent precursor of advanced glycation end-products. The present study was to investigate the protection of NGEN on MG-induced neurotoxicity and the involvement of insulin-like growth factor 1 receptor (IGF-1R) signaling. Methods: NSC34 motor neuron-like cells was used. Cell viability was measured by MTT assay. Protein expressions were analyzed by western blots. Morphological changes of neurites were observed by an inverted microscope. Reactive oxygen species (ROS) production and apoptotic cell numbers were measured by flow cytometer. Glutathione (GSH) level and superoxide dismutase (SOD) activity were measured by ELISA. Results: >NGEN attenuated ROS production and increased GSH level, SOD activity and nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear expression in MG-treated NSC34 cells. NGEN also increased neurite length and enhanced IGF-1R and p-Akt in MG-treated NSC34 cells. Furthermore, NGEN attenuated MG-induced apoptotic death accompanied with down-regulation of cleaved-poly (ADP-ribose) polymerase (PARP) and up-regulation of B-cell lymphoma-2 (Bcl-2). However, AG1024, an IGF-1R antagonist, attenuated the anti-oxidative and anti-apoptotic effects of NGEN in MG-treated cells. Discussion: The present results demonstrated that NGEN decreased neuronal apoptosis and improved antioxidant defense in MG-treated NSC34 cells. Moreover, IGF-1R-mediated antioxidant defense plays an important role in this protective mechanism. These findings suggest the potential benefits of NGEN on the prevention of MG-induced or diabetes/hyperglycemia-related neurotoxicity. In vivo studies are needed for further confirmation on NGEN-mediated neuroprotection.