UPLC-QTOF-MS/MS analysis of Moringa oleifera extract and its protective role in oxidative stress-induced SH-SY5Y neuronal cells

Abstract

Neurodegenerative disorders are characterized by progressive neuronal dysfunction and the loss of neurons, which are strongly associated with oxidative stress. Moringa oleifera, commonly known as moringa, has traditionally been used as a medicinal plant due to its anti-inflammatory, antihypertensive, antimicrobial, antidiabetic, hepatoprotective, and gastroprotective properties. This study aimed to investigate the antioxidant and neuroprotective effects of moringa leaf extract (ME) against oxidative stress. ME exhibited radical scavenging activities against 1,1-diphenyl-2-picrylhydrazyl, 2,2′-azino-bis(3-ethylbenzothiazoline- 6-sulfonic acid), and hydroxyl (·OH) radicals, with IC50 values of 35.78±0.65, 361.66±12.75 and 6.41±5.19 μg/mL, respectively. The total phenolic and flavonoid contents were 47.43±0.88 mg GAE/g and 13.21±4.19 mg QE/g, respectively. In SH-SY5Y neuronal cells, ME protected against H2O2-induced neuronal damage by reducing LDH release, ROS production, and the expression of apoptosis-related proteins, such as Bax and cleaved caspase-3. In contrast, SOD activity and HO-1/ Nrf-2 signaling pathway was enhanced by treatment with ME. The phytochemical profile of ME was analyzed using ultra-high performance liquid chromatography coupled to quadruple timeof- flight tandem mass spectrometry, identifying 11 compounds including 4-O-beta-galactopyranosyl-D-mannopyranose, citric acid, adenosine, neochlorogenic acid, cryptochlorogenic acid, astacin, isovitexcin, quercetin 3-glucoside, quercetin 3-(6''-acetylglucoside), astagalin, and vardenafil. These findings suggest that ME exerts antioxidants and neuroprotective effects against oxidative stress and may serve as a promising natural source for the prevention and treatment of neurodegenerative diseases.