Neuroprotective potential of Ocimum sanctum (Linn) leaf extract in monosodium glutamate induced excitotoxicity

Abstract

The aim of this study was to investigate the potent neuroprotective property of ethanol extract of Ocimum sanctum (EEOS) leaf (Holy basil, Family: Labiataea) against excitotoxicity induced neurodegeneration by using monosodium-L-glutamate (MSG) in Sprague-Dawley rats. The animals received EEOS (50, 100 and 200 mg/kg) and memantine (MMT, 20 mg/kg) daily for 7 days. On all the 7 days, MSG (2g/kg, i.p.) was administered one hour before drug treatment. The animals were observed for neurobehavioral performance on 1 st , 3 rd , 5 th and 7 th day. Oxidative damage and histopathological analysis were also assessed. EEOS (100 and 200 mg/kg, p.o.) and MMT (20 mg/kg, i.p.) administration significantly improved body weight and attenuated locomotor activity, rotarod performance and footfault test as compared with MSG treated group. In addition, EEOS was found to restore reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione reductase (GR), catalase (CAT), super oxide dismutase (SOD) and Na +-K + ATPase. Conversely, the elevated level of lipid peroxidation and nitrite concentration in MSG treated group was attenuated significantly in EEOS group in comparison to MSG treated group. Histopathological evaluation showed that treatment with EEOS and MMT significantly attenuated neuronal death and increased the density of neurons after MSG treatment. Thus, these findings suggest that EEOS contains rosmarinic acid and ursolic acid in addition to other bioactive principles may have utility in the preventing and/or treating the neurodegenerative diseases and its protective effects may be due to the amelioration of excitotoxicity, oxidative stress, neurological and behavioral alterations. However, further studies are necessary to clearly define mechanism responsible.

Antioxidant Properties of Dichrocephala Integrifolia (Asteraceae) in a Mouse Model of Monosodium Glutamate-Induced Neurotoxicity

“…In fact, the brain level of GSH was reduced in the brain of animals of the negative control while the amount of malondialdehyde was elevated in the negative control when compared to those of animal in the distilled water group. Our results are similar with earlier works, which found that MSG administration in rodents could lead to the reduction of antioxidant enzymes such as glutathione and consequent accumulation of reactive oxygen species and neurodegeneration (Ramanathan et al, 2007, Rajagopal et al, 2013. The pretreatment of animal with the decoction of D. integrifolia at the doses of 87.5 and 175 mg/kg significantly inhibited the MSG induced oxidative stress.…”

“…In fact, in case of overstimulation of NMDA by glutamate, MT blocks the receptor channel. This prevents calcium influx to the postsynaptic receptor and subsequent exitotoxicity and oxidative stress (Danysz & Parson, 2012, Rajagopal et al, 2013. The results of the phytochemical analysis of D. integrifolia revealed the presence in the decoction of the plant of some metabolites such as flavonoids, tannins and anthraquinones.…”

“…Neurotoxicity can result in diverse central nervous system diseases such as mood disorders and diverse psychiatric disturbances (Han et al, 2011;Mason et al, 2014). Epilepsy, hypoglycemia, ischemia, Alzheimer's and Parkinson's diseases are among the diseases where neurotoxicity generated by glutamate 148 dysregulation plays a central role (Ganesan et al, 2013, Rajagopal et al, 2013Swamy et al, 2013). Glutamate is the primary excitatory neurotransmitter in the mammalian central nervous system.…”

Effects of monosodium glutamate treatment on calretinin-immunoreactive neurons in hippocampus of postnatal rats

“…However, some CR-negative neurons were morphologically changed in a way which may suggest neuronal death. Thus, the cell density loss may probably be related to the appearance of excitotoxicity phenomenon, which was suggested by results of previous studies [27][28][29]. It has been established that the excitotoxicity caused by different factors leads to serious neuronal disorders and even death of nervous cells.…”

The Effects of Monosodium Glutamate and Tannic Acid on Adult Rats

“…Furthermore, excess MSG may cause sudden neuron death ( 9 ). The in vivo neurotoxic effects of MSG are related to acute degenerative changes and chronic neurodegenerative defects, such as in vivo hypoglycemia, ischemia, trauma, multisystem atrophy, Huntington’s disease, and both dementia and amyotropic Alzheimer’s disease ( 10 ). Furthermore, it has been shown that MSG overdose during the neonatal period causes disorders in learning and memory mechanisms, and can impair the neural system, retinas, and kidneys.…”