Taurine ameliorates neurobehavioral, neurochemical and immunohistochemical changes in sporadic dementia of Alzheimer's type (SDAT) caused by intracerebroventricular streptozotocin in rats.

Oxidative loads in the brain are involved in age related impairments like learning and memory as well as neurodegeneration. Taurine, the most abundant free amino acid in humans has many potential health benefits through its anti-oxidant and anti-inflammatory properties. Therefore, we investigated the neuroprotective potential of taurine on oxidative stress, neuronal loss and memory impairments in streptozotocin model of cognitive impairments in rats. The cognitive impairment was developed by giving single intracerebroventricular (ICV) injection of streptozotocin (STZ) 3 mg/kg body weight bilaterally. An increased latency and path length was observed in ICV-STZ group animals as compared to sham group animals and these were inhibited significantly in STZ group pre-treated with taurine (50 mg/kg body weight orally once daily for 15 days). Moreover, the significantly depleted content of GSH and elevated level of thiobarbituric acid reactive substances (TBARS) in ICV-STZ group animals were protected significantly with pre-treatment of taurine. The activity of antioxidant enzymes, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, catalase, and superoxide dismutase was decreased in STZ group as compared to sham group and pre-treatment of STZ group with taurine has protected their activities significantly. Furthermore, the increased activity of acetylcholine esterase and decreased expression of choline acetyl transferase were attenuated by the pre-treatment of taurine. Taurine also protected the morphology of the hippocampal pyramidal neurons. This study concludes that the prophylactic intervention of taurine may be used to prevent the deterioration of cognitive functions and neurobehavioral activities, often associated with the generation of free radicals.

Azadirachta indica mitigates behavioral impairments, oxidative damage, histological alterations and apoptosis in focal cerebral ischemia-reperfusion model of rats.

Azadirachta indica Linn. (Meliaceae) has been used from ancient times as a remedy for various ailments. The present study was designed to investigate the antioxidant and anti-apoptotic properties of A. indica seed extract (ASE) in transient middle cerebral artery occlusion (MCAO) rat model. Antioxidant potential of ASE was determined in vitro. Further, ASE was evaluated against neurological deficits, histological alterations (TTC, CV and H&E) and oxidative damage (TBARS, GSH and nitrite) in MCAO rats. Moreover, caspase-3 and -9 were analyzed to evaluate the anti-apoptotic activity of ASE. ASE has shown potent in vitro reducing power (126.2 mg AsAE/g extract) and free radical scavenging activities (DPPH 171.0 and NO 176.0 µg/ml). Furthermore, ASE inhibited oxidative stress and decreased the activities of caspase-3 (26.7 %, p < 0.05) and caspase-9 (31.2 %, p < 0.01) thus, reduced neuronal loss in MCAO rats. Our data revealed that ASE has potent antioxidant and anti-apoptotic properties, and may be explored for its active constituents against neurodegenerative diseases.

Neuroprotective efficacy of Nardostachys jatamansi and crocetin in conjunction with selenium in cognitive impairment.

Oxidative stress leads to complex biochemical alterations, and has been implicated in the progressive loss of learning and memory. Supplementing and boosting the endogenous antioxidant defense system could impede the progression of various types of neurodegeneration. In the present study, we have investigated the neuroprotective efficacy of a low-dose combination of certain promising and powerful natural antioxidants in an experimental model of cognitive impairment. Combined pretreatment with the extract of Nardosatchys jatamansi (N), crocetin (C) and selenium (Se) as sodium selenite (N, 200 mg/kg + C, 25 µg/kg + Se, 0.05 mg/kg body weight) for 15 days led to improved behavioral outcomes in streptozotocin (STZ)-induced cognitive impairment in rats. While intracerebroventricular (ICV) infusion of STZ resulted in the significant elevation of markers of oxidative stress and depletion of endogenous antioxidant defense system in the vehicle-pretreated group, these markers of oxidative stress and antioxidant enzymatic as well as non-enzymatic defense lines were attenuated in the group pretreated with the combination of antioxidants (NCSe). NCSe pretreatment markedly improved the performance of animals in passive avoidance test and Morris water maze (MWM) tasks, significantly reduced the level of TBARS, and elevated the content of glutathione and activities of antioxidant enzymes (glutathione peroxidase, glutathione-S-transferase and catalase). Our study reflects the synergistic potential of the above combination and concludes that a multimodal approach could be beneficial rather than a singular intervention.