Exercise training with concomitant nitric oxide synthase inhibition improved anxiogenic behavior, spatial cognition, and BDNF/P70S6 kinase activation in 20-month-old rats

The role of nitric oxide (NO) modulators in obsessive-compulsive disorder (OCD)

Obsessive-compulsive disorder (OCD) is as serious devastating anxiety disorder. Selective serotonin reuptake inhibitors (SSRIs) are largely used for the treatment of this mental disease. This pharmacological approach presents consistent limitations including modest efficacy and important side effects. There is pressing need, therefore, to develop new molecules with higher efficacy and safety. Nitric oxide (NO) is an intra-and inter-cellular messenger in the brain. Its involvement in the pathogenesis of OCD has been proposed. In a series of preclinical studies, the anxiolytic profile of NO modulators has been emerged. In the present review I intended to critically evaluate advances in research of these molecules as potential novel agents for the treatment of OCD, comment their advantages over currently used pharmacological therapy as well remaining challenges. Up to now, few preclinical studies have been carried out to this end. Nonetheless, experimental evidence proposes a role for NO and its modulators in OCD. Additional research is mandatory aiming to definitively determine a role for NO modulators for the treatment of OCD. A note of caution, however, is needed on account of potential neurotoxicity and narrow therapeutic window of NO compounds.

Aerobic Training with Naringin Supplementation Improved Spatial Cognition via H2S Signaling Pathway in Alzheimer's Disease Model Rats

OBJECTIVES

This study examined the effects of one-month naringin administration and exercise training on cognitive impairment and H₂S signaling pathway in an Amyloid β (Aβ)-injected rat.

METHODS

Rats were divided into four groups: control group; rats underwent Aβ microinjection surgery, exercise group; rats underwent Aβ microinjection surgery and trained by treadmill for four weeks, naringin group; rats underwent Aβ microinjection surgery, and rats orally administrated 80 mg.kg^-1 naringin for four weeks, naringin+exercise group; rats underwent Aβ microinjection surgery and were trained by treadmill for four weeks, and also, rats orally administrated 80 mg.kg^-1 naringin for four weeks. After one month of treatment, spatial learning and memory were measured, and then hippocampi were sampled. S-adenosylmethionine (SAM), cystathionine-β-synthase (CBS), hydrogen sulfide (H₂S) levels, and neuronal death were detected in the hippocampi of rats.

RESULTS

Naringin and exercise improved spatial learning (latency time, P < .001) and memory (P < .001) in the Morris Water Maze test in Aβ-injected rats compared with the control group. SAM (P < .01), CBS (P < .001), and H₂S (P < .01) levels are increased in the naringin+exercise group compared with the control group.

CONCLUSION

The result of this study supports the effect of exercise and/or naringin to improve cognitive dysfunction and cell death through the production of H₂S.

Nitric oxide signalling and antidepressant action revisited

Studies about the pathogenesis of mood disorders have consistently shown that multiple factors, including genetic and environmental, play a crucial role on their development and neurobiology. Multiple pathological theories have been proposed, of which several ultimately affects or is a consequence of dysfunction in brain neuroplasticity and homeostatic mechanisms. However, current clinical available pharmacological intervention, which is predominantly monoamine-based, suffers from a partial and lacking response even after weeks of continuous treatment. These issues raise the need for better understanding of aetiologies and brain abnormalities in depression, as well as developing novel treatment strategies. Nitric oxide (NO) is a gaseous unconventional neurotransmitter, which regulates and governs several important physiological functions in the central nervous system, including processes, which can be associated with the development of mood disorders. This review will present general aspects of the NO system in depression, highlighting potential targets that may be utilized and further explored as novel therapeutic targets in the future pharmacotherapy of depression. In particular, the review will link the importance of neuroplasticity mechanisms governed by NO to a possible molecular basis for the antidepressant effects.

Aerobic Interval Training Regulated SIRT3 Attenuates High-Fat-Diet-Associated Cognitive Dysfunction

Cognitive dysfunction is an important complicated disease in obesity. Exercise ameliorates obesity and the related cognitive dysfunction. However, the underlying mechanism is still unclear. In this study, we investigated whether aerobic interval training (AIT) could attenuate high-fat-diet- (HFD-) associated cognitive dysfunction and the possible mechanism of SIRT3-MnSOD pathway. C57BL/6 wild-type (WT) mice and SIRT3 knockout (KO) mice were randomized into control (Con) or HFD group with or without AIT training for 6 weeks. The spatial learning and memory ability were impaired in HFD group compared to the control group. The levels of mitochondrial protein acetylation were increased in the hippocampus of HFD group. The acetylation level of antioxidative MnSOD was increased as well. As a result, the ROS and MDA levels were significantly increased, which leads to the neuron apoptosis in the hippocampus. SIRT3 deficiency further aggravated HFD-induced cognitive dysfunction and susceptibility to oxidative stress injury. However, AIT upregulated neuron SIRT3 expression and decreased the acetylation of MnSOD. The hippocampus neuron oxidative stress and apoptosis were both decreased compared to untrained HFD group, which finally improved cognitive function of HFD mice. Collectively, AIT attenuates HFD-associated cognitive dysfunction through SIRT3 upregulation and improvement of antioxidative MnSOD activity.