Neuroprotective efficacy of nano-CoQ against propionic acid toxicity in rats: Role of BDNF and CREB protein expressions

Reciprocal crosslink among MeCP2/BDNF /CREB signaling pinpointed in autism spectrum disorder

Autism spectrum disorder, or individual disability (ID), is a condition characterized by complications in social interaction, restricted repetitive behavior, and difficulties in social communication. Neuquinon (NQ) possess a powerful therapeutic potential in various neurodegenerative disease. Nevertheless, contributing to NQ's low water solubility and bioavailability, its medicinal use has been constrained. Liposomes were supposed to be prospective drug-delivering agents for NQ, crossing the blood-brain barrier (BBB), and reaching the target organs. The current investigation aims to track the signaling pathways that govern NQ and liposomal neuquinon (LNQ) action in autistic models generated by ethyl formic acid. The neurotransmitters gamma amino-butyric acid (GABA), acetylcholine (ACh), and acetylcholinesterase (AChE) in addition to, the gene expressions of brain-derived neurotrophic factor (BDNF), cAMP response element-binding protein (CREB), and methyl-CpG-binding protein 2 (MeCP2) and the DNA damage COMET analysis at different time intervals of the study, were assessed. EFA in a dose of 500 mg/kg BW was used to induce autism in rats, and then NQ and LNQ were administered in 10 mg/kg and 2 mg/kg BW, respectively. The results revealed that NQ and LNQ significantly down-regulated BDNF, GABA, and AChE; on the other hand, they up-regulated MeCP2, CREB gene expressions, and ACh action. NQ and LNQ displayed improvement in DNA damage in almost all brain regions after EFA alterations; even better results were noticed post-LNQ therapy. Therefore, it may be concluded that neuquinon and liposomal-loaded neuquinon have a therapeutic index versus EFA-induced autism in a rat model.

Neuronal Plasticity and Age-Related Functional Decline in the Motor Cortex

Physiological aging causes a decline of motor function due to impairment of motor cortex function, losses of motor neurons and neuromuscular junctions, sarcopenia, and frailty. There is increasing evidence suggesting that the changes in motor function start earlier in the middle-aged stage. The mechanism underlining the middle-aged decline in motor function seems to relate to the central nervous system rather than the peripheral neuromuscular system. The motor cortex is one of the responsible central nervous systems for coordinating and learning motor functions. The neuronal circuits in the motor cortex show plasticity in response to motor learning, including LTP. This motor cortex plasticity seems important for the intervention method mechanisms that revert the age-related decline of motor function. This review will focus on recent findings on the role of plasticity in the motor cortex for motor function and age-related changes. The review will also introduce our recent identification of an age-related decline of neuronal activity in the primary motor cortex of middle-aged mice using electrophysiological recordings of brain slices.

Acetyl-L-carnitine attenuates Poly I: C- induced sickness behavior in mice

Fatigue is accompanied by a decrease in physical activity or malaise, and might be reduced by acetyl-L-carnitine (ALC) administration. The purpose of this study was to investigate the preventive effects of ALC on Poly I: C-induced sickness behavior in mice. For the experiment, male C3H/HeN mice were used and treated with ALC for 5 days before Poly I: C administration. ALC administration attenuated the decrease in wheel behavior activity of mice at 24 h after Poly I: C administration, and ALC treated mice quickly recovered from the sickness behavior. The gene expression of brain-derived neurotrophic factor (BDNF) in the cerebrum and hippocampus, which is associated with physical activity, was higher in the ALC-treated group. Translocator protein 18kDa (TSPO), which has cytoprotective effects, was up-regulated in the cerebrum and hippocampus, suggesting that ALC suppressed the decrease in activity induced by Poly I: C treatment through enhancement of cytoprotective effects in the brain.

Potential Protective Effect of Coenzyme Q10 on Doxorubicin-Induced Neurotoxicity and Behavioral Disturbances in Rats

The aim of this study was to investigate the potential neuroprotective efficacy of coenzyme Q10 (CoQ10) against doxorubicin (DOX) -induced behavioral disturbances in rats. Female rats were randomly assigned into 4 groups as control, CoQ10, DOX, and DOX plus CoQ10. The CoQ10 groups received CoQ10 (200 mg kg^-1) for 21 days, and the DOX groups received DOX (4 mg kg^-1) on days 7 and 14 of the study. The open field (OF) and elevated plus maze (EPM) tests were performed to assess locomotor activity and anxiety levels. Additionally, malondialdehyde (MDA), and protein carbonyl (PC) levels and acetylcholinesterase (AChE), and glutathione peroxidase (GPx) activities and total antioxidant capacity (TAC) were quantified in brain tissue. DOX administration caused alterations in locomotor activity, and anxiety-like behaviors. Moreover, DOX produced significant elevation in AChE activity . PC level and GPx activity tended to alter with DOX administration. Co-treatment with CoQ10 significantly attenuated DOX-induced behavioral alterations via improving AChE activity in the brain tissue of rats. CoQ10 treatment may be potential for the alleviation of DOX-induced behavioral disturbances. This improvement might be due to the inhibition of AChE activity.

D-Serine produces antidepressant-like effects in mice through suppression of BDNF signaling pathway and regulation of synaptic adaptations in the nucleus accumbens

OBJECTIVE

D-Serine is a crucial endogenous co-agonist of N-methyl-D-aspartate receptors (NMDARs) in the central nervous system and can affect the function of the brain derived neurotrophic factor (BDNF) system, which plays an essential role in modulating synaptic plasticity. The current study aimed to systematically evaluate the role and mechanisms of D-serine in depressive behavior in nucleus accumbens (NAc).

METHODS

D-Serine concentration in the chronic social defeat stress (CSDS) model in NAc was measured using high-performance liquid chromatography (HPLC). The antidepressant-like effects of D-serine were identified using forced swim test (FST) and tail suspension test (TST) in control mice and then assessed in CSDS model. We applied social interaction and sucrose preference tests to identify the susceptibility of CSDS model. Western blotting was further performed to assess the changes of BDNF signaling cascade in NAc after CSDS and D-serine treatment. The BDNF signaling inhibitor (K252a) was also used to clarify the antidepressant-like mechanism of D-serine. Moreover, D-serine effects on synaptic plasticity in NAc were investigated using electrophysiological methods.

RESULTS

D-Serine concentration was decreased in depression susceptible mice in NAc. D-Serine injections into NAc exhibited antidepressant-like effects in FST and TST without affecting the locomotor activity of mice. D-Serine was also effective in CSDS model of depression. Moreover, D-serine down-regulated the BDNF signaling pathway in NAc during CSDS procedure. Furthermore, BDNF signaling inhibitor (K252a) enhanced the antidepressant effects of D-serine. We also found that D-serine was essential for NMDARs-dependent long-term depression (LTD).

CONCLUSION

D-Serine exerts antidepressant-like effects in mice mediated through restraining the BDNF signaling pathway and regulating synaptic plasticity in NAc.

Metabolomic Profiling and Neuroprotective Effects of Purslane Seeds Extract Against Acrylamide Toxicity in Rat's Brain

AIM

Acrylamide (ACR) is an environmental pollutant with well-demonstrated neurotoxic and neurodegenerative effects in both humans and experimental animals. The present study aimed to investigate the neuroprotective effect of Portulaca oleracea seeds extract (PSE) against ACR-induced neurotoxicity in rats and its possible underlying mechanisms. PSE was subjected to phytochemical investigation using ultra-high-performance liquid chromatography (UPLC) coupled with quantitative time of flight mass spectrometry (qTOF-MS). Multivariate, clustering and correlation data analyses were performed to assess the overall effects of PSE on ACR-challenged rats. Rats were divided into six groups including negative control, ACR-intoxicated group (10 mg/kg/day), PSE treated groups (200 and 400 mg/kg/day), and ACR + PSE treated groups (200 and 400 mg/kg/day, respectively). All treatments were given intragastrically for 60 days. PSE markedly ameliorated brain damage as evidenced by the decreased lactate dehydrogenase (LDL), increased acetylcholinesterase (AchE) activities, as well as the increased brain-derived neurotrophic factor (BDNF) that were altered by the toxic dose of ACR. In addition, PSE markedly attenuated ACR-induced histopathological alterations in the cerebrum, cerebellum, hippocampus and sciatic nerve and downregulated the ACR-inclined GFAP expression. PSE restored the oxidative status in the brain as indicated by glutathione (GSH), lipid peroxidation and increased total antioxidant capacity (TAC). PSE upregulated the mRNA expression of protein kinase B (AKT), which resulted in an upsurge in its downstream cAMP response element-binding protein (CREB)/BDNF mRNA expression in the brain tissue of ACR-intoxicated rats. All exerted PSE beneficial effects were dose-dependent, with the ACR-challenged group received PSE 400 mg/kg dose showed a close clustering to the negative control in both unsupervised principal component analysis (PCA) and supervised orthogonal partial least square discriminant analysis (OPLS-Da) alongside with the hierarchical clustering analysis (HCA). The current investigation confirmed the neuroprotective capacity of PSE against ACR-induced brain injury, and our findings indicate that AKT/CREB pathways and BDNF synthesis may play an important role in the PSE-mediated protective effects against ACR-triggered neurotoxicity.

Neuroprotective Effects of Carnitine and Its Potential Application to Ameliorate Neurotoxicity

Carnitine is an essential metabolite that is absorbed from the diet and synthesized in the kidney, liver, and brain. It ferries fatty acids across the mitochondrial membrane to undergo β-oxidation. Carnitine has been studied as a therapy or protective agent for many neurological diseases and neurotoxicity (e.g., prolonged anesthetic exposure-induced developmental neurotoxicity in preclinical models). Preclinical and clinical data support the notion that carnitine or acetyl carnitine may improve a patient's quality of life through increased mitochondrial respiration, release of neurotransmitters, and global gene expression changes, showing the potential of carnitine beyond its approved use to treat primary and secondary carnitine deficiency. In this review, we summarize the beneficial effects of carnitine or acetyl carnitine on the central nervous system, highlighting protective effects against neurotoxicity-induced damage caused by various chemicals and encouraging a thorough evaluation of carnitine use as a therapy for patients suffering from neurotoxicant exposure.