The neurotherapeutic role of a selenium-functionalized quinoline in hypothalamic obese rats

Overexpression of Motopsin, an Extracellular Serine Protease Related to Intellectual Disability, Promotes Adult Neurogenesis and Neuronal Responsiveness in the Dentate Gyrus

Motopsin, a serine protease encoded by PRSS12, is secreted by neuronal cells into the synaptic clefts in an activity-dependent manner, where it induces synaptogenesis by modulating Na+/K+-ATPase activity. In humans, motopsin deficiency leads to severe intellectual disability and, in mice, it disturbs spatial memory and social behavior. In this study, we investigated mice that overexpressed motopsin in the forebrain using the Tet-Off system (DTG-OE mice). The elevated agrin cleavage or the reduced Na+/K+-ATPase activity was not detected. However, motopsin overexpression led to a reduction in spine density in hippocampal CA1 basal dendrites. While motopsin overexpression decreased the ratio of mature mushroom spines in the DG, it increased the ratio of immature thin spines in CA1 apical dendrites. Female DTG-OE mice showed elevated locomotor activity in their home cages. DTG-OE mice showed aberrant behaviors, such as delayed latency to the target hole in the Barnes maze test and prolonged duration of sniffing objects in the novel object recognition test (NOR), although they retained memory comparable to that of TRE-motopsin littermates, which normally express motopsin. After NOR, c-Fos-positive cells increased in the dentate gyrus (DG) of DTG-OE mice compared with that of DTG-SO littermates, in which motopsin overexpression was suppressed by the administration of doxycycline, and TRE-motopsin littermates. Notably, the numbers of doublecortin- and 5-bromo-2'-deoxyuridine-labeled cells significantly increased in the DG of DTG-OE mice, suggesting increased adult neurogenesis. Importantly, our results revealed a new function in addition to modulating neuronal responsiveness and spine morphology in the DG: the regulation of neurogenesis.

Neuro-amelioration of Ficus lyrata (fiddle-leaf fig) extract conjugated with selenium nanoparticles against aluminium toxicity in rat brain: relevance to neurotransmitters, oxidative, inflammatory, and apoptotic events

Aluminium is a non-essential metal, and its accumulation in the brain is linked with potent neurotoxic action and the development of many neurological diseases. This investigation, therefore, intended to examine the antagonistic efficacy of Ficus lyrata (fiddle-leaf fig) extract (FLE) conjugated with selenium nanoparticles (FLE-SeNPs) against aluminium chloride (AlCl₃)-induced hippocampal injury in rats. Rats were allocated to five groups: control, FLE, AlCl₃ (100 mg/kg), AlCl₃ + FLE (100 mg/kg), and AlCl₃ + FLE-SeNPs (0.5 mg/kg). All agents were administered orally every day for 42 days. The result revealed that pre-treated rats with FLE-SeNPs showed markedly lower acetylcholinesterase and Na⁺/K⁺-ATPase activities in the hippocampus than those in AlCl₃ group. Additionally, FLE-SeNPs counteracted the oxidant stress-mediated by AlCl₃ by increasing superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and glutathione contents in rat hippocampus. Besides, the formulated nanoparticles decreased the hippocampal malondialdehyde, carbonyl protein, and nitric oxide levels of AlCl₃-exposed animals. Furthermore, FLE-SeNPs attenuated neural tissue inflammation, as demonstrated by decreased interleukin-1 beta, interleukin-6, nuclear factor kappa B, and glial fibrillary acidic protein. Remarkable anti-apoptotic action was exerted by FLE-SeNPs by increasing B cell lymphoma 2 and decreasing caspase-3 and Bcl-2-associated-X protein in AlCl₃-exposed rats. The abovementioned results correlated well with the hippocampal histopathological findings. Given these results, SeNPs synthesized with FLE imparted a remarkable neuroprotective action against AlCl₃-induced neurotoxicity by reversing oxidative damage, neuronal inflammation, and apoptosis in exposed rats.

Dapagliflozin diminishes memory and cognition impairment in Streptozotocin induced diabetes through its effect on Wnt/β-Catenin and CREB pathway

Diabetic neuropathy is a chronic condition that affects a significant number of individuals with diabetes. Streptozotocin injection intraperitoneally to rodents produces pancreatic islet β-cell destruction causing hyperglycemia, which affect the brain leading to memory and cognition impairment. Dapagliflozin may be able to reverse beta-cell injury and alleviate this impairment. This effect may be via neuroprotective effect or possible involvement of the antioxidant, and anti-apoptotic properties. Forty rats were divided into four groups as follows: The normal control group, STZ-induced diabetes group, STZ-induced diabetic rats followed by treatment with oral dapagliflozin group and normal rats treated with oral dapagliflozin. Behavioral tests (Object location memory task and Morris water maze) were performed. Serum biomarkers (blood glucose and insulin) were measured and then the homeostatic model assessment for insulin resistance (HOMA-IR) was calculated. In the hippocampus the followings were determined; calmodulin, ca-calmodulin kinase Ⅳ (CaMKIV), protein kinase A (PKA) and cAMP-responsive element-binding protein to determine the transcription factor CREB and its signaling pathway also Wnt signaling pathway and related parameters (WnT, B-catenin, lymphoid enhancer binding factor LEF, glycogen synthase kinase 3β). Moreover, nuclear receptor-related protein-1, acetylcholine and its hydrolyzing enzyme acetylcholine esterase, oxidative stress parameter malondialdehyde (MDA) and apoptotic parameter caspase-3 were determined. STZ was able to cause destruction to pancreatic β-cells which was reflected on glucose levels causing diabetes. Diabetic neuropathy was clear in the rats performing the behavioral tests. Memory and cognition parameters in the hippocampus were negatively affected. Oxidative stress and apoptotic parameter were elevated while the electrical activity was declined. Dapagliflozin was able to reverse the previously mentioned parameters and behavior. Thus, to say dapagliflozin significantly showed neuroprotective action along with antioxidant, and anti-apoptotic properties.

Interface of Aging and Acute Peripheral Neuropathy Induced by Oxaliplatin in Mice: Target-Directed Approaches for Na+, K+-ATPase, Oxidative Stress, and 7-Chloro-4-(phenylselanyl) quinoline Therapy

Almost 90% of patients develop pain immediately after oxaliplatin (OXA) treatment. Here, the impact of aging on OXA-induced acute peripheral neuropathy and the potential of 7-chloro-4-(phenylselanyl) quinoline (4-PSQ) as a new therapeutic strategy were evaluated. In Swiss mice, the oxidative damage and its influence on Mg²⁺-ATPase and Na⁺, K⁺-ATPase activities were investigated. The relationship between the reactive oxygen species (ROS) and nitrate and nitrite (NOx) levels, the activity of glutathione peroxidase (GPx), and superoxide dismutase (SOD) with the development of OXA-induced acute peripheral neuropathy was also studied. In this study, it was evidenced that OXA-induced acute peripheral neuropathy was exacerbated by aging through increased oxidative damage as well as Na⁺, K⁺-ATPase, and Mg⁺²-ATPase inhibition. 4-PSQ reversed hypersensitivity induced by OXA and aging-aggravated by reducing ROS and NOx levels, through modulation of GPx and SOD activities. 4-PSQ partially reestablish Na⁺, K⁺-ATPase activity, but not Mg ²⁺-ATPase activity. Locomotor and exploratory activities were not affected. This study is the first of its kind, providing new insight into the aging impact on mechanisms involved in OXA-induced acute peripheral neuropathy. Also, it provides evidence on promising 4-PSQ effects on this condition, mainly on aging.

4-Phenylselanyl-7-chloroquinoline attenuates hepatic injury triggered by neonatal exposure to monosodium glutamate in rats

AIMS

Obesity is associated with a spectrum of hepatic abnormalities that can be experimentally induced by injections of monosodium glutamate (MSG) in neonatal rodents. We investigated the protective actions of the repeated therapy with 4-phenylselenyl-7-chloroquinoline (4-PSQ), a quinoline derivative containing selenium, on damage to the liver triggered by early postnatal administration of MSG in male Wistar rats.

MAIN METHODS

Neonatal rats received MSG (4 g/kg, subcutaneous route) or saline (1 ml/kg) from 5 to 14 postnatal day (PND) to induce obesity with consequent damages in the liver. 4-PSQ treatment (5 mg/kg) or canola oil (1 ml/kg) was administered from 60 to 76 PND by the intragastric route. On 76 PND, animals were anesthetized for blood and liver collection. Plasma markers of hepatic function, hepatic lipoperoxidation levels and histology analysis of liver tissue were assessed.

KEY FINDINGS

Our data revealed that treatment with 4-PSQ reverted the increase in plasma transaminases activities observed in MSG rats. Treatment with 4-PSQ reduced plasma lactate levels in obese rats. In the liver, MSG elevated the content of lipoperoxidation which was reverted by 4-PSQ administrations. Lastly, 4-PSQ therapy attenuated the histological alterations induced by MSG.

SIGNIFICANCE

Together, the results indicate a hepatoprotective action of repeated treatment with 4-PSQ in obese rats.