Effects of systemic administration of beta-casomorphin-5 on learning and memory in mice

New curcumin-loaded nanocapsules as a therapeutic alternative in an amnesia model

This study aimed to investigate the action of two different formulations of curcumin (Cur)-loaded nanocapsules (Nc) (Eudragit [EUD] and poly (ɛ-caprolactone) [PCL]) in an amnesia mice model. We also investigated the formulations' effects on scopolamine-induced (SCO) depressive- and anxiety-like comorbidities, the cholinergic system, oxidative parameters, and inflammatory markers. Male Swiss mice were randomly divided into five groups (n = 8): group I (control), group II (Cur PCL Nc 10 mg/kg), group III (Cur EUD Nc 10 mg/kg), group IV (free Cur 10 mg/kg), and group V (SCO). Treatments with Nc or Cur (free) were performed daily or on alternate days. After 30 min of treatment, the animals received the SCO and were subjected to behavioral tests 30 min later (Barnes maze, open-field, object recognition, elevated plus maze, tail suspension tests, and step-down inhibitory avoidance tasks). The animals were then euthanized and tissue was removed for biochemical assays. Our results demonstrated that Cur treatment (Nc or free) protected against SCO-induced amnesia and depressive-like behavior. The ex vivo assays revealed lower acetylcholinesterase (AChE) and catalase (CAT) activity, reduced thiobarbituric species (TBARS), reactive species (RS), and non-protein thiols (NSPH) levels, and reduced interleukin-6 (IL-6) and tumor necrosis factor (TNF) expression. The treatments did not change hepatic markers in the plasma of mice. After treatments on alternate days, Cur Nc had a more significant effect than the free Cur protocol, implying that Cur may have prolonged action in Nc. This finding supports the concept that it is possible to achieve beneficial effects in nanoformulations, and treatment on alternate days differs from the free Cur protocol regarding anti-amnesic effects in mice.

Dairy, Plant, and Novel Proteins: Scientific and Technological Aspects

Alternative proteins have gained popularity as consumers look for foods that are healthy, nutritious, and sustainable. Plant proteins, precision fermentation-derived proteins, cell-cultured proteins, algal proteins, and mycoproteins are the major types of alternative proteins that have emerged in recent years. This review addresses the major alternative-protein categories and reviews their definitions, current market statuses, production methods, and regulations in different countries, safety assessments, nutrition statuses, functionalities and applications, and, finally, sensory properties and consumer perception. Knowledge relative to traditional dairy proteins is also addressed. Opportunities and challenges associated with these proteins are also discussed. Future research directions are proposed to better understand these technologies and to develop consumer-acceptable final products.

Food-Derived Peptides: Beneficial CNS Effects and Cross-BBB Transmission Strategies

Food-derived peptides, as dietary supplements, have significant effects on promoting brain health and relieving central nervous system (CNS) diseases. However, the blood-brain barrier (BBB) greatly limits their in-brain bioavailability. Thus, overcoming the BBB to target the CNS is a major challenge for bioactive peptides in the prevention and treatment of CNS diseases. This review discusses improvement in the neuroprotective function of food-derived active peptides in CNS diseases, as well as the source of BBB penetrating peptides (BBB-shuttles) and the mechanism of transmembrane transport. Notably, this review also discusses various peptide modification methods to overcome the low permeability and stability of the BBB. Lipification, glycosylation, introduction of disulfide bonds, and cyclization are effective strategies for improving the penetration efficiency of peptides through the BBB. This review provides a new prospective for improving their neuroprotective function and developing treatments to delay or even prevent CNS diseases.

Development and In Vivo Assessment of 4-Phenyltellanyl-7-chloroquinoline-loaded Polymeric Nanocapsules in Alzheimer's Disease Models

Alzheimer's disease (AD) is the most common form of dementia in older people, and available treatments are palliative and produce undesirable side effects. The 4-phenyltellanyl-7-chloroquinoline (TQ) is an organochalcogen compound studied due to its pharmacological properties, particularly its antioxidant potential. However, TQ possesses some drawbacks such as low aqueous solubility and high toxicity, thus warranting the search for tools that improve the safety and effectiveness of new compounds. Here, we developed and investigated the biological effects of TQ-loaded polymeric nanocapsules (NCTQ) in an AD model in transgenic Caenorhabditis elegans expressing human Aβ_1-42 in their body-wall muscles and Swiss mice injected with Aβ_25-35. The NCTQ displayed good physicochemical properties, including nanometer size and maximum encapsulation capacity. The treatment showed low toxicity, reduced Aβ peptide-induced paralysis, and activated an endoplasmic reticulum chaperone in the C. elegans model. The Aβ injection in mice caused memory impairment, which NCTQ mitigated by improving working, long-term, and aversive memory. Additionally, no changes in biochemical markers were evidenced in mice, demonstrating that there was no hepatotoxicity in the tested doses. Altogether, these findings provide insights into the neuroprotective effects of TQ and indicate that NCTQ is a promising candidate for AD treatment.

Does a Little Difference Make a Big Difference? Bovine β-Casein A1 and A2 Variants and Human Health-An Update

For over 20 years, bovine beta-casein has been a subject of increasing scientific interest because its genetic A1 variant during gastrointestinal digestion releases opioid-like peptide β-casomorphin-7 (β-CM-7). Since β-CM-7 is involved in the dysregulation of many physiological processes, there is a growing discussion of whether the consumption of the β-casein A1 variant has an influence on human health. In the last decade, the number of papers dealing with this problem has substantially increased. The newest clinical studies on humans showed a negative effect of variant A1 on serum glutathione level, digestive well-being, cognitive performance score in children, and mood score in women. Scientific reports in this field can affect the policies of dairy cattle breeders and the milk industry, leading to the elimination of allele A1 in dairy cattle populations and promoting milk products based on milk from cows with the A2A2 genotype. More scientific proof, especially in well-designed clinical studies, is necessary to determine whether a little difference in the β-casein amino acid sequence negatively affects the health of milk consumers.

Release of an anti-anxiety peptide in casein hydrolysate with Aspergillus oryzae protease

Food protein-derived peptides with agonistic effects on receptors have great potential for treating anxiety, hypertension, and stress. In the present study, opioid peptides with agonistic activities for δ-receptor-expressing HEK293 cells were screened from casein hydrolysates prepared with five types of food grade proteolytic enzymes, among which casein hydrolysate with Aspergillus oryzae protease ASD showed the highest opioid activity. Eluted fractions showing potent opioid activity were further purified for active peptides by reverse phase-HPLC. The peptide in the active fraction was identified as YPFPGPIPNS, a member of β-casomorphin (CM-10) (β-casein 60-69). Various CM-10 derivative peptides were synthesized and their characteristic features for specificities towards δ- and μ-receptors were determined. Peptides 5 to 12 amino acids long showed relatively higher opioid activities for δ- and μ-receptors. CM-10 was docked into the optimized δ-receptor model. The CDOCKER energies of the CM-10 derivatives were consistent with their opioid activities. In the elevated plus-maze study, CM-10 showed a significant anti-anxiety effect in BALB/c mice at a dose of 10 mg per kg body weight when administered orally, but not via intravenous injection. Furthermore, intravital imaging revealed that Ca²⁺ signaling was induced in the small intestinal villi of a Yellow Cameleon 3.60 (YC3.60)-expressing mouse upon injection with CM-10. However, this decreased in the presence of δ- or μ-receptor antagonists. These results suggest that the opioid peptide CM-10 prepared from casein with ASD has an anti-anxiety effect through interaction with gut δ- and/or μ-opioid receptors in the mouse gut.

SAFETY PROFILE AND PREVENTION OF COGNITIVE DEFICIT IN ALZHEIMER’S DISEASE MODEL OF GRAPHENE FAMILY NANOMATERIALS, TUCUMA OIL (Astrocaryum vulgare) AND ITS SYNERGISMS

Alzheimer's disease is a worldwide health issue, and there are currently no treatments that can stop this disease. Oxidized graphene derivatives have gained prominence in use in biological systems due to their excellent physical-chemical characteristics, biocompatibility and ability to overcome the blood-brain barrier. Other substances highlighted are those of natural origin from the Amazon biome, such as tucuma, a fruit whose oil has been widely studied in therapeutic applications. Thus, the aim of this study was to investigate the action of graphene oxide, reduced graphene oxide and tucuma oil, isolated and combined, as an alternative for treatment of Alzheimer's disease through studies in silico, in vitro, in vivo and ex vivo. Computational simulation via docking was used to verify the affinity of the substances with the proteins β-amyloid and acetylcholinesterase, in which the reduced graphene oxide was the one that showed the most favorable interaction. The results of the ab initio simulation showed that the synergism between the nanostructures and the oil occurs through physical adsorption. The experimental results revealed that the substances and their combinations were nontoxic, both at the cellular and systemic level. In general, all treatments had positive results against induced memory deficit, but reduced graphene oxide was the most prominent, as it was able to protect against memory damage in all behavioral tests performed, with anticholinesterase activity and antioxidant effect. In conclusion, the reduced graphene oxide is, among the treatments studied, the one with great therapeutic potential to be investigated in the treatment of this disease.

Long-term increase in sensitivity to ketamine's behavioral effects in mice exposed to mild blast induced traumatic brain injury

Neurobehavioral deficits emerge in nearly 50% of patients following a mild traumatic brain injury (TBI) and may persist for months. Ketamine is used frequently as an anesthetic, analgesic and for management of persistent psychiatric complications. Although ketamine may produce beneficial effects in patients with a history of TBI, differential sensitivity to its impairing effects could make the therapeutic use of ketamine in TBI patients unsafe. This series of studies examined male C57BL/6 J mice exposed to a mild single blast overpressure (mbTBI) for indications of altered sensitivity to ketamine at varying times after injury. Dystaxia (altered gait), diminished sensorimotor gating (reduced prepulse inhibition) impaired working memory (step-down inhibitory avoidance) were examined in mbTBI and sham animals 15 min following intraperitoneal injections of saline or R,S-ketamine hydrochloride, from day 7-16 post injury and again from day 35-43 post injury. Behavioral performance in the forced swim test and sucrose preference test were evaluated on day 28 and day 74 post injury respectively, 24 h following drug administration. Dynamic gait stability was compromised in mbTBI mice on day 7 and 35 post injury and further exacerbated following ketamine administration. On day 14 and 42 post injury, prepulse inhibition was robustly decreased by mbTBI, which ketamine further reduced. Ketamine-associated memory impairment was apparent selectively in mbTBI animals 1 h, 24 h and day 28 post shock (tested on day 15/16/43 post injury). Ketamine selectively reduced immobility scores in the FST in mbTBI animals (day 28) and reversed mbTBI induced decreases in sucrose consumption (Day 74). These results demonstrate increased sensitivity to ketamine in mice when tested for extended periods after TBI. The results suggest that ketamine may be effective for treating neuropsychiatric complications that emerge after TBI but urge caution when used in clinical practice for enhanced sensitivity to its side effects in this patient population.

Protective effects of octylseleno-xylofuranoside in a streptozotocin-induced mouse model of Alzheimer's disease

Octylseleno-xylofuranoside (OSX) is an organic selenium compound which has previously shown antioxidant and antidepressant-like activities, trough the modulation of monoaminergic system and synaptic plasticity pathways. Since recent studies have suggested Major Depressive Disorder (MDD) as a potential risk factor or condition that precedes and correlates with Alzheimer's Disease (AD), this study aimed to evaluate the protective effects of OSX in an AD mouse model induced by intracerebroventricular injection of streptozotocin (STZ). To address this protective effect, mice were pre-treated with intragastrical OSX (0.1 mg/kg) or vehicle for 20 days. After the pre-treatment, mice were submitted to two alternated intracerebroventricular infusions of STZ (days 21 and 23) or saline. 15 days after the last STZ injection, cognitive and memory skills of the treated mice were evaluated on object recognition test, Y-maze, stepdown passive avoidance and social recognition paradigms. Added to that, measurements of oxidative stress markers and gene expression were evaluated in brain samples of the same mice groups. Mice pre-treatment with OSX protected mice from cognitive and memory decline elicited by STZ. This effect was attributed to the prevention of lipid peroxidation and modulation of acetylcholinesterase and monoamine oxidase activities in cerebral cortices and hippocampi by OSX treatment. Furthermore, OSX treatment demonstrated reduction of amyloidogenic pathway genes expression when compared to the control groups. Besides that, OSX treatment showed no hepatic and renal toxicity in the protocol used for treatment. Considering the antidepressant-like effect of OSX, together with the ability to prevent memory and cognitive impairment, this new compound may be an interesting strategy for targeting the comorbidity between MDD and AD, in a multitarget drug paradigm.

A new arylsulfanyl-benzo-2,1,3-thiadiazoles derivative produces an anti-amnesic effect in mice by modulating acetylcholinesterase activity

The aim of the present study was investigate the binding affinity of 5-((4-methoxyphenyl)thio)benzo[c][1,2,5]thiadiazole (MTDZ) with acetylcholinesterase (AChE). We also evaluated the effect of MTDZ against scopolamine (SCO)-induced amnesia in mice and we looked at the toxicological potential of this compound in mice. The binding affinity of MTDZ with AChE was investigated by molecular docking analyses. For an experimental model, male Swiss mice were treated daily with MTDZ (10 mg/kg, intragastrically (i.g.)) or canola oil (10 ml/kg, i.g.), and induced, 30 min later, with injection of SCO (0.4 mg/kg, intraperitoneally (i.p.)) or saline (0.9%, 5 ml/kg, i.p.) daily. From day 1 to day 10, mice were submitted to the behavioral tasks (Barnes maze, open-field, object recognition and location, Y-maze and step-down inhibitory avoidance tasks), 30 min after induction with SCO. On the tenth day, the animals were euthanized and blood was collected for the analysis of biochemical markers (creatinine, aspartate (AST), and alanine (ALT) aminotransferase). MTDZ interacts with residues of the AChE active site. SCO caused amnesia in mice by changing behavioral tasks. MTDZ treatment attenuated the behavioral changes caused by SCO. In ex vivo assay, MTDZ also protected against the alteration of AChE activity, reactive species (RS) levels, thiobarbituric acid reative species (TBARS) levels, catalase (CAT) activity in tissues, as well as in transaminase activities of plasma caused by SCO in mice. In conclusion, MTDZ presented anti-amnesic action through modulation of the cholinergic system and provided protection from kidney and liver damage caused by SCO.

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

RATIONALE

Obesity is considered one of the major global health problems and increases the risk of several medical complications, such as diabetes and mental illnesses.

OBJECTIVE

The present study investigated the effect of 7-chloro-4-(phenylselanyl) quinoline (4-PSQ) on obesity parameters, behavioral and neurochemical alterations in hypothalamic obese rats.

METHODS

Male Wistar rats received subcutaneous neonatal injections of monosodium glutamate (MSG, 4g/kg) or saline. After the Lee Index evaluation, rats were divided into groups and treated with 4-PSQ (5 mg/kg, intragastric route) or canola oil once a day (post-natal days (PND) 60→76). Open-field, elevated plus-maze, forced swim task, object recognition/location memory, and stepdown inhibitory avoidance tasks were conducted from PND 66 to 74. On PND 76, rats were euthanized and epididymal fat, blood, cerebral cortex, andhippocampus were removed. Blood biochemical parameters and cortical/hippocampal acetylcholinesterase (AChE) and Na /K -ATPase activities were assessed.

RESULTS

MSG increased the Lee Index characterizing the chemically induced hypothalamic obesity model. 4-PSQ reversed the increases of epididymal fat, blood glucose, and triglyceride levels caused by MSG exposure. 4-PSQ attenuated anxiety-like and depression-like behaviors induced by neonatal administrations of MSG. Memory deficits found in MSG-obese rats were reversed by treatment with 4-PSQ. Neurochemical alterations produced by MSG evidenced by stimulation ofNa⁺/K⁺-ATPase and AChE activities in the cerebral cortex and hippocampus of rats were normalized by 4-PSQ treatment.

CONCLUSIONS

In brief, 4-PSQ therapy improved hypothalamic obesity-related parameters, as well as psychiatric symptoms, cognitive impairment, and neurochemical alterations found in obese rats.

Effect of a purine derivative containing selenium to improve memory decline and anxiety through modulation of the cholinergic system and Na+/K+-ATPase in an Alzheimer's disease model

Alzheimer's disease (AD) is a worldwide problem, and there are currently no treatments that can stop this disease. To investigate the binding affinity of 6-((4-fluorophenyl) selanyl)-9H-purine (FSP) with acetylcholinesterase (AChE), to verify the effects of FSP in an AD model in mice and to evaluate the toxicological potential of this compound in mice. The binding affinity of FSP with AChE was investigated by molecular docking analyses. The AD model was induced by streptozotocin (STZ) in Swiss mice after FSP treatment (1 mg/kg, intragastrically (i.g.)), 1st-10th day of the experimental protocol. Anxiety was evaluated in an elevated plus maze test, and memory impairment was evaluated in the Y-maze, object recognition and step-down inhibitory avoidance tasks. The cholinergic system was investigated based on by looking at expression and activity of AChE and expression of choline acetyltransferase (ChAT). We evaluated expression and activity of Na⁺/K⁺-ATPase. For toxicological analysis, animals received FSP (300 mg/kg, i.g.) and aspartate aminotransferase, alanine aminotransferase activities were determined in plasma and δ-aminolevulinate dehydratase activity in brain and liver. FSP interacts with residues of the AChE active site. FSP mitigated the induction of anxiety and memory impairment caused by STZ. FSP protected cholinergic system dysfunction and reduction of activity and expression of Na⁺/K⁺-ATPase. FSP did not modify toxicological parameters evaluated and did not cause the death of mice. FSP protected against anxiety, learning and memory impairment with involvement of the cholinergic system and Na⁺/K⁺-ATPase in these actions.

Effect of QTC-4-MeOBnE Treatment on Memory, Neurodegeneration, and Neurogenesis in a Streptozotocin-Induced Mouse Model of Alzheimer's Disease

Growing evidence suggests that drugs targeting neurogenesis and myelinization could be novel therapeutic targets against Alzheimer's disease (AD). Intracerebroventricular (icv) injection of streptozotocin (STZ) induces neurodegeneration through multiple mechanisms ultimately resulting in reduced adult neurogenesis. Previously, the multitarget compound QTC-4-MeOBnE (1-(7-chloroquinolin-4-yl)-N-(4-methoxybenzyl)-5-methyl-1H-1,2,3-triazole-4-carboxamide) demonstrated beneficial effects in preclinical models of AD. Here we investigated its pharmacokinetics profile and the effect on memory impairments and neurodegeneration induced by STZ. Two icv injections of STZ resulted in significant cognitive and memory impairments, assessed by novel object recognition, Y-maze, social recognition, and step-down passive avoidance paradigms. These deficits were reversed in STZ-injected mice treated with QTC-4-MeOBnE. This effect was associated with reversion of neuronal loss in hippocampal dentate gyrus, reduced oxidative stress, and amelioration of synaptic function trough Na⁺/K⁺ ATPase and acetylcholinesterase activities. Furthermore, brains from QTC-4-MeOBnE-treated mice had a significant increase in adult neurogenesis and remyelination through Prox1/NeuroD1 and Wnt/β-catenin pathways. Overall, our findings support the potential anti-AD effect of QTC-4-MeOBnE through multiple pathways, all of which have been involved in the onset and progression of the disease.

Food-Derived Opioid Peptides in Human Health: A Review

World Health Organization data suggest that stress, depression, and anxiety have a noticeable prevalence and are becoming some of the most common causes of disability in the Western world. Stress-related disorders are considered to be a challenge for the healthcare system with their great economic and social impact. The knowledge on these conditions is not very clear among many people, as a high proportion of patients do not respond to the currently available medications for targeting the monoaminergic system. In addition, the use of clinical drugs is also associated with various side effects such as vomiting, dizziness, sedation, nausea, constipation, and many more, which prevents their effective use. Therefore, opioid peptides derived from food sources are becoming one of the safe and natural alternatives because of their production from natural sources such as animals and plant proteins. The requirement for screening and considering dietary proteins as a source of bioactive peptides is highlighted to understand their potential roles in stress-related disorders as a part of a diet or as a drug complementing therapeutic prescription. In this review, we discussed current knowledge on opioid endogenous and exogenous peptides concentrating on their production, purification, and related studies. To fully understand their potential in stress-related conditions, either as a drug or as a therapeutic part of a diet prescription, the need to screen more dietary proteins as a source of novel opioid peptides is emphasized.

Chrysin loaded lipid-core nanocapsules ameliorates neurobehavioral alterations induced by β-amyloid1-42 in aged female mice

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by a clinically and progressive loss of cognitive function, neuropsychiatric and behavioral disorders. Some studies showed that chrysin has antioxidant and anti-inflammatory properties. However, your bioavailability is relatively low. Therefore, the present study was designed to investigate the effects of chrysin loaded lipid-core nanocapsules (LNCs) on neurochemical and behavioral changes in a model of AD induced by β-amyloid_1-42 (Aβ_1-42) peptide in aged female mice. For this purpose, aged female mice received free chrysin (FC) (5 mg/kg, per oral, p.o.) or chrysin loaded LNCs (C1-LNC and C5-LNC) (1 or 5 mg/kg, p.o.) for 14 days after Aβ_1-42 administration (400 pmol, i.c.v.). Aβ_1-42 induced significant impairments on memory and learning (morris water maze task, object recognition and step-down-type passive avoidance), also caused oxidative stress, reduced the levels of brain-derived neurotrophic factor (BDNF), increased neuroinflammation in prefrontal cortex and hippocampus of aged animals. Thus, C1-LNC and C5-LNC displayed significant effect against Aβ₁_-₄_2, via attenuation of oxidative stress and neuroinflammation, modulation of neurochemical and behavioral changes in a model of AD. These results point to chrysin loaded LNCs (mainly C5-LNC) can be a promising biomedical tool and a new therapeutic approach for treatment and prevention of AD.

Amnesia-ameliorative effect of a quinoline derivative through regulation of oxidative/cholinergic systems and Na+/K+-ATPase activity in mice

The present study evaluated the anti-amnesic activity of 1-(7-chloroquinolin-4-yl)-5-methyl-N-phenyl-1H-1,2,3-triazole-4-carboxamide (QTCA-1) against scopolamine (SCO)-induced amnesia in mice. It was evaluated cholinergic dysfunction, oxidative stress and Na⁺/K⁺-ATPase activity in cerebral cortex and hippocampus of mice. Male Swiss mice were treated with QTCA-1 (10 mg/kg, intragastrically (i.g.), daily) for nine days. Thirty minutes after the treatment with compound, the animals received a injection of SCO (0.4 mg/kg, intraperitoneally (i.p.)). Mice were submitted to the behavioral tasks 30 min after injection of SCO (Barnes maze, open-field, object recognition and location, and step-down inhibitory avoidance tasks) during nine days. In day 9, cerebral cortex and hippocampus of mice were removed to determine the thiobarbituric acid reactive species (TBARS) levels, and catalase (CAT), Na⁺/K⁺-ATPase and acetylcholinesterase (AChE) activities. SCO caused amnesia in mice for changing in step-down inhibitory avoidance, Barnes maze, and object recognition and object location tasks. QTCA-1 treatment attenuated the behavioral changes caused by SCO. Moreover, SCO increased AChE and CAT activities, decreased Na⁺/K⁺-ATPase activity and increased TBARS levels in the cerebral structures of mice. QTCA-1 protected against these brain changes. In conclusion, QTCA-1 had anti-amnesic action in the experimental model used in the present study, through the anticholinesterase effect, modulation of Na⁺/K⁺-ATPase activity and antioxidant action.

Rational design, cognition and neuropathology evaluation of QTC-4-MeOBnE in a streptozotocin-induced mouse model of sporadic Alzheimer's disease

Alzheimer’s disease (AD) is a multifactorial pathology characterized by amyloid deposits, neurofibrillary formation, oxidative stress and cholinergic system dysfunction. In this sense, here we report the rational design of a multi-target directed ligand (MTDL) for AD based on virtual screening and bioinformatic analyses, exploring the molecular targets β-secretase (BACE-1), glycogen synthase kinase-3β (GSK-3β) and acetylcholinesterase (AChE). After this screening, the compound with higher molecular docking affinity was selected, the 1-(7-chloroquinolin-4-yl)-N-(4-methoxybenzyl)-5-methyl-1H-1,2,3-triazole-4 carboxamide(QTC-4-MeOBnE). To further our studies, the protective effect of QTC-4-MeOBnE (0.1 and 1 mg/kg for 20 days) on STZ-induced sporadic AD mice was determined. QTC-4-MeOBnE pretreatment attenuated cognitive and memory deficit induced by STZ in an object recognition test, Y-maze, social recognition test and step-down passive avoidance. The mechanisms underlying this action might be attributed to the reduction of lipid peroxidation and reactive species formation in the prefrontal cortex and hippocampus of mice submitted to STZ. In addition, QTC-4-MeOBnE pretreatment abolished the up-regulation of AChE activity and the overexpression of GSK 3β and genes involved in amyloid cascade such as BACE-1, protein precursor amyloid, у-secretase, induced by STZ. Moreover, toxicological parameters were not modified by QTC-4-MeOBnE chronic treatment. This evidence suggests that QTC-4-MeOBnE exerts its therapeutic effect through multiple pathways involved in AD.

Blood-brain barrier breakdown, memory impairment and neurotoxicity caused in mice submitted to orally treatment with thymol

Several evidences have related the biochemical and pharmacological properties of thymol, but the possible neurotoxic effects of this compound remain unknown and not evaluated. Thus, the purpose of this study was to evaluate whether intake of thymol in different doses (10, 20 and 40 mg/kg) induce neurotoxicity and behavioral alterations using mice as experimental model, as well as the involvement of blood-brain barrier (BBB) and brain neurotransmitters in these alterations. Thymol (20 and 40 mg/kg) significantly decrease latency time to inhibitory avoidance task when compared to control group, indicating a memory loss after 30 days of oral treatment. Also, thymol (20 and 40 mg/kg) induced a significant increase on BBB permeability to Evan's blue dye when compared to control group, which is an indicative of BBB breakdown. Moreover, a significant increase of brain acetylcholinesterase (AChE) was observed in mice treated with 40 mg/kg of thymol, while the activity of sodium-potassium pump (Na⁺, K⁺-ATPase) was inhibited in mice treated with 20 and 40 mg/kg thymol when compared to control group. Finally, mice that received 20 and 40 mg/kg thymol showed a significant increase on cerebral reactive oxygen species (ROS) levels and cerebral xanthine oxidase (XO) activity compared to control group. Based on these evidences, the rupture of BBB can be considered an important pathway linked in thymol-induced memory loss. Also, the augmentation of brain ROS levels elicited by increase on XO activity may be a via involved in the damage to BBB, and an oxidative pathway that impairs the activity of brain neurotransmitters, as AChE and Na⁺, K⁺-ATPase. In summary, the dose of 10 mg/kg thymol can be safe and without neurotoxic effects in a period of 30 days of intake.

Current advances of pharmacological properties of 7-chloro-4-(phenylselanyl) quinoline: Prevention of cognitive deficit and anxiety in Alzheimer's disease model

This study investigated the effect of 7-chloro-4-(phenylselanyl) quinoline (4-PSQ) at a dose of 1 mg/kg in memory impairment and anxiety in an Alzheimer's disease (AD) model induced by amyloid β-peptide (Aβ) (fragment 25-35) in mice. The involvement of acetylcholinesterase (AChE) activity and lipid peroxidation in hippocampus and cerebral cortex was evaluated. Male Swiss mice were pretreated with 4-PSQ (1 mg/kg, intragastrically (i.g.), daily) for fourteen days. Thirty minutes after the first treatment with 4-PSQ, the animals received a single injection of Aβ (3 nmol/3 μl/per site, intracerebroventricular (i.c.v.)). Mice were submitted to the behavioral tasks (open-field, elevated plus maze, Barnes maze, object recognition and location, and step-down inhibitory avoidance tests) from the fifth day onwards. On the fifteenth day, blood was removed for analysis of biochemical markers (glucose, triglycerides, urea, aspartate (AST) and alanine (ALT) aminotrasferases), and cerebral cortex and hippocampus for determination of AChE activity and thiobarbituric acid reactive species (TBARS) levels. Aβ caused memory impairment, anxiogenic behavior, increased AChE activity in the cerebral structures and TBARS levels in the cerebral cortex. 4-PSQ was effective to protect against behavioral changes, AChE activity and TBARS levels. In conclusion, 4-PSQ protected against learning and memory impairment and anxiety in a mouse model of AD induced by Aβ, and anticholinesterase and antioxidant actions are involved in the pharmacological effect of the compound.

Gelidiella acerosa protects against Aβ 25-35-induced toxicity and memory impairment in Swiss Albino mice: an in vivo report

CONTEXT

Alzheimer's disease (AD) is believed to develop due to deposition of β-amyloid (Aβ) peptide. Hence, efforts are being made to develop potent drug that target amyloid hypothesis.

OBJECTIVE

The present study explores the effect of the seaweed Gelidiella acerosa (Forsskål) Feldmann & Hamel (Gelidiellaceae) against Aβ 25-35 peptide in Swiss albino mice.

MATERIALS AND METHODS

The animals were administered through intracerebroventricular (ICV) injection with the Aβ 25-35 peptide (10 μg/10 μL/ICV site) on 21st day of the pretreatment of G. acerosa (whole plant) benzene extract (200 and 400 mg/kg bw). On day 30, animals were sacrificed and brain tissue homogenate was prepared. The activities of AChE, BuChE, b-secretase, MAO-B, and caspase-3 were determined, and Bax expression was assessed by Western blotting.

RESULTS

Gelidiella acerosa benzene extract restored the level of antioxidant enzymes and prevented lipid and protein oxidation significantly (p < 0.05). The extract protected the mice from cholinergic deficit significantly (p < 0.05) by inhibiting the activities of AChE and BuChE, which was about 0.116 ± 0.0088 U/mg of protein and 0.011 ± 0.0014 U/mg of protein respectively, which was otherwise increased in peptide-treated group (0.155 ± 0.007 U/mg of protein and 0.015 ± 0.0012 U/mg of protein respectively). Interestingly, G. acerosa benzene extract inhibited β-secretase and MAO-B activity. Reduction (p < 0.05) in level of caspase-3 activity and Bax expression suggests that G. acerosa protects the cells from apoptosis.

DISCUSSION AND CONCLUSION

The results suggest that G. acerosa possesses excellent neuroprotective potential against peptide mediated toxicity under in vivo conditions.

Organosulfur compound protects against memory decline induced by scopolamine through modulation of oxidative stress and Na+/K+ ATPase activity in mice

The present study investigated the possible effect of BMMS in protecting against memory impairment in an Alzheimer's disease model induced by scopolamine in mice. Another objective was to evaluate the involvement of oxidative stress and Na⁺/K⁺ ATPase activity in cerebral cortex and hippocampus of mice. Male Swiss mice were divided into four groups: groups I and III received canola oil (10 ml/kg, intragastrically (i.g.)), while groups II and IV received BMMS (10 mg/kg, i.g.). Thirty minutes after treatments, groups III and IV received scopolamine (1 mg/kg, intraperitoneal (i.p.)), while groups I and II received saline (5 ml/kg, i.p.). Behavioral tests were performed thirty minutes after scopolamine or saline injection. Cerebral cortex and hippocampus were removed to determine the thiobarbituric acid reactive species (TBARS) levels, non-protein thiols (NPSH) content, catalase (CAT) and Na⁺/K⁺ ATPase activities. The results showed that BMMS pretreatment protected against the reduction in alternation and latency time induced by scopolamine in the Y-maze test and step-down inhibitory avoidance, respectively. In the Barnes maze, the latency to find the escape box and the number of holes visited were attenuated by BMMS. Locomotor and exploratory activities were similar in all groups. BMMS pretreatment protected against the increase in the TBARS levels, NPSH content and CAT activity, as well as the inhibition on the Na⁺/K⁺ ATPase activity caused by scopolamine in the cerebral cortex. In the hippocampus, no significant difference was observed. In conclusion, the present study revealed that BMMS protected against the impairment of retrieval of short-term and long-term memories caused by scopolamine in mice. Moreover, antioxidant effect and protection on the Na⁺/K⁺ ATPase activity are involved in the effect of compound against memory impairment in AD model induced by scopolamine.

Relation between acetylcholinesterase and Na+, K+-ATPase activities with impaired memory of mice experimentally infected by Trypanosoma cruzi

Chagas disease is caused by the protozoan parasite Trypanosoma cruzi and causes severe cardiac and brain damage, leading to behavioral alterations in humans and animals. However, the mechanisms involved in memory impairment during T. cruzi infection remain unknown. It has long been recognized that the enzymatic activities of acetylcholinesterase (AChE) and Na⁺, K⁺-ATPase are linked with memory dysfunction during other trypanosomiasis. Thus, the aim of this study was to evaluate the involvement of cerebral AChE and Na⁺, K⁺-ATPase activities in the memory impairment during T. cruzi (Colombian strain) infection. A significant decrease on latency time during the inhibitory avoidance task was observed in animals infected by T. cruzi compared to uninfected animals, findings compatible to memory dysfunction. Moreover, the cerebral AChE activity increased, while the Na⁺, K⁺-ATPase decreased in T. cruzi infected compared to uninfected animals. Histopathology revealed mild to moderate multifocal gliosis in the cerebral cortex and light focal meningeal lymphoplasmacytic infiltrate, which may have contributed to memory loss. Based on these evidences, we can conclude that T. cruzi (Colombian strain) causes memory impairment in mice experimentally infected. Moreover, the changes in AChE and Na⁺, K⁺-ATPase activities may be considered a mechanism involved in disease pathogenesis.

Identification of peptides present in sour milk whey that ameliorate scopolamine-induced memory impairment in mice

Cognitive impairment is treated with cholinesterase inhibitors that slow cognitive decline but cause significant adverse effects. Functional foods that improve memory without such effects would therefore be valuable. We reported that unidentified components of sour milk whey produced by fermentations using Lactobacillus helveticus and Saccharomyces cerevisiae improved memory in a mouse model of scopolamine-induced memory impairment. Here, we show that casein-derived peptides were the most active components of orally administered fractions of this milk product. Of five peptides tested, β-casein (residues 73-91) was the most effective for ameliorating scopolamine-induced cognitive deficits, as indicated by a significantly higher percentage of alternations of mice orally administered 0.05 nmol/kg peptide (58.0 ± 9.3%) versus vehicle (51.0 ± 5.8%). This orally active peptide may improve cognitive function of patients with dementia.

Nerolidol-loaded nanospheres prevent behavioral impairment via ameliorating Na+, K+-ATPase and AChE activities as well as reducing oxidative stress in the brain of Trypanosoma evansi-infected mice

The aim of this study was to investigate the effect of nerolidol-loaded nanospheres (N-NS) on the treatment of memory impairment caused by Trypanosoma evansi in mice, as well as oxidative stress, and Na⁺, K⁺-ATPase and acetylcholinesterase (AChE) activities in brain tissue. Animals were submitted to behavioral tasks (inhibitory avoidance task and open-field test) 4 days postinfection (PI). Reactive oxygen species (ROS) and thiobarbituric acid-reactive substance (TBARS) levels and catalase (CAT), superoxide dismutase (SOD), Na⁺, K⁺-ATPase and AChE activities were measured on the fifth-day PI. T. evansi-infected mice showed memory deficit, increased ROS and TBARS levels and SOD and AChE activities, and decreased CAT and Na⁺, K⁺-ATPase activities compared to uninfected mice. N-NS prevented memory impairment and oxidative stress parameters (except SOD activity), while free nerolidol (N-F) restored only CAT activity. Also, N-NS treatment was able to prevent alterations in Na⁺, K⁺-ATPase and AChE activities caused by T. evansi infection. A significantly negative correlation was observed between memory and ROS production (p < 0.001; r = -0.941), as well as between memory and AChE activity (p < 0.05; r = -0.774). On the contrary, a significantly positive correlation between memory and Na⁺, K⁺-ATPase activity was observed (p < 0.01; r = 0.844). In conclusion, N-NS was able to reverse memory impairment and to prevent increased ROS and TBARS levels due to amelioration of Na⁺, K⁺-ATPase and AChE activities and to activation of the antioxidant enzymes, respectively. These results suggest that N-NS treatment may be a useful strategy to treat memory dysfunction and oxidative stress caused by T. evansi infection.

Memory deficit, toxic effects and activity of Na(+), K(+)-ATPase and NTPDase in brain of Wistar rats submitted to orally treatment with alpha-terpinene

The neurotoxic effects and activity of Na(+), K(+)-ATPase and NTPDase in Wistar rats after treatment with α-terpinene (daily oral administration of 0.5, 0.75 and 1.0mLkg(-1) for 10days) were examined. Results of the inhibitory avoidance task showed a memory deficit (p<0.05) in rats treated with all doses of α-terpinene. The evaluation of DNA damage in brain tissue revealed an increase (p<0.05) on frequency of damage and damage index in all concentrations. According to the cytotoxicity assay, doses of 0.5, 0.75 and 1.0mLkg(-1) increase the lactate dehydrogenase levels, and doses of 1.0mLkg(-1) also decrease (p<0.05) cell viability in brain cells. A decrease (p<0.05) on Na(+), K(+)-ATPase activity in brain tissue and on NTPDase activity in serum were observed in all concentrations of α-terpinene. These results suggest that the α-terpinene was cytotoxic and genotoxic to the brain cells by inducing loss of cell viability and DNA damage, as well as causing alterations in Na(+), K(+)-ATPase and NTPDase activity, what may contribute to the memory deficit of treated animals. Thus, α-terpinene cannot be consumed by the population at the doses studied.

Rhizophora mucronata attenuates beta-amyloid induced cognitive dysfunction, oxidative stress and cholinergic deficit in Alzheimer's disease animal model

Alzheimer's disease (AD) is a progressive neurodegenerative disorder, characterized by accumulation and deposition of Aβ peptide in human brain. The present study aimed to determine the protective effect of catechin rich extract of MERM (methanolic extract of Rhizophora mucronata) on Aβ (25-35) induced cognitive impairment and neuronal toxicity in mice. In the present study AD characteristics were induced by intracerberoventricular administration of aggregated Aβ (25-35) in the Swiss albino mice. Learning and memory deficits were assessed using behavioral assays such as Morris water maze, Y-maze and step down avoidance tasks. Oxidative stress mediated impairment were assessed by measuring the activities of enzymatic and non-enzymatic antioxidants, level of apoptotic protein and oxidative markers in the hippocampus and frontal cortex region. Histolopathological analysis of brain was also carried out. Results illustrated that oral treatment of MERM (200 and 400 mg/kg bw) significantly attenuated Aβ (25-35) induced memory impairment as evaluated by behavioral tests. In addition treatment with MERM attenuated the elevation of β-secretase activity accompanying the reduced level of Aβ (25-35) in the cortex and hippocampus of brain. MERM also enhanced the cognitive function by significantly inhibiting AChE, BuChE and MAO-B. Furthermore, MERM attenuated lipid peroxidation, protein oxidation, restored the antioxidant status and inhibited neuronal apoptosis by down-regulating the level of caspase 3 and Bax protein. These data suggest that MERM rich in catechin can act as promising drug for AD treatment because of its antioxidant, anti-apoptotic and reducing Aβ oligomer activities.

Meloxicam-loaded nanocapsules as an alternative to improve memory decline in an Alzheimer's disease model in mice: involvement of Na(+), K(+)-ATPase

The objective of this study was to investigate the effect of meloxicam-loaded nanocapsules (M-NC) on the treatment of the memory impairment induced by amyloid β-peptide (aβ) in mice. The involvement of Na(+), K(+)-ATPase and cyclooxygenase-2 (COX-2) activities in the hippocampus and cerebral cortex was also evaluated. Mice received aβ (3 nmol/ 3 μl/ per site, intracerebroventricular) or vehicle (3 μl/ per site, i.c.v.). The next day, the animals were treated with blank nanocapsules (17 mL/kg) or M-NC (5 mg/kg) or free meloxicam (M-F) (5 mg/kg). Treatments were performed every other day, until the twelfth day. Animals were submitted to the behavioral tasks (open-field, object recognition, Y-maze and step-down inhibitory avoidance tasks) from the twelfth day. Na(+), K(+)-ATPase and COX-2 activities were performed in hippocampus and cerebral cortex. aβ caused a memory deficit, an inhibition of the hippocampal Na(+), K(+)-ATPase activity and an increase in the hippocampal COX-2 activity. M-NC were effective against all behavioral and biochemical alterations, while M-F restored only the COX-2 activity. In conclusion, M-NC were able to reverse the memory impairment induced by aβ, and Na(+), K(+)-ATPase is involved in the effect of M-NC.

Synergistic effects of resveratrol (free and inclusion complex) and sulfamethoxazole-trimetropim treatment on pathology, oxidant/antioxidant status and behavior of mice infected with Toxoplasma gondii

This study aimed to investigate the synergistic effects of resveratrol and sulfamethoxazole-trimethoprim (ST) on the treatment of mice experimentally infected by Toxoplasma gondii during the chronic phase of the disease considering infection, behavior, and oxidative/antioxidants profile aspects. For the study, 60 mice were initially divided into two groups: uninfected (n = 24) and infected by T. gondii (n = 36). These two groups were later subdivided into other groups and treated with resveratrol (free and inclusion complex containing resveratrol) alone and co-administered with ST: groups A to D were composed by healthy mice and groups E to J were consisted of animals infected by T. gondii (VEG strain). Treatments began 20 days post-infection for 10 consecutive days with oral doses of 0.5 mg kg(-1) of ST (groups B and F), 100 mg kg(-1) of free resveratrol (groups C and G) and inclusion complex of resveratrol (nanoparticles containing resveratrol) (groups D and H), and lastly an co-administration of both drugs (groups I and J). Behavioral tests (memory, anxiety and locomotion) were performed after treatment. Liver and brain fragments were collected to evaluate pathological changes, brain cysts counts, as well as oxidant and antioxidant levels. A reduction on the number of cysts in the brain of animals treated with both drugs combined was observed; there was also reduced number of lesions on both organs. This drug combined effect was also able to reduce oxidative and increase antioxidant levels in infected mice, which might be interpreted as a resveratrol protective effect. In addition, the combination of ST and resveratrol was able to prevent behavioral changes in infected mice. Therefore, the use of co-administration drugs enhances the therapeutic effect acting on a synergic way, reducing the oxidizing effects of the chemical treatment for toxoplasmosis. In addition, resveratrol in inclusion complex when co-administered with ST showed an improved therapeutic effect of ST reducing oxidative damage, liver damage and the number of cysts in the brain of T. gondii infected mice.

Dairy Products and Health: Recent Insights

Milk, cheese, yogurt, and other dairy products have long been known to provide good nutrition. Major healthful contributors to the diets of many people include the protein, minerals, vitamins, and fatty acids present in milk. Recent studies have shown that consumption of dairy products appears to be beneficial in muscle building, lowering blood pressure and low-density lipoprotein cholesterol, and preventing tooth decay, diabetes, cancer, and obesity. Additional benefits might be provided by organic milk and by probiotic microorganisms using milk products as a vehicle. New research on dairy products and nutrition will improve our understanding of the connections between these products, the bioactive compounds in them, and their effects on the human body.

Bioactive peptides released by in vitro digestion of standard and hydrolyzed infant formulas

Hydrolyzed infant formulas serve as appropriate nutritional sources for infants afflicted with cow's milk allergy, and milk proteins in hydrolyzed formulas are industrially hydrolyzed extensively or partially. To investigate whether industrial hydrolysis may modulate the digestive trajectory of milk proteins, thereby releasing different profiles of bioactive peptides compared with standard formulas, both standard and hydrolyzed formulas were subjected to in vitro digestion and formation of bioactive peptides were compared. One standard, one extensively hydrolyzed, and one partially hydrolyzed infant formula were digested in vitro with pepsin and pancreatin, taking into account the higher gastric pH of infants, and the digesta were subjected to peptidomic analysis. The standard formula released a larger variety of bioactive peptides than from the hydrolyzed formulas, indicating that industrial hydrolysis of milk proteins may generally attenuate their indigenous bioactivities such as antibacterial, immuno-regulatory, and anti-oxidative activities. Conversely, industrial hydrolysis may facilitate the formation of bioactive peptides from hydrophobic proteins/regions such as β-LG and the "strategic zone" of β-CN, which encrypt bioactive peptides including a dipeptidyl dipeptidase-4-inhibitory, hypocholesterolemic, and opioid peptides. Infants fed hydrolyzed infant formulas may be influenced by milk protein-derived bioactive peptides in a manner different from those fed standard formula.

Selenofuranoside Ameliorates Memory Loss in Alzheimer-Like Sporadic Dementia: AChE Activity, Oxidative Stress, and Inflammation Involvement

Alzheimer's disease (AD) is becoming more common due to the increase in life expectancy. This study evaluated the effect of selenofuranoside (Se) in an Alzheimer-like sporadic dementia animal model. Male mice were divided into 4 groups: control, Aβ, Se, and Aβ + Se. Single administration of Aβ peptide (fragments 25-35; 3 nmol/3 μL) or distilled water was administered via intracerebroventricular (i.c.v.) injection. Selenofuranoside (5 mg/kg) or vehicle (canola oil) was administered orally 30 min before Aβ and for 7 subsequent days. Memory was tested through the Morris water maze (MWM) and step-down passive-avoidance (SDPA) tests. Antioxidant defenses along with reactive species (RS) were assessed. Inflammatory cytokines levels and AChE activity were measured. SOD activity was inhibited in the Aβ group whereas RS were increased. AChE activity, GSH, and IL-6 levels were increased in the Aβ group. These changes were reflected in impaired cognition and memory loss, observed in both behavioral tests. Se compound was able to protect against memory loss in mice in both behavioral tests. SOD and AChE activities as well as RS and IL-6 levels were also protected by Se administration. Therefore, Se is promising for further studies.

Behavioral effects of food-derived opioid-like peptides in rodents: Implications for schizophrenia?

Dohan proposed that an overload of dietary peptides, such as those derived from wheat gluten and milk casein, could be a factor relevant to the development or maintenance of schizophrenia (SZ) symptoms in at least a subset of vulnerable individuals. Rodent behavioral models may offer insight into the plausibility of Dohan's exorphin hypothesis by providing a means to directly study the effects of such peptides. Accordingly, a review of the literature on the behavioral effects of food-derived opioid-like peptides in rodents was undertaken. Studies using a variety of behavioral tests to examine the effects of several classes of food-derived opioid-like peptides were identified and reviewed. Peptides derived from casein (β-casomorphins; BCMs, n=19), spinach (rubiscolins; RCs, n=4), and soy (soymorphins; SMs, n=1) were behaviorally active in various paradigms assessing nociception, spontaneous behavior, and memory. Surprisingly, only a single study evaluating a gluten-derived peptide (gliadorphin-7; GD-7, n=1) was identified and included in this review. In conclusion, food-derived peptides can affect rodent behavior, but more studies of GDs using diverse behavioral batteries are warranted. Assuming they occur in sufficient quantities during protein digestion and can access central opioid receptors (which entails crossing both the gastrointestinal and blood-brain barriers intact), these peptides may affect human behavior. Although BCMs and GDs may not be directly pathogenic in SZ, documented associations of casein and gluten sensitivity with SZ justify increased patient screening and dietary intervention where necessary.

Neuroprotective effects of sulforaphane on cholinergic neurons in mice with Alzheimer's disease-like lesions

Alzheimer’s disease (AD) is a common neurodegenerative disease in elderly individuals, and effective therapies are unavailable. This study was designed to investigate the neuroprotective effects of sulforaphane (an activator of NF-E2-related factor 2) on mice with AD-like lesions induced by combined administration of aluminum and d-galactose. Step-down-type passive avoidance tests showed sulforaphane ameliorated cognitive impairment in AD-like mice. Immunohistochemistry results indicated sulforaphane attenuated cholinergic neuron loss in the medial septal and hippocampal CA1 regions in AD-like mice. However, spectrophotometry revealed no significant difference in acetylcholine level or the activity of choline acetyltransferase or acetylcholinesterase in the cerebral cortex among groups of control and AD-like mice with and without sulforaphane treatment. Sulforaphane significantly increased the numbers of 5-bromo-2'-deoxyuridine-positive neurons in the subventricular and subgranular zones in AD-like mice which were significantly augmented compared with controls. Atomic absorption spectrometry revealed significantly lower aluminum levels in the brains of sulforaphane-treated AD-like mice than in those that did not receive sulforaphane treatment. In conclusion, sulforaphane ameliorates neurobehavioral deficits by reducing cholinergic neuron loss in the brains of AD-like mice, and the mechanism may be associated with neurogenesis and aluminum load reduction. These findings suggest that phytochemical sulforaphane has potential application in AD therapeutics.

Curcumin ameliorates memory deficits via neuronal nitric oxide synthase in aged mice

A number of neuroprotective effects of curcumin have been demonstrated in recent years. However, whether curcumin exerts any beneficial effects on age-related impaired cognition and memory has not been well characterized; nor was there any detailed data on the molecular pathways activated by curcumin. The present study attempts to investigate the effects of curcumin on memory decline of aged mice with a focus upon the possible contribution of the neuronal nitric oxide synthase (nNOS)/nitric oxide (NO) pathway in the memory amelioration effect of curcumin. The results showed that chronic administration of curcumin (50mg/kg, i.p., 21 days) significantly ameliorated the memory acquisition ability of aged male mice in the novel object recognition and passive avoidance tasks. Immunoblotting revealed that chronic treatment of curcumin increased nNOS expression in the prefrontal cortex, amygdala and hippocampus, as well as the enhancement of nNOS activity and NO concentration. This enhancement was suppressed by pre-treatment with 7-nitroindazole (7-NI), a specific inhibitor of neuronal nitric oxide synthase (nNOS). Furthermore, inhibition of nNOS synthase by 7-NI also prevented the memory improvement effects of curcumin in aged mice. Taken together, the results of the present study suggest that the amelioration of memory deficits by curcumin in aged mice was mediated, at least in part, by activating the nNOS activity in specific brain regions. These findings reveal the therapeutic potential of curcumin as a preventive agent upon the deterioration of cognitive faculties.

Curcumin ameliorates ethanol-induced memory deficits and enhanced brain nitric oxide synthase activity in mice

Ethanol consumption has well-known deleterious effects on memory. However, the mechanism by which ethanol exerts its effects on memory has received little attention, which has retarded the identification and development of effective therapeutic strategies against ethanol toxicity. The aim of this study was to explore the neuronal mechanisms underlying the protective action of curcumin, a natural polyphenolic compound of Curcuma longa, against ethanol-induced memory deficits. Adult mice were pretreated with curcumin (40 mg/kg, i.p.) before administration of ethanol (1 g/kg, i.p.) for the memory acquisition measurement, or were sacrificed 30 min later for evaluation of regional brain differences in the nitric oxide synthase (NOS) activity and nitric oxide (NO) concentration. The results showed that pretreatment with curcumin significantly ameliorated the memory deficits resulting from acute ethanol administration to mice in the novel object recognition and inhibitory avoidance tasks. Furthermore, acute ethanol treatment increased the NOS activity and NO production in brain regions associated with memory including prefrontal cortex (PFC), amygdala and hippocampus, while this enhancement was suppressed by pretreatment with curcumin. Taken together, these results suggest that the protective effects of curcumin on acute ethanol-induced memory deficits are mediated, at least in part, by suppressing NOS activity in the brain of mice. Thus, manipulation of the NOS/NO signaling pathway might be beneficial for the prevention of ethanol toxicity.

Acute treatment with bis selenide, an organic compound containing the trace element selenium, prevents memory deficits induced by reserpine in rats

Taking into account the promising pharmacological actions of (Z)-2,3-bis(4-chlorophenylselanyl) prop-2-en-1-ol) (bis selenide), an organic compound containing the trace element selenium, and the constant search for drugs that improve the cognitive performance, the objective of the present study was to investigate whether bis selenide treatment ameliorates memory deficits induced by reserpine in rats. For this aim, male adult rats received a single subcutaneous injection of reserpine (1 mg/kg), a biogenic amine-depleting agent used to induce memory deficit. After 24 h, bis selenide at doses of 25 and 50 mg/kg was administered to rats by intragastric route, and 1 h later, the animals were submitted to behavior tasks. The effects of acute administration of bis selenide on memory were evaluated by social recognition, step-down passive avoidance, and object recognition paradigms. Exploratory and locomotor activities of rats were determined using the open-field test. Analysis of data revealed that the social memory disruption caused by reserpine was reversed by bis selenide at both doses. In addition, bis selenide, at the highest dose, prevented the memory deficit resulting from reserpine administration to rats in step-down passive avoidance and object recognition tasks. No significant alterations in locomotor and exploratory behaviors were found in animals treated with reserpine and/or bis selenide. Results obtained from distinct memory behavioral paradigms revealed that an acute treatment with bis selenide attenuated memory deficits induced by reserpine in rats.

β-Casomorphin-7 attenuates the development of nephropathy in type I diabetes via inhibition of epithelial-mesenchymal transition of renal tubular epithelial cells

This study was designed to investigate the putative protective effect of β-casomorphin-7 on diabetic nephropathy in a rat model, and to explore the possible mechanism of this effect. SD rats were randomly divided into the following three groups: control group, diabetes group and β-casomorphin-7-treatment group. All rats were euthanized after 30 days with or without β-casomorphin-7 treatment. Biochemical parameters including blood glucose and renal function were quantified. The concentration of plasma TGF-β1 was measured by ELISA. Histopathological changes to the kidney were studied by Masson and Sirius red staining. Expressions of α-smooth muscle actin (α-SMA), E-cadherin, vimentin, cytokeratin19 and TGF-β1 mRNA in rat renal cortices were analyzed by real-time PCR. Changes in α-SMA and E-cadherin protein expression in rat renal cortices were quantified by Western blot. β-Casomorphin-7 treatment of diabetic rats reduced urinary glucose, urinary protein, serum creatinine, blood urinary nitrogen, plasma TGF-β1 and the ratio of kidney: body weight. Masson and Sirius red staining showed that β-casomorphin-7 treatment attenuated renal interstitial fibrosis in diabetic rats. Compared to the control rats, diabetic rats had elevated expressions of α-SMA, vimentin and TGF-β1 mRNA and α -SMA protein and decreased expression of E-cadherin and cytokeratin19 mRNA, and E-cadherin protein. β-Casomorphin-7 treatment of diabetic rats partially normalized these changes. Our results suggest that administration of β-casomorphin-7 attenuates renal interstitial fibrosis caused by diabetes. This protective effect may be associated, in part, with down regulation of epithelial-mesenchymal transition of renal tubular epithelial cells.