Protective effects of kinetin against aluminum chloride and D-galactose induced cognitive impairment and oxidative damage in mouse

Aluminum chloride and D-galactose induced a zebrafish model of Alzheimer's disease with cognitive deficits and aging

Alzheimer's disease (AD) is an age-related neurodegenerative disorder. Transgenic and pharmacological AD models are extensively studied to understand AD mechanisms and drug discovery. However, they are time-consuming and relatively costly, which hinders the discovery of potential anti-AD therapeutics. Here, we established a new model of AD in larval zebrafish by co-treatment with aluminum chloride (AlCl3) and D-galactose (D-gal) for 72 h. In particular, exposure to 150 μM AlCl3 + 40 mg/mL D-gal, 200 μM AlCl3 + 30 mg/mL D-gal, or 200 μM AlCl3 + 40 mg/mL D-gal successfully induced AD-like symptoms and aging features. Co-treatment with AlCl3 and D-gal caused significant learning and memory deficits, as well as impaired response ability and locomotor capacity in the plus-maze and light/dark test. Moreover, increased acetylcholinesterase and β-galactosidase activities, β-amyloid 1-42 deposition, reduced telomerase activity, elevated interleukin 1 beta mRNA expression, and enhanced reactive oxygen species production were also observed. In conclusion, our zebrafish model is simple, rapid, effective and affordable, incorporating key features of AD and aging, thus may become a unique and powerful tool for high-throughput screening of anti-AD compounds in vivo.

Barbaloin's Chemical Intervention in Aluminum Chloride Induced Cognitive Deficits and Changes in Rats through Modulation of Oxidative Stress, Cytokines, and BDNF Expression

Alzheimer's disease (AD) is a long-term neurodegenerative condition characterized by impaired cognitive functions, particularly in the domains of learning and memory. Finding promising options for AD can be successful with a medication repurposing strategy. The goal of the research was to examine the neuroprotective characteristics of barbaloin in aluminum chloride (AlCl3)-induced cognitive deficits and changes in rats through modulation of oxidative stress, cytokines, and brain-derived neurotrophic factor (BDNF) expression. Thirty male Wistar rats were subjected to AlCl3 at a dosage of 100 mg/kg via the per oral route (p.o.), which induced cognitive decline. Morris water maze (MWM) is used to assess behavioral metrics. Assays for catalase (CAT), malondialdehyde (MDA), reduced glutathione (GSH), acetylcholinesterase (AChE), choline-acetyltransferase (ChAT), interleukins-1β (IL-1β), superoxide dismutase (SOD), tumor necrosis factor-α (TNF-α), nuclear factor kappa-B (NF-κB), interleukins-6 (IL-6), BDNF, and neurotransmitter levels [dopamine (DA), acetylcholine (Ach), and γ-aminobutyric acid (GABA)] were performed. Results: The transfer latency time was notably decreased, and substantial modifications in the concentrations of GSH, MDA, CAT, SOD, AChE, ChAT and observed modulations in the formation of interleukins-6 (IL-6), TNF-α, IL-1β, BDNF, and NF-κB were also evidenced after the treatment of rats with barbaloin in comparison to AlCl3-induced control groups. Significant alterations in neurotransmitter levels (DA, Ach, and GABA) were also seen in barbaloin-treated groups in comparison to AlCl3-induced groups. The current investigation has provided evidence that the administration of barbaloin yielded notable enhancements in cognitive function in rats through the inhibition of MDA, enhancing endogenous antioxidant enzymes, reduction of cytokine levels, and enhancement of neurotransmitter contents in the brain. These effects were observed in comparison to a control group treated with AlCl3 and can be attributable to barbaloin's strong anti-inflammatory and antioxidant properties, and metal chelating properties may contribute to its neuroprotective effects. Barbaloin may also promote neuronal survival and enhance learning and memory by upregulating the expression of BDNF.

Vitamin K2 protects against aluminium chloride-mediated neurodegeneration

Recent studies have shown that, coupled with other environmental factors, aluminium exposure may lead to neurodegeneration resulting in cognitive impairment resembling Alzheimer's disease. Menaquinone, a form of vitamin K2, aids in maintaining healthy bones and avoids coronary calcification. It also has anti-inflammatory and antioxidant properties. Here, we study the neuroprotective effects of vitamin K2 (MK-7) using the animal model of Alzheimer's disease (AD). Aluminium chloride (AlCl3; 100 mg/kg for 3 weeks orally) was administered to Swiss albino mice to induce neurodegeneration and Vitamin K2 (100 g/kg for 3 weeks orally) was applied as treatment. This was followed by behavioural studies to determine memory changes. The behavioural observations correlated with proinflammatory, oxidative, and brain histopathological changes in AlCl3-treated animals with or without vitamin K2 treatment. AlCl3 administration led to memory decline which was partially restored in Vitamin K2 treated animals. Myeloperoxidase levels in the brain increased due to AlCl3-mediated inflammation, which Vitamin K2 prevented. The acetylcholine esterase and oxidative stress markers induced by AlCl3 were reversed by Vitamin K2. Also, Vitamin K2 helps to restore hippocampal BDNF levels and reduced the amyloid β accumulation in AlCl3-administered animals. Additionally, Vitamin K2 protected the hippocampal neurons against AlCl3-mediated damage as observed in histopathological studies. We conclude that Vitamin K2 could partially reverse AlCl3-mediated cognitive decline. It increases acetylcholine and BDNF levels while reducing oxidative stress, neuroinflammation, and β-amyloid deposition, thus protecting the hippocampal neurons from AlCl3-mediated damage.

Neuromodulatory effect of vardenafil on aluminium chloride/D-galactose induced Alzheimer's disease in rats: emphasis on amyloid-beta, p-tau, PI3K/Akt/p53 pathway, endoplasmic reticulum stress, and cellular senescence

Dysregulation of protein homeostasis, proteostasis, is a distinctive hallmark of many neurodegenerative disorders and aging. Deleteriously, the accumulation of aberrant proteins in Alzheimer's disease (AD) is accompanied with a marked collapse in proteostasis network. The current study explored the potential therapeutic effect of vardenafil (VAR), a phosphodiesterase-5 inhibitor, in AlCl3/D-galactose (D-gal)-induced AD in rats and its possible underlying mechanisms. The impact of VAR treatment on neurobehavioral function, hippocampal tissue architecture, and the activity of the cholinergic system main enzymes were assessed utilizing VAR at doses of 0.3 mg/kg and 1 mg/kg. Additionally, the expression level of amyloid-beta and phosphorylated tau proteins in the hippocampus were figured out. Accordingly, VAR higher dose was selected to contemplate the possible underlying mechanisms. Intriguingly, VAR elevated the cyclic guanosine monophosphate level in the hippocampus and averted the repressed proteasome activity by AlCl3/D-gal; hence, VAR might alleviate the burden of toxic protein aggregates in AD. In addition, a substantial reduction in the activating transcription factor 6-mediated endoplasmic reticulum stress was demonstrated with VAR treatment. Notably, VAR counteracted the AlCl3/D-gal-induced depletion of nuclear factor erythroid 2-related factor 2 level. Moreover, the anti-senescence activity of VAR was demonstrated via its ability to restore the balance of the redox circuit. The modulation of phosphatidylinositol-3-kinase/protein kinase B/p53 pathway and the reduction of nuclear factor kappa B level, the key regulator of senescence-associated secretory phenotype mediators release, with VAR treatment were also elucidated. Altogether, these findings insinuate the possible therapeutic benefits of VAR in AD management.

Benzene, 1,2,4-trimethoxy-5-(2-methyl-1-propen-1-yl) Attenuates D-galactose /AlCl3-induced Cognitive Impairment by Inhibiting Inflammation, Apoptosis, and Improving ExpressionofMemory-Related Proteins

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by decreased learning ability and memory deficits. Our previous findings suggested that benzene, 1,2,4-trimethoxy-5-(2-methyl-1-propen-1-yl) (BTY) can ameliorate the dysfunction of GABAergic inhibitory neurons associated with neurological diseases. On this basis, we investigated the neuroprotective effect of BTY on AD and explored the underlying mechanism. This study included in vitro and in vivo experiments. BTY could maintain cell morphology, improve cell survival rate, reduce cell damage, and inhibit cell apoptosis in vitro experiments. Further, BTY has good pharmacological activity in vivo experiments, of which behavioral experiments showed that BTY could improve AD-like mice's learning and memory abilities. Besides, histopathological experiments indicated that BTY could maintain the morphology and function of neurons, reduce amyloid β-protein 42 (Aβ₄₂) and phosphorylated tau (p-tau) accumulation, and decrease the levels of inflammatory cytokines. Finally, western blot experiments showed that BTY could inhibit the expression of apoptosis-related proteins and promote the expression of memory-related proteins. In conclusion, this study indicated that BTY may be a promising drug candidate for AD.

Integrated Lipidomics and Network Pharmacology Reveal Mechanism of Memory Impairment Improvement by Yuanzhi San

Memory impairment (MI) is caused by a variety of causes, endangering human health. Yuanzhi San (YZS) is a common prescription used for the treatment of MI, but its mechanism of action needs further exploration. The purpose of this study was to investigate this mechanism through lipidomics and network pharmacology. Sprague Dawley (SD) rats were divided randomly into the normal, model, and YZS groups. The rats were gavaged with aluminum chloride (200 mg/kg) and intraperitoneally injected with D-galactose (400 mg/kg) every day for 60 days, except for the normal group. From the 30th day, YZS (13.34 g/kg) was gavaged once a day to the rats in the YZS group. Post-YZS treatment, ultra-high-performance liquid chromatography-mass spectrometry (UHPLC/MS) analysis was implemented to conduct a lipidomics study in the hippocampus of rats with memory impairment induced by aluminum chloride and D-galactose. Eight differential metabolites were identified between the normal group and the model group, whereas between the model group and the YZS group, 20 differential metabolites were established. Metabolic pathway analysis was performed on the aforementioned lipid metabolites, all of which were involved in sphingolipid and glycerophospholipid metabolism. Furthermore, serum pharmacochemistry analysis of YZS was carried out at the early stage of our research, which discovered 62 YZS prototype components. The results of the network pharmacology analysis showed that they were related to 1030 genes, and 451 disease genes were related to MI. There were 73 intersections between the YZS and MI targets. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that these targets were closely related to the sphingolipid metabolic, calcium signaling, and other pathways. The integrated approach of lipidomics and network pharmacology was then focused on four major targets, including PHK2, GBA, SPTLC1, and AChE, as well as their essential metabolites (glucosylceramide, N-acylsphingosine, phosphatidylserine, phosphatidylcholine, and phosphatidylcholine) and pathways (sphingolipid, glycerophospholipid, and arachidonic acid metabolism). The significant affinity of the primary target for YZS was confirmed by molecular docking. The obtained results revealed that the combination of lipidomics and network pharmacology could be used to determine the effect of YZS on the MI biological network and metabolic state, and evaluate the drug efficacy of YZS and its related mechanisms of action.

Adenosine protects D-galactose induced alterations in rat model of aging via attenuating neurochemical profile and redox status

Aging is the process that every organism faces. The aging model of brain has been developed by the use of d-galactose (d-Gal). Adenosine (Ad) being a neuroprotective agent that has been utilized in treatment of various neurological disorders. The aim of current study is to evaluate the outcome of Ad on d-Gal induced neurotoxicity which caused behavioral deficits, memory impairment and oxidative stress. Rats were treated with d-Gal at a dose of 300 mg/ml/kg and Ad 1 mg/ml/kg; intraperitoneally for 28 days. Behavioral assessment was performed after the treatment period. Animals were sacrificed after behavioral tests and their brains were collected, hippocampus were removed for biochemical and neurochemical analysis. The results showed that administration of Ad ameliorates the negative effects of d-Gal induced aging in various behavioral tests and increased the time spent in the open arm and light box in elevated plus maze (EPM) and light dark activity (LDA) tests respectively indicate anxiolytic effect; increased the mobility time in tail suspension test (TST) shows antidepressant effect; decreased escape latencies in Morris water maze (MWM) acquisition trials, increase entries and time spent in the target quadrant suggests improvement in learning ability of animals. Administration of Ad also decreased malondialdehyde (MDA) levels, increased antioxidant enzymes activity; decreased acetylcholinesterase (AChE) activity, increased 5-hydroxytryptamine (5-HT, serotonin) metabolism and normalized histopathological alteration in the hippocampus. It is concluded that anxiety, depression and memory impairment induced by d-Gal were protected by Ad through its antioxidant and neuro-modulatory effects.

Rhizoma Gastrodiae Water Extract Modulates the Gut Microbiota and Pathological Changes of P-TauThr231 to Protect Against Cognitive Impairment in Mice

Gastrodiae Rhizoma and its active constituents are known to exhibit neuroprotective effects in Alzheimer’s disease (AD). However, the effect of Rhizoma Gastrodiae water extract (WERG) on AD and the detailed mechanism of action remain unclear. In this study, the mechanism of action of WERG was investigated by the microbiome–gut–brain axis using a D-galactose (D-gal)/AlCl₃-induced AD mouse model. WERG improved the cognitive impairment of D-gal/AlCl₃-induced mice. The expression level of p-Tau^thr231 in the WERG-H treatment group was decreased, and p-Tau^thr231 was found negative in hippocampal DG, CA1, and CA3 regions. Here, the diversity and composition of the gut microbiota were analyzed by 16sRNA sequencing. WERG-H treatment had a positive correlation with Firmicutes, Bacilli, Lactobacillus johnsonii, Lactobacillus murinus, and Lactobacillus reuteri. Interestingly, the Rikenellaceae-RC9 gut group in the gut increased in D-gal/AlCl₃-induced mice, but the increased L. johnsonii, L. murinus, and L. reuteri reversed this process. This may be a potential mechanistic link between gut microbiota dysbiosis and P-Tau^Thr231 levels in AD progression. In conclusion, this study demonstrated that WERG improved the cognitive impairment of the AD mouse model by enriching gut probiotics and reducing P-Tau^Thr231 levels.

Kinetin Ameliorates Cisplatin-Induced Hepatotoxicity and Lymphotoxicity via Attenuating Oxidative Damage, Cell Apoptosis and Inflammation in Rats

Though several previous studies reported the in vitro and in vivo antioxidant effect of kinetin (Kn), details on its action in cisplatin-induced toxicity are still scarce. In this study we evaluated, for the first time, the effects of kinetin in cisplatin (cp)- induced liver and lymphocyte toxicity in rats. Wistar male albino rats were divided into nine groups: (i) the control (C), (ii) groups 2,3 and 4, which received 0.25, 0.5 and 1 mg/kg kinetin for 10 days; (iii) the cisplatin (cp) group, which received a single intraperitoneal injection of CP (7.0 mg/kg); and (iv) groups 6, 7, 8 and 9, which received, for 10 days, 0.25, 0.5 and 1 mg/kg kinetin or 200 mg/kg vitamin C, respectively, and Cp on the fourth day. CP-injected rats showed a significant impairment in biochemical, oxidative stress and inflammatory parameters in hepatic tissue and lymphocytes. PCR showed a profound increase in caspase-3, and a significant decline in AKT gene expression. Intriguingly, Kn treatment restored the biochemical, redox status and inflammatory parameters. Hepatic AKT and caspase-3 expression as well as CD95 levels in lymphocytes were also restored. In conclusion, Kn mitigated oxidative imbalance, inflammation and apoptosis in CP-induced liver and lymphocyte toxicity; therefore, it can be considered as a promising therapy.

Pharmacological evaluation of bromelain in mouse model of Alzheimer's disease

The current study elucidates pharmacological evaluation of bromelain as a bioactive compound obtain from pineapple stem belongs to family Bromeliaceae in AlCl3 and D - galactose induced mice. In mice, co-administration of AlCl3 at dose 5 mg/kg b.w., via the oral route, and D - galactose at dose 60 mg/kg b.w., via intraperitoneal route for 90 days resulted in cognitive impairment, spatial learning, and memory deficits, as well as neurotoxicity. However, 30 consecutive days, treatments via an intraperitoneal route with bromelain low dose (Brm L) at dose 10 mg/kg b.w., bromelain high dose (Brm H) at dose 20 mg/kg b.w., donepezil (Dnpz) at dose 2 mg/kg b.w., and Brm L + Dnpz at doses 10, 2 mg/kg b.w. were considerably reversed the effect of AlCl3 and D - galactose induced AD mice. Consequences of behavioral parameters (Morris water maze, elevated plus maze and locomotor), biochemical estimation (MDA, GSH, SOD, CAT, Nitrite and AChE), and ELISA tests (mouse BACE, Aβ1 - 42, TNF-α, IL-6, and BDNF) confirmed significant (p < 0.05) neuroprotective effect of treatments in AlCl3 and D - galactose induced mice. Additionally, hematoxylin and eosin staining of the cerebral cortex and the hippocampus exposed eosinophilic lesions and hyperchromatic nuclei in AD mice, but these neurodegenerative effects were eliminated by Brm L, Brm H, Dnpz, and Brm L + Dnpz treatments. Thus, bromelain alone and in combination with donepezil prevent AlCl3 and D - galactose induced spatial learning and memory deficits, as well as cognitive impairment, by increasing cholinergic activity and synaptic plasticity, as well as reducing oxidative damage, neuroinflammation, Aβ 1-42 aggregations, and histopathological damage, according to our findings. The present study consequences indicate that bromelain alone and in combination with donepezil appears to have neuroprotective properties. Henceforward, this may be a promising treatment option for Alzheimer's disease.

Cytokinins: Wide-Spread Signaling Hormones from Plants to Humans with High Medical Potential

Nature is a rich source of biologically active novel compounds. Sixty years ago, the plant hormones cytokinins were first discovered. These play a major role in cell division and cell differentiation. They affect organogenesis in plant tissue cultures and contribute to many other physiological and developmental processes in plants. Consequently, the effect of cytokinins on mammalian cells has caught the attention of researchers. Many reports on the contribution and potential of cytokinins in the therapy of different human diseases and pathophysiological conditions have been published and are reviewed here. We compare cytokinin effects and pathways in plants and mammalian systems and highlight the most important biological activities. We present the strong profile of the biological actions of cytokinins and their possible therapeutic applications.

Captopril is more effective than Perindopril against aluminium chloride induced amyloidogenesis and AD like pathology

Alzheimer's disease (AD) is a common neurodegenerative disorder. Aluminium chloride induces AD like pathology in rats. Renin angiotensin system plays a significant role in the pathogenesis and occurrence of Alzheimer's disease. In the present study we evaluated and compared the effect of Captopril and Perindopril against aluminium chloride induced amyloidogenesis and cognitive dysfunction in rats. Wistar rats of both sex were divided randomly into four groups i.e. Group I was served as normal control and treated with normal saline, Group II was administered with AlCl3 (100 mg/kg, p. o.) and Group III and IV received Captopril (30 mg/kg, p. o.) and Perindopril (5 mg/kg, p. o.) respectively 1hr prior to administration of AlCl3. All the doses were given once daily for 42 days. The evaluation of memory function was carried out in Y-maze (spontaneous alternation), radial arm maze (number of correct responses) and elevated plus maze (transfer latency). After behavioral studies, estimation of antioxidant status (brain and serum), amyloid-β content (brain) and histopathology of brain hippocampus region was done. Administration of AlCl3 for 42 days impaired cognitive dysfunction. Captopril and Perindopril prevented AlCl3 induced cognitive dysfunction by improving spontaneous alternation behavior, number of correct responses and reducing transfer latency. They also increase the antioxidant status, reduce the Aβ42 content in the brain and reverse the histopathological changes caused by AlCl3 in hippocampal region. Both Captopril and Perindopril protects against aluminium chloride induced amyloidogenesis and AD like pathology. Captopril is found to be more effective than Perindopril.

Protective effects of hydroxy-α-sanshool from the pericarp of Zanthoxylum bungeanum Maxim. On D-galactose/AlCl3-induced Alzheimer's disease-like mice via Nrf2/HO-1 signaling pathways

Hydroxy-α-sanshool (HAS) is an unsaturated fatty acid amide from Zanthoxylum bungeanum Maxim. with hypolipidemic, hypoglycemic, anti-inflammatory, and neurotrophic effects, etc. In this study, results indicated that HAS effectively ameliorated spontaneous locomotion deficit of mice induced by D-galactose (D-gal) and AlCl₃ treatment in open field test. Results of Morris water maze test (MWM) showed that HAS significantly improved the spatial learning and memory ability of aging mice. Histopathological evaluations revealed that HAS markedly alleviated morphological changes and increased number of Nissl neurons in hippocampus of D-gal/AlCl₃-induced Alzheimer's disease (AD)-like mice. HAS markedly reduced malondialdehyde (MDA) production, and increased the activity of antioxidative enzymes including superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT), showing an inhibitory effect on oxidative stress. Furthermore, HAS treatment obviously reversed the inhibitory expressions of mRNA and protein of HO-1 and Nrf2 in the hippocampus of AD mice, suggesting that neuroprotective effects of HAS against oxidative stress might be mediated by the Nrf2/HO-1 pathway. Meanwhile, HAS significantly inhibited neuronal apoptosis by decreasing mRNA and protein expressions of Cyt-c, Bax and Caspase 3, and increasing Bcl-2 expression in the hippocampus of AD mice. These results suggest that HAS have the potential to be developed as antioxidant drug for the prevention and early therapy of AD.

Wheat embryo globulin nutrients ameliorate d-galactose and aluminum chloride-induced cognitive impairment in rats

Wheat embryo globulin nutrient (WEGN), with wheat embryo globulin (WEG) as the main functional component, is a nutritional combination that specifically targets memory impairment. In this study, we explored the protective role of WEGN on Alzheimer's disease (AD)-triggered cognitive impairment, neuronal injury, oxidative stress, and acetylcholine system disorder. Specifically, we established an AD model via administration of d-galactose (d-gal) and Aluminum chloride (AlCl₃) for 70 days, then on the 36th day, administered animals in the donepezil and WEGN (300, 600, and 900 mg/kg) groups with drugs by gavage for 35 days. Learning and memory ability of the treated rats was tested using the Morris water maze (MWM) and novel object recognition (NOR) test, while pathological changes and neuronal death in their hippocampus CA1 were detected via HE staining and Nissl staining. Moreover, we determined antioxidant enzymes by measuring levels of superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GSH-Px) in serum, cortex, and hippocampus, whereas changes in the acetylcholine system were determined by evaluating choline acetyltransferase (ChAT), and acetylcholinesterase (AChE) activities, as well as choline acetylcholine (Ach) content. Results revealed that rats in the WEGN group exhibited significantly lower escape latency, as well as a significantly higher number of targeted crossings and longer residence times in the target quadrant, relative to those in the model group. Notably, rats in the WEGN group spent more time exploring new objects and exhibited lower damage to their hippocampus neuron, had improved learning and memory activity, as well as reversed histological alterations, relative to those in the model group. Meanwhile, biochemical examinations revealed that rats in the WEGN group had significantly lower MDA levels and AChE activities, but significantly higher GSH, SOD, and ChAT activities, as well as Ach content, relative to those in the model group. Overall, these findings indicate that WEGN exerts protective effects on cognitive impairment, neuronal damage, oxidative stress, and choline function in AD rats treated by d-gal/AlCl₃.

Ameliorative effect of myrcene in mouse model of Alzheimer's disease

Myrcene (Myr) has been reported to show neuroprotective effects in cerebral ischemia. In this research work, we investigated the Myr effect on neurobehavioural, and neuropathological alteration in mice induced by Aluminium trichloride (AlCl₃) and D - galactose. The administration of AlCl₃ (5 mg/kg; p. o.), and D - galactose (60 mg/kg; i. p.) for 90 days in mice resulted in spatial learning and memory deficits, cognitive decline, as well as neurotoxicity. The treatments with Myr low dose (100 mg/kg), Myr high dose (200 mg/kg), donepezil (2 mg/kg), and Myr low dose + donepezil (100 + 2 mg/kg) were administered via intraperitoneal route for 30 days significantly reversed the neurobehavioral, and neuropathological effects of AlCl₃ and D - galactose in mice. The results of behavioural tests such as Morris water maze, elevated plus maze, and locomotor; biochemical analysis such as malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), nitrite, and acetylcholinesterase (AChE); and ELISA tests such as mouse β - secretase (BACE), amyloid-beta peptide_1-42 (Aβ_{1 - 42}), tumor necrosis factor - α (TNF-α), interleukin - 6 (IL-6), and brain-derived neurotrophic factor (BDNF) demonstrated a significant (p < 0.05) neuroprotective effect of the Myr and donepezil co-treatments. In addition, hematoxylin and eosin staining of the cerebral cortex and hippocampus revealed eosinophilic lesions and hyperchromatic nuclei in Alzheimer's disease mice, but treatments with Myr low dose, Myr high dose, donepezil, and Myr low dose + donepezil reversed these neurodegenerative effects. Myr showed these activities by enhancing synaptic plasticity and cholinergic activity, as well as reducing oxidative damage, neuroinflammation, Aβ_1-42 aggregations, and histopathological damage. Myr alone and in combination with donepezil may serve as a potential candidate for the treatment of Alzheimer's disease.

Kinetin stimulates differentiation of C2C12 myoblasts

Kinetin or N6-furfuryladenine (K) belongs to a class of plant hormones called cytokinins, which are biologically active molecules modulating many aspects of plant growth and development. However, biological activities of cytokinins are not only limited to plants; their effects on animals have been widely reported in the literature. Here, we found that Kinetin is a potent small molecule that efficiently stimulates differentiation of C2C12 myoblasts into myotubes in vitro. The highest efficacy was achieved at 1μM and 10μM Kinetin concentrations, in both mitogen-poor and rich media. More importantly, Kinetin was able to strongly stimulate the MyoD-dependent conversion of fibroblasts into myotubes. Kinetin alone did not give rise to fibroblast conversion and required MyoD; this demonstrates that Kinetin augments the molecular repertoire of necessary key regulatory factors to facilitate MyoD-mediated myogenic differentiation. This novel Kinetin pro-myogenic function may be explained by its ability to alter intracellular calcium levels and by its potential to impact on Reactive Oxygen Species (ROS) signalling. Taken together, our findings unravel the effects of a new class of small molecules with potent pro-myogenic activities. This opens up new therapeutic avenues with potential for treating skeletal muscle diseases related to muscle aging and wasting.

Effect of transcranial near-infrared photobiomodulation on cognitive outcomes in D-galactose/AlCl3 induced brain aging in BALB/c mice

Brain photobiomodulation (PBM) therapy (PBMT) modulates various biological and cognitive processes in senescence rodent models. This study was designed to investigate the effects of transcranial near-infrared (NIR) laser treatment on D-galactose (D-gal)/aluminum chloride (AlCl₃) induced inflammation, synaptic dysfunction, and cognitive impairment in mice. The aged mouse model was induced by subcutaneously injecting D-gal (60 mg/kg/day) followed by intragastrically administering AlCl₃ (200 mg/kg/day) for 2 months. NIR PBM (810 nm laser, 32, 16, and 8 J/cm²) was administered transcranially every other day (3 days/week) for 2 months. Social, contextual, and spatial memories were assessed by social interaction test, passive avoidance test, and Lashley III maze, respectively. Then, tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and synaptic markers including growth-associated protein 43 (GAP-43), post-synaptic density-95 (PSD-95), and synaptophysin (SYN) levels were measured in the hippocampus using western blot method. Behavioral results revealed that NIR PBM at fluencies of 16 and 8 J/cm² could reduce D-gal/AlCl3 impaired social and spatial memories. Treatment with NIR attenuated neuroinflammation through down-regulation of TNF-α and IL-6. Additionally, NIR significantly inhibited the down-regulation of GAP-43 and SYN. The results indicate that transcranial PBM at the fluencies 16 and 8 J/cm² effectively prevents cognitive impairment in mice model of aging by inhibiting the production of the inflammatory cytokines and enhancing synaptic markers.

Pomegranate juice reverses AlCl3-Induced neurotoxicity and improves learning and memory in female mice

BACKGROUND

Aluminum is a neurotoxic element that can accumulate in the brain and cause neurodegenerative disorders. In addition, the antioxidants found in pomegranate juice (PJ) are much more than those existing in other fruits. It was proven to provide protection against neurodegenerative diseases.

OBJECTIVES

This experiment aimed to clarify the amelioration efficiency of PJ against aluminum chloride-induced neurobehavioral and biochemical disorders in female mice.

METHODS

The female mice were given oral administrations for 35 days as follows. The control group received tap water, the PJ groups received 20% and 40% pomegranate juice, the aluminum chloride (AlCl₃) group was treated with 400 mg/kg AlCl₃, and the last two groups received AlCl₃ + 20% PJ and AlCl₃ + 40% PJ, respectively. The neurobehavioral features were assessed by shuttle box, T-maze, and Morris water maze devices. Furthermore, the neurotransmitters and oxidative indicators in the brains of the female mice were determined at the end of experiment.

RESULTS

Significant effects of AlCl₃ were observed on female mice in the body weight, during the behavioral tasks (shuttle box, T-maze, and Morris water maze), and in neurotransmitters and oxidative stress parameters. Pomegranate juice, especially at low concentrations, induced remarkable improvements in body weight, spatial memory and learning during T-maze, Morris water maze and shuttle box tasks, as well as in neurotransmitters and oxidative biomarkers in the AlCl₃-treated female mice.

CONCLUSION

PJ reversed AlCl₃-induced neurotoxicity and improved learning and memory in female mice. However, PJ contains a group of antioxidants that may be considered double-edged swords in the cellular redox status especially at high doses.

Effects of Long-Acting Testosterone Undecanoate on Behavioral Parameters and Na + , K+-ATPase mRNA Expression in Mice with Alzheimer`s Disease

Previous studies have shown that testosterone attenuates stress-induced mood dysfunction and memory deterioration. However, the exact mechanism is still unknown. This study was conducted to investigate the role of long-term testosterone undecanoate on the behavioral responses in AD induced by AlCl3 + D-galactose administration and the possible alteration of the gene expression level of the Na/K ATPase pump. Adult male mice received AlCl3 in drinking water (10 mg/kg/day) and (D-gal 200 mg/kg/day), subcutaneously for 90 consecutive days, then received a single intramuscular (I.M) injection of castor oil (vehicle) on day 91, while treated groups received a single I.M injection of either low (100 mg/kg/45 days) or high dose (500 mg/kg/45 days) respectively of long-acting testosterone undecanoate on day 91. The time spent in the interaction zone during the open field test, preference index to novel objects in the novel object recognition test, spontaneous alternation percentage (SAP) in Y-maze test, and escape latency time in the Morris water maze test were used to measure the locomotor activity, long-term memory, and spatial memory in mice, respectively. The results showed that testosterone undecanoate treatment improved locomotor activity, improved preference to novel objects, improved spatial memory, and reversed anxiety and depression induced by AlCl3 + D-galactose administration in male mice, suggesting the enhancement of behavioral and memory functions brought by testosterone treatment. Moreover, testosterone undecanoate treatment did alter gene expression levels of Na/K ATPase isoforms in the brain hippocampus. In most cases, altered gene expression was significant and correlated with the observed behavioral changes. Taken together, our findings provide new insight into the effects of long-acting testosterone undecanoate administration on locomotor activity, long-term memory, anxiety, and spatial memory in male mice with Alzheimer's disease.

Melatonin Improves Short-Term Spatial Memory in a Mouse Model of Alzheimer's Disease

INTRODUCTION

Alzheimer's disease (AD) is a neurodegenerative disease that has become a leading cause of death in recent years. Impairments in spatial learning and memory are an important clinical feature of AD. Melatonin (MLT), the main product secreted by the pineal gland, showed multiple antioxidant, anti-inflammatory, and neuroprotective properties.

PURPOSE

The present study aimed to explore the possible prophylactic effects of MLT against spatial memory deficits in a sporadic mouse model of AD induced by D-galactose and aluminium chloride (AlCl3).

METHODS

Four groups of mice (n = 10 per group) were prepared: control, AD (the D-galactose and AlCl3 AD model group), AD+MLT (AD mice treated with 80 mg/kg MLT), and AD+DON (AD mice treated with 3 mg/kg donepezil). We then used the object location and Y-maze tests to assess spatial memory in the four groups. Gene expression levels of brain-derived neurotrophic factor (Bdnf) and cAMP-responsive element-binding protein (Creb1) were measured using real-time polymerase chain reaction.

RESULTS

We found that MLT improved spatial memory in the sporadic AD mice. MLT ameliorated Creb1 gene expression and significantly increased Bdnf gene expression in the hippocampus of AD model mice compared with the AD group.

CONCLUSION

MLT could have a substantial potential to alleviate memory impairment in sporadic AD if introduced at early stages.

Alendronate reduces the cognitive and neurological disturbances induced by combined doses of d-galactose and aluminum chloride in mice

Neurological disturbances including cholinergic dysfunction, oxidative stress, neuroinflammation, and cognitive impairments are the well-reported consequences of old age-related disorders like Alzheimer's disease (AD) or dementia. Bisphosphonates were shown to ameliorate dementia in osteoporotic patients, neuroinflammation, and cholinesterase activity in rodents. Thus, the present study has been designed to examine the role of alendronate against cognitive and neurological disturbances in mice induced by a combined oral dose of d-galactose and aluminum chloride (AlCl₃ ) for 6 weeks. d-galactose acts as a senescence agent, whereas AlCl₃ is a neurotoxin and in combination generates neuropathologies and cognitive depletion resembling aging and AD. It was found that memory was markedly impaired in d-galactose + AlCl₃ -treated mice as assessed in different behavioral paradigms. Additionally, d-galactose + AlCl₃ led to neurotoxicity assessed on the basis of neuroinflammation, oxidative stress, glial cell activation, neuronal damage, and augmented GSK-3β level in mice hippocampus. Consequently, alendronate administration orally for 15 days in d-galactose + AlCl₃ -exposed mice prominently reversed all these behavioral and neuropathological changes. These findings show that alendronate can be a potential therapeutic molecule with multiple targets for the management of age-related neurological disorders such as AD.

Anticholinesterase activity and antioxidant properties of Heinsia crinita and Pterocarpus soyauxii in Drosophila melanogaster model

Background

Plant alkaloids have become important sources of nutraceuticals owing to their pharmacological importance especially in the management of neurodegenerative diseases such as Alzheimer’s disease. In assessing the therapeutic potentials of plant phytochemicals, the fruit fly (Drosophila melanogaster) has emerged as a very veritable tool and has been largely accepted as an alternative model in biomedical research.

Objectives

In this study, alkaloid extracts from bush apple (Heinsia crinita (Afzel.) G. Taylor and padauk (Pterocarpus soyauxii Taub.) leaves were assessed on D. melanogaster exposed to aluminum toxicity.

Materials and methods

Alkaloid extracts were prepared by solvent extraction method. Thereafter, the extracts were evaluated for their in vitro antioxidant properties, Fe²⁺-chelating abilities and inhibitory effects on drosophila acetylcholinesterase (AChE) activity. The samples were also characterized for their constituent alkaloids via HPLC. Thereafter, effective safe dose of the extracts were determined in D. melanogaster (Harwich strain). Subsequently, flies assaulted with AlCl₃ were co-treated with the extracts (8.3 and 16.6 μg/g) for seven days, during which their survival rate was monitored. This was followed by assaying for the activities of AChE, antioxidant enzymes [superoxide dismutase (SOD), catalase and glutathione-S-transferase (GST)]. Also, the flies were assayed for levels of thiobarbituric acid reaction substance (TBARS) and reactive oxygen species (ROS).

Results

The results revealed that both extracts showed in vitro antioxidant properties with Padauk showing significantly higher antioxidant properties in vitro. However, there was no significant difference in their in vitro AChE inhibition. In vivo, Al-induced toxicity reduced survival rate, elevated AChE, SOD and GST activities, as well as TBARS and ROS levels which were ameliorated by the extracts. It was also revealed that piperine was predominant in PA, while 1-cyclohexen-1-yl-pyrrolidine was predominant in BA.

Conclusion

Our data suggest that the protective abilities of these extracts against Al-induced toxicity can be primarily associated with their anticholinesterase and metal chelating abilities. Thus, these vegetables can be potential sources of nutraceuticals against aluminum toxicity and associated diseases.

Premna odorata extract as a protective agent on neurotoxic effect of aluminum: neurochemical, molecular, and histopathological alterations

Premna odorata Blanco (Lamiaceae) is an ethnomedicinal plant, where some reports claimed their anti-inflammatory, cytotoxic, and antituberculosis effects, without investigating its role on the brain. Therefore, forty mature male rats were equally divided into 4 groups; the 1st was kept as control. Rats in groups 2 and 4 were orally given P. odorata extract daily at a dose of 500 mg/kg B.W., while those in groups 3 and 4 were daily administrated aluminum chloride "AlCl₃" (70 mg/kg B.W.). The treatments extended for 30 successive days. At the end of the experimental period, brain samples were collected for biochemical assay of glutathione reductase (GSH), catalase, malondialdehyde (MDA), and acetylcholinesterase activity (AChE). Besides, monoamines (norepinephrine, dopamine, serotonin), amino acids (glutamine, serine, arginine, taurine and gamma-aminobutyric acid (GABA)), neurotransmitters, DNA damage, cyclooxygenase-2 (COX-2), and tumor necrosis factor (TNF)-α genes were estimated. Moreover, brain samples were obtained for histopathological investigation. Aluminum toxicity resulted in a decline of GSH concentration, elevation of MDA, and AChE activity. Except for GABA which exhibited a significant decrease, there was a marked increase in the measured amino acid and monoamine neurotransmitters. Also, an increase in mRNA expressions of TNF-α and COX-2 was detected. It was noticed that Premna odorata extract reduced the oxidative stress and counteracted the augmentations in AChE caused by AlCl₃. Marked improvements in most measured neurotransmitters with downregulation of pro-inflammatory gene expression were recorded in P. odorata + AlCl₃ group. Premna odorata restores the altered histopathological feature induced by AlCl₃. In conclusion, the present findings clarify that P. odorata extract could be important in improving and treatment of neurodegenerative disorders as it was able to reduce oxidative stress, DNA damage, biochemical alterations, and histopathological changes in rats exposed to AlCl₃ toxicity.

Effect of Treadmill Exercise and Trans-Cinnamaldehyde against d-Galactose- and Aluminum Chloride-Induced Cognitive Dysfunction in Mice

Mild cognitive impairment (MCI) generally refers to impairment in cognition above that which accompanies the normal age-related cognitive decline and has attracted attention in recent years. Trans-cinnamaldehyde (TCA), which is isolated from cinnamon, has anti-inflammatory and antioxidant properties. Treadmill exercise also has diverse positive effects. The purpose of this study was to investigate the combination effects of TCA and treadmill exercise on learning and memory in a cognitive impairment mouse induced by a combination of d-galactose (d-gal) and aluminum chloride (AlCl₃). We found that exercise and TCA attenuated cognitive impairment in mice with induced MCI. This effect was further increased by costimulation of exercise and TCA. To clarify the mechanisms of the positive effects of TCA and exercise, we analyzed the nuclear factor erythroid 2-related factor (Nrf2) and related signaling pathways. We found that TCA and exercise upregulated Nrf2, NAD(P)H dehydrogenase quinone 1 (NQO-1), heme oxygenase 1 (HO-1), and superoxide dismutase 1 (SOD-1); this suggests that TCA and exercise attenuate cognitive dysfunction by reducing oxidative stress. We also found that Nrf2-related signaling pathways, i.e., the AMP-activated protein kinase (AMPK)/Nrf2 and SIRT1/PGC-1a/Nrf2-ARE pathways, exerted antioxidant effects. Together, these results suggest that costimulation with TCA and exercise may be a therapeutic candidate for mild cognitive impairment.

Torularhodin from Sporidiobolus pararoseus Attenuates d-galactose/AlCl3-Induced Cognitive Impairment, Oxidative Stress, and Neuroinflammation via the Nrf2/NF-κB Pathway

Oxidative stress and neuroinflammation are considered as crucial culprits in Alzheimer's disease (AD). Torularhodin, a carotenoid pigment, possesses powerful antioxidant activity. This study aimed to elucidate the protective effects of torularhodin in the AD-like mouse model and investigated the underlying mechanisms. Behavioral and histopathological results suggested that torularhodin relieved cognitive impairments, attenuated Aβ accumulation, and inhibited glial overactivation in d-gal/AlCl₃-induced ICR mice. Simultaneously, torularhodin also markedly increased antioxidant enzyme capacities, lowered the contents of RAGE, and reduced levels of inflammatory cytokines. Western blot results showed that torularhodin ameliorated neuronal oxidative damage via activation of Nrf2 translocation, upregulation of HO-1, and inactivation of NF-κB in vivo and in vitro. Thus, torularhodin effectively ameliorated cognitive impairment, oxidative stress, and neuroinflammation, possibly through the Nrf2/NF-κB signaling pathways, suggesting torularhodin might offer a promising prevention strategy for neurodegenerative diseases.

The plant hormone kinetin in disease therapy and healthy aging

It has been more than 60 years since the discovery of kinetin, the first known member of a group of plant hormones called cytokinins. In this review we summarize the health-promoting activity of kinetin in animal systems, ranging from cells cultured in vitro through invertebrates to mammals. Kinetin has been shown to modulate aging, to delay age-related physiological decline and to protect against some neurodegenerative diseases. We also review studies on its mechanism of action, as well as point out gaps in our current knowledge.

Physical & mental activities enhance the neuroprotective effect of vinpocetine & coenzyme Q10 combination against Alzheimer & bone remodeling in rats

BACKGROUND

Alzheimer's disease is a neurodegenerative disorder characterized by a progressive decline of cognitive abilities as well as bone loss. Physical and mental activities maintain cognitive functions as well as increase bone mass by inhibiting bone resorption. VIN and CoQ10 are neuroprotective drugs that possess anti-inflammatory and antioxidant properties.

AIMS

To study the effect of PH&M on enhancing the neuroprotective role of VIN and CoQ10 combination during induction of AD model in rats besides their role against bone mass loss associated with AD model.

MAIN METHODS

Six groups of rats were received saline, AlCl₃, and PH&M daily either alone or with a combination of VIN and CoQ10 for 4 weeks. Various biochemical analyses were performed to evaluate the extent of brain damage such as ACHE, β-secretase, chitinase, Aβ, tau protein, and monoamines besides the inflammatory and antioxidant parameters. Serum levels of minerals as well as 25-OHD, PTH, RANKL, and OPG levels were measured to detect the extent of bone impairment. Also, histopathological changes were evaluated in different brain regions and hind paw.

KEY FINDINGS

VIN and CoQ10 combination together with PH&M significantly attenuated the neurodegeneration induced by AlCl₃ administration through the improvement of AD markers in brain tissue as well as oxidant and inflammatory markers. Bone resorption markers, serum minerals, and PTH levels were also normalized too.

SIGNIFICANCE

Neuroprotective drugs together with PH&M have a more protective effect against AD and bone loss rather than PH&M alone.

Protective Effects of Centella asiatica on Cognitive Deficits Induced by D-gal/AlCl₃ via Inhibition of Oxidative Stress and Attenuation of Acetylcholinesterase Level

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder with cholinergic dysfunctions and impaired redox homeostasis. The plant Centella asiatica (CA) is renowned for its nutritional benefits and herbal formulas for promoting health, enhancing cognition, and its neuroprotective effects. The present study aims to investigate the protective role of CA on D-gal/AlCl₃-induced cognitive deficits in rats. The rats were divided into six groups and administered with donepezil 1 mg/kg/day, CA (200, 400, and 800 mg/kg/day) and D-gal 60 mg/kg/day + AlCl₃ 200 mg/kg/day for 10 weeks. The ethology of the rats was evaluated by the Morris water maze test. The levels of acetylcholinesterase (AChE), phosphorylated tau (P-tau), malondialdehyde (MDA) and activities of superoxide dismutase (SOD), in the hippocampus and cerebral cortex were estimated by enzyme-linked immunosorbent assay (ELISA). Additionally, the ultrastructure of the prefrontal cortex of the rats’ was observed using transmission electron microscopy (TEM). Rats administered with D-gal/AlCl₃ exhibited cognitive deficits, decreased activities of SOD, and marked increase in AChE and MDA levels. Further, prominent alterations in the ultrastructure of the prefrontal cortex were observed. Conversely, co-administration of CA with D-gal/AlCl₃ improved cognitive impairment, decreased AChE levels, attenuated the oxidative stress in hippocampus and cerebral cortex, and prevented ultrastructural alteration of neurons in the prefrontal cortex. Irrespective of the dose of CA administered, the protective effects were comparable to donepezil. In conclusion, this study suggests that CA attenuated the cognitive deficits in rats by restoring cholinergic function, attenuating oxidative stress, and preventing the morphological aberrations.

Combination of chick embryo and nutrient mixture prevent D-galactose-induced cognitive deficits, immune impairment and oxidative stress in aging rat model

Aging is spontaneous and inevitable processes that lead to changes in biological systems. The present paper was designed to investigate the anti-aging roles of chick embryo (CE) and nutrient mixture (NM) in aging rats. Aging was induced by administration of D-galactose (D-gal, 500 mg/kg/day for 90 days). CE and NM were administered to aging rats through different dose gavage once a day. Cognitive function assessment was performed using the Morris water maze test. At the end of experiment, serum and tissues were collected for immunity and antioxidation function. The organs and tissues were excised for histological study. The results demonstrated that CE plus NM was superior treatment to improve the histopathologic changes and reverse learning and memory impairment of the aging rats. CE plus NM also increased the spleen and thymus index as well as splenocyte proliferation, and reversed inflammatory cytokine levels. In addition, the biochemical index showed that CE plus NM could improve the antioxidant enzyme activity of the aging rats, decrease lipofuscin (LF) and glutamate content. CE plus NM also inhibited the activation of TLR4/NF-κB pathway stimulated by LPS in splenic B lymphocytes. Overall, these results seem to be implying that CE plus NM was used as potentially natural supplement or functional food for preventing aging.

Mitochondrial abnormalities in Parkinson's disease and Alzheimer's disease: can mitochondria be targeted therapeutically?

Mitochondrial abnormalities have been identified as a central mechanism in multiple neurodegenerative diseases and, therefore, the mitochondria have been explored as a therapeutic target. This review will focus on the evidence for mitochondrial abnormalities in the two most common neurodegenerative diseases, Parkinson's disease and Alzheimer's disease. In addition, we discuss the main strategies which have been explored in these diseases to target the mitochondria for therapeutic purposes, focusing on mitochondrially targeted antioxidants, peptides, modulators of mitochondrial dynamics and phenotypic screening outcomes.

N6-Furfuryladenine is protective in Huntington's disease models by signaling huntingtin phosphorylation

The huntingtin N17 domain is a modulator of mutant huntingtin toxicity and is hypophosphorylated in Huntington's disease (HD). We conducted high-content analysis to find compounds that could restore N17 phosphorylation. One lead compound from this screen was N6-furfuryladenine (N6FFA). N6FFA was protective in HD model neurons, and N6FFA treatment of an HD mouse model corrects HD phenotypes and eliminates cortical mutant huntingtin inclusions. We show that N6FFA restores N17 phosphorylation levels by being salvaged to a triphosphate form by adenine phosphoribosyltransferase (APRT) and used as a phosphate donor by casein kinase 2 (CK2). N6FFA is a naturally occurring product of oxidative DNA damage. Phosphorylated huntingtin functionally redistributes and colocalizes with CK2, APRT, and N6FFA DNA adducts at sites of induced DNA damage. We present a model in which this natural product compound is salvaged to provide a triphosphate substrate to signal huntingtin phosphorylation via CK2 during low-ATP stress under conditions of DNA damage, with protective effects in HD model systems.

Schisantherin A Improves Learning and Memory of Mice with D-Galactose-Induced Learning and Memory Impairment Through Its Antioxidation and Regulation of p19/p53/p21/Cyclin D1/CDK4/RB Gene Expressions

Schisantherin A (SCA) was evaluated for possible function in restoring the learning and memory impairment induced by D-galactose in mice. ICR mice were treated with D-galactose subcutaneously (220 mg·kg^-1), and followed by SCA in different doses (1.25, 2.50 and 5.00 mg·kg^-1, administered orally) for 42 days. Effects of SCA on learning and memory were examined by step-through tests and Morris water maze tests. The activity of superoxide dismutase (SOD), the content of malondialdehyde (MDA) in the peripheral blood and hippocampus of mice were assayed by water-soluble tetrazolium-1 (WST-1) and thiobarbituric acid (TBA) methods. The contents of 8 hydroxy deoxy guanosine (8-OHdG) in the hippocampus of mice were detected by immunosorbent assay methods, respectively. Quantitative real-time PCR and Western Blot were respectively used to detect the expression of p19, p53, p21, cyclin D1, CDK4 and RB genes, and the phosphorylation of RB in the hippocampus of mice. We found that SCA significantly improved the learning and memory impairment induced by D-galactose in mice. After SCA treatment, SOD activity was increased and the content of MDA was decreased in both peripheral blood and hippocampus of mice. 8-OHDG content was also decreased in the hippocampus of mice. Furthermore, the expression of p19, p53 and p21 genes was reduced and the expression of cyclin D1 and CDK4 and the phosphorylation of RB protein were elevated in the hippocampus. SCA may improve the learning and memory impairment induced by D-galactose by enhancing the antioxidant capacity, and regulating the expression of p19/p53/p21/cyclinD1/CDK4 genes, and the phosphorylation of RB protein in the hippocampus of mice.

Pharmacological Basis for the Use of Evodiamine in Alzheimer's Disease: Antioxidation and Antiapoptosis

Evodiamine (Evo), a major alkaloid compound isolated from the dry unripened fruit of Evodia fructus, has a wide range of pharmacological activities. The present study sought to explore the neuroprotective effects of Evo in l-glutamate (l-Glu)-induced apoptosis of HT22 cells, and in a d-galactose and aluminum trichloride-developed Alzheimer&rsquo;s disease (AD) mouse model. Evo significantly enhanced cell viability, inhibited the accumulation of reactive oxygen species, ameliorated mitochondrial function, increased the B-cell lymphoma-2 protein content, and inhibited the high expression levels of Bax, Bad, and cleaved-caspase-3 and -8 in l-Glu-induced HT22 cells. Evo also enhanced the phosphorylation activities of protein kinase B and the mammalian target of rapamycin in the l-Glu-induced HT22 cells. In the AD mouse model, Evo reduced the aimless and chaotic movements, reduced the time spent in the central area in the open field test, and decreased the escape latency time in the Morris water maze test. Evo reduced the deposition of amyloid beta 42 (A&beta;42) in the brain, and increased the serum level of A&beta;42, but showed no significant effects on A&beta;40. In addition, six weeks of Evo administration significantly suppressed oxidative stress by modulating the related enzyme levels. In the central cholinergic system of AD mice, Evo significantly increased the serum levels of acetylcholine and choline acetyltransferase and decreased the level of acetylcholinesterase in the serum, hypothalamus, and brain. Our results provide experimental evidence that Evo can serve as a neuroprotective candidate for the prevention and/or treatment of neurodegenerative diseases.

d-galactose and aluminium chloride induced rat model with cognitive impairments

Cognitive impairments and cholinergic dysfunctions have been well reported in old age disorders including Alzheimer's disease (AD). d-galactose (D-gal) has been reported as a senescence agent while aluminium act as a neurotoxic metal, but little is known about their combined effects at different doses. The aim of this study was to establish an animal model with cognitive impairments by comparing the effects of different doses of co-administrated D-gal and aluminium chloride (AlCl₃). In this study male albino wistar rats were administered with D-gal 60 mg/kg.bwt intra peritoneally (I.P) injected and AlCl₃ (100, 200, or 300 mg/kg.bwt.) was orally administered once daily for 10 consecutive weeks. Performance of the rats were evaluated through behavioural assessments; Morris water maze (MWM) and open field tests (OFT); histopathological examination was performed on the hippocampus; moreover biochemical measurements of acetylcholinesterase (AChE) and hyperphosphorylated tau protein (p-tau) were examined. The results of this experiment on rats treated with D-gal 60 + AlCl₃ 200 mg/kg.bwt showed near ideal cognitive impairments. The rats exhibited an obvious memory and learning deficits, marked neuronal loss in hippocampus, showed increase in AChE activities and high expression of p-tau within the tissues of the brain. This study concludes that D-gal 60 + AlCl₃ 200 mg/kg.bwt as the ideal dose for mimicking AD like cognitive impairments in albino wistar rats. It is also crucial to understand the pathogenesis of this neurodegenerative disease and for drug discovery.

Ameliorative effects and possible molecular mechanisms of action of fibrauretine from Fibraurea recisa Pierre on d-galactose/AlCl3-mediated Alzheimer's disease

Fibrauretine is one of the main active ingredients from the rattan stems of Fibraurea recisa Pierre It exhibits a series of significant pharmacological effects. The present study aimed to evaluate the potential anti Alzheimer's disease (AD) effects of fibrauretine on a d-galactose/AlCl₃-induced mouse model, and the underlying mechanisms of action were further investigated for the first time. Our results showed that pretreatment with fibrauretine significantly improved the ability of spatial short-term working memory in the model mice during the Y-maze test, as well as the abilities of spatial learning and memory during the Morris water maze. The levels of brain tissue amyloid (Aβ), P-Tau, Tau and acetylcholinesterase (AchE) were evidently increased in d-galactose/AlCl₃-intoxicated mice, and these effects were reversed by fibrauretine. In contrast, a significant increase in the levels of the neurotransmitter acetylcholine (Ach) and choline acetyl transferase (ChAT) was observed in the fibrauretine-treated groups compared with the model group. Neuronal oxidative stress, evidenced by increased malondialdehyde (MDA) and nitric oxide (NO) levels and a decline in glutathione (GSH), catalase (CAT) and superoxide dismutase (SOD) activity, was significantly alleviated by fibrauretine pretreatment. The suppression of the neuroinflammatory response by fibrauretine was realized not only by the decrease in the levels of tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in the brain tissues and by the enzyme-linked immunosorbent assay (ELISA) but also by the protein expression levels of nuclear factor-κB (NF-κB), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS), which were measured by immunohistochemistry and western blotting. In addition, the protein expression levels of inflammatory factors interleukin-33 (IL-33) and ST2 in the brain tissues were detected by immunohistochemistry. Furthermore, the effects of western blotting demonstrated that the administration of fibrauretine significantly suppressed the protein expression levels of caspase-3, cleaved caspase-3, and Bax and increased the protein expression levels of Bcl-2, and the results of the H&E and TUNEL assay all suggested the inhibition of apoptosis in the neurons. The results clearly suggest that the underlying molecular mechanisms of action of the fibrauretine-mediated alleviation of d-galactose/AlCl₃-induced Alzheimer's disease may involve antioxidant, anti-inflammatory, and anti-apoptotic effects.

Fibrauretine from Fibraurea recisa Pierre exhibits ameliorative effects on d-galactose/AlCl₃-induced Alzheimer's disease. Its mechanism may involve its antioxidant, anti-inflammatory and anti-apoptotic effects.