Atorvastatin improves Y-maze learning behaviour in nicotine treated male albino rats

Metformin mitigates amyloid β1-40-induced cognitive decline via attenuation of oxidative/nitrosative stress and neuroinflammation

Metformin is an antidiabetic medicine widely used for management of type 2 diabetes with neuroprotective effects and promising potential to attenuate cognitive impairment. The efficacy of metformin in attenuation of Alzheimer's disease (AD) pathology has not been well-documented. Thus, this study was designed to assess protective effect of metformin against Aβ_1-40-instigared cognitive impairment. After intra-CA1 microinjection of aggregated Aβ_1-40, rats received oral metformin (50 and/or 200 mg/kg/day) for two weeks. Cognition function was analyzed in various behavioral tasks besides measurement of hippocampal oxidative stress, apoptosis, and inflammation along with H&E staining and 3-nitrotyrosine (3-NT) immunohistochemistry. Obtained data showed significant improvement of discrimination score in novel object recognition test, higher alternation score in Y maze, greater latency in passive avoidance task, and lower working and reference memory errors in radial arm maze in metformin-treated Aβ-injured group. Moreover, metformin treatment attenuated hippocampal levels of nitrite, MDA, protein carbonyl, ROS, TNFα, GFAP, DNA fragmentation intensity, caspase 3 activity, AChE activity, and increased SOD activity and level of IL-10 as an anti-inflammatory factor. In addition, metformin treatment was associated with lower CA1 neuronal loss and it also decreased intensity of 3-NT immunoreactivity as an indicator of nitrosative stress. Taken together, obtained findings showed neuroprotective and anti-dementia property of metformin in male rats and this may have potential benefit in attenuation of cognitive decline and related complications in patients with neurodegenerative disorders such as AD besides diabetes mellitus.

Nobiletin prevents amyloid β1-40-induced cognitive impairment via inhibition of neuroinflammation and oxidative/nitrosative stress

Alzheimer's disease (AD) is presented as an age-related neurodegenerative disease with multiple cognitive deficits and amyloid β (Aβ) accumulation is the most important involved factor in its development. Nobiletin is a bioflavonoid isolated from citrus fruits peels with anti-inflammatory and anti-oxidative activity as well as anti-dementia property that has shown potency to ameliorate intracellular and extracellular Ab. The aim of the present study was to assess protective effect of nobiletin against Aβ_1-40-induced cognitive impairment as a consistent model of AD. After bilateral intrahippocampal (CA1 subfield) injection of Aβ_1-40, rats were treated with nobiletin (10 mg/kg/day; p.o.) from stereotaxic surgery day (day 0) till day + 7. Cognition function was evaluated in a battery of behavioral tasks at week 3 with final assessment of hippocampal oxidative stress and inflammation besides Nissl staining and 3-nitrotyrosine (3-NT) immunohistochemistry. Analysis of behavioral data showed notable and significant improvement of alternation in Y maze test, discrimination ratio in novel object recognition task, and step through latency in passive avoidance test in nobiletin-treated Aβ group. Additionally, nobiletin treatment was associated with lower hippocampal levels of MDA and ROS and partial reversal of SOD activity and also improvement of Nrf2 with no significant effect on GSH and catalase. Furthermore, nobiletin attenuated hippocampal neuroinflammation in Aβ group as shown by lower tissue levels of TLR4, NF-kB, and TNFa. Histochemical findings showed that nobiletin prevents CA1 neuronal loss in Nissl staining in addition to its alleviation of 3-nitrotyrosine (3-NT) immunoreactivity as a marker of nitrosative stress. Collectively, these findings indicated neuroprotective and anti-dementia potential of nobiletin that is partly attributed to its anti-oxidative, anti-nitrosative, and anti-inflammatory property associated with proper modulation of TLR4/NF-kB/Nrf2 pathways.

Pro-neurocognitive and anti-sarcopenic benefits of one-year metformin therapy in ovariectomized aged mice

Health promotion and healthy nutrition significantly increased life expectancy around the world. Aging is associated with an increase in age-related diseases. The use of metformin (Met) as an anti-aging drug has recently been proposed based on its widespread use in clinical practice. Reports have shown that Met acts as an anti-aging agent. In this study, the effects of long-term, 1 year, Met administration on aging-related behaviors and longevity in ovariectomized mice was studied. Met (1 and 10 mg/kg, daily) was administered orally in ovariectomized mice. The anxiety-like behavior, working memory, and physical strength were measured through elevated plus maze, Y-maze, vertical grid holding, and the obligatory swimming capacity tests. Brains were harvested to measure brain-derived neurotrophic factor (BDNF) level. Also, the Kaplan-Meier survival curves were used to show differences and similarities in survival patterns. Met (10 mg/kg) decreased anxiety-like behaviors as well as increased muscle strength and working memory in the ovariectomized mice. Moreover, Met increased the physical strength and longevity as well as the level of BDNF in the ovariectomized mice. Our results indicate that Met administration can be an effective strategy for having a healthy aging in the absence of female gonadal hormones and reverses deleterious effects of ovariectomy-induced aging possibly through BDNF.

Association between Y-Maze Acquisition Learning and Major Histocompatibility Complex Class II Polymorphisms in Mice

Objective

To explore the association between the acquisition process in the Y-maze and H-2 class II polymorphisms in mice.

Methods

Mice were trained for 5 consecutive days in the Y-maze. The value of the slope of the latent period was considered an indication for the acquisition process. A slope < 0 indicated learning during the training and a slope > 0 indicated no learning. The H-2 polymorphism was determined with PCR amplification, and the correlation between the alleles and the acquisition process was analyzed.

Results

The overall percentage of mice that learned was 46.1%. The percentage of mice that had learned with MudoEb5 (37.9%) was significantly lower than that of mice without MudoEb5 (61.1%; P < 0.05). The percentage of mice that had learned with MudoEb7 (26.1%) was significantly lower than that of mice without MudoEb7 (51.9%; P < 0.05).

Conclusions

The major histocompatibility complex (MHC) and other alleles may be involved in the acquisition process. There may be a biological basis for learning in mice.

Atorvastatin modulates drug transporters and ameliorates nicotine-induced testicular toxicity

We studied the changes in mRNA expressions of influx and efflux transporters, blood-testis-barrier proteins (BTB) and key apoptotic genes in the testis of rats coadministered with nicotine and atorvastatin. Rats were divided into four groups: (i) control, (ii) atorvastatin (10 mg/kg b.wt), (iii) nicotine (0.6 mg/kg b.wt) and (iv) atorvastatin (10 mg/kg b.wt) + nicotine (0.6 mg/kg b.wt). Atorvastatin was given by oral intubation and nicotine by intraperitoneal injection. After 60 days of treatment, expressions of key apoptotic genes involved in both intrinsic and extrinsic pathways; solute carrier influx transporters SLCOB1, SLC22A1 and efflux transporter ABCB1 associated with transport of atorvastatin and nicotine, and proteins of BTB were assayed. Nicotine administration activated apoptosis and downregulated SLCOB1, which transport atorvastatin. Atorvastatin administration suppressed apoptotic pathway and downregulated SLC22A1, transporter of nicotine. Coadministration of atorvastatin with nicotine downregulated expressions of apoptotic genes. The combined administration of atorvastatin and nicotine reduced the influx of both atorvastatin and nicotine and enhanced the efflux of these drugs thereby altering the microenvironment of testis and improving testicular function. We conclude that atorvastatin-mediated alterations of BTB and drug transporters might have played a significant role in ameliorating nicotine-induced testicular toxicity.

Protective effect of atorvastatin on d-galactose-induced aging model in mice

Atorvastatin (Ator), competitive inhibitors of 3-hydroxymethyl-3-glutaryl-coenzyme-A reductase, is a cholesterol lowering drug. Ator has been shown to have neuroprotective, antioxidant and anti-inflammatory properties making that a potential candidate for the treatment of central nervous system (CNS) disorders. Here we assessed the effect of Ator on the d-galactose (d-gal)-induced aging in mice. For this purpose, Ator (0.1 and 1mg/kg/p.o.), was administrated daily in d-gal-received (500mg/kg/p.o.) mice model of aging for six weeks. Anxiety-like behaviors and cognitive functions were evaluated by the elevated plus-maze and novel object recognition tasks, respectively. Physical power was assessed by forced swimming capacity test. Animals brains were analyzed for the superoxide dismutase (SOD) and brain-derived neurotrophic factor (BDNF). We found that Ator decreases the anxiety-like behaviors in d-gal-treated mice. Also, our behavioral tests showed that Ator reverses the d-gal induced learning and memory impairment. Furthermore, we found that Ator increases the physical power of d-gal-treated mice. Our results indicated that the neuroprotective effect of Ator on d-gal induced neurotoxicity is mediated, at least in part, by an increase in the SOD and BDNF levels. The results of present study suggest that Ator could be used as a novel therapeutic strategy for the treatment of age-related conditions.