Neuronal marker recovery after Simvastatin treatment in dementia in the rat brain: in vivo magnetic resonance study

Simvastatin-loaded nanoemulsions: development, characterization, stability study and toxicity assays

Aim: The aim of this study is to prepare and characterize simvastatin-loaded nanoemulsions (SIM-LN) as well as evaluate their physicochemical properties and toxicity. Methodology & results: The SIM-LN were prepared, their characteristics evaluated for 30 days, and after that, the SIM-LN toxicity was evaluated using Vero cell culture and the in vivo model of Caenorhabditis elegans. The prepared SIM-LN had an average droplet size of 139 ± 22 nm, with high encapsulation rate (>98.4%). The storage at room temperature proved to be the most optimal condition. Toxicity assays demonstrated no toxicity. Conclusion: It was demonstrated that the surfactants used as emulsifiers optimized the properties without side effects, because no toxicity was measured in preliminary tests.

Overview the effect of statin therapy on dementia risk, cognitive changes and its pathologic change: a systematic review and meta-analysis

Background

Many studies have reported on the role of statin therapy in dementia, but its efficacy remains controversial. We aimed to search for reliable and meaningful articles to assess the efficacy of statin therapy for dementia risk, cognitive items, and pathologic markers.

Methods

Related literature for this study was published in the period from January 1, 1987 to January 1, 2018. Odds ratio (OR) and 95% confidence interval (95% CI) estimates were pooled in either fixed or random effects models.

Results

A total of 23 relevant studies were included after the application of the search strategy. The pooled results showed that statin therapy would downregulate dementia risk according to an analysis of 1,314,431 dementia patients and 1,836,539 healthy controls (OR: 0.64, 95% CI: 0.50, 0.81). In addition, specific changes in mini-mental state examination (MMSE) score were observed in individuals with dementia with statin therapy (OR: 0.46, 95% CI: 0.17, 0.74). However, the results of this meta-analysis showed that statin therapy did not significantly modify the Alzheimer's Disease Assessment Scale (ADAS-cog) score (OR: -0.26, 95% CI: -1.13, 0.62). No significant association was found between statin therapy and activities of daily living performance (OR: -0.69, 95% CI: -4.12, 2.74). When investigating pathological markers, our results indicated a significant influence of statin therapy on plasma amyloid β₄₀ (Aβ₄₀) (OR: 9.27, 95% CI: 0.71, 17.84), plasma Aβ₄₂ (OR: 2.60, 95% CI: 1.07, 4.13), plasma low-density lipoprotein (LDL) cholesterol (OR: -16.95, 95% CI: -25.54, -8.37), plasma lathosterol (OR: -0.11, 95% CI: -0.14, -0.07), plasma 24s-hydroxycholesterol (OR: -10.41, 95% CI: -15.57, -5.25), and cerebrospinal fluid (CSF) lathosterol (OR: -0.07, 95% CI: -0.12, -0.01).

Conclusions

The available data indicate that statin therapy may reduce dementia risk, altering cognitive items and pathologic markers.

Effects of a compound from the group of substituted thiadiazines with hypothermia inducing properties on brain metabolism in rats, a study in vivo and in vitro

The aim of the present study was to examine how administration of a compound of 1,3,4- thiadiazine class 2-morpholino-5-phenyl-6H-1,3,4-thiadiazine, hydrobromide (L-17) with hypothermia inducing properties affects the brain metabolism. The mechanism by which L-17 induces hypothermia is unknown; it may involve hypothalamic central thermoregulation as well as act via inhibition of energy metabolism. We tested the hypothesis that L-17 may induce hypothermia by directly inhibiting energy metabolism. The study in vivo was carried out on Sprague-Dawley adult rats. Two doses of L-17 were administered (190 mg/kg and 760 mg/kg). Brain metabolites were analyzed in control and treated groups using magnetic resonance spectroscopy, along with blood flow rate measurements in carotid arteries and body temperature measurements. Further in vitro studies on primary cultures from rat hippocampus were carried out to perform a mitochondria function test of L-17 pre-incubation (100 μM, 30 min). Analysis of brain metabolites showed no significant changes in 190 mg/kg treated group along with a significant reduction in body temperature by 1.5°C. However, administration of L-17 in higher dose 760 mg/kg provoked changes in brain metabolites indicative of neurotoxicity as well as reduction in carotid arteries flow rate. In addition, a balance change of excitatory and inhibitory neurotransmitters was observed. The L-17 pre-incubation with cell primary cultures from rat brain showed no significant changes in mitochondrial function. The results obtained in the study indicate that acute administration of L-17 190 mg/kg in rats induces mild hypothermia with no adverse effects onto brain metabolism.