Alpha lipoic acid and metformin alleviates experimentally induced insulin resistance and cognitive deficit by modulation of TLR2 signalling

Types of memory, dementia, Alzheimer's disease, and their various pathological cascades as targets for potential pharmacological drugs

Alzheimer's disease (AD) is the most common type of dementia accounting for 90% of cases; however, frontotemporal dementia, vascular dementia, etc. prevails only in a minority of populations. The term dementia is defined as loss of memory which further takes several other categories of memories like working memory, spatial memory, fear memory, and long-term, and short-term memory into consideration. In this review, these memories have critically been elaborated based on context, duration, events, appearance, intensity, etc. The most important part and purpose of the review is the various pathological cascades as well as molecular levels of targets of AD, which have extracellular amyloid plaques and intracellular hyperphosphorylated tau protein as major disease hallmarks. There is another phenomenon that either leads to or arises from the above-mentioned hallmarks, such as oxidative stress, mitochondrial dysfunction, neuroinflammation, cholinergic dysfunction, and insulin resistance. Several potential drugs like antioxidants, anti-inflammatory drugs, acetylcholinesterase inhibitors, insulin mimetics or sensitizers, etc. studied in various previous preclinical or clinical reports were put as having the capacity to act on these pathological targets. Additionally, agents directly or indirectly targeting amyloid and tau were also discussed. This could be further investigated in future research.

α-Lipoic acid improves mitochondrial biogenesis and dynamics by enhancing antioxidant and inhibiting Wnt/Ca2+ pathway to relieve fluoride-induced hepatotoxic injury

Fluoride (F), widely present in water and food, poses a serious threat to liver health, and oxidative damage and mitochondrial damage are its main causes. As a natural mitochondrial protector and antioxidant, α-lipoic acid (ALA)'s alleviating effect on fluorosis liver injury and its underlying mechanism are still unclear. Therefore, this study established a fluorosis ALA intervention mice model to explore the mechanism of mitochondrial biogenesis, mitochondrial dynamics, and Wnt/Ca2+ pathway in ALA attenuating fluorosis liver injury. The results showed that ALA mitigated F-induced weight loss, hepatic structural and functional damage, hepatocytes mitochondrial damage, and decreased antioxidant levels. However, ALA did not reduce F accumulation in the femur. Further mRNA and protein detection results showed that F increased the expression levels of key genes in the mitochondrial fission (Drp1, Mff, and Fis1), mitophagy (Parkin, Pink1, and Prdx3), Wnt/Ca2+ pathway (Wnt5a and CaMK2), and rised the number and intensity of fluorescent spots of Drp1, but decreased the expression levels of key genes in the mitochondrial biogenesis (Sirt1, Sirt3, and PGC-1α) and fusion (OPA1, Mfn2, and Mfn1), and reduced the number and intensity of fluorescent spots of PGC-1α in the liver. However, the intervention of ALA relieved the F-induced changes in the expressions of the above genes. In conclusion, ALA mitigated F-induced hepatic injury through enhancing antioxidant capacity and inhibiting Wnt/Ca2+ pathway to improve mitochondrial biogenesis and dynamics disturbance. This study further reveals the hepatotoxic mechanism of F and the protective mechanism of ALA, and provides a theoretical basis for ALA as a potential preventive and palliative agent for F-induced hepatotoxic injury.

The Correlation between Metformin Use and Incident Dementia in Patients with New-Onset Diabetes Mellitus: A Population-Based Study

The evidence of metformin's effect on dementia is conflicting. This study investigates the association between metformin use and the risk of dementia among patients with diabetes mellitus (DM). This study included patients with new-onset DM between 2002 and 2013. We divided the patients into patients who used metformin and patients who did not. Two models were used to assess metformin use: the cumulative defined daily dose (cDDD) of metformin use and the intensity of metformin use. This study with 3-year and 5-year follow-ups investigated the risk of dementia among patients with DM who used metformin. At the 3-year follow-up, patients who received cDDD < 300 had an odds ratio (OR) of developing dementia of 0.92 (95% confidence interval [CI] = 0.89-0.96); patients who used metformin at intensities <10 and 10-25 DDD/month had ORs of 0.92 (95% CI: 0.87-0.97) and 0.92 (95% CI: 0.85-1.00), respectively. Metformin use at cDDD 300-500 (OR = 0.80, 95% CI = 0.56-1.15) or >500 (OR = 1.48, 95% CI = 0.48-4.60) or at an intensity >25 DDD/month (OR = 0.84, 95% CI = 0.60-1.18) were not associated with an incident of dementia. There were similar results at the 5-year follow-up. Patients with a low intensity of metformin use had a lower risk of dementia. However, higher doses of metformin with higher intensity exhibited no protective role in dementia. Prospective clinical trials are warranted to evaluate the actual underlying mechanisms between metformin dosage and the risk of dementia.

Alpha-Lipoic Acid Ameliorates Doxorubicin-Induced Cognitive Impairments by Modulating Neuroinflammation and Oxidative Stress via NRF-2/HO-1 Signaling Pathway in the Rat Hippocampus

Chemotherapy-induced cognitive impairment (CICI) is a common complication associated with the use of chemotherapeutics. Doxorubicin (DOX) is a reactive oxygen species (ROS) producing anticancer agent capable of causing potential neurotoxic effects via cytokine-induced oxidative and nitrosative damage to brain tissues. On the other hand, alpha-lipoic acid (ALA), a nutritional supplement, is reputable for its excellent antioxidant, anti-inflammatory, and anti-apoptotic activities. Consequently, the objective of the current investigation was to examine any potential neuroprotective and memory-improving benefits of ALA against DOX-induced behavioral and neurological anomalies. DOX (2 mg/kg/week, i.p.) was administrated for 4 weeks to Sprague-Dawley rats. ALA (50, 100, and 200 mg/kg) was administered for 4 weeks. The Morris water maze (MWM) and novel objective recognition task (NORT) tests were used to assess memory function. Biochemical assays with UV-visible spectrophotometry were used to analyze oxidative stress markers [malondialdehyde (MDA), protein carbonylation (PCO)], endogenous antioxidants [reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px)] and acetylcholinesterase (AChE) activity in hippocampal tissue. Inflammatory markers [tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and nuclear factor kappa B (NF-κB)], nuclear factor erythroid 2-related factor-2 (NRF-2) and hemeoxygenase-1 (HO-1) levels were estimated using enzyme-linked immunosorbent assay (ELISA). In addition, reactive oxygen species (ROS) levels were measured in hippocampus tissue using 2-7-dichlorofluorescein-diacetate (DCFH-DA) assay with fluorimetry. ALA treatment significantly protected against DOX-induced memory impairment. Furthermore, ALA restored hippocampal antioxidants, halted DOX-induced oxidative and inflammatory insults via upregulation of NRF-2/HO-1 levels, and alleviated the increase in NF-κB expression. These results indicate that ALA offers neuroprotection against DOX-induced cognitive impairment, which could be attributed to its antioxidant potential via the NRF-2/HO-1 signaling pathway.

α-Lipoic Acid Alleviated Fluoride-Induced Hepatocyte Injury via Inhibiting Ferroptosis

Fluoride is widely used in agricultural production and food packaging. Excessive fluoride in water and food is a serious threat to liver health. α-Lipoic acid, a natural free radical scavenger, has hepatoprotective properties. However, the protective effect of α-lipoic acid on fluorohepatotoxicity is uncertain. The aim of this study was to investigate the mechanism of ferroptosis in α-lipoic acid preventing fluoride-induced hepatotoxicity. Five-week-old ICR mice were treated with sodium fluoride (100 mg/L) and/or α-lipoic acid (200 mg/kg) for 9 weeks. The results showed that α-lipoic acid attenuated fluoride-induced damage to liver morphology and ultrastructure. Moreover, α-lipoic acid alleviated fluoride-induced iron accumulation, increased oxidative stress, and elevated lipid peroxidation in the liver. In addition, the mechanism study found that α-lipoic acid prevented fluoride-induced ferroptosis through the System Xc^-/GPX4 axis, lipid peroxidation axis, and iron metabolism axis, but it was interestingly not regulated by mitochondrial free radical axis in the hepatocytes. Altogether, this study indicated that α-lipoic acid prevents fluoride-induced liver injury by inhibiting ferroptosis, which has potential implications for the prevention and treatment of fluoride-induced liver injury.

Current Insights on the Use of Insulin and the Potential Use of Insulin Mimetics in Targeting Insulin Signalling in Alzheimer's Disease

Alzheimer's disease (AD) and type 2 diabetes (T2D) are chronic diseases that share several pathological mechanisms, including insulin resistance and impaired insulin signalling. Their shared features have prompted the evaluation of the drugs used to manage diabetes for the treatment of AD. Insulin delivery itself has been utilized, with promising effects, in improving cognition and reducing AD related neuropathology. The most recent clinical trial involving intranasal insulin reported no slowing of cognitive decline; however, several factors may have impacted the trial outcomes. Long-acting and rapid-acting insulin analogues have also been evaluated within the context of AD with a lack of consistent outcomes. This narrative review provided insight into how targeting insulin signalling in the brain has potential as a therapeutic target for AD and provided a detailed update on the efficacy of insulin, its analogues and the outcomes of human clinical trials. We also discussed the current evidence that warrants the further investigation of the use of the mimetics of insulin for AD. These small molecules may provide a modifiable alternative to insulin, aiding in developing drugs that selectively target insulin signalling in the brain with the aim to attenuate cognitive dysfunction and AD pathologies.

Dose-Response Association of Metformin with Parkinson's Disease Odds in Type 2 Diabetes Mellitus

Background. Studies have demonstrated that patients with diabetes mellitus who receive metformin have a lower risk of developing Parkinson’s disease (PD). However, studies have also suggested that metformin may increase the risk of PD. In this study, we investigated whether metformin use was associated with the risk of PD in type 2 diabetes mellitus (T2DM). Methods. In this population-based cross-sectional study, patients with T2DM diagnosed between 2001 and 2018 were enrolled. We categorized these patients as metformin users or nonusers. Participants below 50 years old were excluded. Two models were employed to evaluate the associations of metformin exposure and use intensity with PD after 3 and 5 years of follow-up. Results. Patients with T2DM who received <300 cumulative defined daily doses (cDDD) of metformin and those with metformin use intensity of <10 DDD/month had respective odds ratios (ORs) for PD of 0.88 (95% confidence interval [CI] = 0.83−0.94) and 0.87 (95% CI = 0.81−0.93) in a 3-year follow-up. In a 5-year follow-up, such patients had respective ORs for PD of 0.94 (95% CI = 0.90−0.98) and 0.93 (95% CI = 0.89−0.98). Patients with T2DM who received ≥300 cDDD of metformin or used metformin with intensity of ≥10 DDD/month experienced no neuroprotective effects after 3 or 5 years. Conclusions. Metformin was associated with PD odds in T2DM in a dose−response association manner. Patients who received low dosage and intensity of metformin use were associated with lower odds of PD, while higher dosage and intensity of metformin use had no neuroprotective effect.

α-Lipoic Acid Reduces Ceramide Synthesis and Neuroinflammation in the Hypothalamus of Insulin-Resistant Rats, While in the Cerebral Cortex Diminishes the β-Amyloid Accumulation

Background

Oxidative stress underlies metabolic diseases and cognitive impairment; thus, the use of antioxidants may improve brain function in insulin-resistant conditions. We are the first to evaluate the effects of α-lipoic acid (ALA) on redox homeostasis, sphingolipid metabolism, neuroinflammation, apoptosis, and β-amyloid accumulation in the cerebral cortex and hypothalamus of insulin-resistant rats.

Methods

The experiment was conducted on male cmdb/outbred Wistar rats fed a high-fat diet (HFD) for 10 weeks with intragastric administration of ALA (30 mg/kg body weight) for 4 weeks. Pro-oxidant and pro-inflammatory enzymes, oxidative stress, sphingolipid metabolism, neuroinflammation, apoptosis, and β-amyloid level were assessed in the hypothalamus and cerebral cortex using colorimetric, fluorimetric, ELISA, and HPLC methods. Statistical analysis was performed using three-way ANOVA followed by the Tukey HSD test.

Results

ALA normalizes body weight, food intake, glycemia, insulinemia, and systemic insulin sensitivity in HFD-fed rats. ALA treatment reduces nicotinamide adenine dinucleotide phosphate (NADPH) and xanthine oxidase activity, increases ferric-reducing antioxidant power (FRAP) and thiol levels in the hypothalamus of insulin-resistant rats. In addition, it decreases myeloperoxidase, glucuronidase, and metalloproteinase-2 activity and pro-inflammatory cytokines (IL-1β, IL-6) levels, while in the cerebral cortex ALA reduces β-amyloid accumulation. In both brain structures, ALA diminishes ceramide synthesis and caspase-3 activity. ALA improves systemic oxidative status and reduces insulin-resistant rats’ serum cytokines, chemokines, and growth factors.

Conclusion

ALA normalizes lipid and carbohydrate metabolism in insulin-resistant rats. At the brain level, ALA primarily affects hypothalamic metabolism. ALA improves redox homeostasis by decreasing the activity of pro-oxidant enzymes, enhancing total antioxidant potential, and reducing protein and lipid oxidative damage in the hypothalamus of HFD-fed rats. ALA also reduces hypothalamic inflammation and metalloproteinases activity, and cortical β-amyloid accumulation. In both brain structures, ALA diminishes ceramide synthesis and neuronal apoptosis. Although further study is needed, ALA may be a potential treatment for patients with cerebral complications of insulin resistance.

The crosstalk among TLR2, TLR4 and pathogenic pathways; a treasure trove for treatment of diabetic neuropathy

Diabetes is correlated with organ failures as a consequence of microvascular diabetic complications, including neuropathy, nephropathy, and retinopathy. These difficulties come with serious clinical manifestations and high medical costs. Diabetic neuropathy (DN) is one of the most prevalent diabetes complications, affecting at least 50% of diabetic patients with long disease duration. DN has serious effects on patients' life since it interferes with their daily physical activities and causes psychological comorbidities. There are some potential risk factors for the development of neuropathic injuries. It has been shown that inflammatory mechanisms play a pivotal role in the progression of DN. Among inflammatory players, TLR2 and TLR4 have gained immense importance because of their ability in recognizing distinct molecular patterns of invading pathogens and also damage-associated molecular patterns (DAMPs) providing inflammatory context for the progression of a wide array of disorders. We, therefore, sought to explore the possible role of TLR2 and TLR4 in DN pathogenesis and if whether manipulating TLRs is likely to be successful in fighting off DN.

A promising discovery of anti-aging chemical conjugate derived from lipoic acid and sesamol established in Drosophila melanogaster

Phytonutrients, lipoic acid and sesamol, were chemically combined to yield medically important lipoic acid-sesamol conjugate (LSC). NMR and LC-MS/MS techniques were used to determine the chemical structure of LSC. The...

The Neuroprotective Effect of α-Lipoic Acid and/or Metformin against the Behavioral and Neurochemical Changes Induced by Hypothyroidism in Rat

OBJECTIVE

The present study evaluates the neuroprotective effect of α-lipoic acid (ALA) and/or metformin (MET) on the behavioral and neurochemical changes induced by hypothyroidism.

METHODS

Rats were divided into control, rat model of hypothyroidism induced by propylthiouracil, and rat model of hypothyroidism treated with ALA, MET, or their combination.

RESULTS

Behaviorally, hypothyroid rats revealed impaired memory and reduced motor activity as indicated from the novel object recognition test and open-field test, respectively. Hypothyroidism induced a significant increase in lipid peroxidation (malondialdehyde [MDA]) and a significant decrease in reduced glutathione (GSH) and nitric oxide (NO) in the cortex and hippocampus. These were associated with a significant increase in tumor necrosis factor-α (TNF-α) and a significant decrease in brain-derived neurotrophic factor (BDNF). Hypothyroidism decreased significantly the levels of serotonin (5-HT), norepinephrine (NE), and dopamine (DA) and reduced the activities of acetylcholinesterase (AchE) and Na+, K+-ATPase in the cortex and hippocampus. Treatment of hypothyroid rats with ALA and/or MET showed an improvement in memory function and motor activity. Moreover, ALA and/or MET prevented the increase in MDA and TNF-α, and the decline in GSH, NO, BDNF, 5-HT, NE, and DA. It also restored AchE and Na+, K+-ATPase activities in the studied brain regions.

CONCLUSION

ALA and/or MET has a potential neuroprotective effect against the adverse behavioral and neurochemical changes induced by hypothyroidism in rats.

Ferroptosis as a mechanism of neurodegeneration in Alzheimer's disease

Alzheimer's disease (AD) is the most prevalent form of dementia, with complex pathophysiology that is not fully understood. While β-amyloid plaque and neurofibrillary tangles define the pathology of the disease, the mechanism of neurodegeneration is uncertain. Ferroptosis is an iron-mediated programmed cell death mechanism characterised by phospholipid peroxidation that has been observed in clinical AD samples. This review will outline the growing molecular and clinical evidence implicating ferroptosis in the pathogenesis of AD, with implications for disease-modifying therapies.

Activated Microglia Exosomes Mediated miR-383-3p Promotes Neuronal Necroptosis Through Inhibiting ATF4 Expression in Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is the second largest type of stroke, with high mortality and morbidity, and most patients have severe sequelae. Brain injury induced by ICH includes primary damage and secondary damage, and the secondary brain injury is the main reason of neurological impairment. The hallmark of secondary brain injury is cell death. Necroptosis is a type of the cell death and plays vital roles in various neurological diseases, but the roles of necroptosis in ICH are still not fully known. Microglia cell is the type of immune cell, plays protective roles in nerve damage and modulates the activity of neurons through secreting exosomes. Exosome-contained miRNAs are also involved in the regulating neuronal activity. However, the roles and the mechanisms of microglia-secreted exosomes miRNAs in ICH neurons necroptosis need to further explore. In this study, ICH model was construct in rats and cells. Injury of cells in brain was detected by PI staining. Necroptosis in rats and cells was detected by western blot and flow cytometry. The expression of miR-383-3p was detected by RT-qPCR. The roles of activated microglia-secreted exosomes and exosome-contained miR-383-3p were detected through co-culturing medium or exosomes with neurons. The target gene of miR-383-3p was determined by luciferase assay and the expression of target gene was detected by western blot. Rescue experiments were used to confirm the mechanism of miR-383-3p in neurons necroptosis. The miR-383-3p role was verified in vivo through injecting miR-383-3p mimic into ICH rats. Here, we found that the necroptosis of neurons was increased in ICH rats through detecting the expression of RIP1 and RIP3 and PI staining. Microglia that activated by ICH promote neurons necroptosis through secreting exosomes and transferring miR-383-3p into neurons. In mechanism, miR-383-3p negatively regulated the expression of ATF4 and then promoted the necroptosis of neurons. Overall, our results provide a novel molecular basis to neurons necroptosis in ICH and may provide a new strategy to retard the secondary brain injury of ICH.

Roflumilast and tadalafil improve learning and memory deficits in intracerebroventricular Aβ1-42 rat model of Alzheimer's disease through modulations of hippocampal cAMP/cGMP/BDNF signaling pathway

BACKGROUND

Alzheimer's disease (AD) is the most prevalent age-dependent neurodegenerative disease characterized by progressive impairment of memory and cognitive functions. Cyclic nucleotides like cAMP and cGMP are well-known to play an important role in learning and memory functions. Enhancement of cAMP and cGMP levels in the hippocampus by phosphodiesterase (PDE) inhibitors might be a novel therapeutic approach for AD. Thus, the present study was planned to explore the therapeutic potential of roflumilast (RFM) and tadalafil (TDF) phosphodiesterase inhibitors in intracerebroventricular (ICV) Aβ1-42 induced AD in rats.

METHODS

ICV Aβ1-42 was administered in rats followed by treatment with RFM (0.05 mg/kg) and TDF (0.51 mg/kg) for 15 days. Novel object recognition (NOR), and Morris water maze (MWM) test were performed during the drug treatment schedule. On the day, 22 rats were sacrificed, and hippocampus was separated for biochemical, neuroinflammation, and histopathological analysis.

RESULTS

Aβ1-42 infused rats were induce behavioral impairment and increased AChE, BACE-1, Aβ1-42, GSK-3β, phosphorylated tau (p-Tau), pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) levels, oxidative stress (increased MDA, Nitrite and decreased GSH), histopathological changes, and reduced cAMP, cGMP, and BDNF levels. RFM and TDF significantly attenuated Aβ1-42 induced memory deficits and neuropathological alterations in the hippocampus.

CONCLUSION

The outcomes of the current study indicate that RFM and TDF lead to memory enhancement through upregulation of cAMP/cGMP/BDNF pathway, thus they may have a therapeutic potential in cognitive deficits associated with AD.

Systematic approach to selecting licensed drugs for repurposing in the treatment of progressive multiple sclerosis

OBJECTIVE

To establish a rigorous, expert-led, evidence-based approach to the evaluation of licensed drugs for repurposing and testing in clinical trials of people with progressive multiple sclerosis (MS).

METHODS

We long-listed licensed drugs with evidence of human safety, blood-brain barrier penetrance and demonstrable efficacy in at least one animal model, or mechanistic target, agreed by a panel of experts and people with MS to be relevant to the pathogenesis of progression. We systematically reviewed the preclinical and clinical literature for each compound, condensed this into a database of summary documents and short-listed drugs by scoring each one of them. Drugs were evaluated for immediate use in a clinical trial, and our selection was scrutinised by a final independent expert review.

RESULTS

From a short list of 55 treatments, we recommended four treatments for immediate testing in progressive MS: R-α-lipoic acid, metformin, the combination treatment of R-α-lipoic acid and metformin, and niacin. We also prioritised clemastine, lamotrigine, oxcarbazepine, nimodipine and flunarizine.

CONCLUSIONS

We report a standardised approach for the identification of candidate drugs for repurposing in the treatment of progressive MS.

Alpha-lipoic acid: A promising adjuvant for nonsteroidal anti-inflammatory drugs therapy with improved efficacy and gastroprotection

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used in a wide variety of diseases due to their analgesic and anti-inflammatory effects, but their usage have been limited due to significant ulcerogenic side effects. In the present study, we aimed to evaluate the effect of α-lipoic acid (ALA) treatment on the anti-inflammatory activity of indomethacin (Indo) as well as the possible therapeutic effect of ALA on high dose Indo-induced gastropathy in female mice. Mice were treated with Indo (5 or 30 mg/kg, p.o) alone or in combination with ALA (50, 100 or 200 mg/kg, i.p). in vivo anti-inflammatory effect was evaluated by formalin-induced paw edema measured as paw thickness and edema. Gastric damage was evaluated macroscopically and histologically by scoring mucosal hemorrhage, erosion, edema and inflammation. To our results, Indo was ineffective at 5 mg/kg, but co-treatment with Indo and ALA significantly reduced paw edema, implying that ALA augmented the anti-inflammatory effect of subtherapeutic dose of Indo. However, ALA was not able to induce a further increase in the anti-inflammatory effect of Indo at 30 mg/kg. Unlike the treatment with Indo at 5 mg/kg, Indo at 30 mg/kg caused severe gastric damage that prevented by co-treatment with ALA. These results suggest that combination of ALA with NSAIDs can both increase anti-inflammatory effect and prevent NSAIDs-induced gastric damage. ALA would be promising adjuvant that can reduce dose for effective NSAID therapy, which improves safety profile of NSAIDs especially in cases long-term administration of high dose needed.

Toll-like receptor-2 gene knockout results in neurobehavioral dysfunctions and multiple brain structural and functional abnormalities in mice

OBJECTIVE

Toll-like receptor-2 (TLR2), a member of TLR family, plays an important role in the induction and regulation of immune/inflammation. TLR2 gene knockout (TLR2KO) mice have been widely used for animal models of neurological diseases. Since there is close relationship between immune system and neurobehavioral functions, it is important to clarify the exact role of TLR2 defect itself in neurobehavioral functions. The present study aimed to investigate the effect of TLR2KO on neurobehavioral functions in mice and the mechanisms underlying the observed changes.

METHODS

Male TLR2KO and wild type (WT) mice aged 3, 7, and 12 months were used for neurobehavioral testing and detection of protein expression by Western blot. Brain magnetic resonance imaging (MRI), electrophysiological recording, and Evans blue (EB) assay were applied to evaluate regional cerebral blood flow (rCBF), synaptic function, and blood-brain barrier (BBB) integrity in 12-month-old TLR2KO and age-matched WT mice.

RESULTS

Compared to WT mice, TLR2KO mice showed decreased cognitive function and locomotor activity, as well as increased anxiety, which developed from middle age (before 7-month-old) to old age. In addition, significantly reduced regional cerebral blood flow (rCBF), inhibited long-term potentiation (LTP), and increased blood-brain barrier (BBB) permeability were observed in 12-month-old TLR2KO mice. Furthermore, compared with age-matched WT mice, significant reduction in protein levels of tight junction proteins (ZO-1, Occludin, and Claudin-5) and increased neurofilament protein (SMI32) were observed in 7 and 12-month-old TLR2KO mice, and that myelin basic protein (MBP) decreased in 12-month-old TLR2KO mice.

CONCLUSION

Our data demonstrated that TLR2 defect resulted in significantly observable neurobehavioral dysfunctions in mice starting from middle age, as well as multiple abnormalities in brain structure, function, and molecular metabolism.

Impact of thioctic acid on glycemic indices and associated inflammatory-induced endothelial dysfunction in patients with type 2 diabetes mellitus: A case control study

Objective

To evaluate the effects of thioctic acid (TA) add-on metformin therapy on glycemic indices and associated inflammatory reactions induced-endothelial dysfunction (ED) in patients with type 2 diabetes mellitus (T2DM).

Methods

In this case-control clinical study, a total number of 70 patients with T2DM compared with 30 healthy controls were divided into three groups: Group A (n = 30), healthy controls; Group B (n = 36), T2DM patients on metformin and Group C (n = 34), T2DM patients on metformin plus TA 600 mg/day. Anthropometric measurements, lipid profile, and routine biochemical variables were estimated. Serum human vascular cell adhesion molecule-1 (VCAM-1) and E-selectin were measured before and after 10 consecutive week's therapy with metformin and/or TA.

Results

Metformin therapy led to significant reduction of fasting insulin and insulin resistance (IR) with an increment in the insulin sensitivity (P < 0.01). Metformin therapy improved lipid profile compared to the baseline (P < 0.01) with significant reduction of atherogenic index. Metformin plus TA therapy reduced fasting blood glucose, glycated hemoglobin, and IR and showed increment in the insulin sensitivity (P < 0.01) with insignificant effect on fasting insulin (P = 0.09) compared with metformin monotherapy. sVCAM-1 level was high in patients with T2DM (3.74 ± 1.34 ng/ml) at baseline, which decreased by metformin monotherapy to 2.32 ± 0.67 ng/ml or metformin plus TA to 1.98 ± 0.31 ng/ml (P < 0.01), but metformin plus TA illustrated insignificant difference compared to metformin alone (P = 0.29).

Conclusion

TA add on metformin therapy improves glycemic indices and associated inflammatory mediators in patients with T2DM through modulation of IR , IS , and direct direct anti-inflammatory effect.

Adrenomedullin expression in aortic artery wall of diabetic rats given alpha lipoic acid

BACKGROUND

Diabetes mellitus (DM) is a major health problem predisposing to cardiovascular diseases. The aim of this study was to investigate the effects of alpha lipoic acid (ALA) on both the arterial wall of diabetic rats and the adrenomedullin (ADM) gene expression.

METHODS

Twenty-four Wistar Albino rats were divided into three groups as Control, DM + S, and DM + ALA. For DM model, a single dose of 40 mg/kg streptozotocin, for DM + ALA group, 100 mg/kg/day/4 weeks was administered. Hematoxylin & Eosin (H&E) staining was done and vascular endothelial growth factor (VEGF) was detected by immunohistochemical analysis in the artery wall. Total damage score of vessel wall (endothelial cell damage, media layer smooth muscle cell damage, and internal elastic lamina damage) and H score (immunoreactivity intensity) were calculated. Expression of ADM gene was measured by qRT-PCR.

RESULTS

In DM + S group, Total damage score of vessel wall were detected by light microscopy. There were statistically significant differences between the groups Control/DM + S and DM + S/DM + ALA in terms of the vessel total damage score and H score (p < 0.005). ADM expression was increased threefold in both DM + S and DM + ALA groups compared to the control group (p < 0.05).

CONCLUSIONS

ALA may have positive effect on the vessel damage in diabetic rats. However, no significant decrease in ADM expression levels was observed in diabetic rats after ALA administration and we considered that the protective effect of ALA is independent of adrenomedullin. Further studies with different doses and durations of ALA administrations are required to investigate the changes in ADM expression.

Changes in Resting-State Cerebral Activity in Women With Polycystic Ovary Syndrome: A Functional MR Imaging Study

BACKGROUND

Previous studies have found that women with polycystic ovary syndrome (PCOS) have some degree of brain function change as well as cognitive function and emotions, such as poor executive functioning and memory, anxiety and depressive symptoms. However, the neurobiological mechanisms underlying these alterations have not yet been clarified.

METHOD

Fasting serum hormone testing, neuropsychological testing and resting-state magnetic resonance imaging (rs-fMRI) were performed in 41 women with newly diagnosed PCOS and 41 healthy controls matched by age and education during their 2-5 days of menstrual period. Analysis of the amplitude of low-frequency fluctuation (ALFF) was used to calculate the seed points. Then, the functional connectivity (FC) values between these abnormal seed points and other voxels in the whole brain were calculated. Finally, the correlations among clinical indexes, neuropsychological evaluation scores, and neuroimaging data were analyzed.

RESULTS

Compared with the control group, the PCOS group showed higher luteinizing hormone (LH) and serum insulin levels, worse sleep quality, increased depressive and anxiety state scores, and memory and executive function impairments. Pearson's correlation analysis showed that the decreased ALFF value in the left middle frontal gyrus (MFG.L), which is related to poor executive performance and depressive disorders, was negatively correlated with the plasma insulin level in subjects with insulin resistance. Furthermore, the increased FC strength between the MFG.L and left inferior frontal gyrus (IFG.L) was positively correlated with the serum testosterone level. The enhanced FC strength between the left posterior cingulate gyrus (PCG.L) and triangular part of the left inferior frontal gyrus (IFGtriang.L) was negatively correlated with the plasma LH level. When use the right middle occipital gyrus (MOG.R) as the seed point, the FC strength with the right inferior occipital gyrus (IOG.R), which is associated with impaired memory, was decreased.

CONCLUSION

The ALFF and FC results elucidated brain functional abnormalities at the regional and network levels in women with PCOS, while correlation analyses simultaneously demonstrated that these alterations were associated with serum hormones and cognitive function. These results may provide useful information regarding the potential mechanisms of cognitive impairment and emotional changes in this population.