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Objectives: Postmenopausal women are at higher risk of metabolic syndrome and cardiovascular disease, which are aggravated by obesity. Although estrogen provides cardiometabolic protection, chronic high-dose treatment could be harmful. This study investigated the efficacy of combined N-acetylcysteine (NAC) and low-dose estrogen treatment against cardiometabolic dysfunction in female estrogen-deprived obese rats with cardiac ischemia-reperfusion (I/R) injury., Methods: Bilateral ovariectomized (O) female Wistar rats were fed a high-fat diet (H) for 12 weeks. Then, rats were treated for 4 weeks with one of the following: vehicle (OH; sesame oil), regular-dose estrogen (E; 50 μg/kg/d), low-dose estrogen (e; 25 μg/kg/d), NAC (N; 100 mg/kg/d), or combined low-dose estradiol with NAC (eN). All rats then underwent cardiac I/R injury, and the left ventricle (LV) function and mitochondrial function were investigated (n = 6/group). Statistical analysis was performed by one-way ANOVA followed by Fisher's least significant difference post hoc test., Results: Body weight, visceral fat, plasma glucose, and plasma cholesterol were significantly increased with impaired LV function and heart rate variability in OH rats. OH-E rats had decreased plasma insulin and Homeostatic Model Assessment for Insulin Resistance index. Both OH-E and OH-eN rats had similarly improved heart rate variability and LV function. During cardiac I/R, OH-E and OH-eN rats had preserved left ventricular ejection fraction, stroke volume, and attenuated arrhythmias. Impaired cardiac mitochondrial function and infarct size were similarly reduced in OH-E and OH-eN rats., Conclusions: Combined NAC and low-dose estrogen treatment shares similar efficacy as regular-dose estrogen in attenuating cardiac dysfunction, cardiac mitochondrial dysfunction, and protecting the heart against I/R injury in estrogen-deprived obese insulin-resistant rats., Competing Interests: Financial disclosure/conflicts of interest: None reported., (Copyright © 2024 by The Menopause Society.)

The accumulation of lipid as a result of long-term consumption of a high-fat diet (HFD) may lead to metabolic and brain dysfunction. Atorvastatin, a recommended first-line lipid-lowering agent, has shown beneficial effects on metabolic and brain functions in several models. Recently, proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor was approved as an effective therapeutic drug for dyslipidemia patients. However, few studies have reported on the effect of this PCSK9 inhibitor on brain function. In addition, the comparative efficacy on the improvement of metabolic and brain functions between PCSK9 inhibitor and atorvastatin in obese models have not been elucidated. We hypothesized that PCSK9 inhibitor improves metabolic and brain functions in an obese model to a greater extent than atorvastatin. Thirty-two female rats were fed with either a normal diet (ND) or HFD for 15 weeks. At week 13, ND rats were given normal saline and HFD rats were given either normal saline, atorvastatin (40 mg/kg/day) or PCSK9 inhibitor (4 mg/kg/day) for 3 weeks. Oxidative stress, blood brain barrier breakdown, microglial hyperactivity, synaptic dysplasticity, apoptosis, amyloid proteins production in the hippocampus and cognitive decline were found in HFD-fed rats. Atorvastatin and PCSK9 inhibitor therapies equally attenuated hippocampal apoptosis and amyloid protein production in HFD-fed rats. Interestingly, PCSK9 inhibitor had the greater efficacy than atorvastatin on the amelioration of hippocampal oxidative stress, blood brain barrier breakdown, microglial hyperactivity, synaptic dysplasticity in the hippocampus and cognitive decline. These findings suggest that PCSK9 inhibitor may be another drug of choice for improving brain function in the obese condition with discontinued statin therapy., Competing Interests: Declaration of competing interest None., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The myeloid differentiation factor 2 (MD-2)-toll-like receptor 4 (TLR4) signaling pathway has been linked to cognitive decline in obese rats. However, more research is required to fully understand the mechanistic role of MD-2-TLR4 signalling pathway in obese-related cognitive impairment. In this study, we used two novel MD-2 inhibitors-MAC28 (a mono-carbonyl analogue of curcumin 28) and 2i-10 (a cinnamamide-derivative compound)-to better comprehend the mechanistic role of the MD-2-TLR4 signalling pathway in obese-related cognitive impairment. A normal diet (ND) (n = 16) and a high-fat diet (HFD) (n = 64) were given to randomly divided groups of male Wistar rats for 16-weeks. At week 13, 2 types of vehicles were randomly administered to ND-fed and HFD-fed rats, whereas MAC28 (3-doses) and 2i-10 (3-doses) were randomly given to HFD-fed rats until week 16. HFD-fed rats developed obesity with metabolic disturbances, a variety of brain pathologies and cognitive decline. In obese rats, blocking the brain MD-2-TLR4 signalling pathway with MAC28 or 2i-10 improved cognition via reducing brain inflammation, neurodegeneration, microglial activation, dendritic spine loss, brain oxidative stress, as well as preserving adult hippocampal neurogenesis. Our findings highlight to better understand the role of MD-2-TLR4 signaling pathway in obese-related cognitive decline, and MD-2 could be a potential therapeutic target for brain pathologies and cognitive decline in obesity., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

It has recently been accepted that long-term high-fat diet (HFD) intake is a significant possible cause for prediabetes and cognitive and brain dysfunction through the disruption of brain mitochondrial function and dynamic balance. Although modulation of mitochondrial dynamics by inhibiting fission and promoting fusion has been shown to reduce the morbidity and mortality associated with a variety of chronic diseases, the impact of either pharmacological inhibition of mitochondrial fission (Mdivi-1) or stimulation of fusion (M1) on brain function in HFD-induced prediabetic models has never been studied. Thirty-two male Wistar rats were separated into 2 groups and fed either a normal diet (ND, n = 8) or HFD (n = 24) for 14 weeks. At week 12, HFD-fed rats were divided into 3 subgroups (n = 8/subgroup) and given an intraperitoneal injection of either saline, Mdivi-1 (1.2 mg/kg/day), or M1 (2 mg/kg/day) for 2 weeks. Cognitive function and metabolic parameters were determined toward the end of the protocol. The rats then were euthanized, and the brain was immediately removed in order to evaluate brain mitochondrial function and mitochondrial dynamics. HFD-fed rats experienced prediabetes, evidenced by elevated plasma insulin and the HOMA index, impaired mitochondrial function in the brain, altered dynamic regulation, and cognitive impairment were also found. Mdivi-1 and M1 treatment exerted neuroprotection to a similar extent by improving metabolic parameters, balancing mitochondrial dynamics, and reducing mitochondrial dysfunction, resulting in a gradual increase in cognitive function. Therefore, pharmacological targeting of mitochondrial fission and fusion protected the brain against chronic HFD-induced prediabetes. [ABSTRACT FROM AUTHOR]

Obesity causes cognitive weakening and increases the risk of neurodegenerative diseases. Myrtus communis extract (MC) has anti-inflammatory and antioxidant properties. In this study, it is aimed to investigate the effects of Myrtus communis on oxidative brain damage caused by a high-fat diet (HFD), using behavioral and biochemical parameters. Twenty-four Wistar albino rats (200-250 g) were divided into three groups. The control group (C) received a standard diet, while HFD groups were received HFD for 16 weeks. MC (100 mg/kg, oral) was given to the HFD + MC group for the last 4 weeks. At the end of the study, the novel object recognition test (NORT) was performed and the hippocampus and blood samples were collected. Acetylcholinesterase (AChE) and Na+/K+- ATPase activities, malondialdehyde (MDA), 8-hydroxy-2'-deoxyguanosine (8-OHdG) and reduced glutathione (GSH) levels were measured in the hippocampal samples and cholesterol levels were analyzed in sera. Findings have shown that NORT performance of the HFD group was reduced, while administration of MC prevents this reduction and in parallel, increased AChE and decreased Na+/K+ -ATPase activities were ameliorated by administration of MC. Increased MDA and 8-OHdG levels observed in the HFD group, were decreased in the MC treated HFD group. Our results point out that MC has ameliorative effects on hippocampal oxidative stress and cognitive impairment in high fat nutritioninduced obesity. [ABSTRACT FROM AUTHOR]

Purpose: Garlic has been shown to exhibit antioxidant effects and cardioprotective properties. However, the effects of garlic extract on the heart in insulin resistance induced by long-term high-fat-diet consumption are not well defined. Therefore, we sought to determine the effects of garlic extract in the obese insulin-resistant rats. Methods: Male Wistar rats (180-200 g) were divided into two groups: normal-diet or high-fat-diet ( n = 24/group) fed for 12 weeks. Rats in each groups were divided into three subgroups ( n = 8 each): vehicle or garlic extract (250 or 500 mg/kg/day, respectively) treated for 28 days. At the end of the treatment, the metabolic parameters, heart rate variability (HRV), cardiac function, and cardiac mitochondrial function were determined. Results: Rats that received a high-fat-diet for 12 weeks had increased body weight, visceral fat, plasma insulin levels, total cholesterol, oxidative stress levels, depressed HRV, and cardiac mitochondrial dysfunction. Garlic extract at both concentrations significantly decreased the plasma insulin, total cholesterol, homeostasis model assessment index, and oxidative stress levels. Furthermore, garlic extract at both doses restored the HRV, cardiac function, and cardiac mitochondrial function. Conclusion: We concluded that garlic extract at both concentrations exerted cardioprotective effects against cardiac dysfunction and mitochondrial dysfunction in obese insulin-resistant rats. [ABSTRACT FROM AUTHOR]