Oxidative Stress-Induced Brain Damage Triggered by Voluntary Ethanol Consumption during Adolescence: A Potential Target for Neuroprotection?

Behavioral and Amygdala Biochemical Damage Induced by Alternating Mild Stress and Ethanol Intoxication in Adolescent Rats: Reversal by Argan Oil Treatment?

Adolescence is a critical period when the effects of ethanol and stress exposure are particularly pronounced. Argan oil (AO), a natural vegetable oil known for its diverse pharmacological benefits, was investigated for its potential to mitigate addictive-like behaviors and brain damage induced by adolescent intermittent ethanol intoxication (IEI) and unpredictable mild stress (UMS). From P30 to P43, IEI rats received a daily ip ethanol (3 g/kg) on a two-day on/two-day off schedule. On alternate days, the rats were submitted to UMS protocol. Next, a two-bottle free access paradigm was performed over 10 weeks to assess intermittent 20% ethanol voluntary consumption. During the same period, the rats were gavaged daily with AO (15 mL/kg). Our results show that IEI/UMS significantly increased voluntary alcohol consumption (from 3.9 g/kg/24 h to 5.8 g/kg/24 h) and exacerbated withdrawal signs and relapse-like drinking in adulthood. Although AO treatment slightly reduced ethanol intake, it notably alleviated withdrawal signs during abstinence and relapse-like drinking in adulthood. AO's effects were associated with its modulation of the HPA axis (elevated serum corticosterone), restoration of amygdala oxidative balance, BDNF levels, and attenuation of neurodegeneration. These findings suggest that AO's neuroprotective properties could offer a potential therapeutic avenue for reducing ethanol/stress-induced brain damage and addiction. Further research is needed to explore its mechanisms and therapeutic potential in alcohol use disorders.

Klotho Levels and Their Relationship with Inflammation and Survival among Alcoholic Patients

α-Klotho (Klotho) is an antiaging hormone with anti-inflammatory and antioxidative properties. Some studies suggest that Klotho increases in response to enhanced oxidative damage and inflammation. Alcoholism is a proinflammatory condition. The aim of this study was to analyze the relationship between Klotho and the serum levels of the inflammatory markers in alcoholic liver disease and to assess its prognostic value. We included 184 alcoholics and 35 age- and sex-matched controls. We determined the serum levels of Klotho, the tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-8, and malondialdehyde (MDA), and routine laboratory variables. Patients were followed-up with during 16 ± 18 months; 67 patients died. Klotho levels were higher among cirrhotics (with KW = 37.00 and p < 0.001) and were related to the Child−Pugh score (with KW = 15.96 and p < 0.001) and to the TNF-α (ρ = 0.28; p < 0.001) and MDA (ρ = 0.21; p = 0.006). The child’s groups were associated with mortality, both in the univariate (with the log-rank = 13.56, p = 0.001, Breslow = 12.33, and p = 0.002) and multivariate (with β = 0.43, p = 0.02, and OR = 1.53 (1.07−2.15)) analyses, also introducing Klotho and the TNF-α as dichotomic variables. However, the independent prognostic value of the Child’s groups was displaced by Klotho when only cirrhotics were considered; Klotho, over the median (574.4 pg/mL), was associated with higher mortality (with p = 0.04 and OR = 2.68 (1.06−6.84)). We conclude that Klotho is increased in liver cirrhosis. It is directly related to TNF-α, MDA, and to mortality in cirrhotics.

Potential Role of MANF, an ER Stress Responsive Neurotrophic Factor, in Protecting Against Alcohol Neurotoxicity

Alcohol exposure during pregnancy is harmful to the fetus and causes a wide range of long-lasting physiological and neurocognitive impairments, collectively referred to as fetal alcohol spectrum disorders (FASD). The neurobehavioral deficits observed in FASD result from structural and functional damages in the brain, with neurodegeneration being the most destructive consequence. Currently, there are no therapies for FASD. It is exigent to delineate the underlying mechanisms of alcohol neurotoxicity and develop an effective strategy of treatment. ER stress, caused by the accumulation of unfolded/misfolded proteins in the ER, is the hallmark of many neurodegenerative diseases, including alcohol-induced neurodegeneration. Mesencephalic astrocyte-derived neurotrophic factor (MANF) is a newly discovered endoplasmic reticulum (ER) stress responsive neurotrophic factor that regulates diverse neuronal functions. This review summarizes the recent findings revealing the effects of MANF on the CNS and its protective role against neurodegeneration. Particularly, we focus the role of MANF on alcohol-induced ER stress and neurodegeneration and discuss the therapeutic potential of MANF in treating alcohol neurotoxicity such as FASD.

Behavioral alterations induced by intermittent ethanol intake and noise exposure in adolescent rats

Alcohol intake and exposure to noise are common activities of human adolescents performed in entertainment contexts worldwide that can induce behavioral disturbances. Therefore, the aim of the present work was to investigate in an experimental model of adolescent animals whether noise exposure and intermittent ethanol intake, when present individually or sequentially, might be able to modify different behaviors. Adolescent Wistar rats of both sexes were subjected to voluntary intermittent ethanol intake for 1 week followed by exposure to noise for 2 h and tested in a battery of behavioral tasks. Data show that males exposed to noise experienced a deficit in associative memory (AM), increase in anxiety-like behaviors (ALB) and altered reaction to novelty (RN) when compared with sham animals, whereas females also showed an increase in risk assessment behaviors (RAB) and a decrease in exploratory activity (EA). In contrast, ethanol intake induced an increase in RAB and RN in males and females, whereas females also showed a deficit in AM and EA as well as an increase in ALB. When ethanol was ingested before noise exposure, most parameters were counteracted both in male and females, but differed among sexes. In consequence, it could be hypothesized that an environmental acute stressor like noise might trigger a behavioral counteracting induced by a previous repeated exposure to a chemical agent such as ethanol, leading to a compensation of a non-adaptive behavior and reaching a better adjustment to the environment.

Quercetin-Conjugated Superparamagnetic Iron Oxide Nanoparticles Protect AlCl3-Induced Neurotoxicity in a Rat Model of Alzheimer's Disease via Antioxidant Genes, APP Gene, and miRNA-101

Alzheimer's disease (AD) is a neurodegenerative disease with cognitive impairment. Oxidative stress in neurons is considered as a reason for development of AD. Antioxidant agents such as quercetin slow down AD progression, but the usage of this flavonoid has limitations because of its low bioavailability. We hypothesized that quercetin-conjugated superparamagnetic iron oxide nanoparticles (QT-SPIONs) have a better neuroprotective effect on AD than free quercetin and regulates the antioxidant, apoptotic, and APP gene, and miRNA-101. In this study, male Wistar rats were subjected to AlCl3, AlCl3 + QT, AlCl3 + SPION, and AlCl3 + QT-SPION for 42 consecutive days. Behavioral tests and qPCR were used to evaluate the efficiency of treatments. Results of behavioral tests revealed that the intensity of cognitive impairment was decelerated at both the middle and end of the treatment period. The effect of QT-SPIONs on learning and memory deficits were closely similar to the control group. The increase in expression levels of APP gene and the decrease in mir101 led to the development of AD symptoms in rats treated with AlCl3 while these results were reversed in the AlCl3 + QT-SPIONs group. This group showed similar results with the control group. QT-SPION also decreased the expression levels of antioxidant enzymes along with increases in expression levels of anti-apoptotic genes. Accordingly, the antioxidant effect of QT-SPION inhibited progression of cognitive impairment via sustaining the balance of antioxidant enzymes in the hippocampus of AD model rats.

A Spectrum of Topics for 2019: Advances in Neuroinflammation, Oxidative Stress, Obesity, Diabetes Mellitus, Cardiovascular Disease, Autism, Exosomes, and Central Nervous System Diseases

Advances in various fields were discussed in the reviews and original research articles published in 2019 in Current Pharmaceutical Design. Here, I review some of the major highlights for selected areas. A better understanding of disease mechanisms was a prominent recurrent theme and new therapeutic targets based on those mechanisms are highlighted here. Inflammation and oxidative stress are major features of many diseases, therefore, interventions to address these processes are reviewed. Although repurposing of old drugs occurred in several fields, drug targeting and drug delivery, especially of nanoparticles, also continues to be a major area of interest.

Argan oil supplementation attenuates voluntary ethanol consumption and withdrawal syndrome promoted by adolescent intermittent ethanol in rat

The present study investigates the potential neuroprotective effect of argan oil (AO), a natural vegetable oil, commonly used in folk Moroccan medicines, on adolescent intermittent ethanol intoxication (IEI), induced voluntary ethanol consumption, and withdrawal syndrome in rats. Animals were treated with ethanol (intraperitoneally [i.p.], 3 g/kg body weight [bw]) in intermittent doses (2 days on; 2 days off, from postnatal day 30-43), with/without oral AO pre-treatment (10 mL/kg/day bw, from postnatal day 21-121). A 2-bottle free access test was performed over 10 weeks to assess 10% ethanol consumption. Behavioral signs of withdrawal were observed after 2, 6, 24, 48, and 72 h after ethanol removal. Anxiety-like behaviors in the elevated plus maze and the light/dark box tests were also evaluated at 72 h of withdrawal. We found that AO pre-treatment significantly decreased the voluntary ethanol consumption induced by adolescent IEI. In addition, by establishing low ethanol consumption, AO pre-treatment counteracts negative effects of ethanol withdrawal and anxiety-like behaviors in ethanol-treated rats after 72 h of abstinence. Following behavioral assays, oxidative stress markers were evaluated and histologic analysis of neurodegeneration was also performed. The results showed that the low ethanol drinking in the AO-supplemented rats was associated with inhibition of oxidative stress and neurodegeneration in the rats' brains. These findings provide evidence for the promising neuroprotective effect of AO supplementation in voluntary ethanol consumption and withdrawal syndrome, at least in part through counteracting oxidative stress markers and neurodegeneration.