Vanillin improves scopolamine‑induced memory impairment through restoration of ID1 expression in the mouse hippocampus

Amygdalus spinosissima root extract enhanced scopolamine-induced learning and memory impairment in mice

The Amygdalus spinosissima (Rosaceae) plant has been used in the Iranian folk medicine as a remedy for the burn wound. Hence, in this study, we aimed to determine the possible medicinal potential of the plant focusing on the root part. The bioactive phenolic and flavonoid compounds present in the root extract of the Amygdalus spinosissima plant as well as its antioxidant and anti-inflammatory properties were determined. Moreover, the effects of root extract on learning and memory in mice were evaluated. The results revealed that the root methanolic extract contained phenolic and flavonoid compounds including apigenin, quercetin, rutin, kaempferol, gallic acid, syringic acid, ferulic acid, and ellagic acid. The extract possessed antioxidant, acetylcholinesterase (AChE), and butyrylcholinesterase (BChE) inhibitory activities in vitro. These biological activities were attributed to the presence of phenolics and flavonoids. The A. spinosissima root extract improved learning and memory function in scopolamine-induced memory dysfunction in mice as determined using the Morris water maze task. The extract modulated the AChE, BChE, and inflammatory genes and enhanced the expression of the antioxidant enzymes in the brain. Consequently, A. spinosissima root extract could be considered as a promising source of potent bioactive compounds in the retarding the development of neurodegenerative diseases such as Alzheimer's disease.

Potential Effects of Phenolic Compounds That Can Be Found in Olive Oil on Wound Healing

The treatment of tissue damage produced by physical, chemical, or mechanical agents involves considerable direct and indirect costs to health care systems. Wound healing involves a series of molecular and cellular events aimed at repairing the defect in tissue integrity. These events can be favored by various natural agents, including the polyphenols in extra virgin olive oil (EVOO). The objective of this study was to review data on the potential effects of different phenolic compounds that can also be found in EVOO on wound healing and closure. Results of in vitro and animal studies demonstrate that polyphenols from different plant species, also present in EVOO, participate in different aspects of wound healing, accelerating this process through their anti-inflammatory, antioxidant, and antimicrobial properties and their stimulation of angiogenic activities required for granulation tissue formation and wound re-epithelialization. These results indicate the potential usefulness of EVOO phenolic compounds for wound treatment, either alone or in combination with other therapies. Human studies are warranted to verify this proposition.

Acetylcholinesterase Inhibitory and Antioxidant Activity of the Compounds Isolated from Vanda roxburghii

Vanda roxburghii has been used in traditional medicine to treat nervous system disorders including Alzheimer's disease (AD). We reported earlier a high acetylcholinesterase inhibitory and antioxidant activity in the chloroform fraction of this plant. Therefore, this study was designed to explore the compounds with acetylcholinesterase inhibitory and antioxidant activities from the chloroform fraction of Vanda roxburghii. Phytochemical investigation led to the isolation for the first time of a fatty acid ester: methyl linoleate (1), and three phenolics: syringaldehyde (2), vanillin (3), and dihydroconiferyl dihydro-p-coumarate (4) along with the previously reported compound gigantol (5). Among the isolates, vanillin (3) and dihydroconiferyl dihydro-p-coumarate (4) were found to significantly inhibit the activity of acetylcholinesterase, scavenge the free radicals, exhibit the reducing power and total antioxidant activity, and effectively reduce the peroxidation of lipid. Gigantol (5) and syringaldehyde (2), despite lacking the activity against acetylcholinesterase, exhibited antioxidant activity. Among the compounds, gigantol (5) appeared to be the most potent antioxidant. These findings revealed that V. roxburghii contained compounds with potential acetylcholinesterase inhibitory and antioxidant activity, which support its traditional use in the treatment of AD.

Comparison of age-dependent alterations in thioredoxin 2 and thioredoxin reductase 2 expressions in hippocampi between mice and rats

Background

Aging is one of major causes triggering neurophysiological changes in many brain substructures, including the hippocampus, which has a major role in learning and memory. Thioredoxin (Trx) is a class of small redox proteins. Among the Trx family, Trx2 plays an important role in the regulation of mitochondrial membrane potential and is controlled by TrxR2. Hitherto, age-dependent alterations in Trx2 and TrxR2 in aged hippocampi have been poorly investigated. Therefore, the aim of this study was to examine changes in Trx2 and TrxR2 in mouse and rat hippocampi by age and to compare their differences between mice and rats.

Results

Trx2 and TrxR2 levels using Western blots in mice were the highest at young age and gradually reduced with time, showing that no significant differences in the levels were found between the two subfields. In rats, however, their expression levels were the lowest at young age and gradually increased with time. Nevertheless, there were no differences in cellular distribution and morphology in their hippocampi when it was observed by cresyl violet staining. In addition, both Trx2 and TrxR2 immunoreactivities in the CA1-3 fields were mainly shown in pyramidal cells (principal cells), showing that their immunoreactivities were altered like changes in their protein levels.

Conclusions

Our current findings suggest that Trx2 and TrxR2 expressions in the brain may be different according to brain regions, age and species. Therefore, further studies are needed to examine the reasons of the differences of Trx2 and TrxR2 expressions in the hippocampus between mice and rats.

Circulating metabolomics profiling reveals novel pathways associated with cognitive decline in patients with hypertension

Background:

Hypertension is a significant risk factor for cardiovascular disease, and it is associated with dementia, including Alzheimer’s disease (AD). Although it may be correlated with AD in terms of symptoms, the link between hypertension and AD pathological biomarkers, and the potential underlying mechanism of hypertension with cognitive decline, are still not well understood.

Methods:

The Mini-Mental State Examination (MMSE) scores were used to evaluate cognitive function. Enzyme-linked immunosorbent assays were used to examine plasma amyloid-beta (Aβ)₄₀, Aβ₄₂, and tau concentration in hypertensive patients. Metabolomics and metagenomics were performed to identify the significantly changed circulating metabolites and microbiota between healthy individuals and hypertensive patients. Pearson’s correlation was used to examine the association between cognitive indicators and differential metabolites.

Results:

We found significantly decreased MMSE scores, elevated plasma Aβ₄₀, and decreased Aβ₄₂/Aβ₄₀ ratio in hypertensive patients, which are critically associated with AD pathology. Based on metabolomics, we found that significantly altered metabolites in the plasma of hypertensive patients were enriched in the benzoate degradation and phenylpropanoid biosynthesis pathways, and they were also correlated with changes in MMSE scores and Aβ₄₂/Aβ₄₀ ratio. In addition, metabolomics signaling pathway analysis suggested that microbial metabolism was altered in hypertensive patients. We also identified altered blood microbiota in hypertensive patients compared with the controls.

Conclusions:

Our study provides a novel metabolic and microbial mechanism, which may underlie the cognitive impairment in hypertensive patients.

History repeats itself: Role of characterizing flavors on nicotine use and abuse

The popularity of e-cigarettes has skyrocketed in recent years, and most vapers use flavored e-cigarette products. Consumption of flavored e-cigarettes exceeds that of combustible cigarettes and other tobacco products among adolescents, who are particularly vulnerable to becoming nicotine dependent. Flavorings have been used by the tobacco industry since the 17th century, but the use of flavors by the e-cigarette industry to create products with "characterizing" flavors (i.e. flavors other than tobacco or menthol) has sparked a public health debate. This review addresses the possibility that characterizing flavors make nicotine more appealing, rewarding and addictive. It also discusses ways in which preclinical and clinical studies could improve our understanding of the mechanisms by which flavors may alter nicotine reward and reinforcement. This article is part of the special issue on 'Contemporary Advances in Nicotine Neuropharmacology'.