Comparison of the reaction of methylglyoxal (MGO) with murine and human amyloid beta (Aβ): Insights into a mechanism of Alzheimer's disease (AD)

Hyperoside Prevents Aβ42-Induced Neurotoxicity in PC12 Cells and Caenorhabditis elegans

Traditional Chinese medicines such as hyperoside-rich Acanthopanax senticosus and Crataegus pinnatifida have been confirmed to exhibit anti-oxidative stress properties. Hyperoside, the main ingredient of numerous antioxidant herbs, may have the ability to postpone the onset of neurodegenerative diseases. This study investigates the possible therapeutic mechanism of hyperoside as a natural antioxidant against Alzheimer's disease (AD) in Caenorhabditis elegans and PC12 cells. Specifically, hyperoside reduced reactive oxygen species (ROS) level and Aβ42-induced neurotoxicity in C. elegans worms. Meanwhile, hyperoside reduced ROS production and increased mitochondrial membrane potentialin Aβ42-induced PC12 cells, which possibly due to the increase of antioxidant enzymes activity and the diminution of malondialdehyde levels. Hoechst 33,342 staining and flow cytometry analysis results suggested that hyperoside reverses cell apoptosis. Network pharmacology predicts potentially relevant hyperoside targets and pathways in AD therapy. As anticipated, hyperoside reversed Aβ42-stimulated downregulation of the PI3K/Akt/Nrf2/HO-1. The PI3K inhibitor LY294002 partially abolished the protective capability of hyperoside. The results of molecular docking further indicated that the PI3K/Akt pathways may be involved in the protection of Aβ42-induced PC12 cells by hyperoside treatment. The study provides theoretical information for research and development of hyperoside as an antioxidant dietary supplement.

Metabonomics fingerprint of volatile organic compounds in serum and urine of pregnant women with gestational diabetes mellitus

BACKGROUND

Gestational diabetes mellitus (GDM) is a metabolic disease with an increasing annual incidence rate. Our previous observational study found that pregnant women with GDM had mild cognitive decline.

AIM

To analyze the changes in metabonomics in pregnant women with GDM and explore the mechanism of cognitive function decline.

METHODS

Thirty GDM patients and 30 healthy pregnant women were analyzed. Solid-phase microextraction gas chromatography/mass spectrometry was used to detect organic matter in plasma and urine samples. Statistical analyses were conducted using principal component analysis and partial least squares discriminant analysis.

RESULTS

Differential volatile metabolites in the serum of pregnant women with GDM included hexanal, 2-octen-1-ol, and 2-propanol. Differential volatile metabolites in the urine of these women included benzene, cyclohexanone, 1-hexanol, and phenol. Among the differential metabolites, the conversion of 2-propanol to acetone may further produce methylglyoxal. Therefore, 2-propanol may be a potential marker for serum methylglyoxal.

CONCLUSION

2-propanol may be a potential volatile marker to evaluate cognitive impairment in pregnant women with GDM.

Distinct impact of glycation towards the aggregation and toxicity of murine and human amyloid-β

Glycation of human Aβ (hAβ) is implicated to induce the deposition of amyloid aggregates found in the Alzheimer's disease (AD)-affected brain. Murine Aβ (mAβ) differs from hAβ in three different amino acid residues (Gly5, Phe10, and Arg13) and is less likely to form amyloid aggregates. Herein, we report that the advanced glycated end products of mAβ40 over hAβ40 are distinctly generated. The different glycation between the two peptides can govern their aggregation kinetics, structural transition, and cytotoxicity.