Effect of dietary inclusion of Fireweed ( Crassocephalum crepidioides ) on behavioural patterns, memory indices, and activities of cholinergic and monoaminergic enzymes in a fruit fly ( Drosophila melanogaster ) model of Alzheimer's disease

Lycium ruthenicum Murray derived exosome-like nanovesicles inhibit Aβ-induced apoptosis in PC12 cells via MAPK and PI3K/AKT signaling pathways

Plant-derived exosome-like nanovesicles (ELNs) are nano-sized vesicles extracted from edible plants. Lycium ruthenicum Murray (LRM) has been gaining increasing attention due to its nutritional and medicinal value, but the ELNs in LRM has not been reported. In this study, LRM-ELNs were obtained, and the proteins, lipids, microRNAs (miRNAs) and active components in LRM tissues and LRM-ELNs was analyzed by LC-MS/MS, LC-MS, high-throughput sequencing techniques, and physical and chemical analysis. LRM-ELNs can be uptaken by PC12 cells through macropinocytosis and caveolin-mediated endocytosis primarily. Transcriptomic and western blot experiments indicate that LRM-ELNs can inhibit Aβ-induced apoptosis in PC12 cells through the MAPK and PI3K/AKT signaling pathways, with miRNAs playing a crucial role. These results indicate that LRM-ELNs have the protection effect on PC12 cells and can be considered as dietary supplements for alleviating neurodegenerative diseases.

Potential therapeutic natural compounds for the treatment of Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) is a complicated neurodegenerative disease with cognitive impairment occurring in the older people, in which extracellular accumulation of β-amyloid and intracellular aggregation of hyperphosphorylated tau are regarded as the prevailing theories. However, the exact AD mechanism has not been determined. Moreover, there is no effective treatment available in phase III trials to eradicate AD, which is imperative to explore novel treatments.

PURPOSE

A number of up-to-date pre-clinical studies on cognitive impairment is beneficial to clarify the pathology of AD. This review recapitulates several advances in AD pathobiology and discusses the neuroprotective effects of natural compounds, such as phenolic compounds, natural polysaccharides and oligosaccharides, peptide, and lipids, underscoring the therapeutic potential for AD.

METHODS

Electronic databases involving PubMed, Web of Science, and Google Scholar were searched up to October 2023. Articles were conducted using the keywords like Alzheimer's disease, pathogenic mechanisms, natural compounds, and neuroprotection.

RESULT

This review summarized several AD pathologies and the neuroprotective effects of natural compounds such as natural polysaccharides and oligosaccharides, peptide, and lipids.

CONCLUSION

We have discussed the pathogenic mechanisms of AD and the effect natural products on neurodegenerative diseases particularly in treating AD. Specifically, we investigated the molecular pathways and links between natural compounds and Alzheimer's disease such as through NF-κB, Nrf2, and mTOR pathway. Further investigation is necessary in exploring the bioactivity and effectiveness of natural compounds in clinical trials, which may provide a promising treatment for AD patients.

African Under-Utilized Medicinal Leafy Vegetables Studied by Microtiter Plate Assays and High-Performance Thin-Layer Chromatography-Planar Assays

Biological activities of six under-utilized medicinal leafy vegetable plants indigenous to Africa, i.e., Basella alba, Crassocephalum rubens, Gnetum africanum, Launaea taraxacifolia, Solanecio biafrae, and Solanum macrocarpon, were investigated via two independent techniques. The total phenolic content (TPC) was determined, and six microtiter plate assays were applied after extraction and fractionation. Three were antioxidant in vitro assays, i.e., ferric reducing antioxidant power (FRAP), cupric reduction antioxidant capacity (CUPRAC), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging, and the others were enzyme (acetylcholinesterase, butyrylcholinesterase, and tyrosinase) inhibition assays. The highest TPC and antioxidant activity from all the methods were obtained from polar and medium polar fractions of C. rubens, S. biafrae, and S. macrocarpon. The highest acetyl- and butyrylcholinesterase inhibition was exhibited by polar fractions of S. biafrae, C. rubens, and L. taraxacifolia, the latter comparable to galantamine. The highest tyrosinase inhibition was observed in the n-butanol fraction of C. rubens and ethyl acetate fraction of S. biafrae. In vitro assay results of the different extracts and fractions were mostly in agreement with the bioactivity profiling via high-performance thin-layer chromatography-multi-imaging-effect-directed analysis, exploiting nine different planar assays. Several separated compounds of the plant extracts showed antioxidant, α-glucosidase, α-amylase, acetyl- and butyrylcholinesterase-inhibiting, Gram-positive/-negative antimicrobial, cytotoxic, and genotoxic activities. A prominent apolar bioactive compound zone was tentatively assigned to fatty acids, in particular linolenic acid, via electrospray ionization high-resolution mass spectrometry. The detected antioxidant, antimicrobial, antidiabetic, anticholinesterase, cytotoxic, and genotoxic potentials of these vegetable plants, in particular C. rubens, S. biafrae, and S. macrocarpon, may validate some of their ethnomedicinal uses.

Antiaging effect of anthocyanin extracts from bilberry on natural or UV-treated male Drosophila melanogaster

Anthocyanins from bilberry (Vaccinium vitis-idaea) are one of the most abundant sources of polyphenols and are widely used in the food, medicine and cosmetics industries due to their antioxidation properties, but few studies have investigated their antiaging properties. Based on our previous examination, the effect of anthocyanin extracts from bilberry (BANCs) on several characteristics of natural and UV-treated male Drosophila melanogaster, including their lifespan, fecundity, and antioxidant capacity, was studied, and the related mechanisms were preliminary explored. The results indicated that BANCs can effectively prolong the average and maximum lifespan and improve the reproductive capacity and antioxidant capacity of natural and UV-treated flies. In particular, BANCs significantly changed the growth cycle, sex ratio and content of ROS in the fat bodies of the offspring and decreased the expression levels of antioxidant- and autophagy-related genes in UV-treated flies. Collectively, the results demonstrate that BANC supplementation in the medium effectively alleviated the aging process, and this effect was not directly correlated with the antioxidant and autophagy signaling pathways in the body of D. melanogaster.

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BANCs can prolong the lifespan, and improve the reproductive and antioxidant capacity flies.

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BANCs changed the growth cycle, sex ratio and content of ROS in fat bodies for UV-treated flies.

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BANCs decreased the expression levels of antioxidant- and autophagy-related genes in UV-treated flies.