Neuroactive venom compounds obtained from Phlogiellus bundokalbo as potential leads for neurodegenerative diseases: insights on their acetylcholinesterase and beta-secretase inhibitory activities in vitro

Transcriptomic and proteomic analyses reveal the diverse components in the venom of a recently described spider species Macrothele washanensis

Spider venom has been shown to possess a variety of pharmacological activities with promising applications in biomedical and agricultural sciences. However, the molecular structure and functions of these toxins have only been revealed for a few species. In this study, we unveiled the venom composition of Macrothele washanensis venom for the first time using transcriptomics, proteomics, and bioinformatic analyses. A total of 147,492,716 Illumina valid reads were obtained from the transcriptome of the venom glands, and 3,010,024 unigenes were assembled to predict 69 putative toxin sequences, which were classified into 25 toxin superfamilies based on cysteine motifs. Crude venom proteomics analysis identified 43 toxin proteins, including 15 peptide toxins and 28 proteases, including the CAP (CRISP/Allergen/PR) protein family, acetylcholinesterase, metalloproteinases, hyaluronidase, and dermonecrotic toxin. In conclusion, the results of the present study revealed the composition of the venom of M. washanensis, and several peptide toxins with potential medical, such work provides the foundation for further research on the molecular functions of these venom components as well as applied studies for the use of such compounds.

Understanding of Alzheimer's disease pathophysiology for therapeutic implications of natural products as neuroprotective agents

Alzheimer's disease (AD) is a leading cause of dementia, affecting more than 24.3 million people worldwide in 2024. Sporadic AD (SAD) is more common and occurs in the geriatric population, while familial AD (FAD) is rare and appears before the age of 65 years. Due to progressive cholinergic neuronal loss and modulation in the PKC/MAPK pathway, β-secretase gets upregulated, leading to Aβ aggregation, which further activates tau kinases that form neurofibrillary tangles (NFT). Simultaneously, antioxidant enzymes are also upregulated, increasing oxidative stress (OS) and reactive species by impairing mitochondrial function, leading to DNA damage and cell death. This review discusses the classifications and components of several natural products (NPs) that target these signaling pathways for AD treatment. NPs, including alkaloids, polyphenols, flavonoids, polysaccharides, steroids, fatty acids, tannins, and polypeptides derived from plants, microbes, marine animals, venoms, insects, and mushrooms, are explored in detail. A synergistic combination of plant metabolites, together with prebiotics and probiotics has been shown to decrease Aβ aggregates by increasing the production of bioactive compounds. Toxins derived from venomous organisms have demonstrated effectiveness in modulating signaling pathways and reducing OS. Marine metabolites have also shown neuroprotective and anti-inflammatory properties. The cholera toxin B subunit and an Aβ15 fragment have been combined to create a possible oral AD vaccine, that showed enhancement of cognitive function in mice. Insect tea is also a reliable source of antioxidants. A functional edible mushroom snack bar showed an increment in cognitive markers. Future directions and therapeutic approaches for the treatment of AD can be improved by focusing more on NPs derived from these sources.

Preparation of Acetylcholinesterase Inhibitory Peptides from Yellowfin Tuna Pancreas Using Moderate Ultrasound-Assisted Enzymatic Hydrolysis

Bioactive peptides represent a promising therapeutic approach for Alzheimer's disease (AD) by maintaining cholinergic system homeostasis through the inhibition of acetylcholinesterase (AChE) activity. This study focused on extracting AChE inhibitory peptides from yellowfin tuna pancreas using moderate ultrasound-assisted enzymatic hydrolysis (MUE). Firstly, papain and MUE stood out from five enzymes and four enzymatic hydrolysis methods, respectively, by comparing the degree of hydrolysis and AChE inhibitory activity of different pancreatic protein hydrolysates. Subsequently, the optimal MUE conditions were obtained by single-factor, Plackett-Burman, and response surface methodologies. The pancreatic protein hydrolysate prepared under optimal MUE conditions was then purified by ultrafiltration followed by RP-HPLC, from which a novel AChE inhibitory peptide (LLDF) was identified by LC-MS/MS and virtual screening. LLDF effectively inhibited AChE activity by a competitive inhibition mechanism, with an IC50 of 18.44 ± 0.24 μM. Molecular docking and molecular dynamic simulation revealed that LLDF bound robustly to the active site of AChE via hydrogen bonds. These findings provided a theoretical basis for the valuable use of yellowfin tuna pancreas and introduced a new viewpoint on the potential therapeutic advantages of AChE inhibitory peptides for future AD treatment.