Potential Roles of α-amylase in Alzheimer's Disease: Biomarker and Drug Target

Phytochemical constituents analysis in laminaria digitata for Alzheimer's disease: molecular docking and in-silico toxicity approach

Alzheimer's disease (AD) is a common brain disease associated with cognitive impairment and dementia. donepezil, an acetylcholinesterase (AChE) inhibitor drug as a commercial AD drug represents a non-cost-effective treatment with the toxic effects reported. As the prevalence of AD increases, the development of effective therapeutic treatments is urgently required. Laminaria digitata is a brown seaweed claimed to be able to prevent and treat neurodegenerative diseases. Therefore, this study measured and compared the binding affinity and toxicity of seven common phytoconstituents in Laminaria digitata against acetylcholinesterase (AChE) with those of donepezil using a molecular docking approach. The binding free energy values of donepezil, dieckol, eckol, fucodiphlorethol G, 7-Phloroecol, laminaran, alginic acid, and fucoidan with acetylcholinesterase (AChE) were -12.3, -13.5, -10.5, -8,7, -9.7, -8.0, -10.3, and -7.4 kcal/mol. All ligands constantly interacted with the AChE amino acid residues, namely Tyr124. Dieckol, with the strongest and most stable interaction, is classified as class IV toxicity, with an LD50 value of 866 mg/kg. It has aryl hydrocarbon receptor (AhR) and mitochondrial membrane potential (MMP) toxicity at certain doses. Theoretically, based on Lipinski's rule, dieckol is likely to have poor absorption and permeation properties; therefore, several considerations during the drug discovery process are needed.

Characterization of an α-Amylase from the Honeybee Chalk Brood Pathogen Ascosphaera apis

The insect pathogenic fungus, Ascosphaera apis, is the causative agent of honeybee chalk brood disease. Amylases are secreted by many plant pathogenic fungi to access host nutrients through the metabolism of starch, and the identification of new amylases can have important biotechnological applications. Production of amylase by A. apis in submerged culture was optimized using the response surface method (RSM). Media composition was modeled using Box-Behnken design (BBD) at three levels of three variables, and the model was experimentally validated to predict amylase activity (R2 = 0.9528). Amylase activity was highest (45.28 ± 1.16 U/mL, mean ± SE) in media composed of 46 g/L maltose and1.51 g/L CaCl2 at a pH of 6.6, where total activity was ~11-fold greater as compared to standard basal media. The enzyme was purified to homogeneity with a 2.5% yield and 14-fold purification. The purified enzyme had a molecular weight of 75 kDa and was thermostable and active in a broad pH range (> 80% activity at a pH range of 7-10), with optimal activity at 55 °C and pH = 7.5. Kinetic analyses revealed a Km of 6.22 mmol/L and a Vmax of 4.21 μmol/mL·min using soluble starch as the substrate. Activity was significantly stimulated by Fe2+ and completely inhibited by Cu2+, Mn2+, and Ba2+ (10 mM). Ethanol and chloroform (10% v/v) also caused significant levels of inhibition. The purified amylase essentially exhibited activity only on hydrolyzed soluble starch, producing mainly glucose and maltose, indicating that it is an endo-amylase (α-amylase). Amylase activity peaked at 99.38 U/mL fermented in a 3.7 L-bioreactor (2.15-fold greater than what was observed in flask cultures). These data provide a strategy for optimizing the production of enzymes from fungi and provide insight into the α-amylase of A. apis.

Miracle Tree (Moringa oleifera) Attuned GFAP and Synaptophysin Levels, Oxidative Stress and Biomarkers in Cerebellar Fluorosis of Pregnant Rats

<b>Background and Objective:</b> Cerebellar fluorosis is a health issue associated with excessive exposure to fluoride (F) either in direct or indirect ways as pesticides, drinking water and caries preventing prescriptions. It is characterized by elevation in oxidative stress, inflammation, demyelination and Purkinje cell loss. <i>Moringa oleifera</i> (M), is a widely cultivated plant used as a health-booster agent in modulating various disorders because of its high content of vitamins and minerals. The beneficial effect of moringa against fluoride-induced cerebellar toxicity in pregnant rats was investigated in this study. <b>Materials and Methods:</b> Twenty pregnant rats were administered daily 300 mg kg¹ <i>M. oleifera</i> aqueous extract incorporated with 10 mg kg¹ of F intoxication from the 1st day of gestation until the 20th day. Following the termination of the trial, sera were collected and cerebellar tissue was removed for further examinations, along with the assessment of maternity. <b>Results:</b> The <i>M. oleifera</i> significantly normalized serum FSH, LH, progesterone, dopamine and serotonin levels of F-intoxicated mothers. Additionally, <i>M. oleifera</i> markedly prevented the lipid peroxidation and DNA fragmentation indicated by the tail length and moment in comet assay (-34.4 and -75.3%, respectively, when compared to the fluoride intoxicated group), while sustaining the levels of SOD and CAT revealing its antioxidant activity. The <i>M. oleifera</i> regressed the cerebellar α-amylase (-25.4%) and acetylcholinesterase activity (-40.6%), also attenuated GFAP (-73.4%, p<0.0001), synaptophysin level (216.6%, p<0.0001) and IL-6 expression (-91.2%) comparing to fluoride only treated mothers. <b>Conclusion:</b> Histological and ultrastructural examinations confirmed the recuperating effects of <i>M. oleifera</i> on mothers' cerebellar tissue intoxicated with fluoride indicated by intact folia and restored Purkinje cells number and architecture. The maternal study emphasized the anti-abortifacient activity of moringa against fluoride induced-fetotoxicity.

Genetic factors associated with serum amylase in a Japanese population: combined analysis of copy-number and single-nucleotide variants

Amylase activity and levels in humans are heritable quantitative traits. Although many studies exist on the effects of copy-number variants (CNVs) in amylase genes (AMY) on human phenotypes, such as body mass index (BMI), the genetic factors controlling interindividual variation in amylase levels remain poorly understood. Here, we conducted a genome-wide association study (GWAS) of serum amylase levels (SAL) in 814 Japanese individuals to identify associated single-nucleotide variants (SNVs), after adjusting for non-genetic factors. Diploid copy numbers (CN) of AMY (AMY1, AMY2A, and AMY2B) were measured using droplet digital PCR to examine the association between each diploid CN and SAL. We further assessed the relative contribution of the GWAS-lead SNV and AMY CNVs to SAL. GWAS identified 14 significant SNVs (p < 5 × 10^-8) within a linkage disequilibrium block near the AMY cluster on chromosome 1. The association analyses of AMY CNVs and SAL showed a significant association between AMY1 diploid CN and SAL (p = 1.89 × 10^-19), while no significant association with SAL was found for AMY2A CN (p = 0.54) or AMY2B CN (p = 0.15). In a joint association analysis with SAL using the GWAS-lead SNV and AMY1 diploid CN, AMY1 CN remained significant (p = 5.4 ×10^-13), while the association of the lead SNV was marginal (p = 0.08). We also found no association between AMY1 diploid CN and BMI (p = 0.14). Our results indicate that AMY1 CNV is the major genetic factor for Japanese SAL, with no significant association with BMI.