1-Deoxynojirimycin, its potential for management of non-communicable metabolic diseases

1-Deoxynojirimycin attenuates pathological markers of Alzheimer's disease in the in vitro model of neuronal insulin resistance

Insulin resistance, the hallmark of type 2 diabetes mellitus (T2DM), has emerged as a pathological feature in Alzheimer's disease (AD). Given the shared role of insulin resistance in T2DM and AD, repurposing peripheral insulin sensitizers is a promising strategy to preserve neuronal insulin sensitivity and prevent AD. 1-Deoxynojirimycin (DNJ), a bioactive iminosugar, exhibited insulin-sensitizing effects in metabolic tissues and was detected in brain tissue post-oral intake. However, its impact on brain and neuronal insulin signaling has not been described. Here, we investigated the effect of DNJ treatment on insulin signaling and AD markers in insulin-resistant human SK-N-SH neuroblastoma, a cellular model of neuronal insulin resistance. Our findings show that DNJ increased the expression of insulin signaling genes and the phosphorylation status of key molecules implicated in insulin resistance (Y1146-pIRβ, S473-pAKT, S9-GSK3B) while also elevating the expression of glucose transporters Glut3 and Glut4, resulting in higher glucose uptake upon insulin stimuli. DNJ appeared to mitigate the insulin resistance-driven increase in phosphorylated tau and Aβ1-42 levels by promoting insulin-induced phosphorylation of GSK3B (a major tau kinase) and enhancing mRNA expression of the insulin-degrading enzyme (IDE) pivotal for insulin and Aβ clearance. Overall, our study unveils probable mechanisms underlying the potential benefits of DNJ for AD, wherein DNJ attenuates tau and amyloid pathologies by reversing neuronal insulin resistance. This provides a scientific basis for expanding the use of DNJ-containing products for neuroprotective purposes and prompts further research into compounds with similar mechanisms of action.

Glucose-lowering effect of Reducose® enriched with 1-deoxynojirimycin and l-leucine: Studies on insulin secretion in INS-1 cells and reduction of blood glucose in diabetic rats

The extract of mulberry leaf and its active ingredients have already been reported to have anti-diabetic effects; however, further studies are required to obtain better quality extracts and higher yields of active ingredients. Reducose® is a commercially available aqueous extract of mulberry leaves with a high content of active ingredients. In this study, the biological activities of Reducose®, 1-deoxynojirimycin, and l-leucine were evaluated using a glucose-stimulated insulin secretion (GSIS) assay. The GSIS assay results were expressed as the glucose-stimulated index (GSI). Considering the pharmacological safety in pancreatic β-cells, the appropriate non-toxic concentrations were selected by screening for cytotoxicity of Reducose®, 1-deoxynojirimycin, and l-leucine before the GSIS assay. The effect of Reducose®, 1-deoxynojirimycin, and l-leucine on glucose-stimulated insulin secretion in INS-1 cells was compared. Reducose®, 1-deoxynojirimycin, and l-leucine increased the GSI values more effectively than gliclazide (positive control). This was associated with an increase in protein expression, such as peroxisome proliferator-activated receptor-γ, insulin receptor substrate-2, activated pancreatic and duodenal homeobox-1, which are related to the regulation of pancreatic β-cell function and survival. In order to elucidate the effect of Reducose® in anti-diabetic effects, blood glucose levels, insulin levels, and liver and lipid concentrations were investigated in a Sprague-Dawley rat model of high-fat diet/streptozotocin-induced diabetes. We observed that administration of Reducose® can decrease fasting blood glucose levels and reduce the production of AST, ALT, TG, and TC to a similar extent as metformin (positive control). These results suggested that Reducose® play a role in promoting GSIS but not enough to show that the content and proportion of 1-deoxynojirimycin and l-leucine play an important role in the GSIS activity of Reducose®.

Alginate-Based Carriers Loaded with Mulberry (Morus alba L.) Leaf Extract: A Promising Strategy for Prolonging 1-Deoxynojirimicyn (DNJ) Systemic Activity for the Nutraceutical Management of Hyperglycemic Conditions

The iminosugar 1-deoxynojirimicyn (DNJ) contained in mulberry leaves has displayed systemic beneficial effects against disorders of carbohydrate metabolism. Nevertheless, its effect is impaired by the short half-life. Alginate-based carriers were developed to encapsulate a DNJ-rich mulberry extract: Ca-alginate beads, obtained by external gelation, and spray-dried alginate microparticles (SDMs). Mean size and distribution, morphology, drug loading, encapsulation efficiency, experimental yield, and release characteristics were determined for the two formulations. Ca-alginate beads and SDMs exhibited an encapsulation efficiency of about 54% and 98%, respectively, and a DNJ loading in the range of 0.43-0.63 μg/mg. The in vitro release study demonstrated the carriers' capability in controlling the DNJ release in acid and basic conditions (<50% in 5 h), due to electrostatic interactions, which were demonstrated by 1H-NMR relaxometry studies. Thus, alginate-based particles proved to be promising strategies for producing food supplements containing mulberry leaf extracts for the management of hyperglycemic state.

Bitter yet beneficial: The dual role of dietary alkaloids in managing diabetes and enhancing cognitive function

With the rising prevalence of diabetes and its association with cognitive impairment, interest in the use of dietary alkaloids and other natural products has grown significantly. Understanding how these compounds manage diabetic cognitive dysfunction (DCD) is crucial. This comprehensive review explores the etiology of DCD and the effects of alkaloids in foods and dietary supplements that have been investigated as DCD therapies. Data on how dietary alkaloids like berberine, trigonelline, caffeine, capsaicin, 1-deoxynojirimycin, nuciferine, neferine, aegeline, tetramethylpyrazine, piperine, and others regulate cognition in diabetic disorders were collected from PubMed, Research Gate, Web of Science, Science Direct, and other relevant databases. Dietary alkaloids could improve memory in behavioral models and modulate the mechanisms underlying the cognitive benefits of these compounds, including their effects on glucose metabolism, gut microbiota, vasculopathy, neuroinflammation, and oxidative stress. Evidence suggests that dietary alkaloids hold promise for improving cognition in diabetic patients and could open exciting avenues for future research in diabetes management.

Effect of mulberry fruit extract on post-prandial glycaemic and insulinemic responses to different rice types: a randomised trial in healthy adults

We previously reported that the addition of a specified mulberry fruit extract (MFE) to rice consistently reduces post-prandial glycaemic (PPG) and post-prandial insulinemic (PPI) responses. This research tested whether this effect generalises to a broad range of rice types, reflecting the wide variation in rice characteristics known to influence glycaemic responses. In a randomised, balanced, partial factorial crossover design, Sona Masoori (SM), Bora Saul (BS), Gobindobogh (Gb) and Banskati (Bn) rices were tested with and without 0·37 g MFE. Healthy, normal-weight Indian adults (N 120) each consumed four of the eight possible boiled rice meals, all containing about 50 g available carbohydrate. The primary outcome was the effect of MFE on PPG, expressed as the percentage change in the positive, incremental AUC over 2 h. The mean effect of MFE on PPG for all rice types combined was -11·4 % (P < 0·003). The reduction in PPG was in a qualitatively similar range for all rice types (-9·8 to -15·1 %), and this was statistically significant for Bn. MFE also reduced the corresponding PPI response to all rice types combined by a mean of 10·1 % (P < 0·001; range -6·1 to -13·4 %), and the reduction in PPI was statistically significant for SM, Gb and BS. In conclusion, addition of 0·37 g MFE modestly reduced PPG and PPI responses to rices in general, and the effects were statistically significant for specific rice types.

Preliminary Comparisons of Tender Shoots and Young Leaves of 12 Mulberry Varieties as Vegetables and Constituents Relevant for Their Potential Use as Functional Food for Blood Sugar Control

Vegetables are essential for maintaining health and preventing diseases due to their nutrients and functional components. However, vegetables specifically designed for blood sugar control are limited. The mulberry tree (Morus) offers potential as a source of functional vegetables with blood-sugar-lowering properties, mainly attributed to 1-Deoxynojirimycin (DNJ). This study compared the nutritional composition and DNJ content in various edible parts of twelve mulberry tree varieties. Sensory evaluations were also conducted to assess sensory attributes. Interestingly, DNJ was found to show a positive correlation with sensory evaluations. Furthermore, the sugar content, particularly sucrose, was significantly higher in tender shoots than leaves, indicating tender shoots as a preferable choice for development as a functional food for blood sugar control. Finally, VM 19 and VM 22 are considered as good candidates for the mulberry vegetable using varieties after sensory evaluation and combining with the DNJ content. These findings provide valuable insights for future research into vegetable selections for blood sugar management and support the potential commercialization of mulberry leaf vegetables as functional food options.

Intestinal Production of Alpha-Glucosidase Inhibitor by Bacillus coagulans Spores

This study examines the possibility of directly producing and utilizing useful substances in the intestines of animals using anaerobic bacteria that can grow in the intestines of animals. A facultative anaerobe producing a large amount of α-glucosidase inhibitor was isolated from hay and identified and named Bacillus coagulans CC. The main compound of α-glucosidase inhibitor produced by Bacillus coagulans CC was identified as 1-deoxynojirimycin. α-glucosidase inhibitor activity was confirmed in the intestinal contents and feces of mice orally administered with spores of this strain, and it was confirmed that this strain could efficiently reach the intestines, proliferate, and produce α-glucosidase inhibitors. As a result of administering Bacillus coagulans CC to mice at 10⁹ cells per 1 kg body weight of spores for 8 weeks, the high-carbohydrate diet and the high-fat diet showed a 5% lower weight gain compared to the non-administrated group. At this point, in the spore-administered group, a decrease was observed in both the visceral and subcutaneous fat layers of the abdomen and thorax in both high-carbohydrate and high-fat diet groups compared to the non-administered group on computed tomography. The results of this study show that α-glucosidase inhibitors produced in the intestine by specific strains can work efficiently.

Perplexing Polyphenolics: The Isolations, Syntheses, Reappraisals, and Bioactivities of Flavonoids, Isoflavonoids, and Neoflavonoids from 2016 to 2022

Flavonoids, isoflavonoids, neoflavonoids, and their various subcategories are polyphenolics-an extensive class of natural products. These compounds are bioactive and display multiple activities, including anticancer, antibacterial, antiviral, antioxidant, and neuroprotective activities. Thus, these compounds can serve as leads for therapeutic agents or targets for complex synthesis; they are coveted and routinely isolated, characterized, biologically evaluated, and synthesized. However, data regarding the compounds' sources, isolation procedures, structural novelties, bioactivities, and synthetic schemes are often dispersed and complex, a dilemma this review aims to address. To serve as an easily accessible guide for researchers wanting to apprise themselves of the latest advancements in this subfield, this review summarizes seventy-six (76) articles published between 2016 and 2022 that detail the isolation and characterization of two hundred and forty-nine (249) novel compounds, the total and semisyntheses of thirteen (13) compounds, and reappraisals of the structures of twenty (20) previously reported compounds and their bioactivities. This article also discusses new synthetic methods and enzymes capable of producing or modifying flavonoids, isoflavonoids, or neoflavonoids.

Interaction between Gelatin and Mulberry Leaf Polysaccharides in Miscible System: Physicochemical Characteristics and Rheological Behavior

In this study, the miscible system was formed by mixing gelatin (G) with mulberry leaf polysaccharides (MLPs) continuously extracted with a hot buffer (HBSS), a chelating agent (CHSS), a dilute alkali (DASS), and a concentrated alkali (CASS), and the zeta potential, turbidity, particle size, distribution, and rheological properties of the miscible systems were evaluated. Under acidic conditions, the miscible systems of four polysaccharides and gelatin were in a clear state; under alkaline conditions, G-HBSS and G-CHSS were clarified, and G-DASS and G-CASS changed from clarification to turbidity. The zeta potential changed from positive to negative with the increase in pH. When the pH was at 7, it increased with the increase in polysaccharide concentration but was still negative. The four miscible systems all showed polydispersity. The particle sizes of G-HBSS and G-CHSS decreased with the increase in pH, while the particle sizes of G-DASS and G-CASS were increased. The four miscible systems showed “shear thinning” behavior, and the addition of gelatin reduced the apparent viscosity of the four polysaccharide solutions. G-CHSS was highly stable, and G-CASS was more suitable as a stabilizer in the freezing process.

Underutilized Fruit Crops of Indian Arid and Semi-Arid Regions: Importance, Conservation and Utilization Strategies

Nowadays, there is a large demand for nutrient-dense fruits to promote nutritional and metabolic human health. The production of commercial fruit crops is becoming progressively input-dependent to cope with the losses caused by biotic and abiotic stresses. A wide variety of underutilized crops, which are neither commercially cultivated nor traded on a large scale, are mainly grown, commercialized and consumed locally. These underutilized fruits have many advantages in terms of ease to grow, hardiness and resilience to climate changes compared to the major commercially grown crops. In addition, they are exceptionally rich in important phytochemicals and have medicinal value. Hence, their consumption may help to meet the nutritional needs of rural populations, such as those living in fragile arid and semi-arid regions around the world. In addition, local people are well aware of the nutritional and medicinal properties of these crops. Therefore, emphasis must be given to the rigorous study of the conservation and the nutritional characterization of these crops so that the future food basket may be widened for enhancing its functional and nutritional values. In this review, we described the ethnobotany, medicinal and nutritional values, biodiversity conservation and utilization strategies of 19 climate-resilient important, underutilized fruit crops of arid and semi-arid regions (Indian jujube, Indian gooseberry, lasora, bael, kair, karonda, tamarind, wood apple, custard apple, jamun, jharber, mahua, pilu, khejri, mulberry, chironji, manila tamarind, timroo, khirni).

Hepatoprotective effect of different mulberry leaf extracts against acute liver injury in rats by alleviating oxidative stress and inflammatory response

This study investigated the hepatoprotective effect of various mulberry (Morus alba L.) leaf extracts (MLEs), including mulberry ethanol extract (MEE), aqueous extract (MAE) and combination extract (MCE) against D-galactosamine (D-GalN)...

Optimization and characterization of eco-friendly antimicrobial nanocellulose sheet prepared using carbon dots of white mulberry (Morus alba L.)

BACKGROUND

Carbon dots (C-dots) with antimicrobial activity were synthesized from the white mulberry extract with the aim of fabricating anti-listeria nanopaper using bacterial nanocellulose (BNC). Highly dispersed synthesized C-dots with a size smaller than 10 nm (approximately 4.9 nm) were impregnated into BNC by an ex situ coating method and then mechanical, morphological, UV-protectant and antibacterial activity were assessed. Randomized response surface methodology using a central composite design was applied to investigate the optimized concentration of C-dots in the BNC membrane.

RESULTS

An optimized nanopaper including C-dots at a concentration of 530 g L^-1 and an impregnation time of 14 h at 30 °C with significant antimicrobial activity on Listeria monocytogenes was designed. The addition of C-dots into BNC significantly increased ultimate tensile strength and decreased strain with respect to breaking BNC. A BNC sheet with high-efficient UV-blocking property was prepared using C-dots.

CONCLUSION

Based on the results, the designed nanopaper shows a substantial capacity with respect to the fabrication of antimicrobial/UV-blocking sheets for food active packaging. © 2020 Society of Chemical Industry.

Dual-Targeting Antiproliferation Hybrids Derived from 1-Deoxynojirimycin and Kaempferol Induce MCF-7 Cell Apoptosis through the Mitochondria-Mediated Pathway

1-Deoxynojirimycin, an α-glucosidase inhibitor, possesses various biological activities such as antitumor, antidiabetic, and antiviral effects. However, the application of 1-deoxynojirimycin is restricted by its poor lipophilicity and low bioavailability. In this study, three 1-deoxynojirimycin derivatives (8-10) comprising 1-deoxynojirimycin and kaempferol were designed and synthesized to modify their pharmacokinetics and improve their antitumor efficacy. Among them, compound 10, a conjugate of 1-deoxynojirimycin and kaempferol linked through an undecane chain, exhibited excellent lipophilicity, antiproliferative effects, and α-glucosidase inhibitory activity. Compared with 1-deoxynojirimycin, kaempferol, and their combination, compound 10 downregulated cyclooxygenase-2 (COX-2) expression, arrested the cell cycle at the S phase, induced cellular apoptosis, and inhibited the migration of MCF-7 cells. Moreover, further investigation indicated that compound 10 induced MCF-7 cell apoptosis through a mitochondrial-mediated pathway via the loss of mitochondrial membrane potential. This led to increasing intracellular levels of reactive oxygen species (ROS) and Ca²⁺, the downregulation of Bcl-2 expression, and the upregulation of Bax levels.

Physicochemical and Antioxidant Properties of Gelatin and Gelatin Hydrolysates Obtained from Extrusion-Pretreated Fish (Oreochromis sp.) Scales

Fish gelatin and its hydrolysates exhibit a variety of biological characteristics, which include antihypertensive and antioxidant properties. In this study, fish gelatins were extracted from extrusion-pretreated tilapia scales, and then subjected to analyses to determine the physicochemical properties and antioxidant activity of the extracted gelatins. Our findings indicate that TSG2 (preconditioned with 1.26% citric acid) possessed the greatest extraction yield, as well as higher antioxidant activities compared with the other extracted gelatins. Hence, TSG2 was subjected to further hydrolyzation using different proteases and ultrafiltration conditions, which yielded four gelatin hydrolysates: TSGH1, TSGH2, TSGH3, and TSGH4. The results showed that TSGH4 (Pepsin + Pancreatin and ultrafiltration < 3000 Da) had a higher yield and greater antioxidant activity in comparison with the other gelatin hydrolysates. As such, TSGH4 was subjected to further fractionation using a Superdex peptide column and two-stage reverse-phase column HPLC chromatography, yielding a subfraction TSGH4-6-2-b, which possessed the highest 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity compared with the other fractions. Further LC-ESI/MS/MS analysis of TSGH4-6-2-b suggested two novel peptides (GYDEY and EPGKSGEQGAPGEAGAP), which could have potential as naturally-occurring peptides with antioxidant properties. These promising results suggest that these antioxidant peptides could have applications in food products, nutraceuticals, and cosmetics.

GEO-PGS composite shows synergistic and complementary effect on Escherichia coli and improvement of intestinal dysfunction

Palygorskite (PGS) is a kind of clay minerals with the property of absorbent capacity, and ginger essential oil (GEO) is a kind of natural antibacterial substances. In the present study PGS was used as carrier of GEO, and thus, a kind of new anti-bacterial composite GEO-PGS has been obtained. Characterization, inhibitory effect of GEO-PGS on Escherichia coli (E. coli) and its function of improvement of intestinal health would be investigated. Results showed that characterization analysis of GEO-PGS (FTIR, TG-DSC, BET, Zeta potential, specific surface area, total pore volume and size, TEM observation) demonstrated combination of GEO and PGS, and GEO was absorbed on the surface of PGS, partially filled the micropores of PGS. GEO-PGS had obvious inhibitory effect on E.coli, in combination of the antibacterial activity of GEO and bacteria-absorbed capability of PGS. GEO-PGS also had ameliorating effect on enteritis and intestinal dysfunction in vivo, which might be related to the inhibition of gene expression of inflammatory cytokines (TLR2, IL-6, TNFα, and IL-8). In conclusion, the novel composite GEO-PGS has the potential usage as functional component having effect of improving intestinal health.

Purification and identification of antioxidant peptides from round scad (Decapterus maruadsi) hydrolysates by consecutive chromatography and electrospray ionization-mass spectrometry

Round scad (Decapterus maruadsi) was hydrolyzed with a double-enzyme (a mixture of neutrase and trypsin) to obtain antioxidant peptides. The round scad hydrolysates obtained by 5-h hydrolysis (RSH) displayed the strongest antioxidant activities, which could scavenge the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, the hydroxyl radical, and exhibit reducing power. RSH was further separated into four fractions by using an ultrafiltration membrane system, and low-molecular-weight fraction RSH-IV (<5 kDa) showed the highest antioxidant activities. Fraction RSH-IV was then purified with gel filtration chromatography followed by reverse high-performance liquid chromatography (RP-HPLC). The sequence of the purified antioxidant peptide was identified as Lys-Gly-Phe-Arg (506 Da) by liquid chromatography/electrospray ionization tandem mass spectrometry (LC-MS/MS). Additionally, the purified peptide could scavenge DPPH radical at IC₅₀ value of 0.13 mg/mL, and it showed a 49.08-fold higher DPPH radical scavenging activity compared with that of the crude RSH. The results suggest that antioxidant peptides obtained from round scad (Decapterus maruadsi) could be a good source of natural antioxidant.