Carbohydrate Digestive Enzymes Research Articles

Antibacterial and Carbohydrate Digestive Enzyme Inhibitory Effects of Native Plants Used for Medicinal and Culinary Purposes in Cyprus

Natural products are an inexhaustive reservoir of bioactive compounds with diverse effects protecting human health as components of nutrition and as active substances of drugs. The objective of the present study was to evaluate the bactericidal and carbohydrate digestive enzyme inhibitory activity of twelve native plants from Cyprus, that are consumed for medicinal and/ or culinary purposes. Each plant was sequentially extracted with solvents of increasing polarity, from non-polar to polar solvents. At first, the total phenolic (TPC) and flavonoid (TFC) content of the extracts were determined. The bactericidal potential of plant extracts was tested against six bacteria using the broth microdilution method. Furthermore, their inhibitory effects on digestive enzymes, namely α-glucosidase and α-amylase, were also determined. Results demonstrated a substantial diversity in TPC (2.3-483.5 mg gallic acid equivalent g−1) and TFC (4.1-394.6 mg catechin equivalent g−1) of the plant extracts; a great impact of solvent was found. Furthermore, potent antibacterial activity (minimum bactericidal concentration ≤ 500 µg ml−1) of capper, mountain oregano, rosemary, silver thistle, and vine leaf extracts against Gram-positive bacteria was determined. Regarding carbohydrate digestive enzyme inhibitory effects, the inhibition of α-glucosidase enzyme is higher than 80%, when rosemary, silver thistle, and vine leaf extracts are used at a concentration of 500 µg g−1. Overall, the present study describes the antibacterial and inhibitory effect against carbohydrate digestive enzymes of unstudied plant species or known plants from the unexplored island of Cyprus. It provides valuable data for the nutraceutical value of native edible plants as well as assesses these plants as potential sources of antibacterial and carbohydrate digestive enzyme inhibitory agents for drug discovery.

Insulin secretory actions of polyphenols of Momordica charantia regulate glucose homeostasis in alloxan-induced type 2 diabetic rats

Abstract Objective Momordica charantia, commonly known as bitter gourd, is traditionally used as remedies for various diseases including diabetes. The main objective of this study is to investigate the in vitro and in vivo insulinotropic and antidiabetic effects of an 80% ethanolic extract of M. charantia (EEMC) fruit, as well as the underlying molecular mechanism involved and preliminary phytochemical screening. Methods The insulin secretion was measured using clonal pancreatic BRIN-BD11 β-cells and isolated mouse islets. The ability of EEMC to inhibit carbohydrate digestive enzymes and glucose absorption and to scavenge free radicals was assessed via starch digestion, glucose diffusion, and 2,2-diphenyl-1-picrylhydrazyl assay methods. The effects of EEMC on a variety of metabolic parameters were evaluated in alloxan-induced type 2 diabetic rats, including lipid profile. Finally, a preliminary phytochemical screening was conducted to identify the active phytoconstituents. Key findings EEMC increased insulin release through the KATP-dependent/cyclic adenosine monophosphate pathway, which depolarizes the β-cell membrane and elevates intracellular calcium. It also inhibited glucose absorption and free radicals, suggesting its potential to delay gastric emptying, attenuate oxidative stress, and reduce inflammatory cytokines. In vivo studies showed that EEMC improves oral glucose tolerance, food intake, fasting blood glucose, plasma insulin, and lipids and promotes intestinal motility. The active phytoconstituents in EEMC, such as flavonoids, alkaloids, tannins, saponins, steroids, and glycosides, are likely responsible for these effects. Conclusion The antihyperglycemic properties of EEMC indicate that it might be a promising candidate for diabetes management. However, additional study into the application of M. charantia in type 2 diabetes is essential.

Scirpusin B isolated from Passiflora edulis Var. flavicarpa attenuates carbohydrate digestive enzymes, pathogenic bacteria and oral squamous cell carcinoma.

The online version contains supplementary material available at 10.1007/s13205-023-03876-6.

Evaluation of the antidiabetic, antiobesity and antioxidant potential of Anthophycus longifolius ((Turner) Kützing)

Obesity is a major public health problem that is associated with many metabolic disorders including diabetes, hypertension, and cardiovascular diseases. Anthophycus longifolius is a brown seaweed that have been shown to possess antioxidant, antibacterial and anti-inflammatory activities. The present study investigated the anti-diabetic, anti-obesity and oxidative stress ameliorating properties of cold water (CW) and ethanolic (EtOH) extracts of A. longifolius using in vitro and ex vivo experimental models. The extracts significantly inhibited the activities of carbohydrate and lipid digestive enzymes α - glucosidase (IC50 = CW: 176.9±2.1 µg/ml; EtOH: 179.8±1.9 µg/ml); α-amylase (IC50 = CW: 86.1±1.7 µg/ml; EtOH: 77.8±1.9 µg/ml); and pancreatic lipase (IC50 = CW: 184.3±1.7 µg/ml; EtOH: 534.1±2.3 µg/ml), and stimulated adipose glucose uptake (CW: 10- 50.5 mg/g adipose tissue; EtOH: 9 - 79 mg/g adipose tissue). Incubation of adipose tissues with FeSO4 significantly depleted reduced glutathione (GSH) level, super oxide dismutase (SOD) and catalase activities, while concomitantly elevated malondialdehyde (MDA) level. These changes were significantly reversed following the treatment of A. longifolius extracts. Liquid chromatography-mass spectrometry (LC-MS) analysis of the extracts revealed the presence of rhodomycinone, salsolinol, 5-hydroxyconiferyl alcohol, 2-caffeoylisocitrate and demethylalangiside in the cold water extract, while petromyzonol 24-sulfate, atractyloside, abyssinone VI and podecdysone B in the ethanolic extract. Molecular docking analysis revealed potent interactions of the phytochemicals with GLUT4 and leptin. These results indicate the possible antidiabetic, antiobesity and oxidative stress ameliorating potentials of A. longifolius extracts at in vitro and ex vivo experimental models. The identified compounds may be responsible for the observed biological activities.

Postprandial hyperglycemia in patients with type 2 diabetes is reduced by raw insoluble fiber: A randomized trial

Background and aimsA lower risk of type 2 diabetes mellitus (T2DM) is associated with the intake of insoluble fiber. This contradicts the postulate that insoluble fibers do not decrease postprandial glycemic response and that only viscous gel-forming soluble fibers would do this. This study aimed to investigate the effect of a dose of insoluble fibers that meets dietary recommendations on postprandial hyperglycemia in T2DM patients. Methods and resultsThis is a randomized crossover clinical trial. Nineteen T2DM men randomly ate a balanced breakfast either without (Control) or with prior consumption of insoluble fibers (5.8 g) in the form of 15 g of raw wheat bran (RWB). Glycemia was measured at fasting and 15, 30, 45, 60, 90, and 120 min postprandially. Markers of taste intensity and palatability were assessed after breakfast intake. The glucose peak rise of 87 mg/dL and the incremental area under the curve (AUC) elicited by the breakfast were decreased by RWB (15.80 % and 23.14 %, respectively). Time-to-glucose-peak did not differ between groups. The addition of the RWB to the meal decreased its level of creaminess and tasty and increased the sourness and bitterness. ConclusionsThe postprandial hyperglycemia in T2DM patients in response to complex carbohydrates was decreased by prior intake of a recommended dose of raw insoluble fibers. This antihyperglycemic effect is in accordance with the acarbose-like property of raw insoluble fibres, but not of heated ones (e.g., bread and pasta), to inhibit the activities of the carbohydrate-digesting enzymes alpha-glucosidase/alpha-amylase. Registration number for clinical trialsRBR-98tx28b (https://ensaiosclinicos.gov.br/rg/RBR-98tx28b).

The ethanol extract of Muntingia calabura exhibits in vitro antidiabetic potentials by inhibiting carbohydrate digestive enzymes

Objective: The present research study was conducted to investigate in vitro anti-diabetic potentials of ethanol extract of leaves of Muntingia calabura for α-glucosidase and α-amylase inhibitory activities.
 Materials & Methods: The leaves of Muntingia calabura were collected and authenticated. dried and powdered. The powdered drug was defatted using petroleum ether and extracted with ethanol. The ethanol extract of Muntingia calabura was subjected to preliminary phytochemical investigation. The in vitro α-glucosidase inhibitory and α-amylase inhibitory properties were determined for the ethanol extract and concentrations of extract required to inhibit absorbance (IC50 values) EEMC were determined.
 Results: Significant IC50 values were found in both tests that assessed the inhibitory activity of α-glucosidase and α-amylase, demonstrating the capacity of the ethanol extract of Muntingia calabura to block carbohydrate digesting enzymes and prevent postprandial blood glucose.
 Conclusion: The results of the presents investigation recommends that ethanol extract of Muntingia calabura possess significant α-glucosidase and α-amylase inhibitory activity.
 Keywords: Antidiabetic activity, Muntingia calabura, α-glucosidase and α-amylase and IC50values.

Dried tea residue can alter the blood metabolism and the composition and functionality of the intestinal microbiota in Hu sheep.

Ruminant animals face multiple challenges during the rearing process, including immune disorders and oxidative stress. Green tea by-products have gained widespread attention for their significant immunomodulatory and antioxidant effects, leading to their application in livestock production. In this study, we investigated the effects of Dried Tea Residue (DTR) as a feed additive on the growth performance, blood biochemical indicators, and hindgut microbial structure and function of Hu sheep. Sixteen Hu sheep were randomly divided into two groups and fed with 0 and 100 g/d of DTR, respectively. Data were recorded over a 56-day feeding period. Compared to the control group, there were no significant changes in the production performance of Hu sheep fed with DTR. However, the sheep fed with DTR showed a significant increase in IgA (p < 0.001), IgG (p = 0.005), IgM (p = 0.003), T-SOD (p = 0.013), GSH-Px (p = 0.005), and CAT (p < 0.001) in the blood, along with a significant decrease in albumin (p = 0.019), high density lipoprotein (p = 0.050), and triglyceride (p = 0.021). DTR supplementation enhanced the fiber digestion ability of hindgut microbiota, optimized the microbial community structure, and increased the abundance of carbohydrate-digesting enzymes. Therefore, DTR can be used as a natural feed additive in ruminant animal production to enhance their immune and antioxidant capabilities, thereby improving the health status of ruminant animals.

Beyond Syringes and Pills: Advances in Drug Delivery Systems for Diabetes

Diabetes is a chronic disease that affects millions of people worldwide, and its prevalence is increasing. The two primary subtypes, type 1 and 2, have different causes and mechanisms, but both result in abnormal glucose metabolism. The standard of care for diabetes includes insulin therapy, oral anti-diabetic medications, diet, exercise, weight loss, and frequent self-monitoring of blood glucose levels. However, these treatments have limitations that can lead to poor patient compliance and suboptimal outcomes. Alternative insulin delivery systems such as inhalers, patches, and oral sprays offer potential benefits such as increased convenience, reduced pain, and improved adherence. Non-insulin injectables, long-acting basal insulins, and GLP-1 agonists have also shown promise in improving glycemic control and reducing the risk of complications. Nanoparticle-based systems like SLNs are a novel approach that offers several advantages for diabetic management. They allow for targeted drug delivery, controlled release, and improved biocompatibility, enhancing drug efficacy and reducing side effects. SLNs have shown potential in animal models for reducing extracellular matrix degradation, inhibiting carbohydrate digestive enzymes, and enhancing the regeneration of insulin-producing beta cells. More studies are needed to validate their safety and efficacy in humans, but the potential benefits of SLNs make them a promising option for diabetes management.

Assessing food-induced plasticity of digestive enzyme activity during echinoid larval development

Growth and development of planktotrophic larvae are dependent on food availability within a nutritionally heterogeneous ocean. Insufficient food can reduce growth and delay metamorphosis, thereby decreasing survival and recruitment. Phenotypic plasticity allows an organism to adjust its phenotype (morphological, physiological, biochemical) to its environment. Planktotrophic echinoid larvae with low food grow longer arms to increase feeding capacity and with high food grow shorter arms to allocate more resources to faster development of other structures. In this study, we investigated if food-induced plasticity in the Pacific sand dollar, Dendraster excentricus, also involved the regulation of digestive enzyme activities during pre-feeding and early feeding larval stages. We measured protein-specific activities of protein, lipid, and carbohydrate digestive enzymes at 33 h post-fertilization (HPF; pre-feeding stages) and 96 HPF (feeding stages) to examine if algal presence influenced enzyme rates at these stages and if there was an interaction between pre-feeding stage and feeding stage algal presence. While all enzymes studied increased activities during development, there was no significant effect of pre-feeding algae levels on pre-feeding digestive enzyme activities for all three types of enzymes studied. Furthermore, there was no interaction between larval feeding status (pre-feeding vs. feeding stage) and the presence of algal food. Evidence of food-induced plasticity was observed during the 96 HPF feeding stage for esterase (lipid digestion) and amylase (carbohydrate digestion). Both enzymes exhibited an increase in protein-specific rates ~1.6-times greater for larvae reared with algae than for those reared without algae. Protease activities were similar for fed and unfed larvae. The differential responses to food during the larval stage likely reflect the initial biochemical composition of the egg, the composition of algal food, and the unique use of each substrate to sustain larval growth and development. Our results demonstrate a multidimensional food-induced biochemical plasticity response of larvae to their feeding environment which includes discrete temporal windows of sensitivity and different enzyme class-specific responses.

Exploring the Multifaceted Potential of a Peptide Fraction Derived from Saccharomyces cerevisiae Metabolism: Antimicrobial, Antioxidant, Antidiabetic, and Anti-Inflammatory Properties.

The rising demand for minimally processed, natural, and healthier food products has led to the search for alternative and multifunctional bioactive food components. Therefore, the present study focuses on the functional proprieties of a peptide fraction derived from Saccharomyces cerevisiae metabolism. The antimicrobial activity of the peptide fraction is evaluated against various foodborne pathogens, including Candida albicans, Candida krusei, Escherichia coli, Listeria monocytogenes, and Salmonella sp. The peptide fraction antioxidant properties are assessed using FRAP and DPPH scavenging capacity assays. Furthermore, the peptide fraction's cytotoxicity is evaluated in colorectal carcinoma and normal colon epithelial cells while its potential as an antidiabetic agent is investigated through α-amylase and α-glucosidase inhibitory assays. The results demonstrate that the 2-10 kDa peptide fraction exhibits antimicrobial effects against all tested microorganisms, except C. krusei. The minimal inhibitory concentration for E. coli, L. monocytogenes, and Salmonella sp. remains consistently low, at 0.25 mg/mL, while C. albicans requires a higher concentration of 1.0 mg/mL. Furthermore, the peptide fraction displays antioxidant activity, as evidenced by DPPH radical scavenging activity of 81.03%, and FRAP values of 1042.50 ± 32.5 µM TE/mL at 1.0 mg/mL. The peptide fraction exhibits no cytotoxicity in both tumor and non-tumoral human cells at a concentration up to 0.3 mg/mL. Moreover, the peptide fraction presents anti-inflammatory activity, significantly reducing the expression of the TNFα gene by more than 29.7% in non-stimulated colon cells and by 50% in lipopolysaccharide-stimulated colon cells. It also inhibits the activity of the carbohydrate digestive enzymes α-amylase (IC50 of 199.3 ± 0.9 µg/mL) and α-glucosidase (IC20 of 270.6 ± 6.0 µg/mL). Overall, the findings showed that the peptide fraction exhibits antibacterial, antioxidant, anti-inflammatory, and antidiabetic activity. This study represents a step forward in the evaluation of the functional biological properties of S. cerevisiae bioactive peptides.

콩비지추출물과 저칼로리 감미제 첨가가 아침간편식의 품질특성 및 당지수에 미치는 영향

This study developed a nutrition bar and granola, which are low in calories and inhibit the absorption of sugars, and measured changes in product characteristics such as glycemic index and consumer acceptability. This study conducted an inhibition test of carbohydrate digestive enzymes activity and a postprandial glycemic measurement test to verify the glycemic improvement effect of the soy-pulp extract. According to the results of the carbohydrate digestive enzyme inhibition test, the inhibitory activity was higher in the order of soy-pulp &gt; momordica charantia, red bean &gt; ecklonia cava, and black bean. DPPH and ABTS tests also confirmed the antioxidant effect of the soy-pulp extract. In the postprandial glycemic control test conducted on 18 adults aged 20-60 years, nutrition bars containing low-calorie sweeteners and soy-pulp extract showed significantly lower glycemic values at 30, 45, and 120 minutes after consumption compared to sugar-containing products. In case of granola, products containing low-calorie sweeteners and soy-pulp extract (experimental group) showed a significant decrease in glycemic values at 15 minutes after consumption compared to sugar-containing products (control group). In the sensory evaluation to measure the change in consumer preference, the experimental group showed a better preference for sweetness and savory taste than the control group (p &lt; 0.05), and there was no significant difference in color and overall taste. Consequently, if low-glycemic sweeteners and soy-pulp extracts are used instead of sugar in the production of breakfast snacks such as nutrition bars and granola, it is possible to expect not only the effect of suppressing postprandial blood sugar rise but also the improvement of taste, such as sweetness and savory taste.

Assessments of Alpha-Amylase Inhibitory Potential of Tagetes Flavonoids through In Vitro, Molecular Docking, and Molecular Dynamics Simulation Studies.

Diabetes is a chronic fast-growing metabolic disorder that is characterized by high blood glucose levels. Tagetes minuta L. has been used as a traditional remedy for various illnesses for many years, and, furthermore, its oil is used in the perfume and flavor industries. T. minuta contains various metabolites, such as flavonoids, thiophenes, terpenes, sterols, and phenolics, with varied bioactivities. Flavonoids can inhibit carbohydrate-digesting enzymes, such as alpha-amylase, which is a convenient dietary strategy for controlling hyperglycemia. In the current investigation, the isolated flavonoids quercetagetin-6-O-(6-O-caffeoyl-β-D-glucopyranoside), quercetagetin-7-O-β-D-glucopyranoside, quercetagetin-6-O-β-D-glucopyranoside, minutaside A, patuletin-7-O-β-D-glucopyranoside, quercetagetin-7-methoxy-6-O-β-D-glucopyranoside, tagenols A and B, quercetagetin-3,7-dimethoxy-6-O-β-D-glucopyranoside, patuletin, quercetin-3,6-dimethyl ether, and quercetin-3-methyl ether from T. minuta were assessed for their alpha-amylase inhibition (AAI) efficacy using an in vitro assay, as well as molecular docking, dynamics simulation, and ADMET analyses. Our findings show that quercetagetin-6-O-(6-O-caffeoyl-β-D-glucopyranoside) (1), quercetagetin-7-O-β-D-glucopyranoside (2), quercetagetin-6-O-β-D-glucopyranoside (3), minutaside A (4), patuletin-7-O-β-D-glucopyranoside (5), and quercetagetin-7-methoxy-6-O-β-D-glucopyranoside (6) had a notable AAI capacity (IC50s ranged from 7.8 to 10.1 μM) compared to acarbose (IC50 7.1 μM). Furthermore, these compounds with the highest binding affinity among the tested flavonoids revealed high docking scores for AA (ranging from -12.171 to 13.882 kcal/mol) compared to that of acarbose (-14.668 kcal/mol). In MDS, these compounds were observed to show maximum stability and the greatest binding free energy, suggesting that they may contend with native ligands. In addition, the ADMET analysis showed that these active compounds had a broad span of drug-like, pharmacokinetic, and physicochemical features and did not possess any considerable undesired effects. The current results suggest the potential of these metabolites as AAI candidates. However, further in vivo and mechanistic studies are warranted to specify the efficacy of these metabolites.

Blood glucose lowering and anti-oxidant potential of erythritol: An in vitro and in vivo study.

Diabetes is a major cause of death worldwide and Nigeria is not an exception. The quest to lower sugar levels has become a major factor in the management of diabetes; this has occasioned the use of substitutes for refined sugar in beverages. Erythritol is a natural sweetener gaining immense interest in recent times. Like metformin, erythritol has shown hydroxyl radical scavenging ability and has metabolic profile suitable for diabetics. Therefore, the blood glucose-lowering and anti-oxidant properties of erythritol under in vitro and in vivo systems were accessed. Radical scavenging assay (ABTS and DPPH) and inhibition of carbohydrate digestive enzymes (alpha-amylase and alpha-glucosidase) were employed to determine in vitro anti-oxidant and glucose regulatory function of erythritol respectively. Molecular docking studies were performed between 3D structures of human pancreatic alpha-amylase and alpha-glucosidase, isomaltase from saccharomyces cerevisiae with erythritol. The drug-like activity of erythritol was also assessed.Thereafter, we investigated the effect of erythritol on blood glucose and antioxidant status of normal and streptozocin- nicotinamide-induced diabetes rats which were grouped into five (n = 5); Normal, Ery (normal and administered erythritol), Db (diabetic control), Db + Ery (diabetic and administered erythritol), and Db + Met (diabetic and administered metformin). Erythritol showed a considerable radical scavenging activity and an ability to inhibit alpha-amylase and alpha-glucosidase in vitro. Also, a significant reduction in glucose intolerance, blood glucose and hemoglobin A1c levels and improved antioxidant level was seen in erythritol-treated diabetic rats. Erythritol showed anti-oxidant activity, alpha amylase and glucosidase enzyme inhibition property, improved antioxidant status and ameliorated blood glucose, HbA1c, and glucose intolerance following diabetes.

Herbivorous Fish Microbiome Adaptations to Sulfated Dietary Polysaccharides.

Marine herbivorous fish that feed primarily on macroalgae, such as those from the genus Kyphosus, are essential for maintaining coral health and abundance on tropical reefs. Here, deep metagenomic sequencing and assembly of gut compartment-specific samples from three sympatric, macroalgivorous Hawaiian kyphosid species have been used to connect host gut microbial taxa with predicted protein functional capacities likely to contribute to efficient macroalgal digestion. Bacterial community compositions, algal dietary sources, and predicted enzyme functionalities were analyzed in parallel for 16 metagenomes spanning the mid- and hindgut digestive regions of wild-caught fishes. Gene colocalization patterns of expanded carbohydrate (CAZy) and sulfatase (SulfAtlas) digestive enzyme families on assembled contigs were used to identify likely polysaccharide utilization locus associations and to visualize potential cooperative networks of extracellularly exported proteins targeting complex sulfated polysaccharides. These insights into the gut microbiota of herbivorous marine fish and their functional capabilities improve our understanding of the enzymes and microorganisms involved in digesting complex macroalgal sulfated polysaccharides. IMPORTANCE This work connects specific uncultured bacterial taxa with distinct polysaccharide digestion capabilities lacking in their marine vertebrate hosts, providing fresh insights into poorly understood processes for deconstructing complex sulfated polysaccharides and potential evolutionary mechanisms for microbial acquisition of expanded macroalgal utilization gene functions. Several thousand new marine-specific candidate enzyme sequences for polysaccharide utilization have been identified. These data provide foundational resources for future investigations into suppression of coral reef macroalgal overgrowth, fish host physiology, the use of macroalgal feedstocks in terrestrial and aquaculture animal feeds, and the bioconversion of macroalgae biomass into value-added commercial fuel and chemical products.

In Vitro and In Vivo Evaluation of the Antidiabetic Activity of Solidago virgaurea Extracts.

Solidago virgaurea (Asteraceae) has been used for more than 700 years for treating cystitis, chronic nephritis, urolithiasis, rheumatism, and inflammatory diseases. However, the antidiabetic activity of Solidago virgaurea has been rarely studied. Three extracts of Solidago virgaurea were prepared, and their antidiabetic potentials were evaluated by various cell-free, cell-based, and in vivo studies. We found that the Solidago virgaurea contained multiple bioactive phytochemicals based on the GC-MS analysis. The Solidago virgaurea extracts effectively inhibited the functions of the carbohydrate digestive enzyme (α-glucosidase) and protein tyrosine phosphatase 1B (PTP1B), as well as decreased the amount of advanced glycation end products (AGEs). In the L6 myotubes, the Solidago virgaurea methanolic extract remarkably enhanced the glucose uptake via the upregulation of glucose transporter type 4 (GLUT4). The extract also significantly downregulated the expression of PTP1B. In the streptozotocin-nicotinamide induced diabetic mice, the daily intraperitoneal injection of 100 mg/kg Solidago virgaurea methanolic extract for 24 days, substantially lowered the postprandial blood glucose level with no obvious toxicity. The extract's anti-hyperglycemic effect was comparable to that of the glibenclamide treatment. Our findings suggested that the Solidago virgaurea extract might have great potential in the prevention and treatment of diabetes.

Rumen protozoa population and carbohydrate-digesting enzymes in sheep fed a diet supplemented with hydrolysable tannins

Abstract The aim of the study was to compare the effect of adding different sources of hydrolysable tannins to the sheep diet on protozoa population and carbohydrate digestion in the rumen. The study was performed in 3 Polish Lowland ewes fistulated to the rumen in a 3 × 3 Latin square design. Control sheep (CON) received (g/d): meadow hay (600), barley meal (300), soybean meal (100) and vitamin-mineral premix (20). Sheep from the experimental groups were additionally administered 12.6 g/kg DM oak bark extract (OAK) and 3.91 g/kg DM tannic acid (TAN ). The net consumption of tannins was approx. 0.4% DM for both additives. Regarding the count of protozoa, a significant interaction between diet and sampling time was documented for all ciliates (P&lt;0.01), with a significant effect of both factors when considered separately. Experimental diets reduced the number of total protozoa and Entodinium spp. (before feeding, 2 and 4 h after feeding; P&lt;0.01), while increasing the abundance of Isotricha spp. population (4 h after feeding; P&lt;0.01) in the rumen. Interestingly, the count of Ophryoscolex spp. after feeding the TAN diet increased before feeding and 2 h after feeding in comparison to the CON and OAK groups, respectively, and subsequently decreased compared to the CON diet (4 and 8 h after feeding, P&lt;0.01). A significant interaction between the diet and sampling time was observed for xylanolytic activity (P&lt;0.01) in the rumen, with a significant effect of sampling time, which decreased its activity in CON (after feeding) and OAK sheep (2 h after feeding; P&lt;0.01). For amylolytic activity (P&lt;0.10), there was a trend towards a significant interaction between experimental factors, with a significant effect on both diet and sampling time. Detailed analysis showed that the TAN diet significantly reduced amylolytic activity 2 h after feeding compared to the CON group (P&lt;0.05). In conclusion, the TAN diet significantly reduced the number of total protozoa and Entodinium spp., which consequently reduced amylolytic activity in the rumen, without any significant effect on pH and carbohydrate fermentation in the rumen.

Diversity and biological activities of medicinal plants of Santiago island (Cabo Verde)

Plants continue to constitute key elements of medical practice in West African countries. The Cabo Verde archipelago hosts a great diversity of medicinal plants and local markets are considered important sites for trading plants harvested by rural communities. This study has two main goals: (i) to assess the medicinal uses of native species in Santiago, the biggest island of the archipelago, and (ii) to evaluate the antioxidant, antimicrobial and antidiabetic/antihyperglycemic activities of two native trees (Tamarix senegalensis and Sideroxylon marginatum) used in traditional medicine and traded in local markets. Our results revealed that on Santiago Island, 24 native plants are used in traditional medicine. The main uses of these species (e.g., forage, timber, food and fibres), their medicinal applications, the plant parts used, their mode of administration and conservation status are presented here for the first time. Moreover, the pharmacological characterization of two native tree species revealed that hydroethanolic extracts were richer in phenolic compounds and more active than their aqueous counterparts. All the studied extracts revealed significant antioxidant properties (DPPH and FRAP assays) and were generally moderately active against Gram-positive bacteria. All the extracts inhibited the activities of the carbohydrate digestive enzymes α-glucosidase and α-amylase in a dose-dependent manner. For α-glucosidase, the detected inhibitory activity (IC50 values from 2.0 ± 0.2 μg/mL to 9.9 ± 1.2 μg/mL) was significantly higher than that of acarbose, suggesting that extracts of both species can delay glucose absorption, thereby assisting in slowing down the progression of diabetes. Our findings highlight the crucial importance that medicinal plants have for the Cabo Verdean population, while also raising awareness on the need for sustainable use and conservation of native flora, and of tree species traded in local markets in particular.

α-Amylase inhibitory potential of Thunbergia mysorensis leaves extract and bioactive compounds by in vitro and computational approach

In this study, we aim to evaluate the anti-diabetic potential of Thunbergia mysorensis leaves methanolic extract (MeL) using inhibitory assays for α-glucosidase (AG), α-amylase (AM) (carbohydrate digestive enzymes) and aldose reductase (AR) (an enzyme involved in the polyol pathway responsible for glycation). In addition to antidiabetic studies, antioxidant studies were also performed due to the fact that reactive oxygen species (ROS) are produced by various pathways under diabetic conditions. Hyperglycemia induces ROS by activating the glycation reaction and the electron transport chain in mitochondria. The MeL effectively inhibited the enzymes (AG IC50: 27.86 ± 1.0, AM IC50: 12.00 ± 0.0, AR IC50: 4.50 ± 0.09 μg/mL) and showed effective radical ion scavenging activity during the antioxidant assay (DPPH EC50: 30.10 ± 0.75, ABTS EC50: 27.25 ± 1.00, Superoxide EC50: 35.00 ± 1.50 μg/mL). Using activity-guided repeated fractionation on a silica gel column chromatography, two compounds including 3,4-dimethoxy benzoic acid (DMBA) (101 mg) and 3,4-dimethoxy cinnamic acid (DMCA) (87 mg) with potent anti-diabetic activity were extracted from the MeL of T. mysorensis leaves. Both DMBA (IC50 AG: 27.00 ± 1.05, IC50 AM: 12.15 ± 0.10, IC50 AR: 4.86 ± 0.30 μg/mL) and DMCA (IC50 AG: 27.25 ± 0.98, IC50 AM: 12.50 ± 0.20, IC50 AR: 5.00 ± 1.00 μg/mL) were subjected for enzyme inhibition. Since both compounds significantly inhibited AM, enzyme kinetics for AM inhibition was performed. The compounds also showed effective antioxidant potential (DPPH EC50: 30.50 ± 0.99, ABTS EC50: 27.86 ± 0.16, Superoxide EC50: 36.10 ± 0.24 μg/mL), and DMCA (DPPH EC50: 31.00 ± 1.00, ABTS EC50: 28.00 ± 0.25, Superoxide EC50: 36.25 ± 0.37 μg/mL). Further, to elucidate the role of DMBA and DMCA in enzyme inhibition and stability at the molecular level, both compounds were subjected for in silico enzyme inhibitory studies using molecular docking simulation, molecular dynamics (MD) simulation, and binding free energy calculations. Compared to AR and AG, AM was the most significantly inhibited enzyme (DMBA: −6.6 and DMCA: −7.8 kcal/mol), and compounds combined with AM were subjected to MD simulation. Both compounds were stable in the binding pocket of AM till 100 ns and chiefly use Van der Waal’s energy to bind. Compared to the controls, both DMBA and DMCA had a higher efficiency in the inhibition of target enzymes in vitro and in silico. The presence of DMBA and DMCA is more likely to be associated with the potential of MeL in antihyperglycemic activity. This bio-computational study indicates DMBA and DMCA as potential lead inhibitors of AM and could be used as effective anti-diabetic drugs in the near future.

Impact of thermal treatments and simulated gastrointestinal digestion on the α-amylase inhibitory activity of different legumes

Legumes are excellent sources of proteins that can be hydrolysed to generate antidiabetic peptides, which inhibit carbohydrate digestive enzymes. The degree of protein hydrolysis depends on the thermal treatment applied and how it impacts protein denaturation and thus accessibility to enzymes. In this study, α-amylase inhibitory activities of cooked (conventional, pressure, and microwave cooking) and digested (simulated gastrointestinal digestion, GID) green pea, chickpea, and navy beans were evaluated, together with the impact of thermal treatments on peptide profiles after GID. All peptides extracts inhibited α-amylase after cooking and GID, and the peptide fraction <3 kDa was responsible for main activity. In green peas and navy beans, microwave cooking showed the highest impact whereas none thermal treatment highlighted in chickpeas. The peptidomics analysis of the fractions <3 kDa identified a total of 205 peptides, 43 of which were found to be potentially bioactive according to in silico analysis. Also quantitative results evidenced differences in the peptide profile between the type of legume and thermal treatment.

Glucoregulatory Properties of Fermented Soybean Products

Type 2 diabetes mellitus is a chronic metabolic disease, characterized by persistent hyperglycemia, the prevalence of which is on the rise worldwide. Fermented soybean products (FSP) are rich in diverse functional ingredients which have been shown to exhibit therapeutic properties in alleviating hyperglycemia. This review summarizes the hypoglycemic actions of FSP from the perspective of different target-related molecular signaling mechanisms in vitro, in vivo and clinical trials. FSP can ameliorate glucose metabolism disorder by functioning as carbohydrate digestive enzyme inhibitors, facilitating glucose transporter 4 translocation, accelerating muscular glucose utilization, inhibiting hepatic gluconeogenesis, ameliorating pancreatic dysfunction, relieving adipose tissue inflammation, and improving gut microbiota disorder. Sufficiently recognizing and exploiting the hypoglycemic activity of traditional fermented soybean foods could provide a new strategy in the development of the food fermentation industry.