Α-glucosidase Activity Research Articles

Effects of in vitro simulated digestion on the hypoglycaemic capacity of wheat bran-soluble dietary fibre.

Wheat bran-soluble dietary fibre (WB-SDF) is known for its hypoglycaemic properties and its potential to control postprandial blood glucose levels in individuals with hyperglycaemia. However, the digestive process may alter its glucose-lowering potential. This study investigated the effects of in vitro simulated digestion on the hypoglycaemic efficacy of WB-SDF. The hypoglycaemic effects of WB-SDF were determined by examining its glucose-binding capacity, glucose dialysis retardation index and ability to inhibit glucose uptake and transport in Caco-2cells. Structural changes after digestion were analysed via polysaccharide conformation analysis, microstructure observation and particle size measurements to evaluate their impacts on hypoglycaemic efficacy. Results indicate that WB-SDF and digested wheat bran-dietary fibre significantly decreased glucose adsorption and α-glucosidase activity compared with the control group in Caco-2cells. However, simulated digestion resulted in a relatively smaller reduction in α-glucosidase activity compared with the WB-SDF treatment group. The massive loss of surface laminar structure, reduction of -OH groups and partial glycosidic bond breakage in digested wheat bran-dietary fibre after digestion led to reduced glucose adsorption capacity and glucose dialysis retardation index. Moreover, the reduction in particle size after digestion enhanced the inhibition of glucose transport-related gene expression in Caco-2cells. Thus, although digestion weakens the glucose adsorption of WB-SDF, it improves its ability to inhibit glucose transport, highlighting the intricate interplay between structural modifications and hypoglycaemic efficacy.

Antioxidant, antidiabetic, and antimicrobial efficacy of germinated Ocimum gratissimum and Ocimum basilicum seed.

The edible seeds of Ocimum gratissimum and Ocimum basilicum were found to be a potent source of phytochemicals with noteworthy antioxidant, antidiabetic, and antimicrobial properties. This study aimed to investigate the impact of germination and extraction solvents (ethanol (EtOH), distilled water) on the therapeutic properties exhibited and the ability of seed extracts to act as natural food preservatives. The EtOH extracts of germinated O. gratissimum and O. basilicum seeds exhibited more phytoconstituents content with significantly higher phenols (21.03 ± 0.01 mg gallic acid equivalent (GAE)/g and 21.46 ± 0.01 mg GAE/g respectively) and flavonoids (11.92 ± 0.03 mg quercetin equivalent (QE)/g and 14.45 ± 0.04 mg QE/g respectively) than other extracts did. Thus, they exhibited superior antioxidant potential with substantially lower half-maximal inhibitory concentration (IC50) values for scavenging 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cation radical (0.013 ± 0.00 mg mL-1 and 0.007 ± 0.00 mg mL-1 respectively) and superoxide anion radical (4.33 ± 0.01 mg mL-1 and 4.14 ± 0.00 mg mL-1 respectively) and for inhibiting lipid oxidation (2.57 ± 0.00 mg mL-1 and 2.33 ± 0.00 mg mL-1 respectively) compared with other extracts. Further, they exhibited better antidiabetic potential with substantially lower IC50 values for inhibiting α-amylase activity (0.93 ± 0.01 mg mL-1 and 1.01 ± 0.01 mg mL-1 respectively) and α-glucosidase activity (0.60 ± 0.01 mg mL-1 and 0.51 ± 0.01 mg mL-1 respectively). Also, they showed superior antimicrobial potential with higher inhibition zones for Bacillus subtilis (13.98 ± 0.18 mm, 17.02 ± 0.18 mm respectively), Vibrio parahaemolyticus (19.00 ± 0.20 mm, 22.58 ± 0.45 mm respectively), Salmonella enterica (24.98 ± 0.18 mm, 22.17 ± 0.15 mm respectively), and Escherichia coli (23.50 ± 0.50 mm, 27.00 ± 0.20 mm respectively) and better inhibition of Aspergillus flavus growth (93.28% and 81.77% respectively) compared with other extracts. Both the O. gratissimum and O. basilicum seed extracts can be utilized efficiently as therapeutic agents to manage inflammation-driven diseases and diabetes, or as natural preservatives in foods and in edible films or coatings. © 2025 Society of Chemical Industry.

Isolation, In Vitro Antioxidant Capacity, Hypoglycemic Activity and Immunoactivity Evaluation of Polysaccharides from Coriandrum sativum L.

Coriander (Coriandrum sativum) is a classical medicinal and edible herb as well as a spice, but the physicochemical and biological properties of its polysaccharides have not been fully studied. In this study, the polysaccharides were extracted using an ultrasonic-assisted method and purified from fresh coriander, and then the coriander polysaccharide (CSP) fraction was separated using an agarose gel Q-Sepharose Fast Flow column. The total sugar content, protein content and monosaccharides composition of CSPs were determined using a phenol–sulfuric acid method, Coomassie Brilliant Blue method and HPLC. The structural characterization was detected using ultraviolet spectrophotometry and FT-IR spectroscopy. DPPH and ABTS free radicals were used to explore their antioxidant activities, while the inhibitory abilities of α-amylase and α-glucosidase were used to evaluate their hypoglycemic activity. After that, the immunomodulatory and antitumor activities were investigated using macrophage RAW264.7 and HepG2 cells as the targets. The results showed that the total sugar and protein contents of CSPs were 66.90 ± 1.44% and 1.06 ± 0.32%, respectively. CSPs were mainly composed of fucose, rhamnose, arabinose, galactose, glucose, galacturonic acid and glucuronic acid, with a molar ratio of 1.13:15.11:9.60:25.98:1.55:44.33:2.29, and may be an acidic heteropolysaccharide containing pyran rings, α- and β-glycosidic bonds and glucuronic acid. Results from in vitro experiments of biological activities showed that the IC50 of CSPs for scavenging DPPH and ABTS free radicals were 0.759 mg/mL and 1.758 mg/mL, respectively; the IC50 values for inhibiting the activities of α-amylase and α-glucosidase were 0.634 mg/mL and 2.178 mg/mL, respectively; the CSPs with a concentration of 25~200 μg/mL showed no obvious toxicity to macrophage RAW264.7, and when treated with 100 μg/mL of CSPs, the relative cell phagocytosis capacity and secreted nitric oxide amount of RAW264.7 were 153.75 ± 12.01% and 133.56 ± 5.37%, respectively; CSPs showed a concentration-dependent ability to inhibit the growth of HepG2 cells within the test concentration of 0.25–2.0 mg/mL. Summarizing the results, due to their excellent antioxidant, immunomodulatory and anti-tumor activities, the coriander acid polysaccharides were expected to show good potential in comprehensive development of food and medicine.

Intrinsic fluorescence hydrogels for ON/OFF screening of antidiabetic drugs: assessing α-glucosidase inhibition by acarbose.

Diabetes remains one of the most prevalent chronic diseases globally, significantly impacting mortality ratetables. The development of effective treatments for controlling glucose level in blood is critical to improve the quality of life of patients with diabetes. In this sense, smart optical sensors using hydrogels, responsive to external stimuli, have emerged as a revolutionary approach to diabetes care. In this study, changes in the optical properties of a hydrogel are employed for monitoring α-glucosidase activity, a critical enzyme involved in diabetes mellitus type II due to its role in breaking terminal α-glycosidic bonds, releasing α-glucose. The enzyme is encapsulated within a triazine-based hydrogel that exhibits intrinsic blue fluorescence. Upon hydrolysis of the substrate p-nitrophenyl-α-D-glucopyranoside (p-NPG) by α-glucosidase, the fluorescence is quenched due to the release of p-nitrophenol (PNP). However, when exposed to potential antidiabetic drugs, the enzyme's activity is inhibited, and the hydrogel's fluorescence remains intact. This ON/OFF fluorescence-based assay enables rapid screening of drug candidates by evaluating their ability to inhibit α-glucosidase enzymatic activity. Sensor optimization involves conducting swelling studies, fluorescent assays, reusability tests and a trial with a real antidiabetic drug. This innovative approach holds potential for enhancing antidiabetic drug screening and management, offering a more accessible and efficient solution compared to traditional biosensors.

Effect of Drying Temperature on Sensory Quality, Flavor Components, and Bioactivity of Lichuan Black Tea Processed by Echa No. 10.

Lichuan black tea (LBT) is a well-known congou black tea in China, but there is relatively little research on its processing technology. Echa No. 10 is the main tea tree variety for producing LBT. This study investigated the sensory quality, flavor components, and bioactivity of Echa No. 10 Lichuan black tea (LBT) at different drying temperatures (70, 80, 90, 100, 110, 120, and 130 °C). During 80-120 °C, increasing the drying temperature enabled a higher sweet aroma concentration and enhanced the sweetness in the taste, in contrast to reducing the floral, fruity, and sweet aromas, and increasing the bitterness and astringency, at >120 °C. Additionally, with an increasing drying temperature, the contents of tea polyphenols and total catechins significantly decreased, with the theaflavins decreasing first and then increasing, and the alcohols, aldehydes, esters, and hydrocarbons increasing first and then decreasing. Meanwhile, compounds (including linalool, (Z)-linalool oxide (furanoid), (E)-linalool oxide (furanoid), cis-β-Ocimene, and methyl salicylate) contribute more to the floral and fruity aromas at <110 °C. Furthermore, low-temperature drying favors the antioxidant and inhibitory effects of the α-amylase, α-glucosidase, and glucose absorption activity. Both the tea quality and bioactivity results revealed 80-110 °C as the optimal drying temperature range for LBT.

Inhibition of acrylamide and α-amylase and α-glucosidase activities in Echium amoenum powder fortified biscuits.

Echium amoenum (borage) powder (EAP) is consumed traditionally and is known to possess health-promoting effects. In this research, application of Echium amoenum (borage) powder (EAP) at levels of zero, 1 and 2% w/w was investigated in the production of biscuit as a widely consumed snack and some characteristics of dough and biscuit samples were evaluated. By adding EAP and increasing its level, water absorption values and dough stability increased (p<0.05) but the development time of the dough and the degree of loosening of the dough decreased (p<0.05); moisture and fiber content of biscuits increased (p<0.05) and their color changed significantly. Also, by increasing the percentage of EAP in biscuit samples, water loss percent (WL), carbohydrate and total energy decreased significantly; acrylamide content (AAC) also decreased (p<0.05) and beneficial effects improved so that antioxidant activity (AA), total phenol content (TPC), total flavonoid content (TFC), total anthocyanin content (TAC) and enzyme (α-amylase and α-glucosidase) inhibitory activity increased in biscuits (p<0.05). With increasing EAP percentage, diameter, thickness, spread ratio, hardness and fracturability of biscuit samples decreased. In general, it is concluded that by adding EAP (maximum 2% w/w) to the biscuit formulation; it can be expected to produce functional biscuit. EAP has shown therapeutic potential (antioxidative and antidiabetic) in vitro; thus, it can be used for the development of functional foods for oxidative stress and diabetes.

The impact of sulphated polysaccharides from Ecklonia maxima on carbohydrate hydrolyzing enzymes, muscle glucose uptake and intestinal glucose absorption ex vivo

Ecklonia maxima is a rich source of bioactive compounds and has been shown to exhibit several biological activities. However, the antidiabetic potential of sulphated polysaccharide (SP) from E. maxima is yet to be fully explored. This study characterised crude and purified SPs from E. maxima using Fourier-transform infrared Spectroscopy, Ultra Performance liquid chromatography-diode array detector (UPLC-DAD) and Nuclear magnetic resonance spectroscopy. The antidiabetic potential of the SPs was assessed via their effect on carbohydrate hydrolysing enzymes (α-amylase and α-glucosidase), glucose uptake in psoas muscles and intestinal glucose absorption ex vivo. The SPs revealed the presence of glucose, galactose, xylose and galacturonic acid. The crude and purified SPs exhibited strong inhibitory effects on α-amylase and α-glucosidase activity. The SPs significantly increased glucose uptake into yeast cells and psoas muscles. The crude and purified SPs significantly reduced intestinal glucose absorption compared to metformin. The SPs displayed notable potential for glucose uptake in yeast cells and psoas muscle and inhibition of glucose absorption in small intestine. The antidiabetic mechanisms of the SPs could be linked to inhibition of α-amylase and α-glucosidase, reduction of intestinal glucose absorption and increase in glucose uptake into the muscles. SPs from E. maxima exhibit strong antidiabetic potentials and can be explored for the management of type-2 diabetes.

New C-linked diarylheptanoid dimers as potential α-glucosidase inhibitors evidenced by biological, spectral and theoretical approaches.

Diabetes mellitus (DM) is a chronic metabolic disorder characterized by elevated blood glucose levels, generally due to defects of insulin action or secretion. Inhibition of α-glucosidase, an enzyme responsible for carbohydrate degradation, is a promising strategy for managing postprandial hyperglycemia in diabetic patients. In this study, two new C-linked diarylheptanoid dimers, kaemgalanganols A (1) and B (2), were isolated from K. galanga, which showed obvious inhibitory activity on α-glucosidase but weak activity on protein tyrosine phosphatase 1B (PTP1B). Kaemgalanganol B had an IC50 value of 35.1μM against α-glucosidase, obviously more potent than kaemgalanganol A (IC50=78.5μM) and acarbose (IC50=363.0μM). Enzyme kinetic study indicated that 2 was a reversible mixed-type inhibitor of α-glucosidase via non-competitive and anti-competitive inhibition modes. Fluorescence quenching and UV-visible spectroscopic study revealed that fluorescence quenching mechanism of 2 on α-glucosidase is a combination of dynamic quenching and static quenching, accompanied by non-radiative energy transfer. Compound 2 formed complex with α-glucosidase closer to the Tyr residue, and induced changes in both the microenvironment and peptide backbone. Surface hydrophobicity and CD spectra measurement indicated that 2 affected the function of α-glucosidase by decreasing the surface hydrophobicity of α-glucosidase as well as altering the secondary structure instead of the overall three-dimensional framework, which is consistent with the results of fluorescence experiment. Molecular docking manifested that compound 2 had a strong binding affinity (-7.27kcal/mol) with α-glucosidase, higher than 1 (-9.82kcal/mol) and acarbose (-4.48kcal/mol), consistent with the enzyme inhibitory assay. Besides hydrogen bonds, electrostatic interactions and hydrophobic interactions played important roles in the binding of 2 with α-glucosidase. This study disclosed the inhibitory activity and mechanism of 2 against α-glucosidase, which provides a theoretical basis for the development of new antidiabetic drugs form K. galanga.

Comparison in vitro and in silico studies of phenolic acids and flavonoids on α-glucosidase inhibition

Context: Inhibiting α-glucosidase activity has been proven to regulate hyperglycemia for treating diabetes, particularly type 2 diabetes mellitus (T2DM). Plant secondary metabolites consist of phenolic acids and flavonoids, which have been identified as α-glucosidase inhibitory agents. Aims: To assess the ability of the tested phenolic acids and flavonoids as α-glucosidase inhibitors and to predict their binding interactions with α-glucosidase, as well as their pharmacokinetic properties. Methods: The tested phenolic acids and flavonoids were evaluated for α-glucosidase inhibition by in vitro study, and their binding interactions were observed by an in silico molecular docking study utilizing AutoDock 4.2 software, while their pharmacokinetic properties were predicted using SwissADME and pkCSM online software. Results: The results displayed that quercetin (QE; IC50 = 0.85 μg/mL) and gallic acid (GA; IC50 = 26.19 μg/mL) significantly inhibited α-glucosidase activity than acarbose (IC50 = 139.4 μg/mL). Molecular docking analysis revealed that QE exhibited a higher binding affinity (ΔG; -7.53 kcal/mol) compared to acarbose (ΔG; -7.00 kcal/mol). This suggested that QE formed more favorable interactions with the enzyme, as evidenced by its binding to catalytic residues D215 and D352. In contrast, acarbose interacted with only one catalytic amino acid, i.e., D215. Furthermore, GA displayed a lower binding affinity (ΔG; -4.63 kcal/mol) than acarbose and bound to a distinct site on the α-glucosidase involving amino acids K156, S241, and D242. The pharmacokinetic properties predictions revealed that the potential compounds could bind and inhibit the α-glucosidase and were not toxic. Conclusions: Therefore, this study is useful for modifying the structures of phenolic acids and flavonoids to improve their ability to inhibit the α-glucosidase activity.

Insights into in vitro and in silico studies of α-glucosidase inhibitors isolated from the leaves of Grewia optiva (Malvaceae).

α-Glucosidase plays a critical role in glucose metabolism by breaking down complex carbohydrates into simpler sugars for intestinal absorption. Due to the side effects of current α-glucosidase inhibitors, there is increasing interest in exploring alternative therapeutic options. Inspired by the traditional uses of Grewia optiva J.R.Drumm. ex Burret (Malvaceae family) as an anti-diabetic herb, we isolated gnaphaffine A (1), a cyclic glycosylated homolignan, together with kaempferol derivatives (trans-tiliroside 2, cis-tiliroside 3, and astragalin 4) from the ethyl acetate fraction. In vitro antioxidant assays revealed that 1 exhibited anti-DPPH• and anti-ABTS+• activity (IC50 of 39.42 and 52.84μg/mL, respectively), comparable to ascorbic acid (IC50 of 43.34 and 47.56μg/mL, respectively). Moreover, 1 demonstrated a seven-fold stronger inhibition of α-glucosidase activity than acarbose (IC50 of 8.2 and 57.8μg/mL, respectively). Importantly, 1 was non-toxic to AC16 normal cardiomyocyte cell lines. Computational analyses identified two key factors contributing to the α-glucosidase inhibitory activity of 1: (a) hydrogen bonding interactions with catalytic residues (E277 and D352) and (b) a calculated ∆Gbind of -51.20kcal/mol. Furthermore, 3 showed the most favorable in silico binding profile, with the highest ∆Gbind (-55.89kcal/mol) and higher hydrogen bond occupancy compared to 1 and 2. These findings suggest that 1 and 3 may serve as promising lead compounds for the development of new α-glucosidase drugs.

Kinetic Studies on the Inhibition Potential of Bitter Leaf (Vernonia Amygdalin) in the Management of Diabetes

The aim of this study was to investigate the inhibition potential of extracts from Vernonia amygdalina on α-amylase and α-glucosidase activity, and its useful mechanisms in the treatment of diabetes specifically Type 2. The searchlight is beamed on the potential of the plant extract to inhibit the activity of α-amylase and thereby determining its mechanism or mode on inhibition as well as its IC50 value. The inhibition of alpha-amylase and alpha-glucosidase enzymes is a key strategy in managing diabetes. Vernonia amygdalina is a natural plant extract that has been used traditionally to manage diabetes. In this study, the inhibition potential of Vernonia amygdalina on alpha-amylase and alpha-glucosidase was investigated. Kinetic studies were conducted to determine the inhibitory effects of the plant extract on these enzymes. The results showed that vernonia amygdalina exhibited significant inhibition of both alpha-amylase and alpha-glucosidase enzymes. The study also evaluated the kinetic parameters of the inhibition process, including the type of inhibition and the inhibition constant. The findings of this study suggest that Vernonia amygdalina has the potential to be used as a natural inhibitor of alpha-amylase and alpha-glucosidase enzymes, which could lead to the development of new natural remedies for managing diabetes. These results are of interest to researchers studying natural product chemistry and drug development and inhibition of enzyme in bioreactors. Vernonia amygdalina inhibits alpha-amylase and alpha glucosidase activities but with greater inhibitory effects experienced in alpha glucosidase shows that plants tend to have higher inhibitory effect on alpha-glucosidase. With the obtain IC50 values it helps to provide insight into the mechanism of actions of an inhibitor by helping to determine the nature and strength of the interaction between the inhibitor and the enzyme or the biological process being inhibited. Acarbose which serves as inhibitors of these enzymes with greater effect on alpha-amylase but resulting to gastrointestinal adverse effects due to the accumulation of undigested carbohydrates becoming readily available for bacterial fermentation. With these outcomes the possibility exists that controlling glycemic complication is achievable by combining the inhibitory effect of Vernonia amygdalina and acarbose while reducing acarbose dose to alleviate anti-diabetic related adverse effects. Further investigation and studies are warranted in humans to help in glycemic control while in bioreactors this may include the usage of alpha-glucosidase and alpha-amylase as enzyme which similarly employs Vernonia amygdalina. It is noteworthy that the activity of these enzymes can be inhibited in bioreactors.

Antioxidant, Anti-α-Glucosidase, Anti-Tyrosinase, and Anti-Acetylcholinesterase Components from Stem of Rhamnus formosana with Molecular Docking Study.

Rhamnus formosana is a creeping evergreen shrub endemic to Taiwan. In traditional medicine, Rhamnaceae plants are used as herbal remedies for conditions such as itching, difficulty urinating, and constipation. This study explores the inhibitory effects of various solvent extracts and bioactive components of R. formosana on α-glucosidase, tyrosinase, acetylcholinesterase (AChE), and antioxidant activity. The 100 °C water extract exhibited strong antioxidant activity in DPPH, ABTS, superoxide, and FRAP assays. The methanol extract demonstrated the highest α-glucosidase inhibitory effect, while the ethanol extract displayed potent AChE inhibition and the acetone extract showed the most potential tyrosinase inhibitory activity among the extracts. Five main biocomponents were isolated and evaluated for their bioactivities. Among them, kaempferol (1) and quercetin (2) exhibited notable antioxidant activity in DPPH and ABTS assays. Particularly, kaempferol (1) performed the best α-glucosidase inhibitory effect, physcion (5) showed the strongest AChE inhibition, and quercetin (2) demonstrated the most potential for tyrosinase inhibitory activity. Further molecular docking studies revealed that there may be stronger binding mechanisms between bioactive components and target enzymes (including α-glucosidase, acetylcholinesterase, and tyrosinase) than the positive control. These findings suggest that bioactive extracts and compounds from the stems of R. formosana may have potential as natural antioxidant, anti-α-glucosidase, anti-AChE, and anti-tyrosinase drug candidates or dietary supplements for the management of oxidative stress-related conditions, including hyperglycemia, pigmentation disorders, and neurodegenerative diseases.

Inhibitory Effect and Mechanism of Dancong Tea from Different Harvesting Season on the α-Glucosidase Inhibition In Vivo and In Vitro.

Tea polyphenols have been reported to decrease the rate of starch hydrolysis by inhibiting α-glucosidase. However, the effect of the tea harvesting season and the structure of catechin monomers on the inhibitory activity of α-glucosidase is not understood. In this study, the inhibitory effect and underlying mechanism of four seasons of Dancong tea against α-glucosidase were investigated by in vivo and in vitro experiments, multi-spectroscope and molecular dynamic. The Dancong tea harvested in spring and winter showed a stronger inhibitory effect on α-glucosidase due to a higher content of catechin, especially EGCG ((-)-epigallocatechin-3-gallate). The results of in vivo and in vitro experiments showed that EGCG and ECG ((-)-epicatechin-3-gallate) with a higher content of gallate and hydroxyl groups exhibited a stronger inhibitory effect on starch hydrolysis, rise of postprandial blood glucose and activities of α-glucosidase compared to EGC ((-)-epigallocatechin) and EC ((-)-epicatechin). These gallate and hydroxy groups were more effective in interacting with the amino acid residues in the active site of α-glucosidase, leading to structural changes in the enzyme. Certainly, the inhibitory effect of Dancong tea on α-glucosidase explains one of the mechanisms by which it helps alleviate diabetes; the other hypoglycaemic mechanisms of Dancong tea will be further explored.

Parkia biglobosa Jacq. (Locust Bean) leaves and seeds extracts attenuates diabetic-linked cognitive dysfunction in streptozotocin-induced male wistar rats.

Diabetes Mellitus is a metabolic disorder characterized by high blood glucose levels, causing significant morbidity and mortality rates. This study investigated the antidiabetic, neuroprotective, and antioxidant effects of ethanol extracts of Parkia biglobosa (PB) leaves and seeds in streptozotocin (STZ)-induced diabetic rats. The administration of STZ significantly elevated fasting blood glucose levels (FBGL) to 355-400mg/mL compared to 111mg/mL in normal controls, indicating hyperglycemia. Treatment with PB extracts at 100mg/kg and 200mg/kg significantly (p < 0.05) reduced FBGL in a dose-dependent manner. No significant difference was observed between the effects of metformin and PB extracts at 200mg/kg. Cognitive dysfunction, assessed using the Y-maze test, was significantly improved in groups treated with PB extracts (p < 0.05), particularly at 200mg/kg, through inhibition of cholinesterase activity and protection against oxidative damage. Both PB extracts also demonstrated significant inhibition (p < 0.05) of α-amylase and α-glucosidase activity, reducing postprandial hyperglycemia, with a stronger inhibition at 200mg/kg. Additionally, PB extracts significantly increased catalase (CAT) and superoxide dismutase (SOD) activities, reversing the diabetes-induced decline in antioxidant enzyme levels. Monoamine oxidase (MAO) activity, elevated in diabetic conditions, was significantly downregulated by PB treatment, further contributing to neuroprotection. The neuroprotective effects may be attributed to the inhibition of cholinesterase and MAO, which help maintain neurotransmitter levels, alongside the antioxidant properties that mitigate oxidative stress in the brain. These findings suggest that PB extracts could serve as a natural therapeutic agent for diabetes management, with its effects comparable to metformin at higher doses.

Exploring the antidiabetic activity of potential probiotic bacteria isolated from traditional fermented beverage.

Type 2 Diabetes continues to be one of the major public health issues worldwide without any sustainable cure. The modulation of gut microbiota is believed to be caused by probiotic bacteria and several probiotic strains have previously shown antidiabetic activity. The present study aims to isolate potential probiotic bacteria from traditionally used fermented rice beer of Assam, India and to investigate its anti-hyperglycemic effect. Of the 20 isolated bacterial isolates, 5 isolates showed potential probiotic activities, of which, 2 isolates viz. Bacillus sp. FRB_A(A) and Acetobacter sp. FRB_B(S) showed good in vitro anti-oxidant and anti α-glucosidase activities. Based on the in vitro results, isolate Bacillus sp. FRB_A(A) was further used to evaluate the antidiabetic activity in streptozotocin induced diabetic rat model. After 21 days, the blood glucose level in diabetic rats with probiotic administration significantly lowered from 458.00 ± 46.62mg/dl to 108.20 ± 6.76mg/dl (p < 0.001), whereas, in diabetic rats without probiotic remained high (576.20 ± 29.48mg/dl). On analyzing the endogenous antioxidant profile in various tissues of the experimental rats, reduced lipid peroxidation, glutathione level and superoxide dismutase and glutathione peroxidase activity were observed in probiotic administered rats in comparison to the streptozotocin treated diabetic controls. In conclusion, the bacteria Bacillus sp. FRB_A(A) isolated from fermented rice beer possesses probiotic attributes and exhibits significant anti-hyperglycemic activities.

Phenolic Compounds, Antioxidant Activity, Sensorial Analysis and Metabolic Syndrome Enzyme Inhibition Properties of Calafate (Berberis microphylla) Fruit Juice Fermented by Patagonian Lactic Acid Bacteria.

Calafate is a native barberry of Patagonia, used in culinary and medicinal practices since ancient times. The aim of this work was to analyze the ability of lactic acid bacteria (LAB) isolated from calafate fruits and flowers, to increase the phenolic compound concentration and antioxidant capacity as well as to inhibit metabolic-related enzymes in fermented calafate juices. The sensory attributes of the selected fermented juice were also analyzed. The LAB strains grew between 1.33 ± 0.03 and 2.61 ± 0.30 log CFU/ml in the calafate juices at 24h. Fructobacillus fructosus B7 consumed glucose and fructose the most (2.30 ± 0.45g/L and 3.73 ± 0.44g/L, respectively) and produced mannitol (3.89 ± 0.77g/L). The fermented juice by Lacticaseibacillus paracasei B4 showed the highest total phenolic compound concentration (2662.58 ± 344.51mg GAE/100ml) and antioxidant capacity (38916.42 ± 2157.52 µmol TE/100ml). The fermented juices inhibited the activity of metabolic syndrome-related enzymes. The lower IC50 for α-glucosidase activity was observed for F. fructosus B7 and L. paracasei B4 (0.56 ± 0.10 and 0.64 ± 0.05mg GAE/ml, respectively) fermented juices, while for α-amylase the lowest IC50 values were determined for the L. curvatus B34 and L. paracasei B4 (0.34 ± 0.01 and 0.37 ± 0.06mg GAE/ml, respectively) juices. The relative amount of isorhamnetins, which can induce GLUT4 translocation to the plasma membrane preventing hyperglycemia, was increased in the L. paracasei B4 fermented juice. The L. paracasei B4 fermented juice had acceptable sensorial values for consumption.

Ultrasound-assisted extraction, purification, structural characterization, and hypoglycemic activities of a polysaccharide from Momordica charantia L.

Polysaccharides from Momordica charantia L. (MCP) have attracted interest for their diverse biological activities. This study investigated the ultrasound-assisted extraction of MCP, optimizing conditions using response surface methodology. The optimal extraction parameters were a material-liquid ratio of 1:4 (g/mL), a temperature of 74 °C, an extraction time of 2.4 h, and an ultrasonic power of 296 W, resulting in a total carbohydrate content of 40.22 ± 1.69 %, closely matching theoretical predictions. Following extraction, MCP was purified using DEAE Sepharose Fast Flow anion exchange and Sephadex G-100 dextran gel chromatography, isolating a pure polysaccharide fraction, MCPS-3. Structural analysis revealed that MCPS-3, with a molecular mass of 93.796 kDa, consisted of rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, and arabinose in molar ratios of 10.66:3.66:258.0:1.0:51.0:9.338. Methylation and NMR analyses suggested that MCPS-3 was a complex polysaccharide, predominantly homogalacturonan domains with rhamnogalacturonan I side chains. In functional assays, MCPS-3 demonstrated inhibition of α-amylase and α-glucosidase activities. Additionally, in insulin-resistant HepG2 cells, MCPS-3 improved glucose consumption, increased glycogen content, and enhanced the activities of hexokinase and pyruvate kinase. These findings provided insights into the structural properties of MCPS-3 and underscored its potential as a natural compound with significant hypoglycemic activity.

Investigating the antidiabetic properties of Apium graveolens extract and its inhibition of enzymes associated with hyperglycemia.

Apium graveolens Linn., also known as celery, is a member of the Apiaceae family and has shown promising pharmacological properties, including diabetes. Indeed, the current investigation aimed to investigate the potential inhibitory effects of A. graveolens seed aqueous extract on the digestive enzymes involved in carbohydrate metabolism and its efficiency in reducing blood sugar levels in diabetic mice induced by streptozotocin. I administered oral doses of an aqueous extract from A. graveolens seeds to both normal and diabetic animals to evaluate acute toxicity and its potential antidiabetic effects. I observed the glycemia and body weight of the animals for four weeks. In vitro tests were also done to see how the seed extract affected the activities of α-amylase and α-glucosidase. Following administration of the extract, diabetic mice showed a notable reduction in blood glucose concentration. This reduction was similar to the standard metformin treatment after two and four weeks. Moreover, A. graveolens demonstrated significant inhibitory effects on α-amylase and α-glucosidase activity, with IC50 values of 840.15±0.02 and 114.81±0.05, respectively. At 500mg/kg/day, histological analysis indicated degenerative alterations in pancreatic islet cells. These results indicate that the aqueous extract derived from the seeds of A. graveolens possesses promising antihyperglycemic properties in diabetic mice, along with notable inhibition of α-amylase and α-glucosidase activity. Further investigation is needed to characterize the active compounds present in A. graveolens seeds.

Composition, Anti-Diabetic, and Antioxidant Potential of Raphanus sativus Leaves.

Limiting and/or slowing down the starch digestion process and consequently the release of glucose can be an important strategy for the prevention of type 2 diabetes (T2D). The aim of the current in vitro study was to assess the anti-diabetic and antioxidant potential of red radish leaves of the Carmen, Jutrzenka, Saxa, and Warta cultivars. In the context of anti-diabetic activity, the effect of leaves on potato starch digestion and free glucose binding, as well as inhibitory effects of leaf extracts against α-amylase and α-glucosidase and non-enzymatic glycation (AGEs) were determined. The basic chemical composition, quantitative composition of phenolic compounds, and antioxidant activity of leaves were also estimated. This study showed that all radish leaves inhibited the breakdown of potato starch and showed their ability to bind glucose. This activity was correlated with the content of hydroxycinnamic acids, protein and dietary fiber while flavones was probably responsible for glucose binding. Leaf extracts inhibited α-glucosidase activity and formation of AGEs but were practically inactive towards α-amylase. Inhibition of α-glucosidase activity was related to the content of proanthocyanidins and inhibition of AGEs formation to flavonols. These results point to radish leaves, especially the Warta and Jutrzenka cultivars, as a potential natural remedy for treating T2D.

Effect of rhamnolipid on the performance of compound thermophilic bacteria agent pretreatment system for waste sludge hydrolysis.

This study innovatively introduced rhamnolipid (RL) to compound thermophilic bacteria (TB) agent pretreatment system for further accelerating the waste sludge hydrolysis and substrates transformation. The results showed that combined pretreatment was beneficial for the sludge extracellular polymers (EPS) rupture and dissolved organic matters (DOM) release. In the optimal dosage of 40mg/g SS RL, the activities of protease and α-glucosidase increased by 20.7% and 33.3% than that without RL addition, respectively. The addition of RL enhanced efficient contacts between hydrolases and organic substrates, and excitation emission matrix (EEM) spectrum revealed that combined pretreatment with 40mg/g SS RL could achieve higher soluble microbial by-products occupancy (54%) and lower fulvic acid-like substances (6%) occupancy in DOM, promoting the waste sludge biodegradability. High organics availability conducted to more shifts in microbial community structure, compared with TB agent pretreatment, the relative abundance of genus Geobacillus and norank_f__Synergistaceae were enhanced by 29.08 and 0.33 times in combined pretreatment system, respectively, which was conducive to sludge hydrolysis and subsequent anaerobic fermentation process.