Glucose Entrapment Research Articles

Antidiabetic Potential and Metabolite Profile of Leaf and Stem Extract of Castanopsis tungurrut (Blume) A.DC.

<p>Diabetes mellitus is a metabolic disorder caused by high blood sugar levels. One species in <em>the Castanopsis</em> genus is proven with a hypoglycemic effect. Therefore, the study aimed to discover the potential of <em>Castanopsis tungurrut</em> as an antidiabetic. Sample extraction, α-amylase inhibition, glucose diffusion analysis, GC-MS analysis, and molecular docking were applied in this study. Maceration of the leaf ethanol extract showed the highest yield value of 21.08%, while the stem extract was 14.04%. Leaf ethanol extract and stem ethyl acetate extract showed the highest inhibiting α-amylase activity with an inhibition value of 33.74%±1.54 and 34.45%±1.08 at 1 mg/mL concentration. The glucose entrapment assay showed that these two extracts could inhibit the diffusion of glucose in the dialysis bag. The final result was glucose concentration in dialysate for the two extracts of 0.114±0.001 mg/mL and 0.116±0.001 mg/mL which was lower than acarbose in 0.120±0.004 mg/mL. GC-MS analysis showed 6 metabolites in leaf ethanol extract and 22 metabolites in stems ethyl acetate extract from an alkane, salicylic, cinnamic, terpene, steroid, and fatty acid. Molecular docking resulting between the compounds with α-amylase enzymes complex showed γ-sitosterol and ß-bisabolene from <em>C. tungurrut</em> extract have the potential to be developed as an antidiabetic drug due to its good inhibitory activity with binding affinity values of -9.1 and -6.9 that considered better and quite close to acarbose as control of -7.7.</p>

Polysaccharides from ginger stems and leaves: Effects of dual and triple frequency ultrasound assisted extraction on structural characteristics and biological activities

Dual- and triple-frequency ultrasonic processing features advantages such as uniform energy distribution and the ease of resonance within the extracted raw material, which attenuates the directional effect of single frequency ultrasonic treatment. In this study, the effects of dual-frequency and triple-frequency ultrasound extraction were evaluated based on the physicochemical properties, structural characteristics, and biological activities of polysaccharides from ginger stems and leaves (GSLPs). Triple-frequency ultrasound extraction was found to obtain higher polysaccharide yield (10.50 ± 0.20%) than dual-frequency ultrasound extraction (9.74 ± 0.30%). Moreover, the former possessed higher contents of total sugar, uronic acid, and sulfate radicals, but lower molecular weight. Both types of polysaccharides exhibited intact helical structure, similar thermal properties, and clumpy structures with porous surfaces. More importantly, the polysaccharides extracted by triple-frequency ultrasound extraction showed stronger antioxidant activity and better functional properties, while those extracted by dual-frequency extraction exhibited superior rheological properties due to larger molecular weight. The latter also demonstrated better glucose entrapment and α-glucosidase inhibitory activity. In conclusion, dual- and triple-frequency ultrasound treatment may enable a greater range of GSLP applications in functional foods.

LncRNA NBR2 aggravates hepatoblastoma cell malignancy and promotes cell proliferation under glucose starvation through the miR-22/TCF7 axis

ABSTRACT Hepatoblastoma (HB) is the most commonly seen pediatric liver malignancy. With frequent mutations in CTNNB1 gene that encodes β‐catenin, hepatoblastoma has been considered as a Wnt/β‐catenin‐activated malignant tumor. Altered glucose metabolism upon nutrient deprivation (glucose starvation) might also be a critical event in hepatoblastoma carcinogenesis. The present study provides a lncRNA NBR2/miR-22/TCF7 axis modulating proliferation, invasion, migration, and apoptosis of hepatoblastoma cells upon glucose starvation through Wnt and downstream TCF7 signaling pathways. The expression of NBR2 is significantly increased within hepatoblastoma tissue samples; moreover, under incubation with 0 mM glucose (glucose starvation), NBR2 expression is significantly upregulated. NBR2 silencing not only inhibited hepatoblastoma cell viability, invasion, and migration under normal culture condition but also promoted the cell apoptosis under glucose starvation. NBR2 silencing in hepatoblastoma cells also decreased TCF7 mRNA expression and TCF7 protein levels, as well as the protein levels of the cell cycle, glucose entrapment, and EMT markers. miR-22 is directly bound to both NBR2 and TCF7; lncRNA NBR2 counteracted miR-22-mediated repression on TCF7 via acting as a ceRNA. The effects of NBR2 silencing on TCF7 expression, hepatoblastoma cell phenotype, and cell cycle, glucose entrapment, and EMT markers were all significantly reversed by miR-22 inhibition. In conclusion, lncRNA NBR2 aggravates hepatoblastoma cell malignancy through competing with TCF7 for miR-22 binding, therefore counteracting miR-22-mediated repression on TCF7. LncRNA NBR2 might be a promising target to inhibit hepatoblastoma cell proliferation under glucose starvation.

Inhibitory potential of Amaranthus viridis on α-amylase and glucose entrapment efficacy In vitro

Type 2 Diabetes which prevails globally increasing at an alarming rate, is characterized by hyperglycemia where blood glucose levels remain elevated due to poor cellular glucose uptake and metabolism. One way to treat this disease is by a-amylase inhibitors and glucose retention in intestine for longer period. The present study was designed to determine the in vitro antidiabetic potential of Amaranthus virdis extracts. Antidiabetic action was confirmed by the inhibitory effects of the A.viridis extracts on a-amylase activity and significant glucose entrapment ability. The methanolic extract of A. viridis leaves exhibited the highest glucose retention ability of 47.05% (40.125µg/mL) within the dialysis tube which mimics human intestine. Water extract of A. Viridis stem showed the most significant inhibition effect on a-amylase activity (100%) compared to other extracts after 15 minutes of incubation, with IC50 value of (5.058±0.41µg/mL) and which was even equally active to the standard acarbose drug used in the current analysis. Interestingly, the methanol extract of leaf exhibited notable efficacy both on glucose diffusion inhibition and inhibition of alpha amylase as well. This study suggests for further in vivo research to check their activity and toxicity within biological systems and also for the isolation of bioactive inhibitory compounds for novel drug discovery.

Crude Aloe vera Gel Shows Antioxidant Propensities and Inhibits Pancreatic Lipase and Glucose Movement In Vitro.

Aloe vera gel (AVG) is traditionally used in the management of diabetes, obesity, and infectious diseases. The present study aimed to investigate the inhibitory potential of AVG against α-amylase, α-glucosidase, and pancreatic lipase activity in vitro. Enzyme kinetic studies using Michaelis-Menten (K m) and Lineweaver-Burk equations were used to establish the type of inhibition. The antioxidant capacity of AVG was evaluated for its ferric reducing power, 2-diphenyl-2-picrylhydrazyl hydrate scavenging ability, nitric oxide scavenging power, and xanthine oxidase inhibitory activity. The glucose entrapment ability, antimicrobial activity, and total phenolic, flavonoid, tannin, and anthocyanin content were also determined. AVG showed a significantly higher percentage inhibition (85.56 ± 0.91) of pancreatic lipase compared to Orlistat. AVG was found to increase the Michaelis-Menten constant and decreased the maximal velocity (V max) of lipase, indicating mixed inhibition. AVG considerably inhibits glucose movement across dialysis tubes and was comparable to Arabic gum. AVG was ineffective against the tested microorganisms. Total phenolic and flavonoid contents were 66.06 ± 1.14 (GAE)/mg and 60.95 ± 0.97 (RE)/mg, respectively. AVG also showed interesting antioxidant properties. The biological activity observed in this study tends to validate some of the traditional claims of AVG as a functional food.

In vitro Kinetic of Inhibition of Lipase, Antioxidant Activity, Glucose Entrapment and Polyphenolic Content of Solanum linnaeanum

Decoction as traditionally used and methanol extract of a commonly consumed vegetable Solanum linnaeanum (SL) was evaluated for any antioxidant potential (Ferric reducing power (FRAP) assay, nitric oxide, DPPH, and xanthine oxidase inhibitory activity). The inhibitory effect of SL against α-amylase, α-glucosidase and pancreatic lipase activity was studied and the type of inhibition was established by the Lineweaver-Burk plot in vitro. The entrapment ability in decreasing glucose movement in an in vitro model was also investigated. The total phenolic, flavonoid, anthocyanin and tannin content were determined. The aqueous extract (IC50=0.20 µg/ mL) was more active against pancreatic lipase than the methanol extract (IC50=0.40 µg/ mL) and the positive control Orlistat® (IC50=0.35 µg/ mL). An uncompetitive type of inhibition as indicated by a reduction in Vmax and Km was recorded. Methanol extract demonstrated a more efficient DPPH scavenging potential. The FRAP of the methanolic extract was 102.708±1.36 mM trolox equivalent (TE)/mg extract. Decoction extracts showed no significant difference (p>0.05) on glucose entrapment capacities (33.3 %) when compared to the positive control (Arabic gum). Phytochemical screening of SL indicated the presence of phenols (152.80±1.40 (GAE) [g/mL]) and flavonoids (4.34±0.16 Rutin equivalent[μg/mL]) in the methanol extract only and absence of tannin and anthocyanin in both methanol and aqueous extracts. This study is the first attempt to establish valuable baseline data on SL bioactivity. The results can be further exploited for the development of new therapeutic dietary approach for the management of diabetes and obesity.

Hypoglycemic, antihyperglycemic, and antioxidant effects of the edible plant Anoda cristata

Ethnopharmacological relevanceSome studies refer that the entire plant of Anoda cristata is consumed as food and medicine; in particular for treating diabetes, inflammation, fever, cough, and wounds. The aim of this study was to establish the preclinical efficacy of Anoda cristata as hypoglycemic and/or antihyperglycemic agent using well-known animal models. Materials and methodsThe acute toxicity was analyzed by the Lorke method. Acute hypoglycemic as well as oral glucose and sucrose tolerance tests were used to determine the hypoglycemic and antihyperglycemic action of Anoda cristata. Several preparations of the plant, including a mucilage (M), an aqueous (T-AE), a free mucilage aqueous (FM-AE), and an organic (OE) extracts, were tested in healthy and NA-STZ-hyperglycemic mice. Glibenclamide (15mg/kg), acarbose (5mg/kg ) and metformin (200mg/kg) were used as positive controls. The major compounds acacetin (1) and diosmetin (2), isolated from an infusion of the plant applying chromatographic methods, were evaluated as hypoglycemic agents using the same assays. The FM-AE was tested also in rats with metabolic syndrome induced by a high-fructose fed. Finally some assays were performed to determine the antioxidant capacity of the FM-AE in vitro. ResultsThe results demonstrated that the extracts and compounds from Anoda cristata were effective for reducing blood glucose levels in healthy and NA-STZ-hyperglycemic mice when compared with vehicle groups (p<0.05). The FM-AE exerted also positive effect over different biochemical parameters altered in rats with metabolic syndrome induced by a fructose diet. FM-AE has also antioxidant action effectively trapping ONOO− and ROO• radicals. The major flavonoids isolated from the plant, namely acacetin (1) and diosmetin (2), caused significant hypoglycemic effect and possessed antioxidant activity. ConclusionAnoda cristata is effective to diminish glucose levels in vivo and to ameliorate different disorders related with the metabolic syndrome in rats. According to the results, the efficacy of Anoda cristata preparations could be due to the presence of active principles with different mode of actions at the molecular level, including α-glycosidases inhibitors, insulin secretagogues, glucose entrapment and radical trapping agents.

Metformin, cancer and glucose metabolism.

Metformin is the first-line treatment for type 2 diabetes. Results from several clinical studies have indicated that type 2 diabetic patients treated with metformin might have a lower cancer risk. One of the primary metabolic changes observed in malignant cell transformation is an increased catabolic glucose metabolism. In this context, once it has entered the cell through organic cation transporters, metformin decreases mitochondrial respiration chain activity and ATP production that, in turn, activates AMP-activated protein kinase, which regulates energy homeostasis. In addition, metformin reduces cellular energy availability and glucose entrapment by inhibiting hexokinase-II, which catalyses the glucose phosphorylation reaction. In this review, we discuss recent findings on molecular mechanisms that sustain the anticancer effect of metformin through regulation of glucose metabolism. In particular, we have focused on the emerging action of metformin on glycolysis in normal and cancer cells, with a drug discovery perspective.

Inhibitory Potential of Five Traditionally Used Native Antidiabetic Medicinal Plants on α -Amylase, α -Glucosidase, Glucose Entrapment, and Amylolysis Kinetics In Vitro.

Five traditionally used antidiabetic native medicinal plants of Mauritius, namely, Stillingia lineata (SL), Faujasiopsis flexuosa (FF), Erythroxylum laurifolium (EL), Elaeodendron orientale (EO), and Antidesma madagascariensis (AM), were studied for possible α-amylase and α-glucosidase inhibitory property, glucose entrapment, and amylolysis kinetics in vitro. Only methanolic extracts of EL, EO, and AM (7472.92 ± 5.99, 1745.58 ± 31.66, and 2222.96 ± 13.69 μg/mL, resp.) were found to significantly (P < 0.05) inhibit α-amylase and were comparable to acarbose. EL, EO, AM, and SL extracts (5000 μg/mL) were found to significantly (P < 0.05) inhibit α-glucosidase (between 87.41 ± 3.31 and 96.87 ± 1.37% inhibition). Enzyme kinetic studies showed an uncompetitive and mixed type of inhibition. Extracts showed significant (P < 0.05) glucose entrapment capacities (8 to 29% glucose diffusion retardation index (GDRI)), with SL being more active (29% GDRI) and showing concentration-dependent activity (29, 26, 21, 14, and 5%, resp.). Amylolysis kinetic studies showed that methanolic extracts were more potent inhibitors of α-amylase compared to aqueous extracts and possessed glucose entrapment properties. Our findings tend to provide justification for the hypoglycaemic action of these medicinal plants which has opened novel avenues for the development of new phytopharmaceuticals geared towards diabetes management.

Glycemic response in healthy rats fed with composite cereal bars

AbstractThree composite cereal bars containing white maize, blue maize, or unripe banana flours were prepared. The glycemic response in rats feed with a dose available carbohydrates, and the bars effect on a glucose tolerance test were evaluated. A dose of 0.85 g/kg was used in the experiments with the three bars. The experiment with a glucose load showed that rats previously fed with blue maize and unripe banana bars showed reduced glycemic response, probably as consequence of glucose entrapment within the food matrix and produce a slow release. The effect was more pronounced for the unripe banana bar. The groups fed with equivalent load of available carbohydrates from the various bars exhibited lower and slower glycemic responses than a control group administered only with a glucose load. The white maize bar elicited a maximal blood glucose level at 30 min postprandial, blue maize at 45 min and unripe banana bar at 60 min. Bars inducing variable glycemic response may be prepared following the proper choice of functional ingredients.

In Vitro Glucose Entrapment and Alpha-Glucosidase Inhibition of Mucilaginous Substances from Selected Thai Medicinal Plants

As a continuous searching for anti-diabetic(type II) substances, seven mucilage polysaccharides from selected plants were studied as follow: aerial parts of Basella alba Linn., fruits of Hibiscus esculentus Linn., leaves of Litsea glutinosa (Lour.) C.B. Robinson, seeds of Ocimum canum Sims., seeds of Plantago ovata Forssk., fruits of Scaphium scaphigerum G. Don. and seeds of Trigonella foenum-graecum Linn. The bioactive properties for entrapping glucose, inhibiting enzyme alpha-glucosidase and free radical scavenger were in vitro studied compared to glucomannan. The physical characteristics for water holding capacity and viscosity were determined. The chemical characteristics were assayed for monosaccharide composition using methanolysis, TMSderivatization and gas chromatography. O. canum mucilage superiorly entrapped glucose compared to glucomannan. This activity was relevant to its highly viscous gelation. S. scaphigerum showed another property of alphaglucosidase inhibition. S. scaphigerum mucilage (0.5%) inhibited the enzyme activity by 82.6%, compared to 1-Deoxynorjirimycin (by 47.6%). Most mucilages, except O. canum and P. ovata, showed DPPH scavenging activity higher than glucomannan. Galacturonic acid was found in 3 from 7 mucilages namely B. alba, P. ovata and S. scaphigerum. Whereas rhamnose was common sugar found in all seven mucilages. Monosaccharide components of these mucilages were compared to the results from the previous reports.

NHE-1 inhibition-induced cardioprotection against ischaemia/reperfusion is associated with attenuation of the mitochondrial permeability transition

The possible contribution of the cardiac mitochondrial permeability transition pore (PTP) towards the cardioprotective effects of Na(+)-H(+) exchanger-1 (NHE-1) inhibition was studied in hearts subjected to ischaemia/reperfusion (IR). Langendorff-perfused rat hearts were subjected to 40 min of global ischaemia and 60 min of reperfusion in the presence or absence of the NHE-1 specific inhibitor AVE-4890 (AVE, 5 microM). Mitochondrial PTP opening was determined in the intact heart using 2-deoxy-[(3)H]-glucose entrapment and in isolated mitochondria by monitoring the decrease of the calcium-induced light scattering. Mitochondrial respiration was measured with a Clark-type oxygen electrode whereas release of apoptosis-inducing factor (AIF) and endonuclease G (EndoG) and levels of cleaved poly-(ADP-ribose) polymerase (PARP) were analysed by western blotting. IR induced mitochondrial PTP opening, which was inhibited by 28% (P < 0.05) with AVE treatment. Mitochondria isolated from AVE-treated hearts demonstrated significantly less calcium-induced swelling and higher substrate oxidation at complex I and II as well as cytochrome c oxidase and citrate synthase activity. AVE treatment also suppressed IR-induced release of AIF and EndoG from mitochondria, prevented the IR-induced rise in cleaved PARP levels, and was associated with significantly enhanced postischaemic recovery of left ventricular developed pressure and a significant decrease in lactate dehydrogenase release. AVE did not affect PTP opening directly in isolated mitochondria. The beneficial effect of NHE-1 inhibition in hearts subjected to IR is associated with attenuation of mitochondrial PTP opening and apoptosis and the resultant mitochondrial dysfunction. The effect of AVE on PTP opening most likely is indirect, as pore opening was not affected by direct administration of AVE to mitochondrial suspensions.

Glucose Encapsulation in Catanionic Vesicles and Kinetic Study of the Entrapment/Release Processes in the Sodium Dodecyl Benzene Sulfonate/Cetyltrimethylammonium Tosylate/Water System

The sodium dodecyl benzene sulfonate (SDBS)/cetyltrimethyl-ammonium tosylate (CTAT)/water ternary system has previously been shown to give rise to the formation of vesicles for well-defined compositions requiring an excess of one of the surfactants over the other. Two types of vesicular systems can thus be obtained (named V+ and V−, depending on the nature of the excess surfactant, i.e., CTAT or SDBS, respectively). In addition, the pure ion-pair amphiphile (IPA) can be obtained after removing the counterions. These different systems (V+, V−, and IPA) were investigated in regards to their ability to susbtantially retain a hydrophilic probe such as glucose. The influence of the initial glucose and surfactant concentrations was studied, and dialysis experiments were conducted with a view to determine the kinetics of glucose entrapment and release by the vesicles and, thus, to assess the possibility of a long-term encapsulation. The results indicate that all the vesicular systems studied here are characterized by quite a high permeability of the amphiphilic bilayer. However, SDBS-rich (V−) and IPA vesicles proved to be less permeable than CTAT-rich (V+) vesicles.

Preparation and Properties of Vesicles Formed from Phospholipid Analogues of N-(Phosphonoacetyl)-L-aspartate (PALA) by Sonication or Extrusion: Transition Temperature, Particle Size, Glucose Entrapment, and 31P NMR

We characterize here the ability of new amphiphilic compounds to form vesicles that could potentially be used as vectors for therapeutical applications. These compounds are derived from N-phosphonoacetyl-L-aspartate (PALA), a potential antitumoral agent. Vesicular dispersions of phospholipid analogues of PALA with different alkyl chain lengths (diC12-, diC14-, diC16-, and diC18-PALA), which had been previously synthesized, are tested from different points of view. Two kinds of preparation methods are compared: sonication; extrusion. The two preparation methods resulted in important differences in the properties of the dispersions which confirmed the conclusions of a previous investigation from cryo-TEM imaging. The results of fluorescence polarization experiments, performed either with the pure compounds or their mixtures with lecithins or cholesterol, indicated that the transition temperature Tm can be modulated if it is required for the applications. The sonicated particles showed smaller size and much lower glucose encapsulation than the extruded particles. In both cases these properties are only weakly depending on the amphiphile alkyl chain lengths. The glucose permeability has appeared to considerably increase (lower encapsulation) at T > Tm. The effect of Mn2+ on the 31P NMR signal intensity suggested that unilamellar vesicles are coexisting with other types of particle in case of extrusion, whereas in case of sonication only few and less stable vesicles are present, in agreement with the preceding observations.

Vesicle-Forming Properties of New Phospholipid Analogues Derived from N-Phosphonoacetyl-l-aspartate (PALA): Particle Features and Morphology in Relation with Alkyl Chain Lengths

Phospholipid analogues of the anticancer agent PALA (N-phosphonoacetyl-l-aspartate) with varying alkyl chain lengths were synthesized: diC12-, diC14-, diC16-, and diC18-PALA. Their aptitude to form vesicles was tested using two different preparation techniques: sonication and extrusion. The particles obtained were characterized from cryogenic temperature transmission electron microscopy imaging, showing a continuous morphological evolution when increasing the alkyl chain lengths. Spherical vesicles were obtained for the smaller chain lengths, which evolve toward disklike vesicles, faceted objects, and flat disk structures for longer chain lengths. This evolution was correlated with the transition temperatures, Tm, from the gel state to the liquid crystalline state, which were independently determined. The sonication method was found to lead to smaller objects and increased particle fragmentation compared to extrusion. Particle size measurements and glucose entrapment experiments provided additional results in good agreement with the previous observations.