Glucose Diffusion Research Articles

In vitro antidiabetic, antioxidant activities and GC-MS analysis of Rhynchostylis Retusa and Euphorbia Neriifolia leaf extracts.

This study aimed to assess the antidiabetic, and antioxidant potential of Rhynchostylis retusa and Euphorbia neriifolia, well known for traditional ethnomedicinal uses in North-east India. Leaf extracts prepared in water, methanol and petroleum ether were evaluated for in vitro antidiabetic and antioxidant assay using α-amylase inhibition, glucose diffusion method and DPPH radical scavenging activity. The α-amylase inhibition with E. neriifolia methanolic extract at 400μg/ml (66.67%) and R. retusa aqueous extract at 300μg/ml (58.15%) were stronger than in equivalent concentrations of acarbose, i.e., 62.17, and 51.52%, respectively. Aqueous extract R. retusa showed a maximum 67.65% inhibition of glucose diffusion at 180min in comparison to control without leaf extract. The DPPH radical scavenging activity of E. neriifolia extract in methanol was significantly better than equivalent aqueous or ether extract. However, the solvent choice had little impact on antioxidant activity in R. retusa. GC-MS analysis revealed the presence of a large number of phytochemicals in methanol fraction of E. neriifolia aqueous extracts in comparison to R. retusa. Though the in vitro α-amylase inhibition or glucose diffusion retardation implied potential medicinal use of endangered orchid R. retusa and E. neriifolia, further investigation may be warranted for identification of relevant bio-active compounds and in vivo validation of their pharmacological properties.

Dendritic core-shell copper-nickel alloy@metal oxide for efficient non-enzymatic glucose detection

The synergy effect of bimetallic oxide shell and high electrically conductive metallic core enables the dendritic Cu-Ni/ nickel foam (NF) for detecting non-enzymatic glucose. • Binder-free Cu-Ni alloys@metal oxide was prepared by facile electrodeposition method. • The dendritic structure promotes glucose diffusion and provides rich active sites. • The bimetallic oxide shell and metallic core enable highly effective glucose sensing. A success has been achieved in the synthesis of dendritic core-shell copper-nickel alloy@metal oxide on nickel foam (Cu-Ni/NF) electrode for non-enzymatic glucose detection by going through a facile electrodeposition process followed by oxidation in NaOH solution. The direct electrodeposition approach facilitates the transfer of electrons in the binder-free electrode, and the dendritic structure promotes glucose diffusion while providing sufficient active sites required for the process of glucose electrocatlysis. Moreover, the unique core-shell structure promotes the catalytic activity towards glucose oxidation due to the synergistic effect caused by the bimetallic oxide shell and the metallic core that is conductive to electron transport. Accordingly, the Cu-Ni/NF electrode exhibits a high sensitivity of 11.34 mA mM −1 cm -2 , a low detection limit of 2 μM (S/N = 3), and a wide linear range of 1–600 μM for glucose detection. In addition, the electrode demonstrates such advantages as high selectivity, fast response time, and long duration stability. The designed Cu-Ni/NF electrode shows its massive potential of application for non-enzymatic glucose detection.

Disposable electrochemical glucose sensor based on water-soluble quinone-based mediators with flavin adenine dinucleotide-dependent glucose dehydrogenase

Glucose level measurement is essential for the point-of-care diagnosis, primarily for persons with diabetes. A disposable electrochemical glucose sensor is constructed using flavin adenine dinucleotide-dependent glucose dehydrogenase (FAD-GDH) and redox mediator for electron transfer from the enzyme to the electrode surface. Ideally, a suitable mediator should have high water solubility, high kinetic constant, high stability, and redox potential between −0.2 and 0.1 V vs. Ag|AgCl|sat. KCl. We designed and synthesized two new quinone-based water-soluble mediators: quinoline-5,8-dione (QD) and isoquinoline-5,8-dione (IQD). The formal potentials for both QD and IQD at pH 7.0 were −0.07 V vs. Ag|AgCl|sat. KCl. The logarithms of the electron exchange rate constants (k2/(M−1 s−1)) between QD/IQD and FAD-GDH were 7.7 ± 0.1 and 7.4 ± 0.1 for QD and IQD, respectively, which are the highest value among the water-soluble mediators for FAD-GDH reported to date. Disposable amperometric glucose sensors were fabricated by dropping FAD-GDH and QD or IQD onto a test strip. The sensor achieved a linear response up to glucose concentrations of 55.5 mM. The linear response was obtained even when the mediator loading was low (0.5 nmol/strip); loading was only 0.2 mol% of glucose. The results proved that the response current was primarily controlled by glucose diffusion. In addition, the sensor using QD exhibited high stability over 3 months at room temperature.

Characterization of covalent, feruloylated polysaccharide gels by pulsed field gradient-stimulated echo (PFG-STE)-NMR

Translational mobility of guest molecules such as water and glucose in gels that are based on feruloylated polysaccharides appears to be critical to understand their nutritional and functional properties. Here, the applicability of PFG-STE-NMR on feruloylated gels was proven, and relationships to rheological data were studied.Arabinoxylans and pectins were extracted from by-products using varying conditions. Laccase induced coupling of these chemically characterized polymers resulted for most of the feruloylated polysaccharides in homogeneous gels. Rheological studies confirmed that polysaccharide composition affects viscoelastic properties of the resulting gels. Generally, diffusion of water and glucose is hindered in gels. In the feruloylated polysaccharide gels, both polysaccharide concentration and extraction conditions affect the diffusion behavior of these molecules. A simple correlation between rheological data and mobility of guest molecules has not generally been found: although long time acid extracted pectins form highly elastic gels, water diffusion in these gels is less hindered.

Effect of Physicochemical Properties of Carboxymethyl Cellulose on Diffusion of Glucose.

Soluble dietary fibers (SDF) are known to reduce the post-prandial plasma glucose levels. However, the detailed mechanisms of this reduced glucose release in the human gut still remain unclear. The aim of our study was to systematically investigate the effect of different types of SDF on glucose release in an in vitro model as a prerequisite for the selection of fibers suitable for application in humans. Three types of carboxymethyl cellulose (CMC) were used to investigate the correlations between fiber concentration, molecular weight (MW), and viscosity on diffusion of glucose using a side-by-side system. CMC solutions below the coil overlap (c*) influenced the glucose diffusivity only marginally, whereas at concentrations above c* the diffusion of glucose was significantly decreased. Solutions of lower MW exhibited a lower viscosity with lower glucose diffusion compared to solutions with higher MW CMC, attributed to the higher density of the solutions. All CMC solutions showed a systematic positive deviation from Stokes-Einstein behavior indicating a greater rise in viscosity than reduction in diffusion. Therefore, our results pave the way for a new approach for assessing glucose diffusion in solutions comprising dietary fibers and may contribute to further elucidating the mechanisms of post-prandial plasma glucose level reduction.

Effects of Scaffold Pore Morphologies on Glucose Transport Limitations in Hollow Fibre Membrane Bioreactor for Bone Tissue Engineering: Experiments and Numerical Modelling.

In the current research, three electrospun polycaprolactone (PCL) scaffolds with different pore morphology induced by changing the electrospinning parameters, spinning time and rate, have been prepared in order to provide a fundamental understanding on the effects pore morphology have on nutrient transport behaviour in hollow fibre membrane bioreactor (HFMB). After determining the porosity of the scaffolds, they were investigated for glucose diffusivity using cell culture media (CCM) and distilled water in a diffusion cell at 37 °C. The scanning electron microscope (SEM) images of the microstructure of the scaffolds were analysed further using ImageJ software to determine the porosity and glucose diffusivity. A Krogh cylinder model was used to determine the glucose transport profile with dimensionless variables within the HFMB. The paper discusses the roles of various dimensionless numbers (e.g., Péclet and Damköhler numbers) and non-dimensional groups of variables (e.g., non-dimensional fibre radius) on determining glucose concentration profiles, especially in the scaffold region. A negative linear relationship between glucose diffusivities across PCL scaffolds and the minimum glucose concentrations (i.e., concentration on the outer fibre edge on the outlet side (at z = 1 and r = 3.2) was also found. It was shown that the efficiency of glucose consumption improves with scaffolds of higher diffusivities. The results of this study are expected to help in optimizing designs of HFMB as well as carry out more accurate up scaling analyses for the bioreactor.

Biofunctional characteristics of banana peel dietary fibre (BPDF) and its associated in vitro antidiabetic properties

The potential applications of banana peel waste can resolve environmental issues; however, the potentials of banana peels as antidiabetic remain unexplored. Therefore, the present work was carried out to investigate the biofunctional and surface properties of banana peel dietary fibre (BPDF) and its enzyme inhibitory activities. The water holding capacity (WHC), oil holding capacity (OHC), swelling capacity (SC), and glucose absorption capacity (GAC) were measured, and the glucose retardation index (GDRI) was analysed. The inhibitory effect of BPDF against α-amylase activity was also observed. The findings showed that the WHC (0.7 g/g), OHC (0.3 g/g), SC (0.73 mL/g), GDRI (6.58 - 31.72%), and GAC (0.162 - 19.211 mmol/g) of BPDF could have the potential in regulating diabetes, and explain the physiological effects of dietary fibre. The surface morphology of BPDF was analysed using scanning electron microscope. Interestingly, BPDF hampering effects on the diffusion of glucose through α-amylase inhibitory activity with IC50 8.9 µg/mL was found to be comparable to acarbose (IC50 8.6 µg/mL), thus showing potential in lowering postprandial blood glucose (type 2 diabetes mellitus).

Modification of tea residue dietary fiber by high-temperature cooking assisted enzymatic method: Structural, physicochemical and functional properties

The research aimed to assess the effects of high-temperature cooking assisted enzymatic method on the structural, physicochemical and functional properties of soluble dietary fiber (SDF) from tea residue (GM-SDF). Under the optimal extraction conditions obtained by response surface methodology, the GM-SDF yield was significantly higher than that of untreated tea residue (U-SDF). It could be found results showed that GM-SDF possessed more hydrophilic groups, higher crystallinity, as well as a looser and more complicated structure by FTIR, XRD and SEM analysis. Besides, the differences in monosaccharide composition and molecular weight between U-SDF and GM-SDF were observed. Additionally, physicochemical properties analysis showed that water holding capacity, oil holding capacity and water swelling capacity of GM-SDF increased by 73.1%, 57.2% and 81.8% than that of U-SDF, respectively. Moreover, compared with U-SDF, GM-SDF exhibited higher adsorption capacity of glucose, sodium cholate, cholesterol and capacity of delaying glucose diffusion and dialysis. Furthermore, the inhibitory effect of GM-SDF on α-amylase was similar to that of acarbose. To sum up, the study showed that high-temperature cooking assisted enzymatic method can effectively extract dietary fiber from tea residue and improve the physicochemical and functional properties, which possesses great potential for application in functional food.

Flexible porous Ni(OH)2 nanopetals sandwiches for wearable non-enzyme glucose sensors

In this work, flexible sandwich β-Ni(OH)2 nanopetals/nanoporous Ni/metallic glass (β-Ni(OH)2/NP-Ni/MG) electrodes for non-enzyme glucose sensor are fabricated by a facile two-step route, including dealloying Ni40Zr20Ti40 MG in HF solution and subsequently immersing the dealloyed sample in deionized water. The binder-free β-Ni(OH)2/NP-Ni/MG electrodes exhibit an excellent flexibility arising from the MG interlayer, which can be directly applied for glucose sensor without complex modification and assembly. The morphology, surface chemical states, and sensing performance of flexible electrodes are examined. The interwoven β-Ni(OH)2 nanopetals in-situ grown on the NP-Ni network provide large surface areas and affluent catalytic active sites, which accelerates the glucose diffusion and improves the utilization rate of active substances. Using the β-Ni(OH)2/NP-Ni/MG electrodes as non-enzymatic glucose sensor, a high sensitivity of 1.496 mA mM−1 cm−2 and a wide linear detection range up to 18 mM are achieved. Meanwhile, the present sandwich electrode shows high anti-interference ability, enhanced reproducibility, and long-term stability. The potential application of flexible β-Ni(OH)2/NP-Ni/MG electrodes as wearable electrode materials is discussed in detail. Moreover, the growth mechanism of β-Ni(OH)2 nanopetals is proposed. In summary, the β-Ni(OH)2/NP-Ni/MG electrode has a promising application prospect in wearable glucose sensor.

An In Vitro Study on the Effects of Selected Natural Dietary Fiber from Salad Vegetables for Lowering Intestinal Glucose and Lipid Absorption.

Salad vegetables are good sources of dietary fiber and are becoming increasingly popular among consumers. Therefore, these plants have the potential to be developed as functional foods. Using an in vitro model, this study investigated the physical properties and intestinal glucose and lipid absorption capacities of dry dietary fiber from vegetables typically consumed in salads (types of lettuce, including red oak, red coral, green oak, butterhead, and cos). Fiber was prepared from each type of lettuce using an enzymatic method and then characterized. Physical properties, including solubility and water-binding, swelling, cation-exchange, and oil-binding capacities, and antihyperglycemic and antihypercholesterolemic effects of fiber were investigated. The hydration capacity of total dietary fiber and insoluble fiber from the majority of sources was significantly different from that of cellulose. Adsorption and diffusion of glucose were directly proportional to incubation time, and the diffusion rate was significantly lower in the treatments containing fiber compared to the cellulose control. Fiber from these vegetables also inhibited amylase and alpha-glucosidase activities. Moreover, fiber from all sources exhibited significantly higher sodium cholate and cholesterol-binding capacity compared to cellulose, and also retarded pancreatic cholesterol esterase activity in a concentration-dependent manner. This study demonstrates that natural dietary fiber from salad vegetables can reduce glucose and lipid absorption and breakdown rates, thus preventing increases in postprandial blood glucose and cholesterol levels, which can be beneficial to human health.

Toward electron-beam sterilization of a pre-assembled Boston keratoprosthesis

PurposeTo evaluate the effects of electron-beam (E-beam) irradiation on the human cornea and the potential for E-beam sterilization of Boston keratoprosthesis (BK) devices when pre-assembled with a donor cornea prior to sterilization. MethodsHuman donor corneas and corneas pre-assembled in BK devices were immersed in recombinant human serum albumin (rHSA) media and E-beam irradiated at 25 kGy. Mechanical (tensile strength and modulus, and compression modulus), chemical, optical, structural, and degradation properties of the corneal tissue after irradiation and after 6 months of preservation were evaluated. ResultsThe mechanical evaluation showed that E-beam irradiation enhanced the tensile and compression moduli of human donor corneas, with no impact on their tensile strength. By chemical and mechanical analysis, E-beam irradiation caused a minor degree of crosslinking between collagen fibrils. No ultrastructural changes due to E-beam irradiation were observed. E-beam irradiation slightly increased the stability of the cornea against collagenase-induced degradation and had no impact on glucose diffusion. The optical evaluation showed transparency of the cornea was maintained. E-beam irradiated corneal tissues and BK-cornea pre-assembled devices were stable for 6 months after room-temperature preservation. ConclusionsE-beam irradiation generated no detrimental effects on the corneal tissues or BK-cornea pre-assembled devices and improved native properties of the corneal tissue, enabling prolonged preservation at room temperature. The pre-assembly of BK in a donor cornea, followed by E-beam irradiation, offers the potential for an off-the-shelf, ready to implant keratoprosthesis device.

Hypoglycemic and antioxidant effects of green tomato ( Physalis ixocarpa Brot.) calyxes’ extracts

The aim of this study was to evaluate the hypoglycemic and antioxidant potential of green tomato (Physalis ixocarpa Brot.) calyxes' extracts. Three methods were used to obtain the extracts: maceration (M), ultrasound-assisted (US), and infusion. Regarding in vitro hypoglycemic evaluation, glucose diffusion assay and enzymatic inhibitory action of α-amylase and α-glucosidase were performed. Whereas, for in vivo assessment an oral starch tolerance test (OSTT) was tested with aqueous extracts [infusion (40mg/kg b. wt.), maceration (M) water (98mg/kg b. wt.), and US water (82.24mg/kg b. wt.)] on male Wistar rats. Additionally, in vitro antioxidant activity of P. ixocarpa calyxes' was evaluated through inhibition of scavenging radical assay and lipid peroxidation. Extracts decreased the glucose diffusion in a range of 18%-56% compared with the negative control. Additionally, extracts inhibited α-amylase (above 80%) and α-glucosidase enzymes (above 90%). All groups treated with P. ixocarpa calyxes' significantly reduced the glucose levels at 120min (infusion=13.3%, M Water=12.7%, and US Water=19.4%) in comparison with the negative control, and similar levels to acarbose at 120min (13.1%). Finally, extracts showed IC50 values in a range of 2.5-6.6µg/µl for radical scavenging, and 118-199µg/µl for lipid oxidation. Our results show that P. ixocarpa calyxes' extracts induce hypoglycemia and antioxidant effects in vitro and in vivo. PRACTICAL APPLICATIONS: The green tomato is usually consumed in Mexico, the United States, and Central America. This fruit grows inside a calyx, which is considered an agro-food waste. However, some regions of Latin America have a traditional medicine purpose for diabetes affections. To the best of our knowledge, there are no published data that supports its hypoglycemic action. The information provided will be useful to nutraceutical applications that allow value-added products and sustainable green tomato production.

Role of zonulin and GLP-1/DPP-IV in alleviation of diabetes mellitus by peptide/polypeptide fraction of Aloe vera in streptozotocin- induced diabetic wistar rats

Ethno-pharmacological relevanceThe genus Aloe has a long history of usage in medicine. Aloe barbadensis Miller, commonly known as Aloe vera, is said to possess anti-diabetic, anti-inflammatory, anti-cancer, anti-microbial, immunomodulation, wound healing properties. Aim of the studyIn diabetes mellitus, loss in intestinal permeability is observed with high levels of zonulin and low levels of glucagon-like peptide-1 (GLP-1) leading to hyperglycemia. The aim of the study was to understand the role of peptide/polypeptide fraction (PPF) of Aloe vera in the alleviation of diabetes through maintaining the intestinal permeability by regulating the zonulin and GLP-1 levels. Materials and methodsThe PPF of Aloe vera was obtained through trichloroacetic acid precipitation. The anti-diabetic potential of the PPF was tested through DPP-IV inhibition, glucose diffusion assay, and by using Rin-m5F cells. The anti-diabetic potential of the PPF was tested at a dose of 0.450 mg/kg bw in vivo using streptozotocin-induced diabetic Wistar rats. The effect of PPF on fasting plasma glucose, insulin, glucagon, Zonulin, GLP-1, DPP-IV, levels were studied in diabetic rats. The histopathological studies of the pancreas, small intestine, and liver were carried out for organ-specific effects. ResultsPPF has the ability to reduce fasting plasma glucose levels with concomitant increase in insulin levels in streptozotocin-induced diabetic rats. It was also observed that increase in GLP-1 levels with a decrease in DPP-IV and zonulin levels thereby mitigating the loss of intestinal permeability. These findings correlate with the small intestine's histopathological observation where the excessive proliferation of epithelium in the small intestine of diabetic rats was reduced after PPF treatment. ConclusionThese results suggest that the PPF of Aloe vera alleviates diabetes through islet cell rejuvenation via GLP-1/DPP-IV pathway and thereby suggesting the usage of PPF as an alternate medicine for diabetes mellitus with the possibility to reduce the intestinal permeability and zonulin levels.

Finite Element Analysis of Glucose Diffusivity in Cellulose Nanofibril Peripheral Nerve Conduits.

Peripheral neuropathy arising from physical trauma is estimated to afflict 20 million people in the United States alone. In one common surgical intervention, neural conduits are placed over the nerve stumps to bridge the gap and create a microenvironment conducive to regeneration. It has been proposed that a biocompatible material such as cellulose nanofiber may serve as a viable conduit material, providing a non-inflammatory and mechanically stable system. Preliminary studies have shown that cellulose nanofiber conduits successfully aid neural regeneration and further, that the dimensions of the conduit relative to the nerve gap have an impact on efficacy in murine models. It has been hypothesized that the reliance of regeneration upon the physical dimensions of the conduit may be related to modified modes of diffusion and/or distances of key cellular nutrients and waste metabolites to/from the injury site. The present work investigates the concentration profile of glucose within the conduit via finite element analysis as a function of the physical dimensions of the conduit. It was determined that the magnitude of glucose diffusion was greater through the conduit walls than through the luminal space between the nerve and the inner wall of the conduit, and that as such radial diffusion is dominant over axial diffusion.

In vitro starch digestibility, edible quality and microstructure of instant rice noodles enriched with rice bran insoluble dietary fiber

Rice bran insoluble dietary fiber (RBIDF) was added into the noodle formulation at a proportion of 3–12% (w/w) to produce instant rice noodles. The eating quality, texture, and microstructure of noodles were investigated. Meanwhile, the effect of RBIDF and its three main components (cellulose, hemicellulose, and lignin) on the in vitro digestion of noodles was further explored. Noodles with 3%–6% (w/w) RBIDF addition showed appropriate textural quality, where 3% RBIDF addition led to the best sensory performance. Scanning electron microscopy (SEM) results showed that 9% or more RBIDF addition caused rough and porous noodles, which decreased eating quality. In addition, 3%–9% RBIDF significantly delayed the hydrolysis of starch during in vitro digestion. The 3% samples exhibited the highest antidigestive properties, with the final degree of hydrolysis reduced from 88.43% to 83.69% and the resistant starch (RS) content increased from 12.64% to 19.78%. Furthermore, the degree of noodle digestibility reduction followed the sequence: hemicellulose > lignin > cellulose. Hemicellulose, which significantly decreased the diffusion of glucose from 98.86% to 78.14%, played a major role in reducing noodle digestibility. These results indicated that RBIDF (≤6%) can significantly reduce the in vitro digestibility of rice noodles without compromising their eating quality.

Dietary fibers fractionated from gardenia (Gardenia jasminoides Ellis) husk: structure and in vitro hypoglycemic effect.

Gardenia (Gardenia jasminoides Ellis) husk rich in dietary fiber is a byproduct of fructus processing, and commonly discarded as waste. The husk was fractionated by sequential extraction into four fractions: water-soluble fiber (W-SF), acid-soluble fiber (Ac-SF), alkali-soluble fiber (Al-SF) and insoluble residue fiber (IRF). The aim of this study was to investigate the differences in structure and in vitro hypoglycemic effect of these fibers. Monosaccharide composition and Fourier transform infrared spectra showed that the major component might be pectin for W-SF and Ac-SF, xylan as well as pectin for Al-SF and cellulose for IRF. These fibers offered excellent water-holding capacity and swelling capacity, except that IRF was only slightly swellable in water. W-SF exhibited significantly higher capacities to adsorb glucose (2.408 mmol g-1 at a glucose concentration of 200 mmol L-1 ) and inhibit α-amylase activity (29.48-49.45% inhibition rate at a concentration of 4-8mg mL-1 ), probably caused by the higher viscosity and hydration properties; while Ac-SF, Al-SF and IRF (especially Al-SF) were more effective in retarding the glucose diffusion across a dialysis membrane (34.97-41.67% at 20-30min), which might be attributed to particle size and specific surface area. All the fibers could quench the intrinsic fluorescence of α-amylase to some degree. Dietary fiber from gardenia husk, especially W-SF, can be used as a potential hypoglycemic ingredient in diabetic functional foods. © 2020 Society of Chemical Industry.

CHEMICAL AND BIOLOGICAL POTENTIAL OF PASSIFLORA VITIFOLIA FRUIT BYPRODUCTS COLLECTED IN THE COLOMBIAN CENTRAL ANDES

Objective: The objective of the study was to establish potential uses of the fruit peel and seeds from Passiflora vitifolia collected in the Colombian Central Andes.
 Methods: The physical characteristics and chemical profile of the byproducts were determined. The ethanolic extracts of these materials were used to assess the content and phytophenols composition, to establish the antioxidant potential and the antidiabetic activity, in vitro inhibition of α-amylase enzyme and glucose diffusion. The performance and physicochemical composition of the seed oil was also evaluated.
 Results: The seeds contain almost 4 times more phenolic compounds (10 671 mg GAE/100 g sample) than the peel (2817 mg GAE/100 g sample). Likewise, crude protein and fat contents from the seeds are higher (15.5% and 25.6%) than the peel (6.60% and 5.70%, respectively). Nine phytoconstituents were positive for both extracts. Significant variation (p<0.05) of antioxidant and anti-hyperglycemic potential was observed among the peel and seeds in all methods applied.
 Conclusion: Results showed that the byproducts of P. vitifolia fruit could be used to enhance the nutritional quality of functional products. These findings were also confirmed by the ethanolic extract from seeds, which revealed high levels of phenolics, high antioxidant potential, and anti-hyperglycemic activity that make it a promising phytotherapeutic product, all of which gives added value to the fruit of this wild Passiflora.

In-vitro hypoglycemic activity of lawsonia inermis Linn. Leaf extracts

in-vitro hypoglycemic activity of lawsonia inermis Linn. Leaf extracts

In vitro hypoglycemic effects of molokhia leaves (Corchorus olitorius L.)

Background: Corchorus olitorius L., commonly known as molokhia in Arabic, is a leafy vegetable containing large amounts of mucilaginous polysaccharides and reported to exhibit antidiabetic diabetic activity in experimental diabetes. Although antidiabetic effect of molokhia is attributed to the presence of phenolic and non-phenolic compounds, the precise mechanism of action is not explored. Materials and Methods: The present study investigated the ability of molokhia leaves powder (MLP) to modulate starch digestion and glucose diffusion in vitro. Results: MLP at 2% and 4% levels bound significantly higher amount of glucose than wheat bran (2%) and also reduced diffusion of glucose through dialysis membrane as reflected by significantly higher glucose dialysis retardation index. In starch–α-amylase system, MLP (4%) showed complete inhibition of starch digestion and glucose diffusion similar to that of acarbose till 120 min. Further, glucose diffusion was retarded to an extent of 83.7% and 63.5% by MLP (4%) at 180 and 240 min, respectively. On the other hand, MLP (2%) retarded glucose diffusion to an extent of 96%, 65%, and 51% at 120, 180, and 240 min respectively. Furthermore, molokhia leaf extract significantly enhanced uptake of glucose by rat hemidiaphragm in vitro. Conclusion: These findings conclusively demonstrate that the antidiabetic effect of molokhia leaves is mediated through delaying starch digestion and physical adsorption of liberated glucose limiting its diffusion across intestinal lumen and enhancing glucose uptake in peripheral tissues.

Enzyme functionalized microgels enable precise regulation of dissolved oxygen and anaerobe culture.

Anaerobes are a major constituent of the gut microbiome and profoundly influence the overall health of humans. However, the lack of a simple, cost-effective, and scalable system that mimics the anaerobic conditions of the human gut is hindering research on the gut microbiome and the development of therapeutics. Here, we address this gap by using glucose oxidase and catalase containing gelatin microparticles (GOx-CAT-GMPs) to precisely regulate dissolved oxygen concentration [O2] via GOx-mediated consumption of oxygen. Fluorescence images generated using conjugated polymer afterglow nanoparticles showed that [O2] can be tuned from 257.9 ​± ​6.2 to 0.0 ​± ​4.0 ​μM using GOx-CAT-GMPs. Moreover, when the obligate anaerobe Bacteroides thetaiotaomicron was inoculated in media containing GOx-CAT-GMPs, bacterial growth under ambient oxygen was comparable to control conditions in an anaerobic chamber (5.4 ​× ​105 and 8.8 ​× ​105 colony forming units mL−1, respectively). Finally, incorporating GOx-CAT-GMPs into a bioreactor that permitted continuous radial diffusion of oxygen and glucose generated a gut-mimetic [O2] gradient of 132.4 ​± ​2.6 ​μM in the outer ring of the reactor to 7.9 ​± ​1.7 ​μM at the core. Collectively, these results indicate that GOx-CAT-GMPs are highly effective oxygen-regulating materials. These materials can potentially be leveraged to advance gut microbiome research and fecal microbiota transplantation, particularly in low-resource settings.