Carbohydrate Digestive Enzymes Research Articles

Population of protozoa and carbohydrate-digesting enzymes in the rumen of sheep fed a diet supplemented with yeast Saccharomyces cerevisiae

The aim of the study was to compare the effect of two yeast (Saccharomyces cerevisiae) preparations in the diet on the number of protozoa and carbohydrate-digesting enzymes in the rumen of sheep. The experiment was conducted in six sheep with a cannula in the rumen. The animals were divided into three groups of two sheep. Each group received a different sequence of three treatments (control−CON, live yeast–LY or yeast culture–YC), resulting in three study periods. Sheep were fed meadow hay and concentrate alone or the same ration supplemented with LY or YC at a dose of 5 or 30g/day, respectively. The rumen fluid and digesta were collected before (0h) and 2 and 4h after feeding. The lowest pH was recorded for sampling at 2 and 4h after feeding, and the highest at 0h. The number of Diplodinium spp. and Dasytricha sp. was lower when sheep were fed YC and LY, respectively, than when they were fed CON. Fibrolytic and amylolytic activities were lower 2 and 4 after feeding for all groups and YC, respectively, compared to the results at 0h. Our data suggested that the addition of LY and YC to the sheep diet modified the abundance of the protozoan genera Diplodinium and Dasytricha and could affect fibrolytic and amylolytic activities in the rumen.

Azadirachta indica A. Juss (neem) against diabetes mellitus: a critical review on its phytochemistry, pharmacology, and toxicology.

We aim to provide a critical review focused on the various pharmacological activities of Azadirachta indica A. Juss related to diabetes management. We also emphasise on phytochemistry and toxicology of A. indica, which could provide a comprehensive approach for plant-based drug development in future. From 2784 identified studies, only 83 were considered after double screening based on the inclusion criteria. Further, 63 pharmacological investigations were considered for review. Resultant studies deliberated on using different extracts and phytochemicals of A. indica on blood glucose level, lipid profile, oxidative stress, carbohydrate digestion enzymes, diabetic complications, glucose tolerance, and uptake of glucose. In the end, one can know the efficacy of A. indica as a potent antidiabetic herbal medicine. However, based on gaps in research, recommendations have been provided to evaluate A. indica. in a systematic manner to develop plant-based drugs, nutraceuticals, and to evaluate their clinical efficiency and safety against diabetes mellitus.

Barks of Three Wild Pyrus Taxa: Phenolic Constituents, Antioxidant Activity, and in Vitro and in Silico Investigations of α-Amylase and α-Glucosidase Inhibition.

Dry MeOH extracts of the twig barks of Pyrus communis subsp. pyraster, P. spinosa and their hybrid P.×jordanovii nothosubsp. velenovskyi, collected in wild in Serbia, were analyzed. By LC/MS, the contents of arbutin (99.9-131.0 mg/g), chlorogenic acid (2.2-6.3 mg/g), catechin (1.0-5.3 mg/g) and total dimeric and trimeric procyanidins (42.2-61.3 mg/g), including procyanidin B2 (8.9-17.2 mg/g), were determined. Colorimetrically, high contents of total phenolics (436.2-533.4 mg GAE/g) and tannins (339.4-425.7 mg GAE/g), as well as strong total antioxidant activities (FRAP values 4.5-5.9 mmol Fe2+ /g), and DPPH (SC50 =6.6-7.1 μg/ml) and hydroxyl radical (SC50 =447.1-727.7 μg/ml) scavenging abilities were revealed. In vitro, all extracts exhibited notable inhibition of α-amylase (IC50 =310.8-617.7 μg/ml) and particularly strong inhibition of α-glucosidase (IC50 =2.1-3.7 μg/ml). Molecular docking predicted that among identified compounds procyanidin B2 is the best inhibitor of these carbohydrate-digesting enzymes. Obtained results showed that the barks of investigated Pyrus hybrid and its parent taxa have similar composition and bioactivity.

Evaluation of flavonoids from banana pseudostem and flower (quercetin and catechin) as potent inhibitors of α-glucosidase: An in silico perspective

The amelioration of postprandial hyperglycemia in diabetic conditions could be accomplished by the inhibition of α-glucosidases, a set of intestinal carbohydrate digestive enzymes responsible for starch hydrolysis and its absorption. The ethnopharmacological profile of banana depicts the usage of different plant parts in conventional medicinal formulations. The antidiabetic studies of the plant have demonstrated their ability to inhibit α-glucosidase. Besides, our research group has reported the α-glucosidase inhibitory potential of the banana pseudostem and flower extracts in previous studies. In this study, we deliberate on the specific phytoconstituents of banana pseudostem and flower to evaluate their antidiabetic effects through an in silico perspective for the α-glucosidase inhibition. In this context, several phytoconstituents of banana pseudostem and flower identified through GC-MS analysis were retrieved from chemical databases. These phytochemicals were virtually screened through the molecular docking simulation process, from which only two flavonoids (catechin and quercetin) were selected based on their binding affinity and extent of interaction with the α-glucosidase target protein. The lower binding affinities of catechin and quercetin in comparison with that of acarbose as a control proved their binding efficiency with the target protein. In addition, acarbose showed subservient molecular interaction, forming an unfavourable acceptor-acceptor bond. The molecular dynamics simulations also depicted the effective binding and stability of the complexes formed with catechin and quercetin, in comparison with that of acarbose. Further, PASS analysis, druglikeliness, and pharmacokinetic assessments showed that both catechin and quercetin edge over acarbose in terms of drug-score and pharmacokinetic properties. With the positive results obtained from contemporary strategies, the two flavonoids from banana pseudostem and flower might be established as a considerable phototherapeutic approach to inhibit α-glucosidase. Communicated by Ramaswamy H. Sarma

Optimal Replacement of Soybean Meal with Fermented Palm Kernel Meal as Protein Source in a Fish Meal-Soybean Meal-Based Diet of Sex Reversed Red Tilapia (Oreochromis niloticus × O. mossambicus).

Simple SummaryReplacement effects of soybean meal (SBM) with fermented palm kernel meal (FPKM) as a protein source was investigated in sex-reversed red tilapia. The two-month-old fish were fed fish meal-SBM-based diets with replacement by FPKM at 25% (25FPKM), 50% (50FPKM), 75% (75FPKM) and 100% (100FPKM) for 12 weeks, while an FPKM-free diet (0FPKM) was used as a control. Based on growth performance, feed utilization, digestive enzyme activities, flesh quality, carcass composition, hematological parameters and liver histoarchitecture, the 50% replacement level of SBM by FPKM support this alternative. Findings from the current study support the use of FPKM in aquafeed production, providing a low-cost diet for tilapia farming.The solid-state fermentation by effective microorganisms (containing photosynthetic bacteria, lactic acid bacteria, nitrogen-fixing bacteria, yeast and Bacillus sp.) improved the nutritive values of palm kernel meal (PKM). Increased crude protein (20.79%), nitrogen-free extract (40.07%) and gross energy (19.58%) were observed in fermented PKM (FPKM) relative to raw PKM while crude lipid (15.65%), crude fiber (36.45%) and ash (29.54%) were decreased. Replacement of soybean meal (SBM) with FPKM as a protein source was investigated for its effects in sex-reversed red tilapia (Oreochromis niloticus × O. mossambicus). The two-month-old fish (14.85 ± 0.28 g initial weight) were fed fish meal-SBM-based diets with replacement by FPKM at 25% (25FPKM), 50% (50FPKM), 75% (75FPKM) and 100% (100FPKM), while an FPKM-free diet (0FPKM) was used as a control. The five treatments, comprising triplicate cement ponds and forty fish each, were conducted in a recirculating system over 12 weeks. At the end of the feeding trial, fish fed the 50FPKM diet were superior in growth performance, while the feed utilization parameters were similar across all five treatments. Physiological adaptation of the protein-digesting (pepsin and trypsin) and lipid-digesting (lipase) enzymes was detected at all protein replacement levels (except for 25FPKM), as well as of the enzyme for cellulose digestion (cellulase), but not of the carbohydrate-digesting enzymes (amylase). Protein synthesis capacity in flesh was improved in fish fed the 50FPKM diet, while the quality of the main flesh proteins, actin and myosin, showed no significant differences across the five treatments. No differences in carcass composition and no negative effects on hematological parameters or liver histoarchitecture at the 50% replacement level of SBM by FPKM also support this alternative. Findings from the current study indicate the low-cost FPKM-containing diet for tilapia in comparison with control diet.

Effect of particle size on the release behavior and functional properties of wheat bran phenolic compounds during in vitro gastrointestinal digestion

Wheat bran is a rich source of phenolic compounds, and the health benefits of phenolic compounds depend on its bioaccessibility. The release behavior and functional properties of phenolic compounds in different particle size wheat bran during in vitro digestion were investigated. Coarse wheat bran (CWB, 1110.39 μm) was milled by airflow impact mill to produce medium wheat bran (MWB, 235.68 μm), fine wheat bran (FWB, 83.73 μm) and superfine wheat bran (SWB, 19.16 μm). The reduction in particle size increased the release of phenolic compounds, mainly ferulic acid, after digestion. The free p-coumaric acid content in SWB was nearly five times higher than that in CWB, MWB and FWB due to the complete destruction of aleurone cell walls. Moreover, SWB showed higher bioaccessible phenolic compounds content (65.51%) than CWB. The improved phenolic bioaccessibility increased the antioxidant capacities and carbohydrate-digestive enzymes inhibitory activities of SWB and significantly reduced its starch digestibility.

Bioactive Abietane-Type Diterpenoid Glycosides from Leaves of Clerodendrum infortunatum (Lamiaceae).

In this study, two previously undescribed diterpenoids, (5R,10S,16R)-11,16,19-trihydroxy-12-O-β-d-glucopyranosyl-(1→2)-β-d-glucopyranosyl-17(15→16),18(4→3)-diabeo-3,8,11,13-abietatetraene-7-one (1) and (5R,10S,16R)-11,16-dihydroxy-12-O-β-d-glucopyranosyl-(1→2)-β-d-glucopyranosyl-17(15→16),18(4→3)-diabeo-4-carboxy-3,8,11,13-abietatetraene-7-one (2), and one known compound, the C13-nor-isoprenoid glycoside byzantionoside B (3), were isolated from the leaves of Clerodendrum infortunatum L. (Lamiaceae). Structures were established based on spectroscopic and spectrometric data and by comparison with literature data. The three terpenoids, along with five phenylpropanoids: 6′-O-caffeoyl-12-glucopyranosyloxyjasmonic acid (4), jionoside C (5), jionoside D (6), brachynoside (7), and incanoside C (8), previously isolated from the same source, were tested for their in vitro antidiabetic (α-amylase and α-glucosidase), anticancer (Hs578T and MDA-MB-231), and anticholinesterase activities. In an in vitro test against carbohydrate digestion enzymes, compound 6 showed the most potent effect against mammalian α-amylase (IC50 3.4 ± 0.2 μM) compared to the reference standard acarbose (IC50 5.9 ± 0.1 μM). As yeast α-glucosidase inhibitors, compounds 1, 2, 5, and 6 displayed moderate inhibitory activities, ranging from 24.6 to 96.0 μM, compared to acarbose (IC50 665 ± 42 μM). All of the tested compounds demonstrated negligible anticholinesterase effects. In an anticancer test, compounds 3 and 5 exhibited moderate antiproliferative properties with IC50 of 94.7 ± 1.3 and 85.3 ± 2.4 μM, respectively, against Hs578T cell, while the rest of the compounds did not show significant activity (IC50 > 100 μM).

Glycoside Hydrolases and Non-Enzymatic Glycation Inhibitory Potential of Viburnum opulus L. Fruit-In Vitro Studies.

Phytochemicals of various origins are of great interest for their antidiabetic potential. In the present study, the inhibitory effects against carbohydrate digestive enzymes and non-enzymatic glycation, antioxidant capacity, and phenolic compounds composition of Viburnum opulus L. fruits have been studied. Crude extract (CE), purified extract (PE), and ethyl acetate (PEAF) and water (PEWF) fractions of PE were used in enzymatic assays to evaluate their inhibitory potential against α-amylase with potato and rice starch as substrate, α-glucosidase using maltose and sucrose as substrate, the antioxidant capacity (ABTS, ORAC and FRAP assays), antiglycation (BSA-fructose and BSA-glucose model) properties. Among four tested samples, PEAF not only had the highest content of total phenolics, but also possessed the strongest α-glucosidase inhibition, antiglycation and antioxidant activities. UPLC analysis revealed that this fraction contained mainly chlorogenic acid, proanthocyanidin oligomers and flavalignans. Contrary, the anti-amylase activity of V. opulus fruits probably occurs due to the presence of proanthocyanidin polymers and chlorogenic acids, especially dicaffeoylquinic acids present in PEWF. All V. opulus samples have an uncompetitive and mixed type inhibition against α-amylase and α-glucosidase, respectively. Considering strong anti-glucosidase, antioxidant and antiglycation activities, V. opulus fruits may find promising applications in nutraceuticals and functional foods with antidiabetic activity.

Inhibitory effect of Morus australis leaf extract and its component iminosugars on intestinal carbohydrate-digesting enzymes

α-Amylase and α-glucosidase are central enzymes involved in the digestion of carbohydrates. α-Glucosidase includes maltase-glucoamylase and sucrase-isomaltase. We have previously performed the kinetic analysis of the inhibitory effects of powdered or roasted Morus australis leaf extract and its component iminosugars, such as 1-deoxynojirimycin (1-DNJ), fagomine, and 2-O-α-d-galactopyranosyl deoxynojirimycin (GAL-DNJ) on the activity of maltase. In this study, we analyzed the inhibitory effects of the aforementioned compounds against α-amylase, glucoamylase, sucrase, and isomaltase. At pH 6.0 and 37°C, each leaf extract sample inhibited glucoamylase, sucrase, and isomaltase but not α-amylase. 1-DNJ and fagomine showed weak α-amylase inhibitory activity while GAL-DNJ exhibited none. 1-DNJ showed a strong glucoamylase, sucrase, and isomaltase inhibitory potential. The inhibitory potential against these three enzymes was 18-500 and 1500-3000-fold higher in the case of 1-DNJ than that observed in the case of fagomine and GAL-DNJ, respectively. We also observed that the indigestible dextrin could considerably inhibit α-amylase. When the powdered M.australis leaf extract was blended with indigestible dextrin, the mixture inhibited α-amylase, as well as maltase, glucoamylase, sucrase, and isomaltase. These results suggest that the ingestion of the leaf extract blended with indigestible dextrin might have the potential to efficiently suppress the postprandial blood glucose level increase.

Alleviating effects of lupeol on postprandial hyperglycemia in diabetic mice.

This study aimed to investigate the inhibition activities of lupeol on carbohydrate digesting enzymes and its ability to improve postprandial hyperglycemia in streptozotocin (STZ)-induced diabetic mice. α-Glucosidase and α-amylase inhibitory assays were executed using a chromogenic method. The effect of lupeol on hyperglycemia after a meal was measured by postprandial blood glucose in STZ-induced diabetic and normal mice. The mice were treated orally with soluble starch (2g/kgBW) alone (control) or with lupeol (10mg/kgBW) or acarbose (10mg/kgBW) dissolved in water. Blood samples were taken from tail veins at 0, 30, 60, and 120min and blood glucose was measured by a glucometer. Lupeol showed noticeable inhibitory activities on α-glucosidase and α-amylase. The half-maximal inhibitory concentrations (IC50) of lupeol on α-glucosidase and α-amylase were 46.23±9.03 and 84.13±6.82μM, respectively, which were more significantly effective than those of acarbose, which is a positive control. Increase in postprandial blood glucose level was more significantly lowered in the lupeol-administered group than in the control group of both STZ-induced diabetic and normal mice. In addition, the area under the curve was significantly declined with lupeol administration in the STZ-induced diabetic mice. These findings suggest that lupeol can help lower the postprandial hyperglycemia by inhibiting carbohydrate-digesting enzymes.

Major triterpenes, cycloeucalenone and 31‐norcyclolaudenone as inhibitors against both α‐glucosidase and α‐amylase in banana peel

SummaryThe inhibitory activities of banana peel extract against carbohydrate digestive enzymes were investigated. Cycloeucalenone and 31‐norcyclolaudenone were obtained by bioassay‐guided fractionation as effective inhibitors of α‐glucosidase and α‐amylase. The structure–activity relationships of four triterpenes isolated from banana peel, cycloeucalenone, 31‐norcyclolaudenone and cycloeucalenol and its isomer were investigated. The IC50 values of cycloeucalenone and 31‐norcyclolaudenone against α‐glucosidase were 31.83 ± 2.46 μm and 38.85 ± 1.54 μm, respectively, and their IC50 values against α‐amylase were 20.33 ± 0.59 μm and 27.63 ± 0.83 μm, respectively. In contrast, cycloeucalenol and its isomer had insufficient inhibitory activity against either enzyme. The primary active sites of cycloeucalenone and 31‐norcyclolaudenone are the carbonyl group at C‐3 and the double bond in the side chain. Cycloeucalenone induced a parabolic mixed‐type inhibition with a Ki value of 73.86 μm in the α‐glucosidase inhibitory assay. This study provides new evidence for the potential use of banana peel triterpenes as antidiabetic agents.

Comparison of edible brown algae extracts for the inhibition of intestinal carbohydrate digestive enzymes involved in glucose release from the diet.

Type II diabetes is considered the most common metabolic disorder in the developed world and currently affects about one in ten globally. A therapeutic target for the management of type II diabetes is the inhibition of α- glucosidase, an essential enzyme located at the brush border of the small intestinal epithelium. The inhibition of α-glucosidase results in reduced digestion of carbohydrates and a decrease in postprandial blood glucose. Although pharmaceutical synthetic inhibitors are available, these are usually associated with significant gastrointestinal side effects. In the present study, the impact of inhibitors derived from edible brown algae is being investigated and compared for their effect on glycaemic control. Carbohydrate- and polyphenolic-enriched extracts derived from Ascophyllum nodosum, Fucus vesiculosus and Undaria pinnatifida were characterised and screened for their inhibitory effects on maltase and sucrase enzymes. Furthermore, enzyme kinetics and the mechanism of inhibition of maltase and sucrase were determined using linear and nonlinear regression methods. All tested extracts showed a dose-dependent inhibitory effect of α-glucosidase with IC50 values ranging from 0⋅26 to 0⋅47 mg/ml for maltase; however, the only extract that was able to inhibit sucrase activity was A. nodosum, with an IC50 value of 0⋅83 mg/ml. The present study demonstrates the mechanisms in which different brown seaweed extracts with varying composition and molecular weight distribution differentially inhibit α-glucosidase activities. The data highlight that all brown seaweed extracts are not equal in the inhibition of carbohydrate digestive enzymes involved in postprandial glycaemia.

Inhibition of carbohydrate-digestion enzymes and suppression of postprandial elevation of blood glucose by components of mulberry leaf

Inhibition of carbohydrate-digestion enzymes and suppression of postprandial elevation of blood glucose by components of mulberry leaf

Curative Effect of Catechin Isolated from Elaeagnus Umbellata Thunb. Berries for Diabetes and Related Complications in Streptozotocin-Induced Diabetic Rats Model.

In this study, catechin (CTN) isolated from Elaeagnus umbellata was evaluated for in vitro antioxidant potential and inhibition of carbohydrate digestive enzymes (α-amylase and α-glucosidase). The compound was also tested for its in vivo antidiabetic potential using Sprague-Dawley rats as experimental animals. The effects of various doses of catechin in STZ (Streptozotocin) induced diabetic rats on fasting blood glucose level, body weight, lipid parameters, hepatic enzymes, and renal functions were evaluated using the reported protocols. The CTN exhibited the highest percent antioxidant for free radical scavenging activity against DPPH and ABTS free radicals, and inhibited the activity of carbohydrate digestive enzymes (with percent inhibition values: 79 ± 1.5% α-amylase and 80 ± 1.1% α-glucosidase). Administration CTN and standard glibenclamide significantly decreased the fasting blood glucose level and increased the body weight in STZ-induced diabetic rats. CTN significantly decreased the different lipid parameters, hepatic, and renal function enzyme levels along with Hb1c level in diabetic rats, while significantly increasing the high-density lipoprotein (HDL) level with values comparable to the standard glibenclamide. Further, the altered levels of glutathione and lipid peroxides of liver and kidney tissues were restored (by CTN) to levels similar to the control group. CTN significantly increased the antioxidant enzyme activities, total content of reduced glutathione, and reduced the malondialdehyde (MDA) level in rat liver and kidney tissues homogenates, and also corrected the histopathological abnormalities, suggesting its antioxidant potential.

Inhibitory Effect of Antidesma bunius Fruit Extract on Carbohydrate Digestive Enzymes Activity and Protein Glycation In Vitro

Antidesma bunius (L.) spreng (Mamao) is widely distributed in Northeastern Thailand. Antidesma bunius has been reported to contain anthocyanins, which possess antioxidant and antihypertensive actions. However, the antidiabetic and antiglycation activity of Antidesma bunius fruit extract has not yet been reported. In this study, we investigated the inhibitory activity of anthocyanin-enriched fraction of Antidesma bunius fruit extract (ABE) against pancreatic α-amylase, intestinal α-glucosidase (maltase and sucrase), protein glycation, as well as antioxidant activity. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) chromatogram revealed that ABE contained phytochemical compounds such as cyanidin-3-glucoside, delphinidin-3-glucoside, ellagic acid, and myricetin-3-galactoside. ABE inhibited intestinal maltase and sucrase activity with the IC50 values of 0.76 ± 0.02 mg/mL and 1.33 ± 0.03 mg/mL, respectively. Furthermore, ABE (0.25 mg/mL) reduced the formation of fluorescent AGEs and the level of Nε-carboxymethyllysine (Nε-CML) in fructose and glucose-induced protein glycation during four weeks of incubation. During the glycation process, the protein carbonyl and β-amyloid cross structure were decreased by ABE (0.25 mg/mL). In addition, ABE exhibited antioxidant activity through DPPH radical scavenging activity and Trolox equivalent antioxidant capacity (TEAC) with the IC50 values 15.84 ± 0.06 µg/mL and 166.1 ± 2.40 µg/mL, respectively. Meanwhile, ferric reducing antioxidant power (FRAP) showed an EC50 value of 182.22 ± 0.64 µg/mL. The findings suggest that ABE may be a promising agent for inhibiting carbohydrate digestive enzyme activity, reducing monosaccharide-induced protein glycation, and antioxidant activity.

Inhibitory effects of plant extracts and in Silico screening of the bioactive compounds against α-glucosidase

α-glucosidase is a primary carbohydrate digestive enzyme, present in the brush border of the small intestine that acts on the 1–4 associated α-glucose residues and could play an effective role in overall glycemic control. Berberis lycium and Fagonia cretica extracts are traditionally being used as antidiabetic. In the present study, ethanolic and methanolic extracts of B. lycium and F. cretica were tested against α-glucosidase. Furthermore, the isolated phytochemicals of these plants were screened computationally for the evaluation of active compounds. An in vitro assay, the Ethanol and methanol-based extracts of B. lycium and F. cretica for α-glucosidase inhibitory potential at a concentration range of 7.81–1000 µg/ml was used. The α-glucosidase inhibitory effect of extracts was compared based on their resulting IC50 values. The result showed that the extracts showed potent inhibitory activity against alpha-glucosidase. Methanolic extract of B. lycium with an IC50 value of 34.99 µg/ml was the most potentextract. The rest of the extracts showed moderate inhibitory activity with an IC50 value in the range of 48.17 µg/ml, to 66.53 µg/ml. The reported compounds were docked against α-glucosidase along with standard inhibitor (acarbose) to check the inhibitory potential of these compounds using computational tools. Among the 38 phytochemicals, phytic acid and sindamine showed remarkable interaction with α-glucosidase active site residues with docking score -20.0204 and -18.2239 respectively, while quercetin and palmatine-CHCl3 showed comparable docking score -14.7862 and -14.1882 respectively with the standard acarbose having docking score -15.5940 against α-glucosidase. We further validate our results in vitro by using. We concluded from the results that phytochemical extracted from medicinal plants show good potency and however in future in vivo studies are needed to cure diabetes mellitus.

The Anti-Diabetic Effect of Some Plant Extracts Against Streptozotocin - Induced Diabetes Type 2 in Male Albino Rats.

One of the widely spread disorders is Diabetes mellitus, especially type 2 (T2DM). T2DM is attributed to the change in life style and stress. A possible strategy to block dietary carbohydrate absorption is regulation of postprandial blood glucose level as well, the use of some natural plant extracts with inhibitory effect against carbohydrate digestive enzymes such as alpha- amylase and fewer side effects than synthetic drugs. This study was conducted to investigate the anti-diabetic effect of Cinnamon and Saussurea extract, individually, on blood glucose, lipid profile, insulin, interleukin1-beta and weight loss in diabetic rats treated with Streptozotocin (STZ). The experiment was performed on 60 Wistar male rats; the experimental study include 6 groups (10 rats each): (I) normal rats, (II) Streptozotocin- induced diabetic rats, (III) normal rats orally received (200 mg/kg/day) Saussurea ethanolic extract (SEE) for consecutive 4 weeks, (IV) normal rats orally received (100mg/kg/day) Cinnamon aqueous extract (CAE) for consecutive 4 weeks, (V) Streptozotocin -treated rats received SEE orally (200mg /kg/ day) for consecutive 4 weeks, and (VI) Streptozotocin -treated rats received CAE orally (100mg /kg/ day) for consecutive 4 weeks. The results of the following study revealed that SEE has more anti-diabetic effect against Streptozotocin treatment than CAE due to the high α-amylase inhibition potential and higher phenolic content. Also, GC-MS analysis of SEE exhibited higher concentrations of phenolic compounds such as: dehydrocostus lactone, azuleno, eicosa-pentaenoic acid and linoelaidic acid that revealed anti-diabetic, anti-lipidemic and anti-inflammatory activities, while CAE showed the presence of cinnamic and quinic acids. Injection of STZ resulted in a decline in the insulin, high density lipoprotein and body weight values matched with the increase in glucose, total cholesterol, LDL-Cholesterol, triglycerides and interleukin1- β (IL-1β). The administration of extracts of SEE and CAE into STZ-treated rats separately resulted in a decline in the elevated levels of blood glucose, total cholesterol, triglycerides and improving serum HDL-Cholesterol and body weight. Both tested herbal extracts performed anti-diabetic effect that mainly could be mechanized via the α-amylase- inhibitory potentials due to the high phenolic and flavonoids content.

Sequential extracts of red honeybush (Cyclopia genistoides) tea: Chemical characterization, antioxidant potentials, and anti-hyperglycemic activities.

The antioxidant, antidiabetic, and anti-obesogenic potentials of different extracts (dichloromethane, ethyl acetate, ethanol, and aqueous) of the red honeybush (Cyclopia genistoides) tea were investigated in vitro and ex vivo. All extracts exhibited significant scavenging and reducing power activities, with the aqueous and ethyl acetate extracts being the most potent. In vitro antidiabetic analysis revealed the extracts to be potent inhibitors of α-glucosidase and lipase activities. All extracts increased catalase and SOD activities, and glutathione level in oxidative pancreatic injury. GC-MS analysis revealed the presence of fatty acids, fatty acid ester, phytols, sterols, saccharide, ketones, and triterpenes. These results imply that the sequential extracts of honeybush tea (particularly the aqueous and ethyl acetate extracts) may not only exhibit antioxidant potentials but also mediate anti-hyperglycemia activities by inhibiting lipid and carbohydrate digestion. PRACTICAL APPLICATIONS: Red honeybush tea is enjoyed widely in South Africa and around the world due to its no caffeine and very low tannin content, as well as many healthcare attributes. There are however no scientific reports for its sequential extraction of different solvents on antidiabetic effects. The different extracts of honeybush tea (particularly the aqueous and ethyl acetate extracts) inhibited lipid and carbohydrate digestive enzymes linked to type 2 diabetes (T2D), as well as modulate oxidative pancreatic injury. These findings will promote its utilization as a potential nutraceutical in the management of diabetes and its complications.

Postprandial Effect of Yogurt Enriched with Anthocyanins from Riceberry Rice on Glycemic Response and Antioxidant Capacity in Healthy Adults.

The pigment of riceberry rice has been reported to contain anthocyanins which act as a free radical scavenger and inhibitor of carbohydrate digestive enzymes. Since the probiotic yogurt incorporated with the pigment of riceberry rice extract was previously developed, the present study was aimed to investigate the acute effect of riceberry rice yogurt consumption on postprandial glycemic response, antioxidant capacity, and subjective ratings in healthy adults. In a cross-over design, 19 healthy participants were randomized to consume 350 g of yogurt supplemented with 0.25% (w/w) riceberry rice extract or the control yogurt. Postprandial plasma glucose, antioxidant status, and subjective ratings were measured at fasting and intervals (0–3 h) after ingestion of yogurt. The primary outcome was glycemic response; the secondary outcomes were plasma antioxidant capacity. In comparison to the yogurt control, riceberry rice yogurt reduced plasma glucose concentration after 30 min of consumption. The incremental area under the curve (iAUC) was significantly lower after riceberry rice yogurt load than after the control yogurt load. The consumption of riceberry yogurt caused an acute increase in plasma ferric reducing ability of plasma (FRAP), Trolox equivalent antioxidant capacity (TEAC), and oxygen radical absorbance capacity (ORAC) from the baseline values after 60 min of 0.25 ± 0.06 mM FeSO4, 253.7 ± 35.5 mM Trolox equivalents, and 166.8 ± 28.9 mM Trolox equivalents, respectively. Furthermore, the iAUCs for FRAP, TEAC, ORAC, and protein thiol were higher in riceberry yogurt consumption compared with the control yogurt (1.6-, 1.6-, 2.9-, and 1.9-fold, respectively). A decrease in iAUC for plasma malondialdehyde (MDA) concentration was also observed in the riceberry yogurt group. However, consumption of riceberry rice yogurt and control yogurt showed similar subjective rating scores of hunger, desire to eat, fullness, and satiety. In conclusion, acute consumption of riceberry rice yogurt suppressed postprandial glucose level and improved plasma antioxidant capacity in healthy volunteers.

Inhibitory effects of Gymnema inodorum (Lour.) Decne leaf extracts and its triterpene saponin on carbohydrate digestion and intestinal glucose absorption

Ethnopharmacological relevanceChiang-Da, Gymnema inodorum (Lour.) Decne. (GI), is an ethnomedicinal plant that has been used for diabetic treatment since ancient times. One of the anti-diabetic mechanisms is possibly related to the actions of triterpene glycoside, (3β, 16β)-16,28-dihydroxyolean-12-en-3-yl-O-β-D-glucopyranosyl-β-D-glucopyranosiduronic acid (GIA1) in decreasing carbohydrate digestive enzymes and intestinal glucose absorption in the gut system. Aims of the studyTo observe the amount of GIA1 in GI leaf extracts obtained from different ethanol concentrations and to investigate the anti-hyperglycemic mechanisms of the extracts and GIA1. Materials and methodsThe crude extracts were prepared using 50%v/v to 95%v/v ethanol solutions and used for GIA1 isolation. The anti-hyperglycemic models included in our study examined the inhibitory activities of α-amylase/α-glucosidase and intestinal glucose absorption related to sodium glucose cotransporter type 1 (SGLT1) using Caco-2 cells. ResultsGIA1 was found about 8%w/w to 18%w/w in the GI extract depending on ethanol concentrations. The GI extracts and GIA1 showed less inhibitory activities on α-amylase. The extracts from 75%v/v and 95%v/v ethanol and GIA1 significantly delayed the glycemic absorption by lowering α-glucosidase activity and glucose transportation of SGLT1. However, the 50%v/v ethanolic extract markedly decreased the α-glucosidase activity than the SGLT1 function. ConclusionDifferences in the GIA1 contents and anti-glycemic properties of the GI leaf extract was dependent on ethanol concentrations. Furthermore, the inhibitory effects of the 75%v/v and 95%v/v ethanolic extracts on α-glucosidase and SGLT1 were relevant to GIA1 content.