Pancreatic Α-amylase Activity Research Articles

Light-Emitting Diodes improve yield, quality and inhibitory effects on digestive enzymes of strawberry

Strawberries are a widely consumed fruit that are increasingly popular due to the perceived health benefits associated with their consumption. Fruit quality is highly dependent on the growing environment where light is one of the most significant environmental factors influencing plant physiology and metabolism. In the present work we sought to test the hypothesis that manipulation of the light environment in a commercial growing environment would influence fruit yield and quality. Fruit were grown with supplemental light-emitting diodes in the red (623 nm), far-red (727 nm) and blue (470 nm) regions of the spectrum at three different densities. The majority of light treatments resulted in increased fruit yield. All treatments also significantly enhanced contents of anthocyanins and polyphenols. Furthermore fruit exhibited enhanced antioxidant activity. Individual strawberry sugars showed differences depending on sampling date whereas Brix, acidity and ascorbic acid was not affected by the LED lights. Strawberry fruit extracts from all treatments exhibited the capacity to inhibit the digestive enzymes pancreatic lipase and α-amylase activity in vitro, extract from fruit grown under supplemental lighting had a greater inhibitory capacity. These data suggest that strawberry fruit grown in the presence of supplemental light may impart health benefits via enhanced functional compounds and by limiting calorific assimilation. The findings of this study provide the first evidence that the use of light-emitting diodes increase the inhibitory effects of polyphenols on digestive enzymes in strawberry.

Antiobesity and antidiabetes effects of Cyperus rotundus rhizomes presenting protein tyrosine phosphatase, dipeptidyl peptidase 4, metabolic enzymes, stress oxidant and inflammation inhibitory potential

Diabetes is a significant global health concern that increases the vulnerability to various chronic illnesses. In view of this issue, the current research aimed to examine the effects of administering an extract derived from the tubers of Cyperus rotundus L (CrE) on obesity, type 1 diabetes, and liver-kidney toxicity. Through the utilization of HPLC-DAD analysis, it was discovered that the extract contained several components, including quercetin (47.8%), luteolin glucoside (17%), luteolin (7.56%), apigenin-7-glucoside (6.29%), naringinin (4.52%), and seven others. In vitro experiments they have demonstrated that CrE effectively inhibited key digestive enzymes associated with obesity and type 2 diabetes, such as DPP-4, PTP1B, lipase, and α-amylase, as evidenced by their respective IC50 values are about 23, 51,83, and 67 μg/ml respectively. Furthermore, when diabetic rats were administered CrE, the activity of pancreatic enzymes linked to inflammation, namely 5-lipoxygenase (5-LO), hyaluronidase (HAase), and myeloperoxidase (MPO), was significantly suppressed by 48, 41, 75, and 47%, respectively. Moreover, CrE exhibited protective effects on pancreatic β-cells by inhibiting the formation of thiobarbituric acid reactive substances (TBARS) by 65% and the induction of superoxide Dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) activities by 62, 108, and 112% respectively as compared to diabetic untreated rat. Additionally, CrE significantly inhibited the activities of intestinal, pancreatic, and serum lipase and α-amylase activities. In diabetic rats, CrE administration suppressed glycogen phosphorylase (GP) stimulated glycogen synthase (GS) activities by 45 and 30%; and this increased liver glycogen content by 45%. Furthermore, CrE modulated key hepatic enzymes involved in carbohydrate metabolism, including hexokinase (HK), glucose-6-phosphate dehydrogenase (G6PD), glucose-6-phosphatase (G6P), and fructose-1,6-bisphosphatase (FBP). Notably, the average food and water intake (AFI and AWI) of diabetic rats treated with CrE was reduced by 15 and 16% respectively as compared to those without any treatment. Therefore, this study demonstrated the effectiveness of Cyperus rotundus tubers in preventing and treating obesity and diabetes.

Anti-Obesity Potentials of Methanol Extracts of Phragmanthera Incana Leaves Hemi-Parasitic on Guava, Cashew, Kolanut and Mango Trees in High-Fat Diet-Induced Obese Rats

The anti-obesity potential of methanol extracts of Phragmanthera incana leaves hemi-parasitic on guava Psidium guajava (PIPG), cashew Anacardium occidentale (PIAO), mango Mangifera indica (PIMI) and kolanut Cola acuminata (PICA) trees were evaluated. Thirty high-fat diet-induced rats were grouped into six; four experimental, negative control and positive controls were orally administered lipid emulsion (5 mL/kg). Experimental received 400 mg/kg body weight from each of the four methanol extracts in addition to the lipid emulsion, positive control received 120 mg/kg bw Orlistat in addition to lipid emulsion while negative control received lipid emulsion alone. Blood samples were collected from ophthalmic venous plexus at 0, 90, and 180 minutes to determine plasma pancreatic lipase (PL) activity, alpha amylase activity and lipid profiles. PL inhibitory activity of the four methanol extracts showed that methanol extracts of PICA and PIAO had greater than 50% inhibition at 400 µg/mL. The α-amylase inhibitory activity of PICA was significantly higher (p < 0.05) when compared with PIAO, PIPG and PIMI. A significant decrease (p < 0.05) in total cholesterol, low density Lipoprotein-cholesterol levels and atherogenic index of plasma of PICA when compared with other treatment groups after 180 minutes of extracts administration was observed. Methanol extract of PICA was found to exhibit higher inhibitory pancreatic lipase and α-amylase activities and higher hypocholesterolemic activity when compared with those of guava (PIPG), cashew (PIAO) and mango (PIMI). This indicates that methanol extract of P. incana leaves could serve as a source of phyto-compounds that could be developed as antiobesity drugs.

The Phenolic Content of Pistacia lentiscus Leaf Extract and Its Antioxidant and Antidiabetic Properties.

The aims of this study were to determine the polyphenolic profile, to estimate the total phenolic and flavonoid contents, and to evaluate the antioxidant and antidiabetic activities of the extract of Pistacia lentiscus leaves, and the hydroacetonic mixture was employed as an alternative for common solvents in the extraction process. In order to explain the antidiabetic activity, molecular docking has been performed on the main constituents of the leaf extract. The characterization of the extract has been performed by high-performance liquid chromatography (HPLC) leading to the detection of 20 compounds of which gallic acid, ellagic acid, catechin, kaempferol, and quercetin 3-glucoside were identified using authentic standards. The total phenolic and flavonoid contents, assessed using the Folin-Ciocalteu and quercetin methods, were 394.5 ± 0.08 mg gallic acid equivalent/g dry extract (mg GAE/g DE) and 101.2 ± 0.095 mg quercetin equivalent/g dry extract (mg QE/g DE), respectively. On the other hand, the antioxidant activity of leaf extract, quantified by determining the ability to neutralize the free radical DPPH and β-carotene/linoleate model system, reached the values of 0.0027 ± 0.002 mg/mL and 0.128 ± 0.04 mg/mL, respectively. Regarding the antidiabetic activity, based on the inhibition of pancreatic α-amylase activity, a significant inhibition of about 68.20% with an IC50 value of 0.266 mg/mL had been observed. This finding is consistent with the molecular docking study of the main phenolic compounds of the extracts, where a remarkable binding affinity against α-amylase was observed, with values of -7.631 (kcal/mol), -6.818 (kcal/mol), and -5.517 (kcal/mol) for the major compounds catechin, quercetin-3-glucoside, and gallic acid, respectively.

The substitution sites of hydroxyl and galloyl groups determine the inhibitory activity of human pancreatic α-amylase in twelve tea polyphenol monomers

Tea polyphenols have been reported as potential α-amylase inhibitors. However, the quantitative structure–activity relationship (QSAR) between tea polyphenols and human pancreas α-amylase (HPA) is not well understood. Herein, the inhibitory effect of twelve tea polyphenol monomers on HPA was investigated in terms of inhibitory activity, as well as QSAR analysis and interaction mechanism. The results revealed that the HPA inhibitory activity of theaflavins (TFs), especially theaflavin-3′-gallate (TF-3′-G, IC50: 0.313 mg/mL), was much stronger than that of catechins (IC50: 18.387–458.932 mg/mL). The QSAR analysis demonstrated that the determinant for the inhibitory activity of HPA was not the number of hydroxyl and galloyl groups in tea polyphenol monomers, while the substitution sites of these groups potentially might play a more important role in modulating the inhibitory activity. The inhibition kinetics and molecular docking revealed that TF-3′-G as a mixed-type inhibitor had the lowest inhibition constant and bound to the active sites of HPA with the lowest binding energy (−7.74 kcal/mol). These findings could provide valuable insights into the structures-activity relationships between tea polyphenols and the HPA inhibitors.

Characteristics of Nutrition and Metabolism in Dogs and Cats.

Domestic dogs and cats have evolved differentially in some aspects of nutrition, metabolism, chemical sensing, and feeding behavior. The dogs have adapted to omnivorous diets containing taurine-abundant meat and starch-rich plant ingredients. By contrast, domestic cats must consume animal-sourced foods for survival, growth, and development. Both dogs and cats synthesize vitamin Cand many amino acids (AAs, such as alanine, asparagine, aspartate, glutamate, glutamine, glycine, proline, and serine), but have a limited ability to form de novo arginine and vitamin D3. Compared with dogs, cats have greater endogenous nitrogen losses and higher dietary requirements for AAs (particularly arginine, taurine, and tyrosine), B-complex vitamins (niacin, thiamin, folate, and biotin), and choline; exhibit greater rates of gluconeogenesis; are less sensitive to AA imbalances and antagonism; are more capable of concentrating urine through renal reabsorption of water; and cannot tolerate high levels of dietary starch due to limited pancreatic α-amylase activity. In addition, dogs can form sufficient taurine from cysteine (formost breeds); arachidonic acid from linoleic acid; eicosapentaenoic acid and docosahexaenoic acid from α-linolenic acid; all-trans-retinol from β-carotene; and niacin from tryptophan. These synthetic pathways, however, are either absent or limited in all cats due to (a)no or low activities of key enzymes (including pyrroline-5-carboxylate synthase, cysteine dioxygenase, ∆6-desaturase, β-carotene dioxygenase, and quinolinate phosphoribosyltransferase)and (b) diversion of intermediates to other metabolic pathways. Dogs can thrive on one large meal daily, select high-fat over low-fat diets, and consume sweet substances. By contrast, cats eat more frequently during light and dark periods, select high-protein over low-protein diets, refuse dry food, enjoy a consistent diet, and cannot taste sweetness. This knowledge guides the feeding and care of dogs and cats, as well as the manufacturing of their foods. As abundant sources of essential nutrients, animal-derived foodstuffs play important roles in optimizing the growth, development, and health of the companion animals.

Chemical Analysis of the Antihyperglycemic, and Pancreatic α-Amylase, Lipase, and Intestinal α-Glucosidase Inhibitory Activities of Cannabis sativa L. Seed Extracts.

Cannabis is considered (Cannabis sativa L.) a sacred herb in many countries and is vastly employed in traditional medicine to remedy numerous diseases, such as diabetes. This research investigates the chemical composition of the aqueous extracts from Cannabis sativa L. seeds. Furthermore, the impact of these extracts on pancreatic α-amylase and lipase, and intestinal α-glucosidase enzymes is evaluated, as well as their antihyperglycemic effect. Analysis of the chemical composition of the aqueous extract was conducted using high-performance liquid chromatography with a photodiode array detector (HPLC-DAD). In contrast, the ethanol, hexanic, dichloromethane, and aqueous extract compositions have been established. Additionally, the inhibitory effects of ethanolic, dichloromethane, and aqueous extracts on pancreatic α-amylase and lipase, and intestinal α-glucosidase activities were evaluated in vitro and in vivo. The results of HPLC analysis indicate that the most abundant phenolic compound in the aqueous cannabis seed extract is 3-hydroxycinnamic acid, followed by 4-hydroxybenzoic acid and rutin acid. Moreover, administration of ethanolic and aqueous extracts at a dose of 150 mg/Kg significantly suppressed postprandial hyperglycemia compared to the control group; the ethanolic, dichloromethane, and aqueous extracts significantly inhibit pancreatic α-amylase and lipase, and intestinal α-glucosidase in vitro. The pancreatic α-amylase test exhibited an inhibition with IC50 values of 16.36 ± 1.24 µg/mL, 19.33 ± 1.40 µg/mL, 23.53 ± 1.70 µg/mL, and 17.06 ± 9.91 µg/mL for EAq, EDm, EET, and EHx, respectively. EET has the highest inhibitory capacity for intestinal α-glucosidase activity, with an IC50 of 32.23 ± 3.26 µg/mL. The extracts inhibit porcine pancreatic lipase activity, demonstrating their potential as lipase inhibitors. Specifically, at a concentration of 1 mg/mL, the highest inhibition rate (77%) was observed for EDm. To confirm these results, the inhibitory effect of these extracts on enzymes was tested in vivo. The oral intake of aqueous extract markedly reduced starch- and sucrose-induced hyperglycemia in healthy rats. Administration of the ethanolic extract at a specific dose of 150 mg/kg significantly reduced postprandial glycemia compared with the control group. It is, therefore, undeniable that cannabis extracts represent a promising option as a potentially effective treatment for type 2 diabetes.

327 A Novel, in Vivo Model to Increase Endogenous Pancreatic and Small Intestinal Carbohydrase Activity to Evaluate Limitations of Small Intestinal Starch Digestion in Cattle

Abstract Consumption of high-grain diets by cattle can result in large quantities of starch that flow to the small intestine for potential enzymatic digestion. However, small intestinal starch digestion is potentially limited because of insufficient activity of pancreatic and/or small intestinal carbohydrases. Studies suggest regulation of carbohydrase activity is complex in cattle and perhaps uncoordinated in response to luminal carbohydrate flow. The objective of this experiment was to use postruminal casein infusion and exogenous glucagon-like peptide 2 (GLP-2) administration, known stimulators of pancreatic and small intestinal function, to evaluate their effects on pancreatic and small intestinal carbohydrase activities. Twenty-four Holstein steers [250 ± 23 kg body weight (BW)] were used in a randomized complete block design with a 2 × 2 factorial arrangement of treatments. Steers were fed an alfalfa cube-based diet to limit dietary starch intake. Steers received a continuous abomasal infusion of 4 g/kg of BW of raw corn starch combined with either 0 or 1.33 g/kg of BW of casein for 7 d. Steers received subcutaneous injections in two portions daily of excipient (0.5% bovine serum albumin) or 100 µg/kg of BW GLP-2. This resulted in four treatments: control, casein, GLP-2, and casein + GLP-2. At the end of the 7-d treatment period, steers were slaughtered for pancreatic and small intestinal tissue collection. Data were analyzed using the GLM procedure of SAS. Postruminal casein infusion increased (P ≤ 0.03) pancreatic mass by 12.6%, total pancreatic α-amylase activity by 50%, and postruminal starch disappearance from 96.7% to 99.3%. Exogenous GLP-2 increased (P < 0.01) total small intestinal mass and small intestinal mucosal mass by 1.2 kg and 896 g, respectively. Relative to control, GLP-2 and casein + GLP-2 treatments increased (P = 0.04) total small intestinal α-glucosidase activity (sum of maltase, isomaltase, glucoamylase) by 83.5%. Total small intestinal maltase, isomaltase, and glucoamylase activity was 90%, 100%, and 66.7% greater for GLP-2 and casein + GLP-2 steers compared with control. The use of postruminal casein infusion and exogenous GLP-2 administration resulted in four distinct carbohydrase activity phenotypes. Relative to control, casein increased pancreatic α-amylase activity, GLP-2 increased small intestinal α-glucosidase activity, and the combination of casein and GLP-2 increased both pancreatic α-amylase activity and small intestinal α-glucosidase activity. This approach provides a novel in vivo animal model to selectively increase endogenous carbohydrase activity to overcome complications of coordinating carbohydrase activity with luminal nutrient flows. This model could be useful to understand physiological mechanisms that might improve small intestinal starch assimilation and efficiency of cattle consuming high-grain diets.

161 The Effects of Feeding Hempseed Cake on Pancreatic and Intestinal Enzymatic Activity in Finishing Heifers

Abstract Due to the unique nature of the rumen, unlike monogastric animals, ruminants like cattle largely depend on microbial hydrolysis of feed rather than post-ruminal enzymatic degradation. However, in ruminants fed high-grain diets, significant amounts of starch can bypass ruminal fermentation, where pancreatic and small intestinal enzymes play a vital role in digestion. Ruminal microbiota, as well as the host animal, require protein as a nitrogen source to optimize digestibility. Hempseed cake (containing >30% of crude protein) is a by-product of hempseed oil production, but currently is not used as a feed source as it is not an FDA-approved feed ingredient. Presently, the availability and costs of protein supplements are volatile, and sourcing alternative protein sources is needed. Therefore, information is necessary on the effect of feeding hempseed cake on ruminant digestive function. This study aimed to evaluate the effects of feeding hempseed cake on pancreatic and intestinal enzymatic activity in finishing heifers. Angus-crossbred finishing heifers (494 ± 10 kg BW) were fed for 111 days with one of two dietary treatments: 20% [dry matter (DM) basis] of dried corn distillers grains plus solubles (n = 16, control) or hempseed cake (n = 16, hemp). All animals were slaughtered at the end of treatment. Intestinal tissues for digestive enzyme assays were isolated and stored at -800C following immediate flash freezing with liquid nitrogen. The MIXED procedure in SAS was used to analyze the data. There was a tendency (P = 0.09) of greater pancreatic tissue mass in the hemp group than in the control group. The activity of pancreatic α-amylase, trypsin, and lipase relative to protein (U/g protein) was less (P < 0.01) in heifers fed hemp than in heifers fed distillers grains primarily because protein concentration (mg/g) and content (g/pancreas) were greater (P < 0.01) in the hemp group than the control group. However, there were no differences (P ≥ 0.2) in digestive enzyme activity (U/g of tissue) in pancreatic and small intestinal tissues. Overall, our results suggest that there was no adverse effect of feeding hemp on the enzymes responsible for nutrient digestion in the small intestine and that hempseed cake may be useful as an alternative source of protein in cattle fed finishing diets.

Phytochemical Profile, Antilipase, Hemoglobin Antiglycation, Antihyperglycemic, and Anti-Inflammatory Activities of Solanum elaeagnifolium Cav.

In the present investigation, the phenolic compounds of Solanum elaeagnifolium were identified, and the plant’s anti-lipase and anti-glycation effects on hemoglobin were discovered through in vitro experiments, as well as its short-term antihyperglycemic and anti-inflammatory effects. The chemical compound composition was detected using HPLC-DAD, the anti-lipase activity was tested in vitro using 4-nitrophenyl butyrate as a substrate, and the antiglycation activity of the plant extracts was also tested in vitro using a haemoglobin model. The antihyperglycemic effect was determined by inhibiting pancreatic α-amylase and α-glycosidase activity and performing an in vivo glucose tolerance test on normal rats, and the anti-inflammatory activity was determined by inducing paw inflammation with carrageenan. In both the SEFR (fruit) and SEFE (leaf) extracts, chromatographic analysis revealed the presence of quercetin 3-O-β-D-glucoside, rutin, and quercetin. SEFR inhibited the pancreatic lipase enzyme more effectively, with an IC50 of 0.106 ± 0.00 mg/mL. S. elaeagnifolium extracts demonstrated significant antiglycation activity, with 3.990 ± 0.23 mg/mL of SEFE and 3.997 ± 0.14 mg/mL of SEFR. When compared to positive and negative controls, plant extracts had very significant anti-diabetic and anti-inflammatory effects. The findings in this study and previous research on this plant encourage us to investigate other pharmacological activities of this plant besides its duiretic, cictrisant, and anti-ulcer activity.

Insight into biological activities of chemically characterized extract from Marrubium vulgare L. in vitro, in vivo and in silico approaches.

Aqueous extracts of Marrubium vulgare L. (M. vulgare) are widely used in traditional medicine for their therapeutic effects. Hence, this study aims to evaluate in vitro, in vivo, and in silico the biological activities of M. vulgare aqueous extract to further support their traditional use. Qualitative phytochemical tests of M. vulgare extracts showed the presence of primary and secondary metabolites, while quantitative analyses recorded revealed the contents of total phenols, flavonoids, and tannins, with values of 488.432 ± 7.825mg/EAG gallic acid extract/g, 25.5326 ± 1.317mg/EQ Quercetin extract/g and 23.966 ± 0.187mg/EC catechin extract/g, respectively. Characterization of the phytochemical constituents of the extract revealed the presence of catechin and maleic acid as the most abundant while the evaluation of the antioxidant power revealed that the extract possesses significant antioxidant capacity, antimitotic potential, and antimicrobial properties against Streptococcus agalactiae and Staphylococcus epidermidis among many others. The antidiabetic activity of the extract showed a potent antihyperglycemic effect and a significant modulation of the pancreatic α-amylase activity as revealed by both in vitro and in vivo analysis, while an in silico evaluation showed that chemicals in the studied extract exhibited the aforementioned activities by targeting 1XO2 antimitotic protein, W93 antidiabetic protein and 1AJ6 antimicrobial protein, which revealed them as worthy of exploration in drug discovery odyssey. Conclusively, the result of this study demonstrates the numerous biological activities of M. vulgare and gives credence to their folkloric and traditional usage.

Postruminal Casein Infusion and Exogenous Glucagon-Like Peptide 2 Administration Differentially Stimulate Pancreatic α-Amylase and Small Intestinal α-Glucosidase Activity in Cattle

BackgroundIncreasing luminal carbohydrate flow decreases pancreatic α-amylase activity but can increase jejunal maltase activity, suggesting that regulation of carbohydrase activity is perhaps uncoordinated in response to luminal carbohydrate flow. Increasing luminal casein flow increases pancreatic α-amylase activity in cattle, and exogenous glucagon-like peptide 2 (GLP-2) has been shown to increase small intestinal α-glucosidase activity in nonruminants. ObjectivesThe objective was to evaluate the effects of postruminal casein infusion, exogenous GLP-2, or their combination on endogenous pancreatic and small intestinal carbohydrase activity in cattle postruminally infused with starch. MethodsHolstein steers [n = 24; 250 ± 23 kg body weight (BW)] received a continuous abomasal infusion of 3.94 g raw corn starch/kg of BW combined with either 0 or 1.30 g casein/kg of BW. Steers received subcutaneous injections in 2 equal portions daily of excipient (0.5% bovine serum albumin) or 100 μg GLP-2/kg of BW per day. At the end of the 7-d treatment period, steers were slaughtered for tissue collection. Data were analyzed using the MIXED procedure of SAS version 9.4 (SAS Institute Inc.). ResultsPostruminal casein infusion increased (P ≤ 0.03) pancreatic mass by 12.6%, total pancreatic α-amylase activity by 50%, and postruminal starch disappearance from 96.7% to 99.3%. Exogenous GLP-2 increased (P < 0.01) total small intestinal and mucosal mass by 1.2 kg and 896 g, respectively. Relative to control, GLP-2 and casein + GLP-2 increased (P = 0.04) total small intestinal α-glucosidase activity by 83.5%. Total small intestinal maltase, isomaltase, and glucoamylase activity was 90%, 100%, and 66.7% greater for GLP-2 and casein + GLP-2 steers compared with control. ConclusionsCasein increased pancreatic α-amylase activity, GLP-2 increased small intestinal α-glucosidase activity, and the combination of casein and GLP-2 increased both pancreatic α-amylase activity and small intestinal α-glucosidase activity. This novel approach provides an in vivo model to evaluate effects of increasing endogenous carbohydrase activity on small intestinal starch digestion.

Phytochemical Analysis, Antioxidant, and Antihyperglycemic Activities ofCrataegus monogynaJacq Aqueous Extract

ObjectiveThis study aims to evaluate the phytochemical composition, antioxidant, and antihyperglycemic (in vivo, in vitro, and in silico) activities and acute toxicity of Crataegus monogyna Jacq ( C monogyna) aqueous extracts.MethodsThe study analyzed the aqueous extract of C monogyna through various methods such as phytochemical screening, and the high-performance liquid chromatography-ultraviolet (HPLC-UV)-visible analysis. The extract was also tested for antioxidant potential, acute toxicity, antihyperglycemic effect, and inhibitory effect on the pancreatic α-amylase enzyme. Additionally, the study used the molecular docking approach to identify the most potent ligands in the extract.ResultsThe phytochemical screening of the aqueous extract of C monogyna showed the presence of flavonoids, tannins, coumarins, sterol, and triterpene. The extract was rich in total polyphenols (1.65 ± 0.04 mg gallic acid equivalent per gram of extract [GAE/g] DM), total flavonoids (0.33 ± 0.03 EQ/g DM), and condensed tannins (0.28 ± 0.01 EC/mg DM). HPLC-UV-visible analysis identified 9 phenolic compounds, with high levels of gallic acid and caffeic acid. The C monogyna extract has a high antioxidant activity with an IC50of 9.23 ± 0.01 mg/mL by DPPH and 8.32 ± 0.02 mg/mL by FRAP. The aqueous extract of C monogyna was not toxic to albino mice. The glucose tolerance test showed a significant antihyperglycemic effect, with an IC50of 0.070 ± 0.008 mg/mL for the inhibition of pancreatic α-amylase activity by the aqueous extract of C monogyna. The in vivo inhibitory effect of the extract on the pancreatic α-amylase enzyme was confirmed. Two flavonoids, catechin, and rutin, were identified as potent inhibitors of the activity of α-amylase in the in silico part of the study, compared to the native ligand, Acarbose.ConclusionThe study found that C monogyna has significant antioxidant and antihyperglycemic properties. The presence of catechin and rutin may contribute to these effects. The results suggest that C monogyna could be used as a dietary supplement to prevent and treat diabetes.

Physicochemical characterizations, α-amylase inhibitory activities and inhibitory mechanisms of five bacterial exopolysaccharides

Inhibiting pancreatic α-amylase activity can decrease the release rate of glucose, thereby delaying postprandial blood glucose. This study aimed to investigate the physicochemical properties and porcine pancreatic α-amylase (PPA) inhibitory activities of five bacterial exopolysaccharides (EPSs). We also aimed to analyze the differences of their inhibitory activities, exploring the inhibition mechanism between EPSs and PPA. Five EPSs had a low molecular weight (55–66 kDa), which were mainly composed of mannose and glucose with total content exceeding 86 %. The IC50 values of five EPSs (0.162–0.431 mg/mL) were significantly lower than that of acarbose (0.763 mg/mL), indicating that the inhibitory effects of five EPSs on PPA were stronger than acarbose, especially the EPS from Bacillus subtilis STB22 (BS–EPS). Moreover, BS–EPS was a mixed-type inhibitor, whereas other EPSs were noncompetitive inhibitors of PPA. Five EPSs quenched the fluorophore of PPA by the mixed quenching or apparent static quenching. Interestingly, BS–EPS showed stronger binding affinity to PPA than other EPSs. It can be speculated that EPSs with low molecular weight, high carboxylic acid content, and α-glycosidic bond exhibited high PPA inhibitory activity. These results suggest that BS-EPS can effectively inhibit PPA activity and has potential applications in reducing postprandial hyperglycemia.

Inhibitory Potential of Synthetic Amino Acid Derivatives against Digestive Enzymes as Promising Hypoglycemic and Anti-Obesity Agents

Over the last decades, the increased incidence of metabolic disorders, such as type two diabetes and obesity, has motivated researchers to investigate new enzyme inhibitors. In this study, the inhibitory effects of synthetic amino acid derivatives (PPC80, PPC82, PPC84, PPC89, and PPC101) on the activity of digestive enzymes were assessed using in vitro assays. The inhibitory effect was determined by the inhibition percentage and the 50% inhibitory concentration (IC50), and the mechanism of action was investigated using kinetic parameters and Lineweaver–Burk plots. PPC80, PPC82, and PPC84 inhibited pancreatic lipase (IC50 of 167–1023 µM) via competitive or mixed mechanisms. The activity of pancreatic α-amylase was suppressed by PPC80, PPC82, PPC84, PPC89, and PPC101 (IC50 of 162–519 µM), which acted as competitive or mixed inhibitors. Finally, PPC84, PPC89, and PPC101 also showed potent inhibitory effects on α-glucosidase (IC50 of 51–353 µM) as competitive inhibitors. The results suggest that these synthetic amino acid derivatives have inhibitory potential against digestive enzymes and may be used as therapeutic agents to control metabolic disorders.

Phytochemical Profile, Antioxidant, Antimicrobial, and Antidiabetic Activities of Ajuga iva (L.).

In Morocco, many applications in ethnomedicine on Ajuga iva (L.) have been recognized as able to treat various pathologies such as diabetes, stress, and microbial infections. The objective of this work is to carry out phytochemical, biological, and pharmacological investigations on the extracts of Ajuga iva leaves in order to confirm its therapeutic effects. The phytochemical screening carried out on the different extracts of Ajuga iva showed its richness in primary (lipids and proteins) and secondary metabolites (flavonoids, tannins, reducing compounds, oses, and holoside. The best contents of polyphenols, flavonoids, and tannins evaluated by spectrophotometric methods were found in the hydroethanolic extract (69.850 ± 2.783 mg EAG/g DE, 17.127 ± 0.474 mg EQ/g DE, 5.566 ± 0.000 mg EQC/g DE), respectively. Analysis of the chemical composition of the aqueous extract by LC/UV/MS revealed 32 polyphenolic compounds including ferulic acid (19.06%), quercetin (10.19%), coumaric acid (9.63%), and apigenin-7-(2-O-apiosylglucoside) (6.8%). The antioxidant activity of Ajuga iva extracts was evaluated by three methods (DPPH*, FRAP, CAT). The hydroethanolic extract recorded the strongest reducing power: DPPH* (IC50 = 59.92 ± 0.7 µg/mL), FRAP (EC50 = 196.85 ± 1.54 (µg/mL), and CAT (199.21 ± 0.37 mg EAG/gE). A strong correlation between phenolic compounds and antioxidant activities was confirmed by the determination of Pearson's coefficient. The antimicrobial activity of Ajuga iva studied by the microtiter method revealed potent antifungal and antibacterial qualities against Candida parapsilosis and Staphylococcus aureus BLACT. An in vivo oral glucose tolerance test (OGTT) using normal rats revealed that the antihyperglycemic action of the aqueous extract significantly reduced postprandial hyperglycaemia at (30 min, p < 0.01) and area under the curve (AUC glucose), p < 0.01. Similarly, the aqueous extract, tested on pancreatic α-amylase enzyme activity in vitro and in vivo significantly inhibited pancreatic α-amylase activity with IC50 = 1.52 ± 0.03 mg/mL. In conclusion, the extract from Ajuga iva could be a good source of bioactive molecules, which exhibit potent antioxidant and antimicrobial activity, as well as strong antidiabetic activity, for applications in the pharmaceutical industry.

Antidiabetic Effect of Zygophyllum geslini Aerial Part: In Vivo and In Vitro Studies

Zygophyllum geslini Coss. is widely found in the Algerian Sahara. This species is known to treat diabetes mellitus. The objective of this study is to evaluate the glucoselowering effect of aqueous extract of the defatted aerial part from Zygophyllum geslini. Extract was prepared by macerating the plant powder during 24 h in chloroform followed by acetone and water separately. Finally, the aqueous extract (Zygophyllum geslini aqueous extract [ZgAE]) was tested in normal and streptozotocin-induced diabetic rats. In addition, the inhibitory effect of the extract on porcine pancreatic α-amylase was tested. ZgAE is rich with saponins, flavonoids, alkaloids, mucilage, and amino acids. On the fast hyperglycemia, the decrease level is of 21% for the diabetic treated rats by ZgAE (100 mg/kg) and 31% for diabetic treated rats by glimepiride (100 μg/kg). In addition, ZgAE at 0.429 mg/ml can inhibit 50% of the porcine pancreatic α-amylase activity. Plant, especially ZgAE, can be considered as excellent candidate for future studies on diabetes mellitus.

In Vitro Pancreatic Lipase, Alpha-Amylase and Αlpha-Glucosidase Inhibitory Activities of the Phytochemical Barbaloin

In the present study the phytochemical, barbaloin was studied for in-vitro pancreatic lipase, alpha (α)-amylase and alpha (α)-glucosidase inhibitory activities. The aim of this work is to evaluate the inhibitory activities of the phytochemical, barbaloin at different concentrations. Pancreatic lipase is an enzyme that hydrolyzes the lipids obtained from the diet which acts as an important target to treat obesity. The natural medicines that can inhibit pancreatic lipase enzyme and thus decrease absorption of dietary fat in the body gained much attention for the treatment and prevention of obesity. Diabetes mellitus is a metabolic disorder marked by an elevated level of glucose that circulates in the blood plasma. Alpha amylase and alpha glucosidase inhibitors are used to attain control over hyperglycemia in type 2 diabetes mellitus. The present study was designed to screen the novel pancreatic lipase, alpha amylase and alpha glucosidase inhibitors using a phytochemical, barbaloin in order to minimize the toxicity and side effects of the inhibitors which are used at present to treat the disorders like obesity and hyperglycemia. The phytochemical, barbaloin exhibited significant pancreatic lipase, α-amylase and α-glucosidase inhibitory activities with an IC50 value 5.52µg/ml, 8.22µg/ml and 5.81µg/ml respectively and well compared with standard orlistat for pancreatic lipase and acarbose for alpha (α)-amylase and alpha (α)-glucosidase inhibitory activities respectively.

An in vivo approach to the reported effects of phenolic acids and flavonoids on the pancreatic α-amylase activity

Reduction in the activity of the α-amylases which hydrolyze starch and glycogen has been proposed for diminishing the incidence of obesity and diabetes. Many plant extracts contain inhibitors of α-amylases and α-glucosidases and several molecules with this activity have been identified. The present work attempts at investigating if several natural compounds (flavonoids and phenolic acids) that have been reported to be inhibitors of those hydrolytic enzymes can also inhibit starch absorption in vivo. The starch tolerance test in mice was used for assaying starch absorption after administration of 100 mg/kg of five flavonoids (epicatechin, catechin, rutin, quercetin, naringenin) and five phenolic acids (gallic, syringic, vanillic, sinapic, ferulic), which are known in vitro inhibitors of α-amylases. Among the flavonoids, only rutin inhibited starch absorption in mice, even though its effect was only 33% of that one found for the positive control acarbose. Among the five phenolic acids tested only syringic acid produced a clear diminution in starch absorption, which was 47% of that one found with acarbose. On the other hand, other three phenolic acids, namely gallic, sinapic and ferulic acid, caused delay in the absorption of starch, which was characterized by a shift in the time peak of maximal blood glucose concentration, with no modification in the excess of glucose that effectively entered the circulation. Attempts at detecting eventual synergisms by administrating mixtures of flavonoids and phenolic acids were unsuccessful. These results recommend careful translation of in vitro data on the inhibition of α-amylases and α-glucosidases to the in vivo conditions.

Phytochemical Profile, Antioxidant Activity, Anti-Hyperglycemic Effect and Toxicity Assessment of Ridolfia segetum (L.) Moris Extract.

The present work was designed to study the chemical composition, antioxidant, antihyperglycemic effect, and toxicity assessment of Ridolfia segetum (L.) Moris extract. The chemical composition was studied by use of high-performance liquid chromatography (HPLC). Antioxidant power was tested by use of DPPH and FRAP assays. The antihyperglycemic effect was tested by use of a glucose tolerance test, while toxicity assessment was done in vivo by use of Wistar rats for 14 days. Analysis of the extract by HPLC-UV revealed the presence of gallic acid, catechol, vanillic acid, catechin, tannic acid, rosmarinic acid, naringenin, and coumarin acid. The crude hydroethanolic extract possessed high levels of total phenols (15.6 ± 1.76 mg EAG/g), condensed tannins (383.49 mg ECat/g DM), and flavonoid (11.63 mg EQ/g). The findings showed that the studied extract possessed good antioxidant power with IC50 values equal to 550, 650, 700 µg/mL respectively for the decoction, the ethyl acetate fraction (F2M), and the ethyl acetate fraction (F2E). For the antioxidant activity by FRAP, the aqueous fraction (F3E) and the aqueous extract (F4) showed CE50 values of 0.33 mg/mL and 0.4 mg/mL, respectively. Glucose tolerance test analysis showed that R. segetum (L.) Moris decoction had a significant postprandial antihyperglycemic effect in normal Wistar rats. The results of the acute toxicity test showed that the decoction was not toxic even at 2 g/Kg. Pancreatic α-amylase activity was significantly inhibited in the presence of R. segetum (L.) Moris extract (IC50 = 0.133 ± 0.09 mg/mL). The outcome of the present work showed that R. segetum (L.) Moris is very rich in phenolic compounds with potent antioxidant and antihyperglycemic effects.