Effects of α-glucosidase Inhibitors on the Function of Mulberry Leaf Extract as an Additive in Feedstuff

The mulberry juice contains high concentrations of α-glucosidase inhibitors that affect glycometabolism and cause diarrhea in animals, thereby affecting the de-velopment and application of mulberry （Morus alba L.） as feedstuff resources. ln this study, the effects of mulberry leaf extract with and without removal of mulberry juice on starch metabolism were analyzed and compared. The results showed that mul-berry leaf extract with removal of mulberry juice exhibited significantly lower inhibi-tion rate on starch metabolism compared with mulberry leaf extract without removal of mulberry juice. ln animal feeding trials, piglet feedstuff was added with 10% mul-berry leaf powder; compared with mulberry leaf powder without removal of mulberry juice, experimental piglets fed with mulberry leaf powder with removal of mulberry juice exhibited significantly improved weight gain and significantyl reduced diarrhea rate.

α-Glucosidase Inhibitors from Glycyrrhiza uralensis Fisch.

Aim To screen for α-glucosidase inhibitor from Glyeyrrhiza uralensis Fisch.. Methods Glycyrrhizic acid, glycyrrhetinic acid, flavonoids of glycyrrhiza, alkaloids of glycyrrhiza, and glycyrrhiza polysaccharides were isolated from the root of Glycyrrhiza uralensis Fisch. respectively. Three compounds were isolated from the flavonoids of glycyrrhiza as guided by the α-glucosidase inhibitory test in vitro. Moreover, the characteristics of inhibitory kinetics of glycyrol and glycyrrhetinic acid were investi- gated. Results The flavonoids of glycyrrhiza and glycyrrhetinic acid had the strongest α-glucosidase inhibitory activity. Glycyrol,β-sitosterol and liquifitin were isolated and identified. Glycyrol was a fast- binding, reversible, noncompetitive α-glucosidase inhibitor, showing IC50 at 0.26 μg·mL^-1 Glycyrrhetinic acid was a fast-binding, irreversible α-glucosidase inhibitor, showing IC50 at 102.4 μg·mL^-1. Conclusion Glycyrol is an effective α-glucosidase inhibitor.

α-Glucosidase inhibitors isolated from medicinal plants

Objective:α-Glucosidase inhibitors can be used as a new class of antidiabetic drug.By competitively inhibiting glycosidase activity,these inhibitors help to prevent the fast breakdown of sugars and thereby control the blood sugar level.This study provides a wealth of information aboutα-glucosidase inhibitors isolated from medicinal plants;this knowledge will be useful in finding more potent antidiabetic candidates from the natural resources for the clinical development of antidiabetic therapeutics.Results:411 compounds exhibitingα-glucosidase inhibitory activity were summarized and isolated them from medicinal plants.The compound classes isolated include:terpenes(61)from 14 genus,alkaloids(37)from 11 genus,quinines(49)from 4 genus,flavonoids(103)from 24 genus,phenols(37)from 9 genus,phenylpropanoids(73)from 20 genus,sterides(8)from 5 genus,and other types of compounds(43).Conclusion:Compounds withα-glucosidase inhibitory activity are abundant in nature and can be obtained from several sources.They have highα-glucosidase inhibitory potential,and can be clinically developed for treating diabetes mellitus.

Identification of α-glucosidase inhibitors from Clinacanthus nutans leaf extract using liquid chromatography-mass spectrometry-based metabolomics and protein-ligand interaction with molecular docking

The present study used in vitro and in silico techniques, as well as the metabolomics approach to characterise α-glucosidase inhibitors from different fractions of Clinacanthus nutans. C. nutans is a medicinal plant belonging to the Acanthaceae family, and is traditionally used to treat diabetes in Malaysia. nHexane, n-hexane: ethyl acetate(1:1, v/v), ethyl acetate, ethyl acetate: methanol(1:1, v/v), and methanol fractions were obtained via partitioning of the 80% methanolic crude extract. The in vitro α-glucosidase inhibitory activity was analyzed using all the fractions collected, followed by profiling of the metabolites using liquid chromatography combined with mass spectrometry. The partial least square(PLS) statistical model was developed using the SIMCA P^+14.0 software and the following four inhibitors were obtained:(1) 4,6,8-Megastigmatrien-3-one;(2) N-Isobutyl-2-nonen-6,8-diynamide;(3) 1′,2′-bis(acetyloxy)-3′,4′-didehydro-2′-hydro-β, ψ-carotene; and(4) 22-acetate-3-hydroxy-21-(6-methyl-2,4-octadienoate)-olean-12-en-28-oic acid. The in silico study performed via molecular docking with the crystal structure of yeast isomaltase(PDB code: 3 A4 A) involved a hydrogen bond and some hydrophobic interactions between the inhibitors and protein. The residues that interacted include ASN259, HID295, LYS156, ARG335,and GLY209 with a hydrogen bond, while TRP15, TYR158, VAL232, HIE280, ALA292, PRO312, LEU313,VAL313, PHE314, ARG315, TYR316, VAL319, and TRP343 with other forms of bonding.

Screening ofα-glucosidase inhibitors in large-leaf yellow tea by offline bioassay coupled with liquid chromatography tandem mass spectrometry

Larger-leaf yellow tea(LYT)is a characteristic type of Chinese tea produced in Huoshan County,Anhui Province,which is made by mature leaves with stems.According to recent report,LYT showed competitive effects in anti-hyperglycemia in comparison to other teas such as green or black tea.However,the bioactive compounds of LYT are still undiscovered so far.For this purpose,5 fractions of LYT were prepared by sequential extraction.The in vitro bioassay results indicated that the ethyl acetate fraction of LYT had the strongest inhibitory effects onα-glucosidase andα-amylase.Fluorescence-quenching analysis and proteinbinding test revealed that the compounds of ethyl acetate fraction could inhibitα-glucosidase andα-amylase activities through binding to enzymes or other mechanisms.All chromatographic peaks of high-performance liquid chromatography(HPLC)of ethyl acetate fraction were separated and collected.The purified compounds were identified by liquid chromatography-mass spectrometry(LC-MS),and subsequently screened by calculating their inhibition ratio onα-glucosidase at the real concentration in LYT infusion.The results showed that(-)-epigallocatechin gallate,(-)-gallocatechin gallate,caffeine,N-ethyl-2-pyrrolidone-substituted flavan-3-ols were effective inhibitors forα-glucosidase.

New flavanone-monoterpene hybrids as α-glucosidase inhibitors from the root bark of Morus alba

Objective The Morus alba root bark is a well-known Chinese herbal medicine called Sang-Bai-Pi and has often been used to relieve the hyperglycemic symptom of diabetes patients.The current work aims to further explore its bioactive constituents with α-glucosidase inhibitory activity for the potential treatment of diabetes.Methods A combination of different separating techniques including routine column chromatograph and HPLC especially on chiral columns were applied for the isolation of target molecules,while comprehensive spectroscopic experiments comprising MS,NMR,ECD,etc.were carried out to complete the structural assignment.The anti-hyperglycemic property of the isolates was evaluated by an in vitro α-glucosidase inhibitory bioassay.Results Two pairs of new flavanone-monoterpene hybrid enantiomers were isolated and identified,and an interesting phenomenon of mutual transformation between these cometabolites were detected,which resulted in their regio-isomerization and enantiomerization.The bioassay results revealed remarkable α-glucosidase inhibitory activity for these fascinating molecules.Conclusions The Morus alba root bark is a rich source of bioactive flavonoid derivatives and deserves further investigations to develop new potential chemotherapies for diabetes control and treatment.

Determination of α-glucosidase inhibitors from Scutellaria baicalensis using liquid chromatography with quadrupole time of flight tandem mass spectrometry coupled with centrifugal ultrafiltration

The present study aimed at identifying potential lead compounds for diabetes mellitus drug discovery. We developed a novel method involving centrifugal ultrafiltration separation subsequent liquid chromatography with quadrupole time of flight tandem mass spectrometry （LC-Q/TOF-MS/MS） determination to screen a-glucosidase inhibitors in complex Scutellaria baicalensis Georgi （SBG） extract. By adding a second filter to the screening process, the level of non-specific binding of Compounds 1, 3, 10 and 11 was significantly decreased, and the level of non-specific binding of Compounds 5 and 15 also was reduced. As a result, five flavonoids identified as baicalein, baicalein, wogonin, chrysin, and oroxylin A, were rapidly found to interact with α-glucosidase and possess potent anti-a-glueosidase aetivity in vitro. Specific binding of ligands to a-glucosidase was demonstrated though the proposed method and the ligands could be ranked in order of affinity for α-glucosidase, which were corresponded to the order of inhibitory activity in vitro. In conclusion, our results indicated that the developed method is a rapid and effective screening method for rat intestinal α-glucosidase inhibitors from complex herbal medicines such as SBG.

Tsaokols A and B,unusual flavanol-monoterpenoid hybrids asα-glucosidase inhibitors from Amomum tsao-ko

Tsaokols A(1)and B(2),two complicated flavanol-monoterpenoid hybrids,were isolated from the dried fruits of Amomum tsao-ko under the guidance of LCMS and bioassay.Their structures were determined by extensive spectroscopic analyses and electronic circular dichroism(ECD)calculations.Compounds 1 and2 shared a flavanol backbone fused with 5/7 and 5/6 bicyclic monoterpenoid scaffolds,which were biogenetically condensed by Michael addition and acetalization.Compounds 1 and 2 exhibited significantα-glucosidase inhibitory activity with IC_(50)values of 18.8 and 38.6μmol/L(acarbose,IC_(50)=213μmol/L).Docking study supported the strong interactions of 1 and 2 bonding with enzyme by mainly hydrophobic and hydrogen-bond effects.Compounds 1 and 2 could be fast distinguished by the diagnostic ions at m/z 289 and 313 in negative MS^(2)experiments.

Discovery of pyrogallol thermal reaction products from a model process of roasting coffee beans as potentα-glucosidase inhibitors

The roasting process of pyrogallol,a polyphenol compound distributed in coffee beverages,significantly enhanced itsα-glucosidase inhibitory activity.In this study,a bioassay-guided isolation of the thermal reaction products of pyrogallol led to the identification of two potentα-glucosidase inhibitors,4-4′dimer of pyrogallol(4,4′-DP)and 4-5′dimer of pyrogallol(4,5′-DP).Theirα-glucosidase inhibitory activity was higher than that of pyrogallol,as evidenced by comparing the IC_(50)values(206.2±1.2μM for 4,4′-DP,187.6±2.6μM for 4,5′-DP,2660±60.1μM for pyrogallol).And the roasting products were more potentα-glucosidase inhibitors compared to acarbose(IC_(50)=695±12.7μM).Enzyme kinetics demonstrated that 4,4′-DP and 4,5′-DP inhibitedα-glucosidase in an uncompetitive and a non-competitive manner,respectively.Docking simulations revealed that the main interaction forces between these two compounds andα-glucosidase were hydrogen bonding and hydrophobic effect.These results suggested that a simple roasting process might increase theα-glucosidase inhibitory activity of pyrogallol-containing foods such as coffee beverages.

Assessing the corrosion protection property of coatings loaded with corrosion inhibitors using the real-time atmospheric corrosion monitoring technique

The atmospheric corrosion monitoring(ACM)technique has been widely employed to track the real-time corrosion behavior of metal materials.However,limited studies have applied ACM to the corrosion protection properties of organic coatings.This study compared a bare epoxy coating with one containing zinc phosphate corrosion inhibitors,both applied on ACM sensors,to observe their corrosion protection properties over time.Coatings with artificial damage via scratches were exposed to immersion and alternating dry and wet environments,which allowed for monitoring galvanic corrosion currents in real-time.Throughout the corrosion tests,the ACM currents of the zinc phosphate/epoxy coating were considerably lower than those of the blank epoxy coating.The trend in ACM current variations closely matched the results obtained from regular electrochemical tests and surface analysis.This alignment highlights the potential of the ACM technique in evaluating the corrosion protection capabilities of organic coatings.Compared with the blank epoxy coating,the zinc phosphate/epoxy coating showed much-decreased ACM current values that confirmed the effective inhibition of zinc phosphate against steel corrosion beneath the damaged coating.

Proton pump inhibitors and all-cause mortality risk among cancer patients

BACKGROUND Proton pump inhibitors(PPIs)are widely used,including among cancer patients,to manage gastroesophageal reflux and other gastric acid-related disorders.Recent evidence suggests associations between long-term PPI use and higher risks for various adverse health outcomes,including greater mortality.AIM To investigate the association between PPI use and all-cause mortality among cancer patients by a comprehensive analysis after adjustment for various confounders and a robust methodological approach to minimize bias.METHODS This retrospective cohort study used data from the TriNetX research network,with electronic health records from multiple healthcare organizations.The study employed a new-user,active comparator design,which compared newly treated PPI users with non-users and newly treated histamine2 receptor antagonists(H2RA)users among adult cancer patients.Newly prescribed PPIs(esomeprazole,lansoprazole,omeprazole,pantoprazole,or rabeprazole)users were compared to non-users or newly prescribed H2RAs(cimetidine,famotidine,nizatidine,or ranitidine)users.The primary outcome was all-cause mortality.Each patient in the main group was matched to a patient in the control group using 1:1 propensity score matching to reduce confounding effects.Multivariable Cox regression models were used to estimate hazard ratios(HRs)and 95% confidence interval(CI).RESULTS During the follow-up period(median 5.4±1.8 years for PPI users and 6.5±1.0 years for non-users),PPI users demonstrated a higher all-cause mortality rate than non-users after 1 year,2 years,and at the end of follow up(HRs:2.34-2.72).Compared with H2RA users,PPI users demonstrated a higher rate of all-cause mortality HR:1.51(95%CI:1.41-1.69).Similar results were observed across sensitivity analyses by excluding deaths from the first 9 months and 1-year post-exposure,confirming the robustness of these findings.In a sensitivity analysis,we analyzed all-cause mortality outcomes between former PPI users and individuals who have never used PPIs,providing insights into the long-term effects of past PPI use.In addition,at 1-year follow-up,the analysis revealed a significant difference in mortality rates between former PPI users and non-users(HR:1.84;95%CI:1.82-1.96).CONCLUSION PPI use among cancer patients was associated with a higher risk of all-cause mortality compared to non-users or H2RA users.These findings emphasize the need for cautious use of PPIs in cancer patients and suggest that alternative treatments should be considered when clinically feasible.However,further studies are needed to corroborate our findings,given the significant adverse outcomes in cancer patients.

Novel carbohydrate-triazole derivatives as potentialα-glucosidase inhibitors

A series of novel pyrano[2,3-d]trizaole compounds were synthesized and theirα-glucosidase inhibitory activities were evaluated by in vitro enzyme assay.The experimental data demonstrated that compound 10 f showed up to 10-fold higher inhibition(IC5074.0±1.3μmol·L-1)than acarbose.The molecular docking revealed that compound 10 f could bind toα-glucosidase via the hydrophobic,π-πstacking,and hydrogen bonding interactions.The results may benefit further structural modifications to find new and potentα-glucosidase inhibitors.

α-Glucosidase inhibitors and antioxidants from root bark of Morusalba

Objective: To study the chemical constituents from root bark of Morus alba and their α-glucosidase inhibition and DPPH radical scavenging activities.Methods: The chemical constituents were isolated and purified by repeated column chromatographies on silica gel, Sephadex LH-20, and preparative HPLC. Their structures were elucidated by 1 D and 2 D NMR spectra and HR-ESI-MS.Results: Thirteen compounds 1–13 were isolated and identified. The bioactive assays revealed that compounds 1, 3 and 8 displayed strong α-glucosidase inhibitory activity with IC50 values of(147.1 ± 1.1),(314.1 ± 0.8), and(207.6 ± 0.1) μmol/L, respectively, which were stronger than the positive control of acarbose(418.6 ± 0.1 μmol/L). Compounds 10 and 11 displayed potent DPPH scavenging activity with EC50 values of(2.9 ± 0.1) and(5.0 ± 0.1) μmol/L [EC50 of positive control Vitamin C was(54.8 ± 0.1) μmol/L],respectively.Conclusion: To the best of our knowledge, this is the first report about the compounds 1, 3, and 8 of M.alba with α-glucosidase inhibitory effects.

Screening potential α-glucosidase inhibitors from Anemarrhena asphodeloides using response surface methodology coupled with grey relational analysis

Objective: To screen potential α-glucosidase inhibitors from Anemarrhena asphodeloides.Methods: Response surface methodology employing Box-Behnken design was used to optimize conditions for the extraction of α-glucosidase inhibitory active compounds from A. asphodeloides. The powders(20.0 g) of A. asphodeloides were extracted under the optimized conditions. The extract was applied to a D-101 macroporous resin column. It was eluted with ethanol and water to give six fractions. Compounds from the active fraction were identified by UPLC-Q-TOF-MS. The structure-activity relationship was discussed based on grey relational analysis.Results: The optimum extraction conditions were as follows: ethanol concentration, 100%; extraction temperature, 51 ℃; and solvent to solid ratio, 23 mL/g. It indicated that the active compounds were concentrated into 80% ethanol fraction. Twenty five steroid saponins from 80%ethanol fraction were identified by UPLC-Q-TOF-MS. Peaks 19 and 23 were tentatively identified as new structures. The predicted α-glucosidase inhibitory activities of the compounds were 7 > 2 > 1 > 22 > 23 > 3 > 9 > 21 > 24 > 4 > 13 > 8 > 14 > 16 > 17 > 25 > 6 > 19.Conclusion: The fraction eluted by 80% ethanol showed the best inhibitory activity. After analyzing the data of UPLC-Q-TOF-MS, 25 steroid saponins were tentatively identified in this fraction.

Macroalage as a source of alpha-glucosidase inhibitors

Alpha-glucosidase inhibitors were screened from organic solvent extracts of macroalgae by a spec- trophotometrical method with p-nitrophenyl-D-glucopyranosidase as the substrate. The result indicates that or- ganic crude extracts from some macroalgae such as Rhodomela confervoides (Huds.) Silva, Gracilaria textorii (Suringar) DeToni, Plocamium telfairiae Harv., Dictyopteris divaricata (Okam.) Okam, Ulval pertusa and En- teromorpha intestinalis (L.) Link et al. show strong inhibitory activity of alpha-glucosidase at concentration of 79.6 μg/ml.

Metal complexes of anthranilic acid derivatives: A new class of noncompetitive α-glucosidase inhibitors

Metal complexes of anthranilic acid derivatives that constitute a novel class of non-sugar-type α- glucosidase inhibitors were synthesized and assessed in vitro for inhibitory activity. All of the AgO） complexes （9-16） inhibited α-glucosidase at the nanomolar scale, while 3,5-dichloroanthranilic acid silver（1） （9） was the most potent （ICso = 3.21 nmol/L）. Analysis of the kinetics of enzyme inhibition indicated that the mechanism of the newly prepared silver complexes was noncompetitive. The structure-activity relationships were also analyzed, and thev are discussed in this report.

Risk of hepatitis B virus reactivation in oncological patients treated with tyrosine kinase inhibitors:A case report and literature analysis

Hepatitis B virus(HBV)reactivation(HBVr)represents a severe and potentially life-threatening condition,and preventive measures are available through blood test screening or prophylactic therapy administration.The assessment of HBVr traditionally considers factors such as HBV profile,including hepatitis B surface antigen(HBsAg)and antibody to hepatitis B core antigen,along with type of medication(chemotherapy;immunomodulants).Nevertheless,consideration of possible patient’s underlying tumor and the specific malignancy type(solid or hematologic)plays a crucial role and needs to be assessed for decision-making process.

Blood glucose-lowering activity of protocatechuic acid is mediated by inhibiting a-glucosidase

α-Glucosidase inhibitors are effective in controlling postprandial hyperglycemia,which play crucial roles in the management of type 2 diabetes.Protocatechuic acid(PCA)is one of phenolic acids existing not only in various plant foods but also as a major microbial metabolite of dietary anthocyanins in the large colon.The present study investigated the inhibitory mechanism of PCA on a-glucosidase in vitro and examined its effect on postprandial blood glucose levels in vivo.Results from in vitro experiments demonstrated that PCA was a mix-type inhibitor of a-glucosidase.Driven by hydrogen bonds and van der Waals interactions,PCA reversibly bound withα-glucosidase to form a stable a-glucosidase-PCA complex in a spontaneous manner.The computational simulation found that PCA could insert into the active cavity of a-glucosidase and establish hydrogen bonds with catalytic amino acid residues.PCA binding aroused the steric hindrance for substrates to enter active sites and caused the structural changes of interacted catalytic amino acid residues.PCA also exhibited postprandial hypoglycemic capacity in diabetic mice.This study may provide the theoretical basis for the application of PCA as an active ingredient of functional foods in dietary management of diabetes.

Sodium-dependent glucose transporter 2 inhibitors effects on myocardial function in patients with type 2 diabetes and asymptomatic heart failure

BACKGROUND Sodium-dependent glucose transporter 2 inhibitors(SGLT2i)have shown efficacy in reducing heart failure(HF)burden in a very heterogeneous groups of patients,raising doubts about some contemporary assumptions of their mechanism of action.We previously published a prospective observational study that evaluated mechanisms of action of SGLT2i in patients with type 2 diabetes who were in HF stages A and B on dual hypoglycemic therapy.Two groups of patients were included in the study:the ones receiving SGLT2i as an add-on agent to metformin and the others on dipeptidyl peptidase-4 inhibitors as an add-on to metformin due to suboptimal glycemic control.AIM To evaluate the outcomes regarding natriuretic peptide,oxidative stress,inflammation,blood pressure,heart rate,cardiac function,and body weight.METHODS The study outcomes were examined by dividing each treatment arm into two subgroups according to baseline parameters of global longitudinal strain(GLS),N-terminal pro-brain natriuretic peptide,myeloperoxidase(MPO),high-sensitivity C-reactive protein(hsCRP),and systolic and diastolic blood pressure.To evaluate the possible predictors of observed changes in the SGLT2i arm during follow-up,a rise in stroke volume index,body mass index(BMI)decrease,and lack of heart rate increase,linear regression analysis was performed.RESULTS There was a greater reduction of MPO,hsCRP,GLS,and blood pressure in the groups with higher baseline values of mentioned parameters irrespective of the therapeutic arm after 6 months of follow-up.Significant independent predictors of heart rate decrease were a reduction in early mitral inflow velocity to early diastolic mitral annular velocity at the interventricular septal annulus ratio and BMI,while the predictor of stroke volume index increase was SGLT2i therapy itself.CONCLUSION SGLT2i affect body composition,reduce cardiac load,improve diastolic/systolic function,and attenuate the sympathetic response.Glycemic control contributes to the improvement of heart function,blood pressure control,oxidative stress,and reduction in inflammation.

Hepatic arterial infusion chemotherapy with anti-angiogenesis agents and immune checkpoint inhibitors for unresectable hepatocellular carcinoma and meta-analysis

BACKGROUND Hepatic arterial infusion chemotherapy(HAIC)has been proven to be an ideal choice for treating unresectable hepatocellular carcinoma(uHCC).HAIC-based treatment showed great potential for treating uHCC.However,large-scale studies on HAIC-based treatments and meta-analyses of first-line treatments for uHCC are lacking.AIM To investigate better first-line treatment options for uHCC and to assess the safety and efficacy of HAIC combined with angiogenesis inhibitors,programmed cell death of protein 1(PD-1)and its ligand(PD-L1)blockers(triple therapy)under real-world conditions.METHODS Several electronic databases were searched to identify eligible randomized controlled trials for this meta-analysis.Study-level pooled analyses of hazard ratios(HRs)and odds ratios(ORs)were performed.This was a retrospective single-center study involving 442 patients with uHCC who received triple therapy or angiogenesis inhibitors plus PD-1/PD-L1 blockades(AIPB)at Sun Yat-sen University Cancer Center from January 2018 to April 2023.Propensity score matching(PSM)was performed to balance the bias between the groups.The Kaplan-Meier method and cox regression were used to analyse the survival data,and the log-rank test was used to compare the suvival time between the groups.RESULTS A total of 13 randomized controlled trials were included.HAIC alone and in combination with sorafenib were found to be effective treatments(P values for ORs:HAIC,0.95;for HRs:HAIC+sorafenib,0.04).After PSM,176 HCC patients were included in the analysis.The triple therapy group(n=88)had a longer median overall survival than the AIPB group(n=88)(31.6 months vs 14.6 months,P<0.001)and a greater incidence of adverse events(94.3%vs 75.4%,P<0.001).CONCLUSION This meta-analysis suggests that HAIC-based treatments are likely to be the best choice for uHCC.Our findings confirm that triple therapy is more effective for uHCC patients than AIPB.