BACKGROUND The possible existence of an acini–islet–acinar(AIA)reflex,involving mutual amylase and insulin interactions,was investigated in the current acute experiment on pigs.AIM To confirm the existence of an AIA reflex and justify the placement of the exocrine and endocrine pancreatic components within the same organ.METHODS The study was performed on six pigs under general anesthesia.An intravenous glucose tolerance test was performed,with a bolus infusion of 50%glucose to the jugular vein,while amylase(5000 U/kg)or vehicle intrapancreatic infusions were administered via the pancreaticoduodenalis cranialis artery during 30 min with a 1 mL/min flow rate.RESULTS The amylase infusion to pancreatic arterial circulation inhibited and delayed the insulin release peak which is usually associated with the highest value of blood glucose and is typically observed at 15 min after glucose infusion,for>1 h.The intrapancreatic infusion of the vehicle(saline)did not have any effect on the time frame of insulin release.Infusion of 1%bovine serum albumin changed the insulin release curve dramatically and prolonged the high range of insulin secretion,far beyond the glucose peak.CONCLUSION Intrapancreatic arterial infusion of amylase interrupted the integrated glucose–insulin interactions.This confirms an AIA reflex and justifies placement of the exocrine and endocrine pancreatic components within the same organ.
Diabetes is one of the most difficult chronic diseases to cure in the world,which seriously affects people’s health and quality of life.Flavonoids in buckwheat can regulate blood glucose levels by inhibitingα-amylase activity.Therefore,sweet buckwheat produced in Inner Mongolia was used as the research object,and buckwheat fl avonoids were extracted by ultrasonic-assisted extraction method.Total fl avonoids content was determined by ultraviolet-visible spectrophotometry.With acarbose as the positive control,the inhibition test ofα-amylase was carried out by DNS colorimetry to study the inhibition behavior of fl avonoids onα-amylase activity.The results showed that the extraction process of flavonoids was stable and reliable,and the established method for the determination of flavonoids was simple,accurate and reproducible.The total flavonoids content of buckwheat samples was 2.706 mg/g,buckwheat total fl avonoids extraction solution had an inhibitory eff ect onα-amylase,and its median inhibition concentration(IC_(50))was 38.53 mg/mL.The results of this experiment provide a technical reference for the development and utilization of fl avonoids in Inner Mongolia sweet buckwheat,and provide a theoretical reference for the development and application of flavonoid-rich hypoglycemic food.
Acarbose is a potent glycosidase inhibitor widely used in the clinical treatment of type 2 diabetes mellitus(T2DM).Various acarbose analogs have been identified while exploring compounds with improved pharmacological properties.In this study,we found that AcbE from Actinoplanes sp.SE50/110 catalyzes the production of acarbose analogs that exhibit significantly improved inhibitory activity towardsα-amylase than acarbose.Recombinant AcbE mainly catalyzed the formation of two new compounds,namely acarstatins A and B,using acarbose as substrate.Using high-resolution mass spectrometry,nuclear magnetic resonance,and glycosidase hydrolysis,we elucidated their chemical structures as O-α-d-maltosyl-(1→4)-acarbose and O-α-d-maltotriosyl-(1→4)-acarbose,respectively.Acarstatins A and B exhibited 1584-and 1478-fold greater inhibitory activity towards human salivaryα-amylase than acarbose.Furthermore,both acarstatins A and B exhibited complete resistance to microbiome-derived acarbose kinase 1-mediated phosphorylation and partial resistance to acarbose-preferred glucosidase-mediated hydrolysis.Therefore,acarstatins A and B have great potential as candidate therapeutic agents for T2DM.
Xin ZhangQungang HuangZiyue GuoFeifei CaiQianjin KangLinquan Bai
Background:This study aims to explore the significance of serum amylase levels in patients with organophosphorus pesticide(OP)poisoning and to provide a new perspective for evaluating the severity and prognosis of OP poisoning.Methods:The clinical data of 67 patients with acute OP poisoning,who had been treated in the emergency department of the General Hospital of Ningxia Medical University between September 2020 and August 2022,were retrospectively analyzed.Using Spearman rank correlation,serum amylase levels during admission and severity of poisoning correlated with discharge outcomes.Based on serum amylase levels,receiver operating characteristic curves were plotted to predict the severity and mortality of patients who experience organophosphate poisoning.The optimal threshold serum amylase level at admission was determined based on the maximum Youden index.Results:Using Spearman rank correlation analysis,serum amylase levels at admission positively correlated with the severity of poisoning and discharge outcomes,but the degree of correlation was weak(r_(s):0.344;0.264;P<0.05).The patients’serum amylase levels at admission had receiver operating characteristic area under the curve values of 0.726 and 0.735 to predict the degree of severe poisoning and death,respectively.Based on the maximum Youden index,the optimal threshold of serum amylase were 97.8 and 194.1 U/L when the degree of poisoning was severe and the discharge outcome of patients was died.In comparison to patients with serum amylase levels≤194.1 U/L at admission,the OR values of death in patients with serum amylase levels>194.1 U/L at admission was 15.944(95%CI:1.825-139.274).Conclusion:Serum amylase levels in patients with organophosphate poisoning correlate with the degree of poisoning and discharge outcomes.Higher serum amylase level was a risk factor for organophosphorus poisoning death.
OBJECTIVE:To investigate the effects of Hippeastrum hybridum(HH)as a free radical scavenger,and an inhibitor of the two enzymes i-e Alpha-amylase(α-amylase)and acetylcholinesterase(AChE).METHODS:In this study,HH plant was preliminary analyzed for phytochemical screening and then tested for its antioxidant,anti-α-amylase,and anti-AChE efficiency via standard procedures.RESULTS:Phytochemical analysis shows the existence of different compounds;while Coumarins and quinones were absent.The total phenolic,flavonoid,and tannins content were found to be(78.52±0.69)mg GAE/g,(2.01±0.04)mg RUE/g,and(58.12±0.23)mg TAE/g of plant extract respectively.28.02%±0.02%alkaloid and 2.02%±0.05%saponins were present in the HH extract.The HH extract showed the anti-oxidant property with IC50(50%inhibition)of(151.01±0.13)(HH),(79.01±0.04)(Ascorbic acid)for ferric reducing,(91.48±0.13)(HH),(48.02±0.11)(Ascorbic acid)against Ammonium molybdenum,(156.02±0.31)(HH),(52.38±0.21)(Ascorbic acid)against DPPH,136.01±0.21(HH),52.02±0.31(Ascorbic acid)against H_(2)O_(2),and 154.12±0.03(HH),(40.05±0.15)(Ascorbic acid)μg/mL against ABTS respectively.Statistical analysis indicated that HH caused a competitive type of inhibition ofα-amylase(V_(max)remained constant and Km increases from 10.65 to84.37%)while Glucophage caused the un-competitive type of inhibition i-e both Km and V_(max)decreased from40.49 to 69.15%and 38.86 to 69.61%respectively.The K_(i),(inhibition constant);K_(I),(dissociation constant),K_(m),(Michaelis-Menten constant),and IC50 were found to be62,364,68.1,and 38.08±0.22 for HH and 12,101.05,195,34.01±0.21 for Glucophage.Similarly,HH causes an anon-competitive type of inhibition of AChE i-e Km remains constant while V_(max)decreases from 60.5%to74.1%.The calculated K_(i),K_(I),K_(m),and IC50 were found to be 32,36.2,0.05,and 18.117±0.018.CONCLUSION:From the current results,it is concluded that HH extract contains bioactive compounds,and could be a good alternative to controlling oxidants,Alzheimer‘s and Type-�
