Hypothesis that alpha-amylase evokes regulatory mechanisms originating in the pancreas,gut and circulation,which govern glucose/insulin homeostasis

The anti-incretin theory involving the abolishment of diabetes type(DT)II by some of methods used in bariatric surgery,first appeared during the early years of the XXI century and considers the existence of anti-incretin substances.However,to date no exogenous or endogenous anti-incretins have been found.Our concept of the acini-islet-acinar axis assumes that insulin intra-pancreatically stimulates alpha-amylase synthesis(“halo phenomenon”)and in turn,alphaamylase reciprocally inhibits insulin production,thus making alpha-amylase a candidate for being an anti-incretin.Additionally,gut as well as plasma alphaamylase,of pancreatic and other origins,inhibits the appearance of dietary glucose in the blood,lowering the glucose peak after iv or oral glucose loading.This effect of alpha-amylase can be interpreted as an insulin down regulatory mechanism,possibly limiting the depletion of pancreatic beta cells and preventing their failure.Clinical observations agree with the above statements,where patients with high blood alpha-amylase concentrations are seldom obese and seldom develop DT2.Obese-DT2,as well as DT1 patients,usually develop exocrine pancreatic insufficiency(EPI)and vice versa.Ultimately,DT2 patients develop DT1,when the pancreatic beta cells are exhausted and insulin production ceases.Studies on biliopancreatic diversion(BPD)and on BPD with duodenal switch,a type of bariatric surgery,as well as studies on EPI pigs,allow us to observe and investigate the above-mentioned phenomena of intra-pancreatic interactions.

Chronic Urticaria Due to Allergy to Wheat Alpha-Amylase Inhibitor Proteins

Chronic spontaneous urticaria (CSU) is defined as the spontaneous appearance of wheals, angioedema, or both, for at least 6 weeks, due to known or unknown causes [1]. In some patients who present a CSU with daily or almost daily symptoms a type I allergy could be the underlying cause. We present one adult patient with chronic urticaria who was finally diagnosed as a non-occupational case of IgE-mediated wheat allergy manifested following exposure by 3 different routes: inhalation (rhinitis and bronchial asthma), dermal absorption (contact urticaria) and ingestion (systemic chronic urticaria). We were able to detect the culprit proteins by immunoblotting. Serum IgE binds mainly to alpha-amylase/trypsin inhibitors and, to a lesser extent, to other proteins associated with food allergy to grains (e.g. beta-glucanase, serpin, peroxidase). In our opinion, skin prick tests with a food standard battery could help in the etiological diagnosis of chronic urticaria. The identification of responsible allergens could be difficult because only a few complex in vitro techniques allow detecting the allergy to several proteins.

Salivary Alpha-Amylase Reactivity under Psycho-Physiological Stress. A Nonverbal Communication Measurement Tool?

Previous studies have shown that changes in salivary alpha-amylase (sAA) levels are dependent on psychosocial stress stimulation and reflect the activity of the sympathetic nervous system. sAA measurement can be performed easily and quickly;therefore, it may be useful for evaluating psychosocial or physical stress. The aim of this preliminary study was to examine the use of sAA measurements as objective indicators of psychological and physiological stress levels by examining sAA changes in volunteers subjected to conditions similar to those suffered by children with severe motor and intellectual disabilities and cerebral paralysis. Twelve healthy volunteers were required to not move or speak, as is found in patients suffering from total paralysis, for 30 min. Saliva samples were taken at three points, and sAA activity was measured using a hand-held monitor before the test, immediately after the test, and 10 min after the test. In the present study, a marked increase in sAA activity due to physiological stress and a rapid return to the baseline level were observed. Many subjects felt bodily pain and psychotic discomfort. This measurement method is useful for evaluating stress in children with severe motor and intellectual disabilities, who can not fully express their emotions or communicate with their caregivers.

Increase in Salivary Alpha-Amylase Levels among Non-Attending Junior High School Students Diagnosed with Social Anxiety Disorder

Purpose: Several studies have demonstrated that the measurement of salivary alpha-amylase (sAA) levels is a useful tool for evaluating the autonomic nervous system. Psychosocial stress increases the release of sAA as a useful marker for autonomic nervous system (ANS). To our knowledge, although some studies have evaluated sAA levels under psychosocial stress, no studies have investigated the changes in sAA activity that occur in junior high school students who are not attending school due to social anxiety disorder (SAD). We aimed to investigate the relationship between the sAA levels and psychiatric states of such patients. Methods: The study subjects consisted of SAD patients (n = 39) and healthy controls (n = 57). We used a portable hand-held monitor to measure the level of sAA and State-Trait Anxiety Index (STAI) to evaluate the psychiatric state. Results: The patients’ sAA activity was significantly higher than that of the controls (n = 57) (p < 0.001). Significant differences in heart rate (HR) (76.10 ± 11.96 vs. 68.69 ± 10.61, respectively, p < 0.01) and STAI scores (both the STAI-State and STAI-Trait scores) (49.35 ± 10.57 vs. 41.24 ± 8.59, respectively, p < 0.01;55.69 ± 10.44 vs. 45.61 ± 9.36, respectively, p < 0.001) were detected between the patients and healthy controls. Conclusions: These results indicated that junior high school students with SAD exhibit a higher state of anxiety and high autonomic activity, probably due to changes in the sympathetic nervous system. As a result, junior high school students with SAD are expected to exhibit high levels of sAA accompanied by anxiety symptoms.

The association of salivary alpha-amylase, heart rate variability, and psychological stress on objectively measured sleep behaviors among college students

Objective:This study aimed to evaluate sleep behaviors among college students,to assess salivary alpha-amylase(sAA)and heart rate variability(HRV)in association with stress,and to investigate sleep-related factors including sAA,HRV,and stress among them.Methods:Saliva samples for sAA assessment and HRV measurements in the supine position were taken between 3 PM and 6 PM.The level of prolonged psychological stress for the previous week was evaluated using the Korean version of the Global Assessment of Recent Stress(GARS-K),and sleep behaviors were assessed using an actigraphy device.Results:A total of 86 healthy college students participated in this study.Sleep behaviors of the college students were not good,with 84%sleep efficiency(SE)and 62.7 min wake after sleep onset(WASO).The average sAA level was 65.8 U/mL in the participants.Although neither the sAA level nor HRV indices were significantly correlated with prolonged psychological stress,decreased normalized high frequency(nHF)on HRV was independently associated with a higher level of stress when adjusted for age and sex.Higher stress(r=-0.276,P=0.011)and lower sAA(r=0.266,P=0.030)had significant correlations with shorter time in bed;however,it was sAA that was independently associated with time in bed(β=0.244,p=0.044).Decreased nHF(β=0.245,P=0.027)and higher body mass index(BMI)(β=-0.224,P=0.043)were independently related to and poorer SE.Conclusions:Poor sleep behaviors were associated with decreased parasympathetic activity,a physiological change to psychological stress,rather than with psychological stress itself among college students.Thus,sAA and HRV should be considered as significant factors for impaired sleep behaviors in relation to psychological stress.

In vitro inhibition activity of polyphenol-rich extracts from Syzygium aromaticum(L.)Merr.& Perry(Clove)buds against carbohydrate hydrolyzing enzymes linked to type 2 diabetes and Fe^(2+)-induced lipid peroxidation in rat pancreas

Objective:To investigate and compare the inhibitor)'properties)of free and bound phenolic extracts of clove bud against carbohydrate hydrolyzing enzymes(alpha-amylase&alphaglucosidase)and Fe^(2+)-induced lipid peroxidation in rat pancreas in vitro.Methods:The free phenolics were extracted with 80%.(v/v)acetone,while bound phenolics were extracted from the alkaline and acid hydrolyzed residue with ethyl acetate.Then,the interaction of the extracts with alpha-amylase and alpha-glucosidase was subsequently assessed.Thereafter,the total phenolic contents and antioxidant activities of the extracts were determined.Results:The result revealed that both extracts inhibited alpha-amylase and alpha-glucosidase in a dose-dependent manner.However,the alpha-glucosidase inhibitory activity of the extracts were significantly(P<0.05)higher than their alpha-amylase inhibitory activity.The free phenolics(31.67 mg/g)and flavonoid(17.28 mg/g)contents were significantly(P<0.05)higher than bound phenolic(23.52 mg/g)and flavonoid(13.70 mg/g)contents.Both extracts also exhibited high antioxidant activities as typified by their high reducing power,LI diphenyl-2-picrylhydrazyl(DPPH)and 2,2-azinobis-3-ethylbenzo-thiazoline-6-sulfonate(ABTS)radical scavenging abilities,as well as inhibition of Fe^(2+)-induced lipid peroxidation in rat pancreas in vitro.Conclusions:This study provides a biochemical rationale by which clove elicits therapeutic effect on type 2 diabetes.

Tylophora hirsuta L. leaf extract attenuates alloxan-induced diabetes in mice by suppressing oxidative stress and α-amylase

Objective:To evaluate the antidiabetic potential of leaf extracts of Tylophora hirsuta(T.hirsuta).Methods:The methanolic and ethyl acetate extracts of T.hirsuta leaves were analyzed by high pressure liquid chromatography.In vitro antioxidant activity was determined by ferric ion reduction,1,1-diphenyl-2-picrylhydrazyl,and hydrogen peroxide scavenging methods.In vitro alpha amylase(α-amylase)inhibitory activity of the plant extracts was assessed.In vivo antidiabetic potential was determined in alloxan-induced diabetic mice to assess glycated hemoglobin(HbA1c),oral glucose tolerance,serum amylase,lipid profile,fasting blood glucose,and body weight.Histopathological lesions of the pancreas,liver and kidney were observed.Oxidative stress biomarkers such as superoxide dismutase,catalase and peroxidase were also determined.Results:Quercetin,chlorogenic acid,p-coumaric acid,and m-coumaric acid were found in the plant extracts.The methanolic plant extract exhibited higher in vitro antioxidant activities than the ethyl acetate extract.Moreover,methanolic plant extract exhibited(83.90±1.56)%α-amylase inhibitory activity at 3.2 mg/mL concentration.Animal study showed that the methanolic extract of T.hirsuta improved the levels of fasting blood glucose,HbA1c,serumα-amylase,lipid profile,liver function biomarkers,and kidney functions of diabetic mice.Moreover,the methanolic extract ameliorated diabetes-related oxidative stress by increasing superoxide dismutase and catalase activities and decreasing peroxidase and malondialdehyde levels.Histopathological examination showed that the plant extract had improved the integrity of pancreatic islets of Langerhans and reduced the pathological lesions in the liver and kidney of diabetic mice.Conclusions:The methanolic extract of T.hirsuta exhibits pronounced antidiabetic activity in mice through reduction of oxidative stress.The plant extract has several natural antioxidants such as phenolic acids.T.hirsuta extract could serve as a nutraceutical for managing diabetes mellitus.

Optimum Conditions for Bioethanol Production from Potato of Bangladesh

Bangladesh produces a huge amount of potatoes every year. This research was carried out to find the optimum conditions for bioethanol production from potato of Bangladesh. From this study, optimum growth of yeast (Saccharomyces cerevisiae CCD) was observed at pH 6.0 and temperature 31°C. Addition of a small amount of alpha-amylase enzyme to potato solution was found to enhance the potato starch degradation and made the fermentation process quicker. This study observed that 1750 unit alpha-amylase is enough to degrade the starch in 15% of 500 ml potato starch solution. From fermentation time study, 6-day incubation time was found to be enough to complete the fermentation process and optimum production of bioethanol form potato starch. Suitable concentration of potato in fermentation process was determined using five different potato solutions (5%, 10%, 15%, 20% and 30%). A highest production of bioethanol was found in ?20% potato treatment. Therefore, 20% potato solution is recommended for high-scale production of bioethanol from potato starch.

Potential of fungal thermostable alpha amylase enzyme isolated from Hot springs of Central Anatolia(Turkey)in wheat bread quality

Many industrial processes may quickly proceed with biotechnological and enzymatic support.Functional and production facilitator properties of enzymes have provided variable advantages for industry.Therefore,enzyme utilization has become inevitable for industry and supplied financial advantages in case of the high energy requirement process.In the study,the amylase enzymes were isolated from thermal spring sources,and the effect on bread quality was examined.Firstly,fungal amylases were isolated from thermal spring sources(29-98◦C)in various places around Turkey.After determining the functional properties of amylase enzymes,the most active enzyme was used in bread production to examine their effect on bread quality.The maximum alpha-amylase activity(38.6 U/mg)has been detected in Aspergillus niger G 2-1 isolate.When compared with the commercially available one,native alpha-amylase increased the bread volume.A significant difference(p<0.01)was found in the color properties and size of the bread between microbial produced in this study and commercially produced alpha-amylase.Five ppm alpha-amylase addition showed the optimum bread properties for dough processing.

Phytochemical analysis and inhibitory effects of Calligonum polygonoides on pancreatic α-amylase and β-glucosidase enzymes

OBJECTIVES:To estimate the existence of phytochemicals and then to determine the antidiabetic activity againstα-amylase andβ-glucosidase inhibition in vitro.METHODS:The study was carried out by following standard procedures.RESULTS:Phytochemicals analysis indicated the presence of different phytochemicals.The total phenolic content was 6.055 mg GAE/g and the total flavonoid content was 5.706 mg RU/g in the plant extract.The total saponins,alkaloids,and tannins contents were(0.044%),(2.88%)and(2.862 nm)respectively.α-amylase inhibition activity of Calligonum polygonoides(CP)extract was 70%with IC50 of 610μg/mL and that ofβ-glucosidase inhibition activity was 65%with IC50 of 640μg/mL.CONCLUSION:The findings reported for the first time the antidiabetes-promoting effects of an extract of CP in vitro,thus validating their promising anti-diabetes potential.