α-amylase is an endonucleoside hydrolase that hydrolyzes the α-1, 4-glycosidic bonds inside polysaccharides, such as starch, to generate oligosaccharides, dextrins, maltotriose, maltose and a small amount of glucose. Due to the importance of α-amylase in food industry, human health monitoring and pharmaceuticals, detection of its activity is widely required in the breeding of α-amylase producing strains, in vitro diagnosis, development of diabetes drugs, and the control of food quality. In recent years, many new α-amylase detection methods have been developed with improved speed and sensitivity. This review summarized recent processes in the development and applications of new α-amylase detection methods. The major principle of these detection methods were introduced, and their advantages and disadvantages were compared to facilitate future development and applications of α-amylase detection methods.
Humans ; alpha-Amylases/chemistry* ; Polysaccharides ; Oligosaccharides ; Starch ; Maltose

Glucocorticoids/urine* ; Humans ; Hydrocortisone ; Marathon Running ; Saliva/chemistry* ; alpha-Amylases/analysis*

Seed vigor is a key factor affecting seed quality. The mechanical drying process exerts a significant influence on rice seed vigor. The initial moisture content (IMC) and drying temperature are considered the main factors affecting rice seed vigor through mechanical drying. This study aimed to determine the optimum drying temperature for rice seeds according to the IMC, and elucidate the mechanisms mediating the effects of drying temperature and IMC on seed vigor. Rice seeds with three different IMCs (20%, 25%, and 30%) were dried to the target moisture content (14%) at four different drying temperatures. The results showed that the drying temperature and IMC had significant effects on the drying performance and vigor of the rice seeds. The upper limits of drying temperature for rice seeds with 20%, 25%, and 30% IMCs were 45, 42, and 38 °C, respectively. The drying rate and seed temperature increased significantly with increasing drying temperature. The drying temperature, drying rate, and seed temperature showed extremely significant negative correlations with germination energy (GE), germination rate, germination index (GI), and vigor index (VI). A high IMC and drying temperature probably induced a massive accumulation of hydrogen peroxide (H₂O₂) and superoxide anions in the seeds, enhanced superoxide dismutase (SOD) and catalase (CAT) activity, and increased the abscisic acid (ABA) content. In the early stage of seed germination, the IMC and drying temperature regulated seed germination through the metabolism of H₂O₂, gibberellin acid (GA), ABA, and α-amylase. These results indicate that the metabolism of reactive oxygen species (ROS), antioxidant enzymes, GA, ABA, and α-amylase might be involved in the mediation of the effects of drying temperature on seed vigor. The results of this study provide a theoretical basis and technical guidance for the mechanical drying of rice seeds.
Abscisic Acid/metabolism* ; Antioxidants/pharmacology* ; Catalase/metabolism* ; Gene Expression Regulation, Plant/drug effects* ; Germination ; Gibberellins/metabolism* ; Hydrogen Peroxide/chemistry* ; Malondialdehyde/chemistry* ; Oryza/metabolism* ; Oxygen/chemistry* ; Plant Proteins/genetics* ; Reactive Oxygen Species ; Seeds/metabolism* ; Superoxide Dismutase/metabolism* ; Superoxides/chemistry* ; Temperature ; Weather ; alpha-Amylases/metabolism*

OBJECTIVEThe current study was designed to evaluate the various antioxidant potentials and inhibitory effects of phenolic-rich leaf extracts of Bridelia ferruginea (BF) on the in vitro activities of some key enzymes involved in the metabolism of carbohydrates.

METHODSIn this study, BF leaf free and bound phenolic-rich extracts were used. We quantified total phenolic and flavonoid contents, and evaluated several antioxidant activities using assays for ferric reducing antioxidant power, total antioxidant activity (phosphomolybdenum reducing ability), 1,1-diphenyl-2-picrylhydrazyl and thiobarbituric acid reactive species. Also, extracts were tested for their ability to inhibit α-amylase and α-glucosidase activity.

RESULTSThe total phenolic and total flavonoid contents in the free phenolic extract of BF were significantly greater than in the bound phenolic extract. Also, all the antioxidant activities considered were significantly greater in the free phenolic extract than in the bound phenolic extract. In the same vein, the free phenolic-rich extract had a significantly higher percentage inhibition against α-glucosidase activity (IC = 28.5 µg/mL) than the bound phenolic extract (IC = 340.0 µg/mL). On the contrary, the free phenolic extract (IC = 210.0 µg/mL) had significantly lower inhibition against α-amylase than the bound phenolic-rich extract (IC = 190.0 µg/mL).

CONCLUSIONThe phenolic-rich extracts of BF leaves showed antioxidant potentials and inhibited two key carbohydrate-metabolizing enzymes in vitro.

Animals ; Antioxidants ; chemistry ; pharmacology ; Diabetes Mellitus, Type 2 ; enzymology ; metabolism ; Enzyme Inhibitors ; chemistry ; pharmacology ; Glycoside Hydrolase Inhibitors ; chemistry ; pharmacology ; Humans ; Iron ; adverse effects ; Magnoliopsida ; chemistry ; Oxidative Stress ; drug effects ; Pancreas ; drug effects ; enzymology ; metabolism ; Phenols ; chemistry ; pharmacology ; Plant Extracts ; chemistry ; pharmacology ; Rats ; Swine ; alpha-Amylases ; antagonists & inhibitors ; chemistry ; alpha-Glucosidases ; chemistry

BACKGROUND: Wood is a valuable material for interiors, and the psychophysiological relaxation effects of volatile organic compounds (VOCs) from wood chips and essential oils have been reported. However, few studies have identified the odors in full-scale wooden environment, and also, differences in gender have not been clarified. In this study, we aimed to confirm the effects of VOCs emitted from interior wood walls in both human male and female participants. METHODS: We used Japanese cedar timber and analyzed VOCs in the experimental rooms with and without Japanese cedar timber by gas chromatography-mass spectrometry (GC-MS). The physiological effects were measured using neuroendocrinological and immunological parameters in saliva. A questionnaire was used to evaluate the subjective responses to each odor in the experimental rooms. RESULTS: The main compound emitted from Japanese cedar timber was δ-cadinene, and the total volume of VOCs in the wood condition (presence of VOCs emitted from Japanese cedar) was 282.4 (μg/m). Significant differences between genders in salivary parameters were shown that there were decreases of α-amylase in wood condition and increases of cortisol in the control (absence of VOCs) condition in female participants compared to male participants. The results demonstrated that VOCs in the experimental room with Japanese cedar timber tend to suppress the activation of the sympathetic nervous activity and non-VOCs of Japanese cedar in the control room increase cortisol in female participants. CONCLUSIONS These results suggest that an indoor environment with wood interior materials has the potential to be useful for health management, especially women's health.
Adult ; Air Pollutants ; analysis ; Air Pollution, Indoor ; adverse effects ; analysis ; Cryptomeria ; chemistry ; Female ; Gas Chromatography-Mass Spectrometry ; Humans ; Hydrocortisone ; metabolism ; Male ; Saliva ; chemistry ; Salivary alpha-Amylases ; metabolism ; Sesquiterpenes ; analysis ; Sex Factors ; Volatile Organic Compounds ; adverse effects ; Wood ; chemistry ; Young Adult

The present study was designed to characterize the polyphenols isolated from Acacia mearnsii bark crude extract (B) and fractions (B1-B7) obtained by high-speed counter-current chromatography (HSCCC) and evaluate their anti-inflammatory and carbolytic enzymes (α-glucosidase and α-amylase) inhibitory activities. Fractions B4, B5, B6, B7 (total phenolics 850.3, 983.0, 843.9, and 572.5 mg·g, respectively; proanthocyanidins 75.7, 90.5, 95.0, and 44.8 mg·g, respectively) showed significant activities against reactive oxygen species (ROS), nitric oxide (NO) production, and expression of pro-inflammatory genes interleukin-1β (IL-1β) and inducible nitric oxide synthase (iNOS) in a lipopolysaccharide (LPS)-stimulated mouse macrophage cell line RAW 264.7. All the extracts suppressed α-glucosidase and α-amylase activities, two primary enzymes responsible for carbohydrate digestion. A. mearnsii bark samples possessed significantly stronger inhibitory effects against α-glucosidase enzyme (IC of 0.4-1.4 μg·mL) than the pharmaceutical acarbose (IC 141.8 μg·mL). B6 and B7 (IC 17.6 and 11.7 μg·mL, respectively) exhibited α-amylase inhibitory activity as efficacious as acarbose (IC 15.4 μg·mL). Moreover, B extract, at 25 µg·mL, significantly decreased the non-mitochondrial oxidative burst that is often associated with inflammatory response in human monocytic macrophages.
Acacia ; chemistry ; Animals ; Anti-Inflammatory Agents ; isolation & purification ; pharmacology ; Carbohydrate Metabolism ; drug effects ; Glycoside Hydrolase Inhibitors ; pharmacology ; Inflammation ; metabolism ; Interleukin-1beta ; metabolism ; Lipopolysaccharides ; Macrophages ; drug effects ; Mice ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type II ; metabolism ; Plant Bark ; chemistry ; Plant Extracts ; chemistry ; pharmacology ; Polyphenols ; isolation & purification ; pharmacology ; Proanthocyanidins ; pharmacology ; RAW 264.7 Cells ; alpha-Amylases ; antagonists & inhibitors ; alpha-Glucosidases ; metabolism

OBJECTIVE: To evaluate the therapeutic effects of recombinant Exendin-4 and double-stranded adeno-associated virus (Exendin-4/dsAAV) on SD rats with type 2 diabetes (T2DM) through injecting it into submandibular gland (SG).
 METHODS: The Exendin-4/dsAAV was injected into submandibular gland of diabetic rat. The insulin and α-amylase were detected by real-time PCR at the 2nd, 4th and 8th weeks. The immunohistochemisty was used to detect the insulin contents in SG at the 8th week. The concentration of blood glucose and levels of insulin secretion were detected after pancreatectomy.
 RESULTS: The SG gland was bigger in Exendin-4/dsAAV group than that in the control group, but the changes in α-amylase were not significant. The Exendin-4 and insulin gene expression was increased in the Exendin-4/dsAAV group (P<0.05). The Exendin-4 and insulin were positive in the SG. The blood glucose was lower and insulin concentration was higher in the Exendin-4/dsAAV group than those in the control group after pancreatectomy (P<0.05), and the insulin content was also increased in the dsAAV groups.
 CONCLUSION Continuous expression of Exendin-4 in SG may improve glucose control and insulin secretion in T2DM rats through inducing expression of insulin.
Animals ; Blood Glucose ; analysis ; Dependovirus ; Diabetes Mellitus, Experimental ; therapy ; Diabetes Mellitus, Type 2 ; therapy ; Exenatide ; Genetic Therapy ; Injections ; Insulin ; chemistry ; Peptides ; genetics ; therapeutic use ; Rats ; Rats, Sprague-Dawley ; Real-Time Polymerase Chain Reaction ; Recombinant Proteins ; genetics ; therapeutic use ; Submandibular Gland ; chemistry ; Venoms ; genetics ; therapeutic use ; alpha-Amylases ; chemistry

The inclusion complex of isotretinoin was prepared by sealed-control temperature method and amylose was used as carrier. The formation of inclusion complex was confirmed by powder X-ray diffraction and DSC. The equation of enzymatically-controlled drug release was established by kinetic theory, and the release characteristic of drug was confirmed by using the kinetic equation. The results show that the drug release was attributed to first order reaction without alpha-amylase. However, with alpha-amylase, the drug release was an acceleration process by the effect of both dissociation and enzymatic hydrolysis simultaneously. The research indicates that drug release from the inclusion complex was modulated by the addition of alpha-amylase.
Amylose ; chemistry ; Calorimetry, Differential Scanning ; Dermatologic Agents ; chemistry ; Drug Carriers ; chemistry ; Hydrolysis ; Isotretinoin ; chemistry ; Kinetics ; Temperature ; X-Ray Diffraction ; alpha-Amylases ; chemistry

OBJECTIVETo evaluate the stress level during parachuting training by salivary biomarker and to study the dynamic characteristics.

METHODSTwenty recruits of military parachuting training completed 8 trainings in a month. The saliva samples were collected at 2 h and 1h before boarding and at 0.5 h after landing on the 1st, 4th and 7th trainings. The levels of cortisol, chromogranin A and &alpha;-amylase in saliva samples were detected.

RESULTSThe concentrations of cortisol, chromogranin A and activity of &alpha;-amylase increased significantly from pre-boarding to landing during 3 trainings. The concentrations of cortisol, chromogranin A and activity of &alpha;-amylase at 2 h before boarding and at 0.5 h after landing decreased significantly with the training times. However, the changes of 3 biomarkers at 1 h before boarding among 3 trainings were not significant.

CONCLUSIONThe levels of stress increased significantly for 20 recruits from pre-boarding to landing during parachuting trainings. The stress levels of 20 recruits before boarding and after landing significantly decreased with parachuting training times.

Aviation ; Biomarkers ; analysis ; Chromogranin A ; analysis ; Humans ; Hydrocortisone ; analysis ; Male ; Saliva ; chemistry ; Stress, Psychological ; Young Adult ; alpha-Amylases ; analysis

OBJECTIVETo investigate and compare the inhibitory properties of free and bound phenolic extracts of clove bud against carbohydrate hydrolyzing enzymes (alpha-amylase & alpha-glucosidase) and Fe(2+)-induced lipid peroxidation in rat pancreas in vitro.

METHODSThe 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.

RESULTSThe 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, 1,1 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.

CONCLUSIONSThis study provides a biochemical rationale by which clove elicits therapeutic effect on type 2 diabetes.

Animals ; Antioxidants ; chemistry ; Carbohydrate Metabolism ; drug effects ; Diabetes Mellitus, Type 2 ; metabolism ; Dose-Response Relationship, Drug ; Enzyme Inhibitors ; chemistry ; pharmacology ; Ferrous Compounds ; pharmacology ; Flavonoids ; chemistry ; Glycoside Hydrolase Inhibitors ; chemistry ; pharmacology ; Inhibitory Concentration 50 ; Lipid Peroxidation ; drug effects ; Pancreas ; drug effects ; metabolism ; Phenols ; chemistry ; Plant Extracts ; chemistry ; pharmacology ; Polyphenols ; chemistry ; pharmacology ; Rats ; Syzygium ; chemistry ; alpha-Amylases ; antagonists & inhibitors ; alpha-Glucosidases