Evaluation of trans-cinnamaldehyde as an anti-hyperglycemic compound through inhibition of ?- amylase

The present study aims to evaluate the effectiveness of Cinnamon (Cinnamomum verum) derive bioactive compound viz.trans-cinnamaldehyde, cinnamyl alcohol, and cinnamic acid on inhibition of Bacillus licheniformis ?-amylase (BLA) and pancreatic porcine ?-amylase (PPA) activity. The inhibition extent of each of the compounds was determined along with their inhibition kinetics and compared with standard inhibitor-acarbose (Synthetic anti-diabetic agent). The IC50 values for trans-cinnamaldehyde with respect to BLA and PPAwere observed to 5.38 ?g mL?1 and 3.76 ?g mL?1, respectively. The IC50 value of acarbose was estimated to be 6.2 ?g mL?1 for both the amylases. The maximum percent enzyme inhibition of 75.8 (at 10.75 µg mL?1) and 71.6 (5.38 µg mL?1) were observed in case of BLA and PPA, respectively, using trans-cinnamaldehyde. Cinnamyl alcohol and cinnamic acid on the other hand were observed to show no specific inhibitory effect on the both the ?-amylases even at high concentrations. Catalytic efficiency (Vmax/Km) of both the amylases was observed to decrease significantly in presence of trans-cinnamaldehyde compared to acarbose. Overall, trans-cinnamaldehyde was observed as a better inhibitor of ?-amylase compared to known synthetic inhibitor-acarbose. Thus, trans-cinnamaldehyde could effectively be used for controlling hyperglycemia and diabetes mellitus.

Isolation and activity of an α-amylase inhibitor from white kidney beans / 药学学报

An α-amylase inhibitor (α-AI) was isolated from white kidney beans (Phaseolus vulgaris. L) by ethanol fractional precipitation, ion exchange chromatography and gel filtration column chromatography. It was a homogeneity glycoprotein demonstrated by SDS-PAGE and gel filtration on CL-6B. The glycoprotein contained 88.2% protein and was rich in aspartic acid, glutamic acid, leucine, threonine and serine. The carbohydrate moiety was consisted of Man, Glc, Gal and Xyl in a mole ratio of 2.42∶1.50∶1.52∶1.00. The glycan and the core protein backbone was connected by O-linkage as determined by β-elimination reaction. The continuous oral administration of the α-AI (150 mg·kg-1·d-1 ) for 7 days can lower fasting blood glucose and 300 mg·kg-1 ·d-1 α-AI for 7 days can improve the sugar tolerance on alloxan-dependent diabetic model rats. The result showed the α-AI obtained from white kidney beans had good hypoglycemic effect on alloxan induced diabetic rats and may have high potential pharmaceutical value as a regulative digestive-starch degradation in patients suffering from diabetes.

Atividade inibidora de amilase e protease de milho contra Fusarium verticillioides durante a germinação / Amylase and protease inhibition activity against Fusarium verticillioides in corn germination

Fusarium verticillioides, patógeno primário do milho, destaca-se pela produção da fumonisina, prejudicial à saúde humana e animal. Considerando que os mecanismos naturais de defesa são ferramentas promissoras no controle de fitopatógenos, avaliou-se: a atividade dos inibidores de amilase e protease presente nos híbridos de milho AG 5011 e CD 307 durante a germinação em câmara de germinação (25°C e 90-95 UR) e em casa de vegetação (sem controle de temperatura e umidade) contra amilase e protease de F. verticillioides. Paralelamente, avaliada nos tempos 0, 24, 48, 72, 96 e 168 h, aumentou durante a germinação em ambos os híbridos, sendo que a atividade inibidora de amilase variou de 2,8 a 39,5 UIA/g, enquanto que a tividade inibidora de protease variou de 550,0 a 3633,9 UIP/g. Os maiores índices de atividade inibidora foram observados em câmara de germinação, e em CD 307. O híbrido AG 5011 apresentou-se menos susceptível a S. zeamais e tendeu a maior atividade inibidora de enzimas no tempo 0 h. Os resultados obtidos indicaram possível desempenho de inibidores enzimáticos na germinação na defesa do milho contra F. verticillioides e S. zeamais.

The primary maize pathogen, Fusarium verticillioides (F. moniliforme Sheldon) is responsible forfumonisin production, which is harmful to human and animal health. In addition, maize can be moresusceptible to fungal infection after insect attack. The activity of amylase and protease inhibitors in AG5011 and CD 307 hybrids were determined during germination with controlled and not controlled conditions of temperature and relative humidity and, they were correlated to maize resistance against Sithophiluszeamais. The inhibitory activity during corn germination was evaluated at 0, 24, 48, 72, 96 and 168 h.Amylase and protease inhibitory activity increased during germination in both hybrids, which rangedrespectively from 2.8 to 39.5 UIA/g, and 550.0 to 3633.9 UIP/g. The highest levels of inhibitory activityoccurred in hybrid CD 307 in germination chamber. The biologic cycle and susceptible rate were evaluatedfor corn resistance test. The AG 5011 hybrid was less susceptible to S. zeamais and showed higherinhibitory activity (time 0 h), demonstrating possible relationship between resistance against the insectand inhibitory enzymes. These results indicated that maize natural defense mechanism plays an importantrole on phytopathogen control

Purification and properties of an α-amylase inhibitor specific for human pancreatic amylase from proso (Panicium miliaceum) seeds.

An α-amylase inhibitor was purified to homogeneity by acid extraction, ammonium sulphate fractionation, chromatography on carboxymethyl-cellulose, diethylaminoethylcellulose and Sephadex G-100 from proso grains (Panicium miliaceum). The calculated molecular weight was 14000. The inhibitor was fairly heat stable and stable under acidic and neutral conditions. The factor was more effective by two orders of magnitude in its action on human pancreatic amylase than on human salivary amylase. It did not inhibit on A. oryzae, B. subtilis and porcine pancreatic amylases. Pepsin rapidly inactivated the inhibitor. Chemical modification studies revealed that amino and guanido groups are essential for the action of the inhibitor. The inhibitor was found to protect both human salivary and pancreatic amylases against inactivation by acid. The mode of inhibition was found to be uncompetitive.

Proteases in germinating finger millet (Eleusine coracana) seeds.

Proteolytic activity was estimated in germinated finger millet seedlings using the endogenous trypsin/amylase inhibitor as substrate and also with haemoglobin and albumin as substrates. The maximal proteolytic activity was observed on the third day of germination. With the inhibitor as substrate, the proteolytic activity was maximal at pH 2.5. The protease that acted on the inhibitor required sulphydryl groups for maximal activity and was suppressed by diazoacetyl norleucine methyl ester and Pepstatin. The protease that acted on haemoglobin with optimum pH of 5.0, was more stable on storage, did not depend on sulphydryl groups for activity and was unaffected by reagents that react with carboxyl groups.