Blocking alpha-amylase is an appealing strategy for developing effective antidiabetic drugs without side effects. Natural proteinaceous inhibitors have been identified from bacteria, plants and animals sources that can effectively inhibit mammalian a-amylase activity through substrate mimicry or tight protein binding; one well-studied example is found within Phaseolus vulgaris’ common bean Phaseolus vulgaris belonging to knottin family that shares homology with phytohemagglutinin (a-AI1).
Inhibitory peptides
Inhibitory peptides are bioactive molecules used to block alpha-amylase. They can be produced via enzymatic hydrolysis of food proteins under specific conditions, including ideal temperature, pH levels, E/S ratio and reaction time. Furthermore, inhibitory peptides have proven their efficacy at lowering high blood pressure by stopping the production of angiotensin-I-converting enzyme (ACE).
Researchers identified LSGYGP peptide as an ACE-inhibiting peptide with significant antihypertensive properties in vivo. As a mixed noncompetitive inhibitor it proved more effective than captopril in terms of ACE inhibition; additionally it demonstrated excellent digestive stability without showing cytotoxicity even at higher doses.
Peptides extracted from marine organisms contain many bioactive properties, including stimulating apoptosis, increasing tubulin-microtubule balance and blocking angiogenesis. They also possess many antimicrobial and antioxidant properties as well as being capable of transporting various drugs, liposomes, or nanoparticles into cells; making them an attractive alternative to traditional medications.
Plant extracts
Plant extracts play an integral part in the cosmetics industry. Not only are they an abundant source of natural antioxidants to combat oxidative stress in cells, but they can also provide anti-inflammatory and antibacterial benefits that provide added value to products like lotions.
Many different aqueous and organic plant extracts were examined for their ability to inhibit alpha-amylase activity, including rosemary, garlic, Lepidium sativum white been cumin coffee peel linseed green tea cinnamon extracts. All were shown to possess high free radical scavenging activity.
5g of powdered plants was mixed with 50mL of boiling deionized water for 24 hours at room temperature before being extracted with lyophilization and stored at 4degC for storage. Both aqueous and methanolic extracts from each plant were then utilized in an alpha-amylase inhibition assay; hydroalcoholic extract of Pelargonium grandiflorum and bark extract of Albizia lebbeck showed strong inhibition activity against alpha-amylase enzyme activity while the latter demonstrated strong inhibition from enzyme activation while the latter showed higher activity compared with their respective counterparts aqueous counterparts.
Natural compounds
Natural compounds play an integral part in managing diabetes mellitus therapy, acting to decrease oxidative stress in pancreatic cells that is common complication of this condition. Their antidiabetic effect comes from their ability to inhibit enzymes that break down starches into maltose and glucose; or stop action of a-glucosidase which breaks polysaccharides down into monosaccharides.
Acacia catechu, Dioscorea bulbifera and Swertia chirata plant extracts were identified as promising a-amylase inhibitors on account of their folkloric significance as well as their activity against this enzyme. An evaluation method for their inhibition activity involved using modified starch iodine assay to measure change in absorbance at 405nm and determine their ability to inhibit this assay.
Lineweaver-Burk plots of various extracts and fractions showed distinct patterns, with values being compared against that of acarbose as an inhibitor of a-amylase activity.
Chemicals
Human bodies rely heavily on complex carbohydrates as a source of energy, with salivary a-amylase enzyme breaking them down into monosaccharides for use by various body systems and stored as glycogen and triglycerides in liver, adipose tissue and plasma as the body needs them. A-amylase inhibitors are compounds that work against this enzymatic activity of a-amylase; typically composed of proteinaceous substances from legume seeds they can be divided into seven distinct types such as knottin-like type; Kunitz type; Thaumatin type; and lectin type.
These inhibitors contain peptides which bind hydrophobically with a-amylase through both hydrogen bonds, electrostatic forces, and Van der Waals interactions – including hydrogen bonds, electrostatic forces, Van der Waals interactions, aromatic residues such as phenylalanine and tryptophan that form additional interactions and help delay intestinal absorption of carbohydrates while also helping control diabetes. They may prevent degradation into monosaccharides and reduce blood glucose levels thus helping manage it better.