Alpha-amylase inhibitors from mycelium of an oyster mushroom

An Update on Dipeptidyl Peptidase-IV Inhibiting Peptides

Diabetes is a chronic metabolic disorder. According to the International Diabetes Federation, about 537 million people are living with diabetes. The two types of diabetes are type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM), among which the population affected by T2DM is relatively higher. A major reason for T2DM is that insulin stimulation is hampered due to the inactivation of incretin hormones. Dipeptidyl peptidase-IV (DPP-IV) is a serine protease that is directly involved in the inactivation of incretin hormones, e.g., glucagon-like peptide-1 (GLP-1). Therefore, the inhibition of DPP-IV can be a promising method for managing T2DM, in addition to other enzyme inhibition strategies, such as inhibition of α-amylase and α -glucosidase. Currently, about 12 different gliptin drugs are available in the market that inhibit DPP-IV in a dose-dependent manner. Instead of gliptins, 'peptides' can also be employed as an alternative and promising way to inhibit DPP-IV. Peptide inhibitors of DPP-IV have been identified from various plants and animals. Chemically synthesized peptides have also been experimented for inhibiting DPP-IV. Most peptides have been analysed by biochemical assays, whereas some in vitro assays have also been reported. Molecular docking analysis has been applied to comprehend the mechanism of inhibition. In this review, certain aspects of natural as well as synthetic peptides are described that have been proven to inhibit DPP-IV.

Metabolites extracted from microorganisms as potential inhibitors of glycosidases (α-glucosidase and α-amylase): A review

α-Glucosidase and α-amylase are the two main glycosidases that participate in the metabolism of carbohydrates. Inhibitors of these two enzymes are considered an important medical treatment for carbohydrate uptake disorders, such as diabetes and obesity. Microbes are an important source of constituents that have the potential to inhibit glycosidases and can be used as sources of new drugs and dietary supplements. For example, the α-glucosidase inhibitor acarbose, isolated from Actinoplanes sp., has played an important role in adequately controlling type 2 diabetes, but this class of marketed drugs has many drawbacks, such as poor compliance with treatment and expense. This demonstrates the need for new microorganism-derived resources, as well as novel classes of drugs with better compliance, socioeconomic benefits, and safety. This review introduces the literature on microbial sources of α-glucosidase and α-amylase inhibitors, with a focus on endophytes and marine microorganisms, over the most recent 5 years. This paper also reviews the application of glycosidase inhibitors as drugs and dietary supplements. These studies will contribute to the future development of new microorganism-derived glycosidase inhibitors.

Molecular modelling and in vitro studies of Daruharidra as a potent alpha-amylase inhibitor

The present study aims at exploring the potential of the Daruharidra plant (stem and bark) for inhibition of alpha-amylase. Aqueous and ethanolic extraction yielded the highest total phenolic content (TPC) of 101.4 and 111.8 mcg of gallic acid equivalent. Methanol and ethanol extract had Total flavonoid content (TFC) of 319.6 and 288.3 mcg of quercetin equivalent, respectively. In contrast, petroleum ether extraction resulted in the lowest TPC of 23.6 and TFC of 8.33 mcg, respectively. Methanol (5.554 mg/ml), acetone (6.576 mg/ml), and ethanol (7.321 mg/ml) extract had the lowest IC50 values in alpha-amylase inhibition with the mode of inhibition being non-competitive inhibition. HR-LCMS was used for comprehension of phytoconstituents present in the extract. Amongst hundreds of hits observed 10 ligands of alkaloid nature were used for docking studies. Berbamine, alloxanthine, protopine and benazepril along with reference molecule (Acarbose) were subjected to Molecular dynamics (MD) simulation to analyze the stability of the docked protein-ligand complex. The values of RMSD, RMSF, RG, H-Bond and SASA, the interaction energy of all protein-ligand complexes were calculated after 150 ns of MD simulation. The results of screened complexes revealed good stability as compared to reference Acarbose. These screened ligands used for simulation have the most negative binding energies that interacted with alpha amylase enzyme having -9.28 kcal/mol, -7.51 kcal/mol, -7.73 kcal/mol and -8.00 kcal/mol, energies respectively. The results show significant alpha-amylase inhibitory activity and interaction of ligands targeting this enzyme, which can be used for cross-validation, in vitroCommunicated by Ramaswamy H. Sarma.

Antidiabetic potential evaluation of aqueous extract of waste Syzygium cumini seed kernel's by in vitro α-amylase and α-glucosidase inhibition

Syzygium cumini, owing to higher bioactive constituents, its parts principally kernels are used for the antidiabetic purpose since the olden days. The current manuscript illustrated batch extraction of phenolic compounds from S. cumini using a stirred extractor. The yields 0.61 mg/g, 35.9 mg/g, 79.89 mg GAE/g, and 7.29 mg CE/g of catechin, gallic acid, TPC and TFC, respectively, were obtained in 105 min. at 1:20 SCKP to water, 50 ± 2 °C temperature, 4 pH, at 250 rpm and 106 µm particle size of SCKP. In vitro evaluation of the antioxidant and antidiabetic potential of the obtained aqueous extract was carried out by DPPH, α-amylase, and α-glucosidase inhibitory assays. The IC₅₀ values of SCKP aqueous extract obtained were 12.97, 9.03, and 7.13 µg/mL for DPPH scavenging, inhibition of α-amylase, and α-glucosidase, respectively. The cost required to extract 1 kg of catechin, gallic acid, TPC, and TFC was Rs 6691.6, 113.7, 51.1, and 559.93/-, respectively. Stirred batch extraction technique manifests traditional but simple, ecofriendly, and efficient compared to other traditional techniques. The output of this research bestows support to utilize the SCKP stirred batch extract as a promising source of antioxidant and antidiabetic compounds in ayurvedic formulations.