Dataset Information

Postprandial Hyperglycemia Lowering Effect of the Isolated Compounds from Olive Mill Wastes - An Inhibitory Activity and Kinetics Studies on ?-Glucosidase and ?-Amylase Enzymes.

ABSTRACT: In the present study, we isolated seven compounds from olive mill wastes (OMW), one of them being novel, and investigated their antidiabetic potential through inhibition of ?-glucosidase and ?-amylase enzymes. To assist the possible characterization of the mechanisms involved, we analyzed the inhibitory kinetics of the active compounds. Oleanolic acid 1, maslinic acid 2, 1-acetoxypinoresinol 3, and luteolin-7-O-?-d-glucoside 6 exhibited stronger inhibitory activity against both enzymes, with IC50 values less than or close to that of acarbose. Other compounds pinoresinol and hydroxytyrosol-containing compounds (hydroxytyrosol acetate 4, hydroxytyrosol 7, and the novel one, 3,4-dihydroxyphenyl-2-methoxyethanol 5) showed weak activity against both enzymes (IC50 > 500 ?M). Our findings show that, first, the esterification of C-1 of the furofuran ring is the key feature for the stronger activity of 1-acetoxypinoresinol 3 against both enzymes (IC50 = 13.9 and 313 ?M for ?-amylase and ?-glucosidase, respectively), as compared to pinoresinol; second, the oleanane skeletons of the triterpenes (1 and 2) are optimum for the ?-glucosidase and ?-amylase inhibitory activities, while the hydroxytyrosol moiety may be responsible for the weak activities of 4, 5, and 7. Additionally, kinetics analysis of 1, 6, and 3 revealed that they inhibit ?-glucosidase in mixed-type, noncompetitive, and uncompetitive mechanisms, respectively. We confirmed their mechanisms by measuring their affinity for the enzyme (K i), and they all (1, 6, and 3) had a higher affinity for the enzyme, K i > 1. This work adds more value to OMW for further studies as a potential source of lead antidiabetic compounds for the prevention and/or treatment of type 2 diabetes.

SUBMITTER: Mwakalukwa R

PROVIDER: S-EPMC7439263 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Postprandial Hyperglycemia Lowering Effect of the Isolated Compounds from Olive Mill Wastes - An Inhibitory Activity and Kinetics Studies on α-Glucosidase and α-Amylase Enzymes.

Mwakalukwa Rogers R Amen Yhiya Y Nagata Maki M Shimizu Kuniyoshi K

ACS omega 20200807 32

In the present study, we isolated seven compounds from olive mill wastes (OMW), one of them being novel, and investigated their antidiabetic potential through inhibition of α-glucosidase and α-amylase enzymes. To assist the possible characterization of the mechanisms involved, we analyzed the inhibitory kinetics of the active compounds. Oleanolic acid 1, maslinic acid 2, 1-acetoxypinoresinol 3, and luteolin-7-O-β-d-glucoside 6 exhibited stronger inhibitory acti ...[more]

PMID: 32832761

Similar Datasets

Project description:Compounds from Zanthoxylum chalybeum Engl. were previously reported for inhibitory activities of amylase and glucosidase enzymatic action on starch as a preliminary study toward the establishment of a management strategy against postprandial hyperglycemia, however, the inhibitory kinetics and molecular interaction of these compounds were never established. A study was thus designed to establish the inhibitory kinetics and in silico molecular interaction of α-glucosidase and α-amylase with Z. chalybeum metabolites based on Lineweaver-Burk/Dixon plot analyses and using Molecular Operating Environment (MOE) software, respectively. Skimmianine (5), Norchelerythrine (6), 6-Acetonyldihydrochelerythrine (7), and 6-Hydroxy-N-methyldecarine (8) alkaloids showed mixed inhibition against both α-glucosidase and α-amylase with comparable Ki to the reference acarbose (p > 0.05) on amylase but significantly higher activity than acarbose on α-glucosidase. One phenolic 2,3-Epoxy-6,7-methylenedioxyconiferol (10) showed a competitive mode of inhibition both on amylase and glucosidase which were comparable (p > 0.05) to the activity of acarbose. The other compounds analyzed and displayed varied modes of inhibition between noncompetitive and uncompetitive with moderate inhibition constants included chaylbemide A (1), chalybeate B (2) and chalybemide C (3), fagaramide (4), ailanthoidol (9), and sesame (11). The important residues of the proteins α-glucosidase and α-amylase were found to have exceptional binding affinities and significant interactions through molecular docking studies. The binding affinities were observed in the range of -9.4 to -13.8 and -8.0 to -12.6 relative to the acarbose affinities at -17.6 and -20.5 kcal/mol on α-amylase and α-glucosidase residue, respectively. H-bonding, π-H, and ionic interactions were noted on variable amino acid residues on both enzymes. The study thus provides the basic information validating the application of extracts of Z. chalybeum in the management of postprandial hyperglycemia. Additionally, the molecular binding mechanism discovered in this study could be useful for optimizing and designing new molecular analogs as pharmacological agents against diabetes.

Project description:The fruits of Canarium tramdenum are commonly used as foods and cooking ingredients in Vietnam, Laos, and the southeast region of China, whilst the leaves are traditionally used for treating diarrhea and rheumatism. This study was conducted to investigate the potential use of this plant bark as antioxidants, and α-amylase and α-glucosidase inhibitors. Five different extracts of C. tramdenum bark (TDB) consisting of the extract (TDBS) and factional extracts hexane (TDBH), ethyl acetate (TDBE), butanol (TDBB), and water (TDBW) were evaluated. The TDBS extract contained the highest amount of total phenolic (112.14 mg gallic acid equivalent per g dry weight), while the TDBB extract had the most effective antioxidant capacity compared to other extracts. Its IC50 values were 12.33, 47.87, 33.25, and 103.74 µg/mL in 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (ABTS), reducing power (RP), and nitric oxide (NO) assays, respectively. Meanwhile, the lipid peroxidation inhibition of the four above extracts was proximate to that of butylated hydroxytoluene (BHT) as a standard antioxidant. The result of porcine pancreatic α-amylase inhibition showed that TDB extracts have promising effects which are in line with the commercial diabetic inhibitor acarbose. Interestingly, the inhibitory ability on α-glucosidase of all the extracts was higher than that of acarbose. Among the extracts, the TDBB extract expressed the strongest activity on the enzymatic reaction (IC50 = 18.93 µg/mL) followed by the TDBW extract (IC50 = 25.27 µg/mL), TDBS (IC50 = 28.17 µg/mL), and TDBE extract (IC50 = 141.37 µg/mL). The phytochemical constituents of the TDB extract were identified by gas chromatography⁻mass spectrometry (GC-MS). The principal constituents included nine phenolics, eight terpenoids, two steroids, and five compounds belonging to other chemical classes, which were the first reported in this plant. Among them, the presence of α- and β-amyrins were identified by GC-MS and appeared as the most dominant constituents in TDB extracts (1.52 mg/g). The results of this study revealed that C. tramdenum bark possessed rich phenolics and terpenoids, which might confer on reducing risks from diabetes. A high quantity of α- and β-amyrins highlighted the potentials of anti-inflammatory, anti-ulcer, anti-hyperlipidemic, anti-tumor, and hepatoprotective properties of C. tramdenum bark.

Dataset Information

Postprandial Hyperglycemia Lowering Effect of the Isolated Compounds from Olive Mill Wastes - An Inhibitory Activity and Kinetics Studies on ?-Glucosidase and ?-Amylase Enzymes.

Publications

Postprandial Hyperglycemia Lowering Effect of the Isolated Compounds from Olive Mill Wastes - An Inhibitory Activity and Kinetics Studies on α-Glucosidase and α-Amylase Enzymes.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets