Evaluation of some plants for potential dipeptidyl peptidase IV inhibitory effects in vitro

2015 ◽  
Vol 40 (3) ◽  
Author(s):  
Ali Zeytünlüoğlu ◽  
Figen Zihnioğlu

AbstractObjective: Dipeptidyl peptidase IV (DPP IV) is a serine amino (exo) peptidase which regulates various processes most notably plasma glucose homeostasis by cleaving incretin peptide hormones as glucagon-like peptide-1 (GLP-1) and glucose-dependent insulin releasing polypeptide (GIP). Realization of the inhibition of this enzyme in controlling diabetes is one of the strategies adopted in recent years. The present study was designed to investigate the DPP IV inhibitory effects of sixteen plant having antidiabetic property in aqueous extracts in correlation with their protein content.Methods: In vitro DPP IV inhibition was evaluated by the specific inhibitory activity of plant aqueous extracts prepared without and with heat (60°C) treatment.Results: Among the tested plants Vitis vinifera L., Artemisia dracunculus L., Prunus laurocerasus L., Rubus caesius L. and Olea europaea L. extracts showed DPP IV inhibitory activity with respect to IC50 values of 0.04-0.09 mg protein/ml. Kinetic analysis indicated that the inhibitor potency of A. dracunculus extract was stronger than the other extracts.Conclusion: The present study is the first report on screening and preliminary characterization of DPP IV inhibitory activity in aqueous extracts of selected antidiabetic medicinal food. This study could provide a new insight into DPP IV inhibitors from plants that could be useful for treatment of Type 2 diabetes.

2019 ◽  
Vol 20 (2) ◽  
pp. 322 ◽  
Author(s):  
Yating Lu ◽  
Peng Lu ◽  
Yu Wang ◽  
Xiaodong Fang ◽  
Jianming Wu ◽  
...  

Dipeptidyl peptidase IV (DPP-IV) inhibitors occupy a growing place in the drugs used for the management of type 2 diabetes. Recently, food components, including food-derived bioactive peptides, have been suggested as sources of DPP-IV inhibitors without side effects. Chinese black tea is a traditional health beverage, and it was used for finding DPP-IV inhibitory peptides in this study. The ultra-filtrated fractions isolated from the aqueous extracts of black tea revealed DPP-IV inhibitory activity in vitro. Four peptides under 1 kDa were identified by SDS-PAGE and LC-MS/MS (Liquid Chromatography-Mass Spectrometry-Mass Spectrometry) from the ultra-filtrate. The peptide II (sequence: AGFAGDDAPR), with a molecular mass of 976 Da, showed the greatest DPP-IV inhibitory activity (in vitro) among the four peptides. After administration of peptide II (400 mg/day) for 57 days to streptozotocin (STZ)-induced hyperglycemic mice, the concentration of glucagon-like peptide-1 (GLP-1) in the blood increased from 9.85 ± 1.96 pmol/L to 19.22 ± 6.79 pmol/L, and the insulin level was increased 4.3-fold compared to that in STZ control mice. Immunohistochemistry revealed the improved function of pancreatic beta-cells and suppressed proliferation of pancreatic alpha-cells. This study provides new insight into the use of black tea as a potential resource of food-derived DPP-IV inhibitory peptides for the management of type 2 diabetes.


Nutrients ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 794 ◽  
Author(s):  
Yuchen Li ◽  
Gilda Aiello ◽  
Carlotta Bollati ◽  
Martina Bartolomei ◽  
Anna Arnoldi ◽  
...  

Arthrospira platensis (spirulina) is a cyanobacterium, which contains mainly two phycobiliproteins (PBP), i.e., C-phycocyanin (C-PC) and allophycocyanin (APC). In this study, PBP were hydrolyzed using trypsin, and the composition of the hydrolysate was characterized by HPLC-ESI-MS/MS. Furthermore, the potential anti-diabetic activity was assessed by using either biochemical or cellular techniques. Findings suggest that PBP peptides inhibit DPP-IV activity in vitro with a dose-response trend and an IC50 value falling in the range between 0.5 and 1.0 mg/mL. A lower inhibition of the DPP-IV activity expressed by Caco-2 cells was observed, which was explained by a secondary metabolic degradation exerted by the same cells.


2004 ◽  
Vol 180 (3) ◽  
pp. 379-388 ◽  
Author(s):  
BD Green ◽  
MH Mooney ◽  
VA Gault ◽  
N Irwin ◽  
CJ Bailey ◽  
...  

Glucagon-like peptide-1(7-36)amide (GLP-1) possesses several unique and beneficial effects for the potential treatment of type 2 diabetes. However, the rapid inactivation of GLP-1 by dipeptidyl peptidase IV (DPP IV) results in a short half-life in vivo (less than 2 min) hindering therapeutic development. In the present study, a novel His(7)-modified analogue of GLP-1, N-pyroglutamyl-GLP-1, as well as N-acetyl-GLP-1 were synthesised and tested for DPP IV stability and biological activity. Incubation of GLP-1 with either DPP IV or human plasma resulted in rapid degradation of native GLP-1 to GLP-1(9-36)amide, while N-acetyl-GLP-1 and N-pyroglutamyl-GLP-1 were completely resistant to degradation. N-acetyl-GLP-1 and N-pyroglutamyl-GLP-1 bound to the GLP-1 receptor but had reduced affinities (IC(50) values 32.9 and 6.7 nM, respectively) compared with native GLP-1 (IC(50) 0.37 nM). Similarly, both analogues stimulated cAMP production with EC(50) values of 16.3 and 27 nM respectively compared with GLP-1 (EC(50) 4.7 nM). However, N-acetyl-GLP-1 and N-pyroglutamyl-GLP-1 exhibited potent insulinotropic activity in vitro at 5.6 mM glucose (P<0.05 to P<0.001) similar to native GLP-1. Both analogues (25 nM/kg body weight) lowered plasma glucose and increased plasma insulin levels when administered in conjunction with glucose (18 nM/kg body weight) to adult obese diabetic (ob/ob) mice. N-pyroglutamyl-GLP-1 was substantially better at lowering plasma glucose compared with the native peptide, while N-acetyl-GLP-1 was significantly more potent at stimulating insulin secretion. These studies indicate that N-terminal modification of GLP-1 results in DPP IV-resistant and biologically potent forms of GLP-1. The particularly powerful antihyperglycaemic action of N-pyroglutamyl-GLP-1 shows potential for the treatment of type 2 diabetes.


Author(s):  
Adel Yarizade ◽  
Hsan Hasani Kumle ◽  
Ali Niazi

Objective: Diabetes mellitus (DM) causes hyperglycemia, which is one of the most common diseases in the world. One of the strategies for the treatment of diabetes is maintaining postprandial glucose level through inhibition of dipeptidyl peptidase IV (DPP-IV) and α-glucosidase enzymes. The aim of this study was to determine in vitro antidiabetic potential of Ferula assa-foetida via DPP-IV and α-glucosidase inhibitory activities.Methods: F. assa-foetida seeds were extracted in methanol, ethanol, ethanol-methanol, and water. Inhibitory activity on DPP-IV and α-glucosidase wasperformed in vitro and measured spectrophotometrically at λ=405 nm.Results: The result showed that the F. assa-foetida seed extract is effective against both enzymes. All fractions had DPP-IV inhibitory activity, but the ethanolic fraction had the highest inhibitory activity on DPP-IV enzyme and significantly decreased DPP-IV activity (24.5%). With respect to α-glucosidase inhibitory activity, the aqueous extract has the highest inhibitory activity (28%).Conclusion: According to the results of this study, F. assa-foetida contains DPP-IV and α-glucosidase inhibitors and could be a potential source for the discovery of active constituents as α-glucosidase and DPP-IV inhibitors to treat Type 2 DM.Keywords: Diabetes mellitus, Herbal medicine, Dipeptidyl peptidase IV, α-glucosidase.


2020 ◽  
Vol 131 ◽  
pp. 108989 ◽  
Author(s):  
Pádraigín A. Harnedy-Rothwell ◽  
Chris M. McLaughlin ◽  
Martina B. O'Keeffe ◽  
Aurélien V. Le Gouic ◽  
Philip J. Allsopp ◽  
...  

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Po-Kai Huang ◽  
Shian-Ren Lin ◽  
Chia-Hsiang Chang ◽  
May-Jwan Tsai ◽  
Der-Nan Lee ◽  
...  

Abstract Dipeptidyl peptidase IV (DPP IV) is a surface glycoprotein that can degrade glucagon like pepetide-1 (GLP-1) by decreasing blood sugar. Herbal medicines for diabetic therapy are widely used with acceptable efficacy but unsatisfied in advances. DPP IV was chosen as a template to employ molecular docking via Discovery Studio to search for natural phenolic compounds whether they have the inhibitory function of DPP IV. Then, docking candidates were validated and further performed signal pathway via Caco-2, C2C12, and AR42J cells. Lastly, a diet-induced diabetes in mice were applied to examine the efficacy and toxicity of hit natural phenolic products in long-term use (in vivo). After screening, curcumin, syringic acid, and resveratrol were found in high affinity with DPP IV enzymes. In enzymatic tests, curcumin and resveratrol showed potential inhibition of DPP IV. In vitro assays, curcumin inhibited of DPP IV activity in Caco-2 cells and ERK phosphorylation in C2C12 cells. Additionally, curcumin attenuated blood sugar in S961-treated C57BL/6 mice and in diet-induced diabetic ICR mice and long-term regulate HbA1c in diabetic mice. Curcumin targeted to DPP IV for reducing blood glucose, it possesses potential and alternative substitution of synthetic clinical drugs for the medication of diabetes.


2002 ◽  
Vol 172 (2) ◽  
pp. 355-362 ◽  
Author(s):  
CF Deacon ◽  
S Wamberg ◽  
P Bie ◽  
TE Hughes ◽  
JJ Holst

The incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are degraded by dipeptidyl peptidase IV (DPP IV), thereby losing insulinotropic activity. DPP IV inhibition reduces exogenous GLP-1 degradation, but the extent of endogenous incretin protection has not been fully assessed, largely because suitable assays which distinguish between intact and degraded peptides have been unavailable. Using newly developed assays for intact GLP-1 and GIP, the effect of DPP IV inhibition on incretin hormone metabolism was examined. Conscious dogs were given NVP-DPP728, a specific DPP IV inhibitor, at a dose that inhibited over 90% of plasma DPP IV for the first 90 min following treatment. Total and intact incretin concentrations increased (P<0.0001) following a mixed meal, but on control days (vehicle infusion), intact peptide concentrations were lower (P<0.01) than total peptide concentrations (22.6 +/- 1.2% intact GIP; 10.1 +/- 0.4% intact GLP-1). Following inhibitor treatment, the proportion of intact peptide increased (92.5 +/- 4.3% intact GIP, P<0.0001; 99.0 +/- 22.6% intact GLP-1, P<0.02). Active (intact) incretins increased after NVP-DPP728 (from 4797 +/- 364 to 10 649 +/- 106 pM x min for GIP, P<0.03; from 646 +/- 134 to 2822 +/- 528 pM x m in for GLP-1, P<0.05). In contrast, total incretins fell (from 21 632 +/- 654 to 12 084 +/- 1723 pM x min for GIP, P<0.002; from 5145 +/- 677 to 3060 +/- 601 pM x min for GLP-1, P<0.05). Plasma glucose, insulin and glucagon concentrations were unaltered by the inhibitor. We have concluded that DPP IV inhibition with NVP-DPP728 prevents N-terminal degradation of endogenous incretins in vivo, resulting in increased plasma concentrations of intact, biologically active GIP and GLP-1. Total incretin secretion was reduced by DPP IV inhibition, suggesting the possibility of a feedback mechanism.


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