Identification of Multiple Pancreatic and Extra-Pancreatic Pathways Underlying the Glucose-Lowering Actions of Acacia arabica Bark in Type-2 Diabetes and Isolation of Active Phytoconstituents
| Autor: | Peter R. Flatt, J M A Hannan, P Harriott, Prawej Ansari, Yasser Abdel-Wahab |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
insulin
obesity medicine.medical_treatment Glucose uptake Plant Science Type 2 diabetes Pharmacology Article 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Tolbutamide Diabetes mellitus medicine Diazoxide Glucose homeostasis glucose Ecology Evolution Behavior and Systematics 030304 developmental biology islets 0303 health sciences Ecology diabetes Chemistry Insulin Botany medicine.disease beta cells DPP-IV 030220 oncology & carcinogenesis QK1-989 phytochemistry Kaempferol medicine.drug |
| Zdroj: | Plants Plants, Vol 10, Iss 1190, p 1190 (2021) Volume 10 Issue 6 |
| ISSN: | 2223-7747 |
| Popis: | Acacia arabica is used traditionally to treat a variety of ailments, including diabetes. This study elucidated the antidiabetic actions of A. arabica bark together with the isolation of bioactive molecules. Insulin secretion and signal transduction were measured using clonal β cells and mouse islets. Glucose uptake was assessed using 3T3-L1 adipocytes, and in vitro systems assessed additional glucose-lowering actions. High-fat-fed (HFF) obese rats were used for in vivo evaluation, and phytoconstituents were isolated and characterised by RP-HPLC followed by LC-MS and NMR. Hot-water extract of A. arabica (HWAA) increased insulin release from clonal β cells and mouse islets by 1.3–6.8-fold and 1.6–3.2-fold, respectively. Diazoxide, verapamil and calcium-free conditions decreased insulin-secretory activity by 30–42%. In contrast, isobutylmethylxanthine (IBMX), tolbutamide and 30 mM KCl potentiated the insulin-secretory effects. The mechanism of actions of HWAA involved membrane depolarisation and elevation of intracellular Ca2+ together with an increase in glucose uptake by 3T3-L1 adipocytes, inhibition of starch digestion, glucose diffusion, dipeptidyl peptidase-IV (DPP-IV) enzyme activity and protein glycation. Acute HWAA administration (250 mg/5 mL/kg) enhanced glucose tolerance and plasma insulin in HFF obese rats. Administration of HWAA (250 mg/5 mL/kg) for 9 days improved glucose homeostasis and β-cell functions, thereby improving glycaemic control, and circulating insulin. Isolated phytoconstituents, including quercetin and kaempferol, increased insulin secretion in vitro and improved glucose tolerance. The results indicate that HWAA has the potential to treat type 2 diabetes as a dietary supplement or as a source of antidiabetic agents, including quercetin and kaempferol. |
| Databáze: | OpenAIRE |
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