Abstract
Chocolate vine (Akebia quinata) is consumed as a fruit and is also used in traditional medicine. In order to identify the bioactive components of A. quinata, a phytosterol glucoside stigmasterol-3-O-β-d-glucoside (1), three triterpenoids maslinic acid (2), scutellaric acid (3), and hederagenin (4), and three triterpenoidal saponins akebia saponin PA (5), hederacoside C (6), and hederacolchiside F (7) were isolated from a 70% EtOH extract of the fruits of A. quinata (AKQU). The chemical structures of isolates 1–7 were determined by analyzing the 1D and 2D nuclear magnetic resonance (NMR) spectroscopic data. Here, we evaluated the effects of AKQU and compounds 1–7 on insulin secretion using the INS-1 rat pancreatic β-cell line. Glucose-stimulated insulin secretion (GSIS) was evaluated in INS-1 cells using the GSIS assay. The expression levels of the proteins related to pancreatic β-cell function were detected by Western blotting. Among the isolates, stigmasterol-3-O-β-d-glucoside (1) exhibited strong GSIS activity and triggered the overexpression of pancreas/duodenum homeobox protein-1 (PDX-1), which is implicated in the regulation of pancreatic β-cell survival and function. Moreover, isolate 1 markedly induced the expression of extracellular signal-regulated protein kinases 1 and 2 (ERK1/2), insulin receptor substrate-2 (IRS-2), phosphoinositide 3-kinase (PI3K), and Akt, which regulate the transcription of PDX-1. The results of our experimental studies indicated that stigmasterol-3-O-β-d-glucoside (1) isolated from the fruits of A. quinata can potentially enhance insulin secretion, and might alleviate the reduction in GSIS during the development of T2DM.
Highlights
Diabetes mellitus (DM) is one of the top 10 causes of global deaths, and affected 463 million people worldwide in 2019
We found that the AKQU increased Glucose-stimulated insulin secretion (GSIS) in INS-1 cells
± 0.05, 1.73 ± 0.06, and 3.58 ± 0.01 at concentrations of 2.5, 5, and 10 μg/mL, respectively. These results were 0.98 ± 0.05, 1.73 ± 0.06, and 3.58 ± 0.01 at concentrations of 2.5, 5, and 10 μg/mL, respectively. These results indicated that AKQU stimulates insulin secretion in INS-1 cells without inducing indicated thatAsAKQU
Summary
Diabetes mellitus (DM) is one of the top 10 causes of global deaths, and affected 463 million people worldwide in 2019. Experts expect that the number of patients with DM will increase to 578 million by. Type 2 diabetes mellitus (T2DM) is a metabolic disease, which comprises approximately. 90% of all cases of DM [3]. The clinical characteristics of patients with T2DM are decreased insulin production and impaired insulin function, which leads to persistent hyperglycemia [4]. T2DM are unable to control the disease by lifestyle changes alone, and require drugs and insulin for reducing the hyperglycemia. One of the major factors in the development of T2DM is the Plants 2020, 9, 1087; doi:10.3390/plants9091087 www.mdpi.com/journal/plants
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
