Apigenin Alleviates Endoplasmic Reticulum Stress-Mediated Apoptosis in INS-1 β-Cells.

Area of Science:

• Endocrinology and Metabolism
• Molecular Biology
• Cell Biology

Background:

• Flavonoids, natural polyphenols, show potential in managing type 2 diabetes.
• Limited research exists on the specific effects of apigenin on pancreatic beta-cell function.
• Understanding apigenin's impact on insulin secretion and apoptosis is crucial for diabetes research.

Purpose of the Study:

• To investigate the anti-diabetic effects of apigenin on pancreatic beta-cell insulin secretion and apoptosis.
• To elucidate the underlying mechanisms of apigenin's action in the INS-1D cell line.
• To assess apigenin's potential in promoting beta-cell survival and function.

Main Methods:

• Utilized the INS-1D beta-cell line for in vitro studies.
• Measured glucose-induced insulin secretion at varying apigenin concentrations.
• Assessed apoptosis using flow cytometry (Annexin V/PI staining) and DNA fragmentation assays.
• Quantified the expression of endoplasmic reticulum (ER) stress markers like CHOP and TXNIP.

Main Results:

• Apigenin dose-dependently enhanced glucose-stimulated insulin secretion, peaking at 30 µM.
• Apigenin inhibited thapsigargin-induced ER stress markers (CHOP, cleaved caspase-3, TXNIP) in a dose-dependent manner.
• Apigenin significantly reduced beta-cell apoptosis, correlating with reduced ER stress markers.

Conclusions:

• Apigenin exhibits potent anti-diabetic properties by improving beta-cell function.
• Apigenin facilitates glucose-stimulated insulin secretion and protects beta-cells from apoptosis.
• The protective effects are likely mediated by the downregulation of ER stress pathways involving CHOP and TXNIP.