Olive Oil Lipophenols Induce Insulin Secretion in 832/13 β-Cell Models

Glycemic control is a mainstay of type 2 diabetes mellitus (T2DM) clinical management. Despite the continuous improvement in knowledge and progress in terms of treatment, the achievement of the physiologic metabolic profile is still an ongoing challenge in diabetic patients. Pancreatic β-cell line INS-1 832/13 was used to assess the insulin secretagogue activity of hydroxytyrosyl oleate (HtyOle) and tyrosyl oleate (TyOle), two naturally occurring lipophenols deriving from the conjugation of oleic acid (OA) and hydroxytyrosol (Hty) or tyrosol (Ty), respectively. The insulin secretion was determined under a glucose-induced insulin secretion (GSIS) condition by the ELISA method. The potential involvement of G-protein-coupled receptor 40 (GPR40), also known as free fatty acid receptor 1 (FFAR1), was investigated by both molecular docking and functional pharmacological approaches. Herein, we demonstrated that HtyOle and TyOle exerted a facilitatory activity on insulin secretion under the GSIS condition. Moreover, we provided evidence that both lipophenols are natural modulators of FFAR1 receptor. From our results, the anti-diabetes properties associated with olive oil consumption can be partly explained by the HtyOle and TyOle effects.