The insulinotropic activity of oleosomes prepared from various sea buckthorn cultivars in mouse and human pancreatic β cell lines

Sea buckthorn berries contain numerous bioactive lipids such as fatty acids, carotenoids, tocols, and sterols. Among fatty acids, a high concentration of rare in nature palmitoleic acid is characteristic of sea buckthorn pulp oil. We previously showed the potency of pulp oil from the Luczystaja cultivar to augment glucose-induced insulin secretion in pancreatic β cells. Since the composition of sea buckthorn berries varies depending on the cultivar, here we compared the activity of oleosomes from Botaniczeskaja Ljubitelskaja, Golden Rain, Prozracznaja, Maryna and Luczystaja cultivars in two different pancreatic cell lines, a mouse MIN6 and human EndoC-betaH1. Besides the characterization of particle size and ζ-potential, we evaluated the influence of crude and digested oleosomes on cell viability, insulin secretion, and intracellular calcium mobilization. Additionally, the antioxidant activity measured with the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+) radical cation-based assay was determined and compared.