Buglossoides spp. seeds, a land source of health-promoting n-3 PUFA and phenolic compounds

Abstract

Ahiflower oil© is extracted from the seeds of Buglossoides arvensis, which contains high amounts of stearidonic acid (SDA, 18:4n-3), while its phenolic composition still is unreported. Moreover, several Buglossoides taxa remain unstudied and could become natural sources of SDA. In this work, seeds of several Buglossoides taxa and Ahiflower oil© were screened for fatty acids, phenolic compounds, and in vitro antiproliferative activities against colorectal cancer cells. Four flavonoids and 16 phenolic acids were identified and quantified. Among Buglossoides taxa, the highest amounts of phenolic compounds were found in samples collected in Spain, under a warm Mediterranean climate. Rosmarinic and lithospermic acids were the main phenols found in Buglossoides seeds. The MTT assay showed dose- and time-dependent inhibitory effects of B. arvensis extracts on HT-29 cancer cells, with a GI₅₀value of ∼280 μg/mL after 72 h of cell exposure to seed extracts. The latter showed lower antiproliferative activity than that of pure phenolics due to the simultaneous presence of other compounds in the extracts, as evidenced by ¹H NMR. This work constitutes the first approach to evaluate the seeds of several Buglossoides taxa as functional oils-providers to use them as functional foods.

Keywords: Buglossoides spp.; HT-29 cells; Phenolic compounds; Stearidonic acid; γ-linolenic acid.