In vitro effect of flaxseed oil and α-linolenic acid against the toxicity of lipopolysaccharide (LPS) to human umbilical vein endothelial cells

Consumption of α-linolenic acid (ALA)-rich flaxseed oil is a possible way to supplement ω-3 polyunsaturated fatty acids, but the beneficial effects to cardiovascular systems are still controversial. In this study, human umbilical vein endothelial cells (HUVECs) treated with 100 ng/mL lipopolysaccharide (LPS) were used as the in vitro model and the potential beneficial effects of well-characterized flaxseed oil and ALA were studied. Exposure of HUVECs to LPS for 24 h significantly promoted inflammatory response as release of interleukin 6 (IL-6), soluble intercellular cell adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule 1 (sVCAM-1) as well as adhesion of THP-1 monocytes, but did not induce cytotoxicity or oxidative stress. ALA, but not flaxseed oil, significantly reduced LPS-induced release of sICAM-1 and sVCAM-1, without effect on THP-1 adhesion. No radical scavenging activity was observed after flaxseed oil or ALA exposure. Rather, ALA at high concentrations promoted intracellular superoxide associated with damages to lysosomes, which was not observed in flaxseed oil exposed cells. These results indicated that ALA at high concentrations could inhibit inflammatory responses in LPS-treated HUVECs in vitro but might also promote a modest effect in cytotoxicity and oxidative stress.