The influence of trans-palmitoleic acid on gene expression of fatty acid synthase and lipid accumulation in liver cells

Prevalence of obesity has remarkably been elevated during the recent years and therefore its consequences, including liver and cardiovascular disorders, have increased. The previous studies have shown that trans-palmitoleic acid (tPA) has beneficial effects in metabolic disorders. Thus, the aim of the present study was to study the effects of tPA on lipid accumulation in liver cells and the gene expression of fatty acid synthase (FAS) enzyme and the activity of peroxisome proliferator-activated receptor alpha (PPARα).

In the present experimental in vitro study, HepG2 liver cells were cultured and treated with different concentrations of tPA and palimitic acid. Intracellular triglyceride (TG) levels were measured with an enzymatic method, and the expression of FAS gene was assessed using real-time PCR. The activity of PPARα was also evaluated via luciferase reporter assay, using the vector comprising the PPARα response element.

Both fatty acids caused TG deposition in liver cells; however, the TG levels were significantly lower in cells treated with tPA compared to the cells that were treated with palmitic acid (P<0.001). The gene expression of FAS was enhanced by both fatty acids, but in cells treated with tPA, it was significantly lower than palmitic acid (P<0.001). Also, tPA was obserced to activate PPARα, especially at lower concentrations (P<0.001), while palmitic acid did not have any effect on this nuclear receptor.

The results showed that less TG is accumulated in liver cells treated with tPA as compared with palmitic acid and thus this fatty acid has better influence on liver cells compared with its saturated counterpart.