Figure 1.

Dose-dependent response evaluation of dihomo-γ-linolenic acid (DGLA) free acid and ethyl ester forms in RAW264.7 macrophages. Cells were treated with increasing concentrations of DGLA in its free or ethyl ester form for 24 h. Cell viability was determined by 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) (A) and tetrazolium-formazan (XTT) (B) assays, as indicated in the Methods section. Prostaglandin E1 (PGE1) (C) and prostaglandin E2 (PGE2) (D) were quantified in culture supernatants. Dimethyl sulfoxide (DMSO) at 1:1000 (the final concentration in the cell culture media was 0.1% in all treatment groups) was used as a vehicle control and did not affect the cells viability. Data are presented as mean ± standard deviation (SD). * denotes a significant difference compared to untreated control, p < 0.05, n = 3.