BACKGROUND: Docosahexaenoic acid (DHA) is an indispensable component of cell membranes that is required at high levels during pregnancy.

STUDY DESIGN: We investigated the effects of DHA (0 to 100 microM) in the placenta on oxidative stress using a trophoblast cell line, BeWo.

RESULTS: Oxidative stress levels (as evaluated using a fluorescent probe) and lipid peroxidation were significantly higher in cells preincubated with 100 microM of DHA. Oxidative DNA damage in cells preincubated with modest levels of DHA (1 or 10 microM) was significantly lower than for untreated cells or cells preincubated with 100 microM DHA. Survival rates of cells preincubated with modest levels of DHA after oxidative challenge (with H(2)O(2) or Xanthine plus Xanthine oxidase) were significantly higher than without DHA preincubation.

CONCLUSION: Modest levels of DHA alleviate oxidative DNA damage whereas high levels of DHA accelerate lipid peroxidation. Thus, DHA supplementation during pregnancy may exert oxidative or antioxidant properties via different mechanisms and depending on dosage.

Key Words: Oxidative Stress, DHA, Docosahexaenoic Acid