Oral eicosapentaenoic acid supplementation as possible therapy for endometriosis

Objective

To investigate the anti-inflammatory effect of n-3 eicosapentaenoic acid (EPA) compared with n-6 linoleic acid (LA) in an endometriosis rat model. We focused on the relationship between lipid metabolism and inflammatory reactions in endometriosis based on the hypothesis that a lipid intake imbalance is one of the factors responsible for the recent increase of endometriosis.

Design

Prospective, randomized experimental study.

Setting

Animal surgery laboratory in a university hospital.

Animal(s)

Sprague-Dawley rats (female, 6 weeks old).

Intervention(s)

Rats were fed a diet with EPA (n = 9) or with LA (n = 9) for 2 weeks. Two weeks after feeding, the uterus was autotransplanted to the peritoneum to construct an endometriosis model. Feeding was continued for a total of 6 weeks. Two and 4 weeks after autotransplantation, three rats of each group were killed and evaluated.

Main Outcome Measure(s)

Endometriotic lesions were morphologically evaluated and their fatty acid composition was examined. Gene expression in these tissues was evaluated by cDNA microarray analysis and quantative real-time reverse transcriptase-polymerase chain reaction (RT-PCR).

Result(s)

In the EPA group, the n-3:n-6 ratio in each tissue significantly increased and the thickening of the interstitium, an active site for inflammation in endometriosis, was significantly suppressed (0.30 ± 0.09 mm [EPA group] vs. 0.77 ± 0.23 mm [LA group]). The mRNA of metalloproteinases, interleukin-1β, interleukin-1r, prostaglandin E synthase (Ptges), and nuclear factor (NF)-κB were reduced in the EPA group.

Conclusion(s)

EPA supplementation might be a valid strategy for the treatment of endometriosis.

Key Words: Endometriosis, dysmenorrhea, chronic inflammation, n-3 fatty acid, EPA