Fig. 3

Inhibitory effect of EPA on the size of intracranial aneurysms in a rat model. a Plasma concentration of EPA, docosahexaenoic acid (DHA), and arachidonic acid (AA) in rats orally administered EPA. Rats were orally administered EPA (vehicle, n = 9, 100 mg/kg/day, n = 8, 1000 mg/kg/day, n = 9) once a day and, on the 5th day, plasma concentration of EPA, DHA, and AA was measured and the ratio of EPA over AA was also calculated. Data represents box-and-whisker plots. Statistical analysis was done by a Kruskal-Wallis test. *p < 0.05. b, c Effect of EPA on the size of induced aneurysms. EPA was administered in a rat model subjected to aneurysm induction once a day for 12 days and the size of induced aneurysms at right anterior cerebral-olfactory artery bifurcation was measured after Elastica van Gieson staining (vehicle, n = 8, 100 mg/kg/day, n = 10, 1000 mg/kg/day, n = 9). The representative microscopic images of induced aneurysms with Elastica van Gieson staining in each group are shown in b. Bar; 50 μm. Data represents box-and-whisker plots (c). Statistical analysis was done by a Kruskal-Wallis test. *p < 0.05. d Plasma concentration of Resolvin E1 in rats administered EPA. Rats were orally administered EPA once a day and, after 12 days, plasma concentration of Resolvin E1 was measured by ELISA (vehicle, n = 8, 1000 mg/kg/day, n = 9). Data represents box-and-whisker plots. Statistical analysis was done by a Mann-Whitney test. *p < 0.05