Ecklonia stolonifera Okamura extract (ESE) has been reported to have various bioactive effects, but its effects on
cardiovascular disease have not yet been investigated. First, primary neonatal rat cultured cardiomyocytes were treated with ESE and stimulated with
phenylephrine (PE) for 48 h. ESE (1000 µg/mL) significantly suppressed PE-induced cardiomyocyte
hypertrophy,
hypertrophy-related gene transcription, and the acetylation of
histone H3K9. An in vitro p300-HAT assay indicated that ESE directly inhibited p300-HAT activity. Next, one week after
myocardial infarction (MI) surgery, rats (left ventricular fractional shortening (LVFS) < 40%) were randomly assigned to three groups: vehicle (saline, n = 9), ESE (0.3 g/kg, n = 10), or ESE (1 g/kg, n = 10). Daily
oral administration was carried out for 8 weeks.
After treatment, LVFS was significantly higher in the ESE (1 g/kg) group than in the vehicle group. The ESE treatments also significantly suppressed MI-induced increases in myocardial cell diameter, perivascular
fibrosis,
hypertrophy- and
fibrosis-related gene transcription, and the acetylation of
histone H3K9. These results suggest that ESE suppressed both hypertrophic responses in cardiomyocytes and the development of
heart failure in rats by inhibiting p300-HAT activity. Thus, this dietary extract is a potential novel therapeutic strategy for
heart failure in humans.