Purpose: Vinegar has been reported to lower blood pressure, but its mechanism is unclear. This study explored whether vinegar plays antihypertensive effect by activating AMP-activated protein kinase (AMPK) pathway.
Methods: Male spontaneously hypertensive rats (SHRs) were assigned to vinegar, acetic acid, nifedipine, nifedipine + vinegar, or distilled water by oral gavage for 8 weeks. Blood and aortas were analyzed for biochemical indices and protein expression levels. Sv40-transformed aortic rat endothelia cell line (SVAREC) cells were treated with acetate at different doses for 24 h; protein expression levels were assessed.
Results: Vinegar and acetic acid decreased blood pressure in SHRs on weeks 6 and 8, and nifedipine + vinegar had a better effect on blood pressure control than vinegar or nifedipine alone. Vinegar and acetic acid could decrease serum renin and angiotensin-converting enzyme (ACE) activities, angiotensin II and aldosterone concentrations in SHRs. Vinegar and acetic acid also increased AMP/ATP ratios and expression levels of pAMPK, PPARγ coactivator-1α (PGC-1α), and PPARγ while inhibited angiotensin II type 1 receptor (AT1R) expression in SHRs. The changes in these protein expressions were also found in SVAREC cells treated with 200 or 400 μmol/L acetate. In the presence of AMPK inhibitor or PGC-1α small interfering RNA, the effects of acetate on their downstream protein expression in SVAREC cells were abolished, respectively.
Conclusion: Vinegar activates AMPK by increasing AMP/ATP ratios, thereby increases PGC-1α and PPARγ expressions, and inhibits AT1R expression in SHRs. Acetic acid is responsible for the antihypertensive effects of vinegar. There is a joint effect between vinegar and nifedipine in blood pressure control.
Keywords: AMPK; Angiotensin II type 1 receptor; Blood pressure; Vinegar.