Anti-hypertensive Effect of Hesperidin and Hesperidin-containing Fermented Mikan Tea in Spontaneously Hypertensive Rats

The anti-hypertensive effects of hesperidin and hesperidin-containing fermented Mikan tea were investigated in 8-week-old spontaneously hypertensive rats (SHRs) at a dose of 50 mg/kg body weight for both, over 20 weeks. At the end of the protocol, a significant (P < 0.05) reduction in the systolic blood pressure (SBP) of approximately 60 mmHg was observed in the SHRs with the intake of hesperidin and Mikan tea. No change in the heart rate was observed between groups. Hesperidin altered the impaired vasomotor response in 28-week-old SHRs. Investigation of receptor expression related to mitogen-stimulated vasomotor action revealed that the Mas receptor (MasR) in the aorta of hesperidin-administered SHRs was up-regulated, while no changes in angiotensin II-type 1 and type 2 receptor expressions were observed. An increase in cAMP levels was confirmed in the aorta of hesperidin-administered SHRs, demonstrating that anti-hypertensive hesperidin plays a role in vessel regulation via the upregulated-MasR/cAMP axis.