A traditional Korean fermented food, Gochujang exerts anti-hypertensive effects, regardless of its high salt content by regulating renin-angiotensin-aldosterone system in SD rats

The current study aimed to investigate the distinct outcomes of table salt and salt in Gochujang on blood pressure (BP). Animals were divided into 3 groups, including normal diet (NS, 0.5 % NaCl), high-salt diet (HS, normal diet with 8 % NaCl), or high-salt Gochujang diet (HSG, normal diet with Gochujang containing 8 % NaCl). Compared to the NS groups, the HS group showed significantly increased systolic blood pressure (SBP), while the HSG group did not elevate SBP. The HS group had lower serum angiotensin II and aldosterone levels than the NS group, while the HSG group showed higher levels of those parameters than the HS group. The renal mRNA expression related to the renin-angiotensin-aldosterone system (RAAS) was significantly higher in the HS group than the NS group, while the HSG group had markedly lower expression of those markers. The urinary and fecal Na⁺/K⁺ proportion was higher in both HS and HSG groups relative to the NS group, but the HSG group showed a decreased Na⁺/K⁺ ratio in urine and feces compared to the HS group. Moreover, the HS group had a significantly upregulated mRNA level of Na⁺/HCO₃ ⁻ co-transporter (Slc4a4) in the kidney than the NS group, whereas the HSG group showed downregulated mRNA expression of Slc4a4 compared to the HS group. This study demonstrates that Gochujang has anti-hypertensive effects regardless of its high salt content and provide the evidence regarding the distinct impacts between salt in Gochujang and the table salt.