Effect of long‐term Western style diet and folate supplementation on aortic response and hepatic C‐reactive protein level in C57BL/6 mice

Abstract

Dietary folate and Western style diet (WD) are associated with the risk of CVD. After mandatory folate fortification was implemented, folate intake and blood folate concentrations in the US population have dramatically increased. We investigated vascular reactivity and systemic inflammation status from various long term (18 mo) folate intake levels (replete, 2mg/kg diet; deplete, 0.23mg/kg; and supplemented, 8 mg/kg) in C57BL/6 mice fed either control diet (AIN‐76A) or WD. Vascular reactivity of aortic rings of mice was measured by a multi‐chamber myograph. Following contraction of aortic rings with 0.3μmol/L phenylephrine, we measured the relaxation in response to acetylcholine (ACH; 0.01–10μmol/L). Hepatic C‐reactive protein (CRP) was measured by ELISA. Our results show that mice fed WD had less relaxation response to ACH, and this response was independent of folate intake. Folate supplementation reduced aortic ring relaxation by 21% compared to control group and by 30% in mice fed WD supplemented with folate compared to WD control. The level of CRP, regardless of folate levels in the diets, was higher in mice fed WD (100.77 ± 14.26 vs 75.38 ± 6.71, % ± S.D, p<0.05). Long‐term WD is associated with increased systemic inflammation as evident from increased liver CRP levels, and long‐term inclusion of folate in WD may have negative effect on vascular reactivity. Supported by USDA agreement #58‐1950‐7‐707