The dietary hydroxycinnamate caffeic acid and its conjugate chlorogenic acid increase vitamin E and cholesterol concentrations in Sprague-Dawley rats

Vegetarian diets are correlated with a reduced risk of developing cardiovascular disease and comprise a great variety of bioactive compounds, including hydroxycinnamic acid derivatives. Therefore, this study aimed to identify dietary hydroxycinnamic acid derivatives that may alter two important factors related to the development of cardiovascular disease, namely, tocopherol (T) and cholesterol (C) concentrations in the body. The effects of caffeic acid (CA), chlorogenic acid (CGA), and ferulic acid (FA) on α-T, γ-T, and C levels in blood plasma, liver, and lungs were investigated after these compounds had been fed to rats for 4 weeks at concentrations of 2 g/kg in semisynthetic diets. None of the regimens affected weight gain, feed intake, or absolute weights of livers and lungs, although CA increased the liver weight relative to the body weight (P < 0.05). CA- and CGA-fed animals showed a tendency toward sparing vitamin E in all tissues, but statistical significance was obtained only for γ-T in the liver of CA-fed animals (P < 0.005) and for α-T in the lungs of CGA-treated rats (P < 0.05). CGA supplementation reduced concentrations of lipids in the lung tissue (P < 0.05). CA and CGA elevated the concentrations of C in liver tissue and lipids to a similar extent, but only CA decreased the ratio of high-density lipoprotein C to total C in blood plasma (P < 0.05 for all effects). Animals eating FA showed T and C values comparable to those in the control group. In conclusion, this study demonstrates that dietary caffeic and chlorogenic acid may elevate tocopherols and cholesterol in vivo.