Both dietary carbohydrate (CARB) and cholesterol (CHOL) may impact hepatic lipid accumulation and liver oxidative stress. Hartley male guinea pigs (10 /group) were fed either low (L) (0.04 g/ 100g) or high (H) (0.25g/100g) CHOL in combination with either L (10% energy) or H (54.2% en) (CARB). Hepatic free cholesterol and triglyceride concentrations were 3-fold and 1.7-fold higher in guinea pigs fed H-CHOL (p < 0.001) independent of CARB intake. H-CHOL increased liver weight by 100% (p < 0.001) and L-CARB by about 25% (p < 0.05). The L-CARB had higher concentrations of plasma and hepatic α and γ tocopherol (p < 0.05) compared to the H-CARB groups in agreement with dietary intake. H-CHOL increased the concentrations of oxidized glutathione (p < 0.0001) in liver. Finally, H-CHOL diets affected oxidative stress by increasing MDA concentrations (P < 0.001). Interestingly L-CARB diets reduced MDA concentrations substantially (P < 0.0001) and these reduction was associated with hepatic α-tocopherol (r = -0.52, P < 0.02). These findings suggest that high concentrations of CHOL result in excessive accumulation of free cholesterol, and decreased antioxidant capacity in the liver while low CARB results in higher concentrations of both α- and γ-tocopherol, which leads to antioxidant protection.
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