Serum and liver micronutrient antioxidants and serum oxidative stress in patients with chronic hepatitis C

Abstract

OBJECTIVES: The exact pathogenesis of liver injury and fibrosis in chronic hepatitis C (CHC) is unclear. Free radicals play a role in CHC liver damage. Antioxidants (AO) (enzymatic and nonenzymatic) scavenge free radicals and prevent tissue injury. The aims of our study were to estimate serum levels of malondialdehyde (MDA), serum and liver levels of nonenzymatic fat-soluble AO, and to correlate the liver AO levels with the degree of inflammation and fibrosis on biopsy. METHODS: AO levels were estimated by high-pressure liquid chromatography in the pretreatment serum and liver biopsy specimen of 20 treatment-naı̈ve patients with CHC who were not on vitamin supplements. Serum levels of MDA were measured as a marker of increased oxidative stress. Twenty-two healthy individuals with no history of vitamin supplementation served as controls. AO analyzed were: retinol, α- and γ-tocopherol, lutein, β-cryptoxanthin, lycopene, and α- and β-carotene. RESULTS: Twenty CHC patients (11 men, nine women, mean age 48.5 ± 7.9 yr) were studied. Patients and controls were comparable in age and sex. Serum MDA levels were significantly higher in CHC patients compared with controls (1.62 ± 0.57 vs 0.23 ± 0.15 μmol/L, p = < 0.0000). Serum levels of all AO except lutein were significantly decreased in CHC patients, and their levels were two to ten times lower than serum levels in controls. Liver levels of α-carotene ( p = 0.0004), β-carotene ( p = 0.006), and lutein ( p = 0.002) correlated with the serum levels, whereas the levels of retinol, α-tocopherol, lycopene, and β-cryptoxanthin showed no correlation. Serum MDA levels were significantly higher in patients with moderate-to-severe inflammation or fibrosis compared with those with mild inflammation or fibrosis. The levels of all liver AO except α-carotene were significantly lower in patients with moderate-to-severe fibrosis. The severity of inflammation (portal or lobular) did not affect liver AO levels. CONCLUSIONS: Our findings suggest that increased oxidative stress is present in patients with CHC. Micronutrient AO are severely depleted in serum and liver tissue of patients with CHC, and liver levels of some AO appear to reflect serum levels. Increasing fibrosis is associated with decreased liver AO levels indicating that severe disease may be a consequence of AO depletion or decreased liver storage resulting from fibrosis.