Antioxidant capacity of vitamin C in mouse liver and kidney tissues

In the present study, the antioxidant capacity of vitamin C was examined in the liver and the kidney tissues of mice with or without ciprofloxacin (CFX) treatment. The antioxidant capacity of the vitamin was evaluated in terms of lipid hydroperoxides (LOOH) and thiobarbituric acid reactive substances (TBARs). The experimental design was 15 days of water (control and CFX groups) or vitamin C (vitamin C and vitamin C plus CFX groups) in drinking water. One dose of CFX was injected, 15 minutes before sacrifice, in the corresponding mice. The initial nmol of lipid hydroperoxides/g of tissue were 137 +/- 11 in the kidney and 145 +/- 15 in the liver, and the nmol of TBARs were 13 +/- 0.7 and 12 +/- 0.6, respectively.Pre-treatment with vitamin C reduced the levels of LOOH in the liver to 45 +/- 11 (p < 0.01) and vitamin C with CFX injection to 54 +/- 9 (p < 0.01). Vitamin C treatment also reduced the LOOH levels in the kidney roughly duplicated by CFX. Through the TBARs method we have not observed these effects. Quantification of LOOH is more sensitive than that of TBARs for estimating lipid peroxidation. CFX is used especially for urinary infections and can produce oxidative stress in the kidney. Pre-treatment with vitamin C may ameliorate this stress and also may improve the oxidative balance in the liver.

Increase of tissue lipid hydroperoxides as determination of oxidative stress

Increased levels of lipid hydroperoxides (LOOH) are frequently associated with the oxidative mechanisms involved in physiological states as ageing and with serious pathological conditions. In the present work the physiological and the CCl4-induced lipid hydroperoxides levels in mice liver and kidney were determined. The analysis of LOOH tissue levels was performed through the oxidation of 1-napthyldiphenylphosphine (NDPP) into its oxide (ONDPP) and further quantification by high pressure liquid chromatography at 292 nm UV detection. The physiological level of lipid hydroperoxides levels was higher in the kidney (245 +/- 8 nmol LOOH/g of tissue) than in liver (164 +/- 5 nmol of LOOH/g tissue). After a single administration of CCl4 (0.25 ml/g) tissue LOOH reached a maximum level after 15 min (416 +/- 21 nmol/g kidney and 303 +/- 6 nmol/g liver) and then slowly decreased. LOOH levels in liver afforded an early indicator (15 min) of oxidative damage. LOOH levels in kidney remained significatively increased up to 60 min post administration. The described HPLC assay is a useful, simple and sensitive method to detect cellular oxidative stress and damage.