Lipid peroxidation in plasma of rats treated with ferric-nitrilotriacetate, in relation to kidney and liver modifications

Ameliorative effect of polyphenols from Padina boergesenii against ferric nitrilotriacetate induced renal oxidative damage: With inhibition of oxidative hemolysis and in vitro free radicals

The aim of this study was to evaluate the antioxidant activities of diethyl ether (DEE) and methanol (M) extracts from brown alga Padina boergesenii using in vitro and in vivo antioxidant assay, which may help to relate the antioxidant properties with the possible outline of its ameliorative effect. M extract showed higher radical scavenging activity through ferric reducing antioxidant power 139.11 µmol tannic acid equivalent/g; DPPH 71.32 ± 0.56%; deoxyribose radical 88.31 ± 0.47%, and total antioxidant activity 0.47 ± 0.02 mg ascorbic acid equivalents/g. Oxidative red blood cell (RBC) hemolysis inhibition rate was significantly higher in M extract (150 mg/kg body weight) in reference to total phenolic content (r = 0.935). Rats administered with DEE and M extracts (150 mg/kg body weight) for seven days before the administration of ferric nitrilotriacetate (9 mg of Fe/mg/kg bodyweight). Rats pretreated with extracts significantly changed the level of renal microsomal lipid peroxidation, glutathione, and antioxidant enzymes in post-mitochondrial supernatant (P < 0.05). Ameliorative effect of extracts against renal oxidative damage was evident in rat kidney through changes in necrotic and epithelial cells. HPTLC technique has identified the presence of rutin with reference to retardation factor (Rf ) in both the extracts. These findings support the source of polyphenols (rutin) from P. boergesenii had potent antioxidant activity; further work on isolation of bioactive compounds can be channeled to develop as a natural antioxidant.

Protective effect of olive oil minor polar components against oxidative damage in rats treated with ferric-nitrilotriacetate

The phenolic fraction of virgin olive oil exerts preventive effects against reactive oxygen species mediated degenerative diseases. To investigate its action as inhibitor of lipid peroxidation in vivo, we treated Wistar rats with olive oil minor polar components (MPC) (25-50 mg/kg bw) prior to the administration of a sublethal dose (15 mg Fe/kg bw) of ferric-nitrilotriacetate (Fe-NTA). Intraperitoneal injection (i.p.) of Fe-NTA lead to increased oxidative stress associated with extensive peroxidation of membrane lipids in plasma, kidney, and liver of treated rats. Fe-NTA treatment induced a significant decrease of the major oxidizable membrane lipids, alpha-tocopherol, fatty acids and cholesterol, together with an increase of fatty acids hydroperoxides (HP) and 7-ketocholesterol (7-keto). I.p. administration of MPC significantly inhibited fatty acids and cholesterol oxidation, and reduced the levels of HP and 7-keto. In summary, MPC administration protects organs against lipid peroxidation and conserves the endogenous alpha-tocopherol.

Are 4-hydroxy-2(E)-nonenal derived mercapturic acids and 1H NMR metabonomics potential biomarkers of chemically induced oxidative stress in the kidney?

Various markers derived from radical-mediated oxidative damage to cellular macromolecules have been proposed as tools for the detection of alterations in redox status, but there is strong debate as to which may be the most sensitive and reliable indicator of oxidative stress conditions. This study was aimed to investigate the use of mercapturic acids derived from conjugation of the lipid peroxidation product 4-hydroxy-2(E)-nonenal (HNE) with glutathione and (1)H NMR metabonomics in two rodent models of oxidative kidney damage. Treatment of rats with FeNTA resulted in a marked increase in the concentrations of 4-hydroxy-2(E)-nonenal derived mercapturic acids in plasma and kidney within 5h. 1,4-dihydroxynonenal mercapturic acid (DHN-MA) remained elevated 24h after compound administration, while other markers returned to control levels, suggesting that DHN-MA may present a more stable indicator of lipid peroxidation. However, significant changes were only evident in the presence of severe nephrotoxicity, indicating that HNE-derived mercapturic acids were less sensitive than nonspecific markers of renal injury. In contrast to FeNTA, continuous administration of potassium bromate for 2 weeks had no effect on the concentrations of DHN-MA or 4-hydroxyononenal-3-yl-mercapturic acid in kidney, plasma or urine of treated animals, although a dose-dependent increase in 8-oxo-7,8-dihydro-2'deoxyguanosine was observed in kidney DNA in the absence of nephrotoxicity. These data suggest that markers of lipid peroxidation may not be suitable to detect alterations in redox status induced by potassium bromate at doses known to cause tumors after chronic treatment. Alterations in urine (1)H NMR spectra were detected in both models but reflect nonspecific alterations as a result of impaired renal function rather than specific changes indicative of oxidative stress. In summary, it appears that - depending on the pathological circumstances and the chemical nature of the insult - different types of oxidative stress exist, and it is therefore not possible to define a universal marker of oxidative stress.