Ferric nitrilotriacetate

Numerous studies were dedicated to the effects of flavonoids on microsomal and mitochondrial lipid peroxidation. Kaempferol, quercetin, 7,8-dihydroxyflavone and D-catechin inhibited lipid peroxidation of light mitochondrial fraction from the rat liver initiated by the xanthine oxidase system [126]. Catechin, rutin, and naringin inhibited microsomal lipid peroxidation, xanthine oxidase activity, and DNA cleavage [127]. Myricetin inhibited ferric nitrilotriacetate-induced DNA oxidation and lipid peroxidation in primary rat hepatocyte cultures and activated DNA repair process [128]. 

Ferric nitrilotriacetate is soluble at neutral pH. In the absence of nitrilotriacetate, Fe33 precipitates as Fe(OFi)3 in neutral solution. Nitrilotriacetate binds Fe3 through four atoms, shown in bold type ... 

Figure 7-5 shows the titration of 2.000 mL of apotransferrin with 1.79 X I0-3 M ferric nitrilotriacetate solution. As iron is added to the protein, red color develops and absorbance increases. When the protein is saturated with iron, no further color can form, and the curve levels off. The extrapolated intersection of the two straight portions of the titration curve at 203 p-L in Figure 7-5 is taken as the end point. The absorbance continues to rise slowly after the equivalence point because ferric nitrilotriacetate has some absorbance at 465 nm. 

The absorbance measured after adding 125 p.L (=0.125 mL) of ferric nitrilotriacetate to 2.000 mL of apotransferrin was 0.260. Calculate the corrected absorbance that should be plotted in Figure 7-5. 

Figure 7-5 Spectrophotometric titration of transferrin with ferric nitrilotriacetate Absorbance is corrected as if no dilution had taken place. The initial absorbance of the solution, before iron is added, is due to a colored impurity.

Iqbal M, Okazaki Y, Okada S. 2003. In vitro curcumin modulates ferric nitrilotriacetate (Fe-NTA) and hydrogen peroxide (H202)-induced peroxidation of microsomal membrane lipids and DNA damage. Teratog Carcinog Mutagen Suppl 1 151-160. 

Yukihiro S, Okada S, Takeuchi K, et al. 1995. Experimental osteodystrophy of chronic renal failure induced by aluminum- and ferric-nitrilotriacetate in Wistar rats. Pathol Int 45 19-25. 

When ferric iron (preferably as ferric nitrilotriacetate) is added to egg white, with a little salt, and the mixture is shaken, a vivid red color develops. This simple experiment introduces the protein ovotransferrin (formerly known as conalbumin) and the most striking property of transferrins, their ability to rapidly and tightly bind iron. 

The rise in the 465-nm absorbance as Fe3+ is added to the apoprotein (generally as a ferric nitrilotriacetate or ferric citrate complex) can be used to monitor iron binding and forms the basis of iron titrations that demonstrate the presence of two specific sites per molecule (Fig. 17). 

In vivo uptake of iron by transferrins usually involves its addition as a ferric-chelate complex, to prevent hydrolytic attack on the ferric ion (211). Complexes such as ferric citrate and ferric nitrilotriacetate are commonly used. Under these conditions, kinetic schemes for the uptake of iron by transferrins have identified five steps in the formation of the specific metal-anion-transferrin ternary complex (120). These may be summarized as follows. 

Toyokuni S, Uchida K, Okamoto K, Hattori-Nakakuki Y, Hiai H, Stadt-man ER (1994) Formation of 4-hydroxy-2-nonenal-modified proteins in the renal proximal tubules of rats treated with a renal carcinogen, ferric nitrilotriacetate. Proc Natl Acad Sci USA 91 2616-2620. 

Trott, T., Henwood, R.W. and Langford, C.H., 1972. Sunlight photochemistry of ferric nitrilotriacetate complexes. Environ. Sci. Technol., 6 367—368. 

Toyokuni, S. et al.. Treatment of Wistar rats with a renal carcinogen, ferric nitrilotriacetate, causes DNA-protein cross-linking between thymine and tyrosine in their renal chromatin, Int J. Cancer, 62 (3), 309, 1995. 

D. Electronic Absorption Spectra. The absorption spectra of the complexes formed by exchange from ferric nitrilotriacetate were determined in 0.1 M phosphate, pH 7- t, with a Beckman Model 25 recording spectrophotometer over the range kOO-700 nm. Agrobactin and parabactin gave wine colored iron complexes with a broad adsorption band centered at about 500 nm. At pH 7., the... 

Induction of poly(ADP-ribosyl)ation was reported in the kidney after in vivo application of renal carcinogens such as trichloroethene and dichloroacetylene subsequent to DNA double-strand breaks. Potassium bromate and ferric nitrilotriacetate, whose nephrotoxicity is thought to result from ROS formation, both induced poly(ADP-ribosyl)ation with the concomitant formation of DNA double-strand breaks. Recendy, PARP activation has been associated with both gentamicin and cisplatin-induced nephrotoxicity.Both types of nephrotoxicity involve the generation of ROS and the beneficial effects of different therapeutic approaches aimed at reducing ROS formation have been evaluated. 

Iron chelates as Fe(III) nitrilotriacetate were ge-notoxic in HeLa cells and V79 cells (Hartwig et al. 1992, 1993). Ferric nitrilotriacetate promoted N-diethylnitrosamine-induced renal tumorigenesis in the rat (Athar and Iqbal 1998). In renal cell carcinoma induced by ferric nitrilotriacetate, glutathione S-transferase Yp isozyme was over expressed and Ya isozyme concomitantly down-regulated (Tanaka et al. 1998). 

In primary rat hepatocyte cultures 100 jiM ferric nitrilotriacetate induced five oxidation products of cellular DNA derived from both purines and pyrimidines (Abalea et al. 1999). Addition of increasing concentrations of myricetin (25-50-100 iM) simultaneously with iron prevented both lipid peroxidation and accumulation of oxidation products in DNA. Moreover, as an activation of DNA repair pathways, myricetin stimulated the release of DNA oxidation bases into culture media, especially of purine-derived oxidation products. The removal of highly mutagenic oxidation products from DNA of hepatocytes might correspond to an activation of DNA excision-repair enzymes by myricetin. This was verified by RNA blot analysis of DNA polymerase P gene expression, which was induced by myricetin in a dose-dependent manner. 

Imlay JA, Chin SM, Linn S (1988) Toxic DNA damage by hydrogen peroxide through the Fenton reaction in vivo and in vitro. Science 240 640-642 Inoue S, Kawanishi S (1987) Hydroxyl radical production and human DNA damage induced by ferric nitrilotriacetate and hydrogen peroxide. Cancer Res 47 6522-6527... 

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