Tags

Type your tag names separated by a space and hit enter

Antioxidant properties of S-adenosyl-L-methionine in Fe(2+)-initiated oxidations.
Free Radic Biol Med. 2004 May 15; 36(10):1303-16.FR

Abstract

S-Adenosylmethionine (SAM) is protective against a variety of toxic agents that promote oxidative stress. One mechanism for this protective effect of SAM is increased synthesis of glutathione. We evaluated whether SAM is protective via possible antioxidant-like activities. Aerobic Hepes-buffered solutions of Fe2+ spontaneously oxidize and consume O2 with concomitant production of reactive oxygen species and oxidation of substrates to radical products, e.g., ethanol to hydroxyethyl radical. SAM inhibited this oxidation of ethanol and inhibited aerobic Fe2+ oxidation and consumption of O2. SAM did not regenerate Fe2+ from Fe3+ and was not consumed after incubation with Fe2+. SAM less effectively inhibited aerobic Fe2+ oxidation in the presence of competing chelating agents such as EDTA, citrate, and ADP. The effects of SAM were mimicked by S-adenosylhomocysteine, but not by methionine or methylthioadenosine. SAM did not inhibit Fe2+ oxidation by H2O2 and was a relatively poor inhibitor of the Fenton reaction. Lipid peroxidation initiated by Fe2+ in liposomes was associated with Fe2+ oxidation; these two processes were inhibited by SAM. However, SAM did not show significant peroxyl radical scavenging activity. SAM also inhibited the nonenzymatic lipid peroxidation initiated by Fe2+ + ascorbate in rat liver microsomes. These results suggest that SAM inhibits alcohol and lipid oxidation mainly by Fe2+ chelation and inhibition of Fe2+ autoxidation. This could represent an important mechanism by which SAM exerts cellular protective actions and reduces oxidative stress in biological systems.

Authors+Show Affiliations

Department of Pharmacology and Biological Chemistry, Mount Sinai School of Medicine, New York, NY 10029, USA.No affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

15110395

Citation

Caro, Andres A., and Arthur I. Cederbaum. "Antioxidant Properties of S-adenosyl-L-methionine in Fe(2+)-initiated Oxidations." Free Radical Biology & Medicine, vol. 36, no. 10, 2004, pp. 1303-16.
Caro AA, Cederbaum AI. Antioxidant properties of S-adenosyl-L-methionine in Fe(2+)-initiated oxidations. Free Radic Biol Med. 2004;36(10):1303-16.
Caro, A. A., & Cederbaum, A. I. (2004). Antioxidant properties of S-adenosyl-L-methionine in Fe(2+)-initiated oxidations. Free Radical Biology & Medicine, 36(10), 1303-16.
Caro AA, Cederbaum AI. Antioxidant Properties of S-adenosyl-L-methionine in Fe(2+)-initiated Oxidations. Free Radic Biol Med. 2004 May 15;36(10):1303-16. PubMed PMID: 15110395.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Antioxidant properties of S-adenosyl-L-methionine in Fe(2+)-initiated oxidations. AU - Caro,Andres A, AU - Cederbaum,Arthur I, PY - 2003/12/09/received PY - 2004/01/29/revised PY - 2004/02/06/accepted PY - 2004/4/28/pubmed PY - 2004/12/16/medline PY - 2004/4/28/entrez SP - 1303 EP - 16 JF - Free radical biology & medicine JO - Free Radic Biol Med VL - 36 IS - 10 N2 - S-Adenosylmethionine (SAM) is protective against a variety of toxic agents that promote oxidative stress. One mechanism for this protective effect of SAM is increased synthesis of glutathione. We evaluated whether SAM is protective via possible antioxidant-like activities. Aerobic Hepes-buffered solutions of Fe2+ spontaneously oxidize and consume O2 with concomitant production of reactive oxygen species and oxidation of substrates to radical products, e.g., ethanol to hydroxyethyl radical. SAM inhibited this oxidation of ethanol and inhibited aerobic Fe2+ oxidation and consumption of O2. SAM did not regenerate Fe2+ from Fe3+ and was not consumed after incubation with Fe2+. SAM less effectively inhibited aerobic Fe2+ oxidation in the presence of competing chelating agents such as EDTA, citrate, and ADP. The effects of SAM were mimicked by S-adenosylhomocysteine, but not by methionine or methylthioadenosine. SAM did not inhibit Fe2+ oxidation by H2O2 and was a relatively poor inhibitor of the Fenton reaction. Lipid peroxidation initiated by Fe2+ in liposomes was associated with Fe2+ oxidation; these two processes were inhibited by SAM. However, SAM did not show significant peroxyl radical scavenging activity. SAM also inhibited the nonenzymatic lipid peroxidation initiated by Fe2+ + ascorbate in rat liver microsomes. These results suggest that SAM inhibits alcohol and lipid oxidation mainly by Fe2+ chelation and inhibition of Fe2+ autoxidation. This could represent an important mechanism by which SAM exerts cellular protective actions and reduces oxidative stress in biological systems. SN - 0891-5849 UR - https://www.unboundmedicine.com/medline/citation/15110395/Antioxidant_properties_of_S_adenosyl_L_methionine_in_Fe_2+__initiated_oxidations_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0891584904001327 DB - PRIME DP - Unbound Medicine ER -