Abstract
A detailed evaluation of the antioxidant and pro-oxidant properties of lipoic acid (LA) and dihydrolipoic acid (DHLA) was performed. Both compounds are powerful scavengers of hypochlorous acid, able to protect α1-antiproteinase against inactivation by HOCl. LA was a powerful scavenger of hydroxyl radicals (OH-) and could inhibit both iron-dependent OH' generation and peroxidation of ox-brain phospholipid liposomes in the presence of FeCl3 -ascorbate, presumably by binding iron ions and rendering them redox-inactive. By contrast. DHLA accelerated iron-dependent OH- generation and lipid peroxidation, probably by reducing Fe3+ to Fe2+. LA inhibited this pro-oxidant action of DHLA. However, DHLA did not accelerate DNA degradation by a ferric bleomycin complex and slightly inhibited peroxidation of arachidonic acid by the myoglobin-H2O2 system. Under certain circumstances, DHLA accelerated the loss of activity of αantiproteinase exposed to ionizing radiation under a N2O/O2 atmosphere and also the loss of creatine kinase activity in human plasma exposed to gas-phase cigarette smoke. Neither LA nor DHLA reacted with superoxide radical (O2 -) or H2O2 at significant rates, but both were good scavengers of trichloromethylperoxyl radical (CCl3O2). We conclude that LA and DHLA have powerful antioxidant properties. However, DHLA can also exert pro-oxidant properties, both by its iron ion-reducing ability and probably by its ability to generate reactive sulphur-containing radicals that can damage certain proteins, such as α1-antiproteinase and creatine kinase.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 119-133 |
| Number of pages | 15 |
| Journal | Free Radical Research |
| Volume | 20 |
| Issue number | 2 |
| DOIs | |
| State | Published - 1994 |
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Keywords
- Antioxidant
- Dihydrolipoic acid
- Hydroxyl radical
- Hypochlorous acid
- Lipid peroxidation
- Lipoic acid
- Superoxide
- Trichloromethylperoxyl radical
ASJC Scopus subject areas
- Biochemistry
Cite this
Lipoic and dihydrolipoic acids as antioxidants. A critical evaluation. / Scott, Brigitte C.; Aruoma, Okezie I.; Evans, Patricia J.; O'neill, Charles; Van Der Vliet, Albert; Cross, Carroll E; Tritschler, Hans; Halliwell, Barry.
In: Free Radical Research, Vol. 20, No. 2, 1994, p. 119-133.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Lipoic and dihydrolipoic acids as antioxidants. A critical evaluation
AU - Scott, Brigitte C.
AU - Aruoma, Okezie I.
AU - Evans, Patricia J.
AU - O'neill, Charles
AU - Van Der Vliet, Albert
AU - Cross, Carroll E
AU - Tritschler, Hans
AU - Halliwell, Barry
PY - 1994
Y1 - 1994
N2 - A detailed evaluation of the antioxidant and pro-oxidant properties of lipoic acid (LA) and dihydrolipoic acid (DHLA) was performed. Both compounds are powerful scavengers of hypochlorous acid, able to protect α1-antiproteinase against inactivation by HOCl. LA was a powerful scavenger of hydroxyl radicals (OH-) and could inhibit both iron-dependent OH' generation and peroxidation of ox-brain phospholipid liposomes in the presence of FeCl3 -ascorbate, presumably by binding iron ions and rendering them redox-inactive. By contrast. DHLA accelerated iron-dependent OH- generation and lipid peroxidation, probably by reducing Fe3+ to Fe2+. LA inhibited this pro-oxidant action of DHLA. However, DHLA did not accelerate DNA degradation by a ferric bleomycin complex and slightly inhibited peroxidation of arachidonic acid by the myoglobin-H2O2 system. Under certain circumstances, DHLA accelerated the loss of activity of αantiproteinase exposed to ionizing radiation under a N2O/O2 atmosphere and also the loss of creatine kinase activity in human plasma exposed to gas-phase cigarette smoke. Neither LA nor DHLA reacted with superoxide radical (O2 -) or H2O2 at significant rates, but both were good scavengers of trichloromethylperoxyl radical (CCl3O2). We conclude that LA and DHLA have powerful antioxidant properties. However, DHLA can also exert pro-oxidant properties, both by its iron ion-reducing ability and probably by its ability to generate reactive sulphur-containing radicals that can damage certain proteins, such as α1-antiproteinase and creatine kinase.
AB - A detailed evaluation of the antioxidant and pro-oxidant properties of lipoic acid (LA) and dihydrolipoic acid (DHLA) was performed. Both compounds are powerful scavengers of hypochlorous acid, able to protect α1-antiproteinase against inactivation by HOCl. LA was a powerful scavenger of hydroxyl radicals (OH-) and could inhibit both iron-dependent OH' generation and peroxidation of ox-brain phospholipid liposomes in the presence of FeCl3 -ascorbate, presumably by binding iron ions and rendering them redox-inactive. By contrast. DHLA accelerated iron-dependent OH- generation and lipid peroxidation, probably by reducing Fe3+ to Fe2+. LA inhibited this pro-oxidant action of DHLA. However, DHLA did not accelerate DNA degradation by a ferric bleomycin complex and slightly inhibited peroxidation of arachidonic acid by the myoglobin-H2O2 system. Under certain circumstances, DHLA accelerated the loss of activity of αantiproteinase exposed to ionizing radiation under a N2O/O2 atmosphere and also the loss of creatine kinase activity in human plasma exposed to gas-phase cigarette smoke. Neither LA nor DHLA reacted with superoxide radical (O2 -) or H2O2 at significant rates, but both were good scavengers of trichloromethylperoxyl radical (CCl3O2). We conclude that LA and DHLA have powerful antioxidant properties. However, DHLA can also exert pro-oxidant properties, both by its iron ion-reducing ability and probably by its ability to generate reactive sulphur-containing radicals that can damage certain proteins, such as α1-antiproteinase and creatine kinase.
KW - Antioxidant
KW - Dihydrolipoic acid
KW - Hydroxyl radical
KW - Hypochlorous acid
KW - Lipid peroxidation
KW - Lipoic acid
KW - Superoxide
KW - Trichloromethylperoxyl radical
UR - http://www.scopus.com/inward/record.url?scp=0028345285&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0028345285&partnerID=8YFLogxK
U2 - 10.3109/10715769409147509
DO - 10.3109/10715769409147509
M3 - Article
C2 - 7516789
AN - SCOPUS:0028345285
VL - 20
SP - 119
EP - 133
JO - Free Radical Research
JF - Free Radical Research
SN - 1071-5762
IS - 2
ER -