TY - JOUR
T1 - Influence of flavan-3-ols and procyanidins on UVC-mediated formation of 8-oxo-7,8-dihydro-2′-deoxyguanosine in isolated DNA
AU - Ottaviani, Javier I.
AU - Carrasquedo, Fernando
AU - Keen, Carl L
AU - Lazarus, Sheryl A.
AU - Schmitz, Harold H.
AU - Fraga, Cesar G.
PY - 2002
Y1 - 2002
N2 - The flavan-3-ols (-)-epicatechin (epicatechin) and (+)-catechin (catechin) and their related oligomers (procyanidins) isolated from cocoa were assayed for their capacity to inhibit the UVC-mediated formation of 8-oxo-7,8-dihydro-2′-deoxyguanosine (oxo8dG) in calf thymus DNA. The above-mentioned compounds inhibited oxo8dG production in a concentration- and time-dependent manner. After 30 min of irradiation (30 kJ/m2), 0.1, 1.0, 10, and 100 μM epicatechin inhibited oxo8dG formation by 20, 36, 64, and 74%, respectively. For the same dose of UVC, 0.1, 1.0, 10, and 100 μM catechin inhibited oxo8dG formation by 1, 23, 50, and 70%, respectively. Epicatechin was more efficient than catechin with respect to inhibiting oxo8dG formation (IC50 1.7 ± 0.7 vs 4.0 ± 0.7 μM). Monomer, tetramer, and hexamer fractions were equally effective in inhibiting oxo8dG formation when assayed at 10 μM monomer equivalent concentration. At similar concentrations (1-50 μM), the inhibition of the UVC-mediated oxo8dG formation by flavan-3-ols and procyanidins was in the range of that of α-tocopherol, Trolox, ascorbate, and glutathione. These results support the concept that flavan-3-ols and their related procyanidins can protect DNA from oxidation at concentrations that can be physiologically relevant. Both epimerism and degree of oligomerization are important determinants of the antioxidant activity of flavan-3-ols and procyanidins.
AB - The flavan-3-ols (-)-epicatechin (epicatechin) and (+)-catechin (catechin) and their related oligomers (procyanidins) isolated from cocoa were assayed for their capacity to inhibit the UVC-mediated formation of 8-oxo-7,8-dihydro-2′-deoxyguanosine (oxo8dG) in calf thymus DNA. The above-mentioned compounds inhibited oxo8dG production in a concentration- and time-dependent manner. After 30 min of irradiation (30 kJ/m2), 0.1, 1.0, 10, and 100 μM epicatechin inhibited oxo8dG formation by 20, 36, 64, and 74%, respectively. For the same dose of UVC, 0.1, 1.0, 10, and 100 μM catechin inhibited oxo8dG formation by 1, 23, 50, and 70%, respectively. Epicatechin was more efficient than catechin with respect to inhibiting oxo8dG formation (IC50 1.7 ± 0.7 vs 4.0 ± 0.7 μM). Monomer, tetramer, and hexamer fractions were equally effective in inhibiting oxo8dG formation when assayed at 10 μM monomer equivalent concentration. At similar concentrations (1-50 μM), the inhibition of the UVC-mediated oxo8dG formation by flavan-3-ols and procyanidins was in the range of that of α-tocopherol, Trolox, ascorbate, and glutathione. These results support the concept that flavan-3-ols and their related procyanidins can protect DNA from oxidation at concentrations that can be physiologically relevant. Both epimerism and degree of oligomerization are important determinants of the antioxidant activity of flavan-3-ols and procyanidins.
KW - Antioxidants
KW - Cardiovascular disease
KW - Cocoa
KW - Flavan-3-ols
KW - Flavonoids
KW - Mutation
KW - Polyphenols
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U2 - 10.1016/S0003-9861(02)00455-1
DO - 10.1016/S0003-9861(02)00455-1
M3 - Article
C2 - 12361708
AN - SCOPUS:0036401135
VL - 406
SP - 203
EP - 208
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
SN - 0003-9861
IS - 2
ER -