BACKGROUND: Phenylketonuria (PKU), an inborn error of metabolism, is treated with a low phenylalanine (Phe) lifelong diet, which can be characterized as vegetarian. 8-Hydroxy-2-deoxyguanosine (8-OHdG) is highly implicated in degenerative diseases. OBJECTIVE: To evaluate the effect of plasma total antioxidant status (TAS) and Phe on the serum marker of DNA damage, 8-OHdG, in PKU. METHODS: Twenty-four PKU patients on a strict diet (group A), 25 PKU patients on a "loose diet" (group B), and 24 healthy children (controls) participated in this study. Plasma TAS was evaluated spectrophotometrically. 8-OHdG and Phe were measured in blood with immunoassays. RESULTS: TAS levels were significantly higher (P < 0.001) in group A (1458 +/- 140 micromol/L) and controls (1452 +/- 235 micromol/L) than those in group B (907 +/- 150 micromol/L). In contrast, 8-OHdG serum levels were 2-fold higher in group B (0.22 +/- 0.03 ng/mL) as compared with those in group A (0.11 +/- 0.02 ng/mL) and 3-fold higher than those in controls (0.08 +/- 0.02 ng/mL) (P < 0.001). As expected, Phe levels were also significantly higher in group B than those in the other study groups. Positive correlation coefficients were found between Phe and 8-OHdG levels, whereas negative correlations were evaluated between TAS and 8-OHdG in all groups. CONCLUSIONS: The high Phe and the low TAS plasma levels in PKU patients on a "loose diet" may induce DNA oxidation, as evidenced by the measured high 8-OHdG level in their sera. 8-OHdG evaluation may be a useful marker of increased risk for a neurodegenerative process.
BACKGROUND:Phenylketonuria (PKU), an inborn error of metabolism, is treated with a low phenylalanine (Phe) lifelong diet, which can be characterized as vegetarian. 8-Hydroxy-2-deoxyguanosine (8-OHdG) is highly implicated in degenerative diseases. OBJECTIVE: To evaluate the effect of plasma total antioxidant status (TAS) and Phe on the serum marker of DNA damage, 8-OHdG, in PKU. METHODS: Twenty-four PKUpatients on a strict diet (group A), 25 PKUpatients on a "loose diet" (group B), and 24 healthy children (controls) participated in this study. Plasma TAS was evaluated spectrophotometrically. 8-OHdG and Phe were measured in blood with immunoassays. RESULTS:TAS levels were significantly higher (P < 0.001) in group A (1458 +/- 140 micromol/L) and controls (1452 +/- 235 micromol/L) than those in group B (907 +/- 150 micromol/L). In contrast, 8-OHdG serum levels were 2-fold higher in group B (0.22 +/- 0.03 ng/mL) as compared with those in group A (0.11 +/- 0.02 ng/mL) and 3-fold higher than those in controls (0.08 +/- 0.02 ng/mL) (P < 0.001). As expected, Phe levels were also significantly higher in group B than those in the other study groups. Positive correlation coefficients were found between Phe and 8-OHdG levels, whereas negative correlations were evaluated between TAS and 8-OHdG in all groups. CONCLUSIONS: The high Phe and the low TAS plasma levels in PKUpatients on a "loose diet" may induce DNA oxidation, as evidenced by the measured high 8-OHdG level in their sera. 8-OHdG evaluation may be a useful marker of increased risk for a neurodegenerative process.
Authors: Priscila Nicolao Mazzola; George Albert Karikas; Kleopatra H Schulpis; Carlos Severo Dutra-Filho Journal: Metab Brain Dis Date: 2013-05-09 Impact factor: 3.584
Authors: A Sitta; A G Barschak; M Deon; T Terroso; R Pires; R Giugliani; C S Dutra-Filho; M Wajner; C R Vargas Journal: Metab Brain Dis Date: 2006-12-05 Impact factor: 3.584
Authors: A Sitta; C S Vanzin; G B Biancini; V Manfredini; A B de Oliveira; C A Y Wayhs; G O S Ribas; L Giugliani; I V D Schwartz; D Bohrer; S C Garcia; M Wajner; C R Vargas Journal: Cell Mol Neurobiol Date: 2010-12-30 Impact factor: 5.046