AZT treatment induces molecular and ultrastructural oxidative damage to muscle mitochondria. Prevention by antioxidant vitamins

• Published in: The Journal of clinical investigation Vol. 102; no. 1; pp. 4 - 9
• Main Authors: de la Asunción, J G, del Olmo, M L, Sastre, J, Millán, A, Pellín, A, Pallardó, F V, Viña, J
• Format: Journal Article
• Language: English
• Published: United States 01-07-1998
• Subjects: Adult; Animals; Anti-HIV Agents - adverse effects; Antioxidants - pharmacology; Ascorbic Acid - pharmacology; Deoxyguanosine - analogs & derivatives; Deoxyguanosine - urine; DNA Damage; DNA, Mitochondrial - drug effects; Humans; Hydrogen Peroxide - metabolism; Male; Mice; Mitochondria, Muscle - drug effects; Mitochondria, Muscle - ultrastructure; Vitamin E - pharmacology; Zidovudine - adverse effects
• ISSN: 0021-9738
• DOI: 10.1172/JCI1418

AIDS patients who receive zidovudine (AZT) frequently suffer from myopathy. This has been attributed to mitochondrial (mt) damage, and specifically to the loss of mtDNA. This study examines whether AZT causes oxidative damage to DNA in patients and to skeletal muscle mitochondria in mice, and whether this damage may be prevented by supranutritional doses of antioxidant vitamins. Asymptomatic HIV-infected patients treated with AZT have a higher urinary excretion (355+/-100 pmol/kg/d) of 8-oxo-7, 8-dihydro-2'-deoxyguanosine (8-oxo-dG) (a marker of oxidative damage to DNA) than untreated controls (asymptomatic HIV-infected patients) (182+/-29 pmol/kg/d). This was prevented (110+/-79 pmol/kg/d) by simultaneous oral treatment with AZT plus antioxidant vitamins (C and E). Mice treated with AZT also had a significantly higher urinary excretion of 8-oxo-dG than controls. Skeletal muscle mtDNA of mice treated with AZT had more 8-oxo-dG than controls. mt lipoperoxidation was also increased and skeletal muscle glutathione was oxidized. These effects may be due to an increased peroxide production by muscle mitochondria of AZT-treated animals. Dietary supplements with vitamins C and E at supranutritional doses protect against oxidative damage to skeletal muscle mitochondria caused by AZT.