Reduction of DNA damage in older healthy adults by Tri E Tocotrienol supplementation.
OBJECTIVE
The free radical theory of aging (FRTA) suggests that free radicals are the leading cause of deteriorating physiologic function during senescence. Free radicals attack cellular structures or molecules such as DNA resulting in various modifications to the DNA structures. Accumulation of unrepaired DNA contributes to a variety of disorders associated with the aging process.


METHODS
A randomized, double-blinded placebo-controlled study was undertaken to evaluate the effect of Tri E Tocotrienol on DNA damage. Sixty four subjects 37-78 y old completed the study. A daily dose of 160 mg of Tri E Tocotrienol was given for 6 months. Blood samples were analyzed for DNA damage using comet assay, frequency of sister chromatid exchange (SCE), and chromosome 4 aberrations.


RESULTS
Results showed a significant reduction in DNA damage as measured by comet assay after 3 mo (P < 0.01) and remained low at 6 mo (P < 0.01). The frequency of SCE was also reduced after 6 mo of supplementation (P < 0.05), albeit more markedly in the >50 y-old group (P < 0.01) whereas urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels were significantly reduced (P < 0.05). A strong positive correlation was observed between SCE with age, whereas weak positive correlations were observed in DNA damage and 8-OHdG, which were reduced with supplementation. However, no translocation or a stable insertion was observed in chromosome 4.


CONCLUSIONS
Tri E Tocotrienol supplementation may be beneficial by reducing DNA damage as indicated by a reduction in DNA damage, SCE frequency, and urinary 8-OHdG.
Chin
Siok-Fong
SF
Department of Biochemistry, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia.
Hamid
Noor Aini Abdul
NA
Latiff
Azian Abdul
AA
Zakaria
Zaiton
Z
Mazlan
Musalmah
M
Yusof
Yasmin Anum Mohd
YA
Karim
Aminuddin Abdul
AA
Ibahim
Johari
J
Hamid
Zalina
Z
Ngah
Wan Zurinah Wan
WZ
D000080242:8-Hydroxy-2'-Deoxyguanosine; D000328:Adult; D000368:Aged; D000375:Aging; D000975:Antioxidants / Q000494:pharmacology*; D002894:Chromosomes, Human, Pair 4 / Q000187:drug effects; D020552:Comet Assay; D004249:DNA Damage / Q000187:drug effects*; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000652:urine; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D017382:Reactive Oxygen Species; D012854:Sister Chromatid Exchange / Q000187:drug effects; D024508:Tocotrienols / Q000494:pharmacology*
D000975:Antioxidants; D017382:Reactive Oxygen Species; D024508:Tocotrienols; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine