Vitamin E (a-tocopherol) is a major lipid antioxidant in
the membranes of cells and subcellular organelles. It can
react directly with free radicals and interrupt lipid peroxidation
by scavenging the thiobarbituric acid reactive substances.
15 Vitamin C (ascorbic acid) is an important watersoluble
vitamin and has a synergistic effect with vitamin E,
which can reduce the tocopheroxyl radical, an oxidized
form of a-tocopherol, back to a-tocopherol.16 It is not only
a potent antioxidant against free radicals, but also has
prooxidant activity as a result of the Fenton reaction; a
process in which free radicals are formed.17 The results
reported about the serum levels of vitamins in RAS patients
with active lesions were inconsistent. Decreased serum
levels of vitamins A, C, and E in RAS patients with active
lesion were demonstrated by Saral et al,9 whereas a
converse conclusion was observed by Khademi et al,10 who
detected no significant differences in vitamins between RAS
patients with active lesions and healthy controls. In the
current study, the minimum serum vitamin E level was in
Group A, which indicated that there was a deficiency of
vitamin E during the active phase of RAS. However, there
was no significant difference in serum vitamin C level between
any two groups, which may be explained by the
double-faced character of vitamin C.
There were two limitations to the current study. First,
the age of the participants was low, which may have been
due to the frequent occurrence of minor RAS in young
adults. Second, disease severity was not considered. As the
patients with major and herpetiform RAS were excluded, it
is uncertain whether the current results obtained would be
the same with different types of RAS patients. Future
studies with a larger number of patients should be performed
to clarify this question.
In conclusion, the elevated serum MDA level and
decreased vitamin E level in RAS patients with active lesions
indicate that there is increased oxidative stress.
Moreover, there were no significant differences between
RAS patients in the remission stage and healthy individuals
with regards to the parameters investigated in this study,
indicating that the balance of oxidant/antioxidant systems
is recovered in the remission stage of RAS.
Conflict of interest
The authors have no conflicts of interest relevant to this
article.
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