basement membrane, disrupt cell metabolism, and
MDA reactions with DNA will form mutagenic
MDA deoxyguanosine (Mi-dG) (Choi, 1999; Drake,
1998).
Production of ROS in the H. pylori-infected
gastric epithelium is linked to the presence of
cagPAI and contribute to the oxidative stress
response in gastric epithelial cells (Ding, 2007). It is
well known that H. pylori infection causes elevated
level of polyamines, in particular spermine and this
is associated with an induction of spermine oxidase
(Cheng, 2009). Action of spermine oxidase on
spermine leads to the production of elevated levels
of hydrogen peroxide, which is a powerful oxidizing
agent and also contributes to the production of free
radicals such as hydroxyl radial (Xu, 2004).
Additionally, H. pylori will activate macrophages
which will result in a significant upregulation of
spermine oxidase, contributing to oxidative stress
and damage to the gastric epithelial cells
(Chaturvedi, 2004).
In a previous study, Subha et al reported that
there were statistically significant decrease of mean
GPX levels in cancer patients compared to control
groups. Cancer patients showed a lower mean of
GPX levels than control group. Research on GPX
levels in patients with premalignant lesions of
gastric is still limited. In this study there were
significant difference in GPX levels among chronic
atrophic gastritis, intestinal metaplasia, and
dysplasia. GPX levels were significantly lower in
patients with dysplasia than chronic atrophic
gastritis and there were no significant difference in
GPX levels between patients with intestinal
metaplasia and chronic atrophic gastritis or
dysplasia. Lower GPX levels are associated with the
progression of precancerous lesions, which is
supported by GPX levels that were significantly
lower in dysplasia than chronic atrophic gastritis.
This study showed that antioxidant supplements may
be considered in patients with gastric premalignant
lesions. A further study is needed to evaluate the
antioxidant options and their role in the
improvement of oxidative stress in patients with
gastric premalignant lesion.
5 CONCLUSION
GPX levels were significantly lower in patients with
dysplasia than chronic atrophic gastritis.
ACKNOWLEDGEMENT
The authors would like to thank for the funding
support by Research Institute, Universitas Sumatera
Utara (Contract number : 61/UN5.2.3.1/PPM-KP-
TALENTAUSU/2018)
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