doi:10.1038/nindia.2015.135 Published online 17 October 2015
Researchers have gained new insights into the circadian rhythm (24-hour cycle) of antioxidant enzymes and lipid peroxides in ulcer patients1. These insights promise to yield better therapeutic avenues for treating ulcers.
The stomach keeps harmful pathogens at bay by secreting strong acid and counters pathogen-induced oxidative stress by employing antioxidant enzymes. But persistent bacteria such as Helicobacter pylori can overcome these defenses and trigger peptic ulcers. Previous studies had linked the circadian rhythm of oxidative stress makers (antioxidant enzymes and lipid peroxides) to various diseases, but not to peptic ulcers.
The researchers measured the blood levels of various antioxidant enzymes and analysed lipid peroxidation in terms of malondialdehyde for both ulcer patients and healthy individuals every 6 hours for a week.
They found ulcer patients had lower malondialdehyde levels, which caused an imbalance between protective and degrading factors at the tissue and cellular levels, resulting in mucosal erosion and ulcer formation in the stomach. The researchers also found that levels of superoxide dismutase, glutathione reductase and glutathione peroxidase, which remove cell-damaging reactive oxygen species such as hydrogen peroxide, were lower in ulcer patients.
A clear circadian pattern was identified in the activities and levels of all the antioxidant enzymes, suggesting that they can be used as markers to optimize the timing and efficacy of ulcer treatment, the researchers say.
1. Singh, R. et al. Circadian time structure of circulating plasma lipid peroxides, antioxidant enzymes and other small molecules in peptic ulcers. Clin. Chim. Acta (2015) doi:10.1016/j.cca.2015.09.033