Although chemotherapy succeeds in reducing tumor burden, the efficacy is limited due to acquired drug resistance and often irreparable side effects. Studies show that antioxidants may influence the response to chemotherapy and its side effects, although their use remains controversial. The evidence shows that some chemo-drugs induce oxidative stress and lead to normal tissue apoptosis and the entry of cancer cells to a dormant G0 state. Through the suppression of oxidative stress, antioxidants could protect normal cells and bring the tumor out of dormancy so as to expose it to chemotherapies. This review is focused on the redox biology of cancer/normal cells and association of reactive oxygen species with drug resistance, cancer dormancy, and side effects. To this end, evidence from cellular, animal, and clinical studies is provided to better understand the conundrum of dietary antioxidants in cancer chemotherapy.

Metadiscourse markers (MDMs) are lexical resources that writers employ to organize their discourse and state their stance towards the content or the reader. This study investigated the frequency with which interactive and interactional MDMs were employed in biological research articles (RAs). It also explored the possible relationship between the frequency of these markers and Impact Factor (IF) of journals as an index of quality. Moreover, it aimed at finding out the difference(s) between two groups of authors (Iranian and American) in their use of these markers. Forty biological RAs published in years 2008-2011 written by Iranian non-native authors and published in four ISI journals with different IFs and 40 articles with the same characteristics published by American native authors were selected and examined for the use of the markers. The results showed that there was a strong positive correlation between the frequency of MDMs and IF of the journals. Regarding the frequency of MDMs, it was observed that Iranian authors employed interactive and interactional markers slightly more than their American counterparts. These results may provisionally confirm the considerable role of MDMs in enhancing the coherence and organization of articles for possible publication in high-impact journals. © 2016 by The International Union of Biochemistry and Molecular Biology, 44(4):349-360, 2016.