8-Hydroxy-2′-deoxyguanosine (8-OHdG) as a biomarker of oxidative DNA damage induced by occupational exposure to nanomaterials: a systematic review

Abstract

In nuclear and mitochondrial DNA, 8-hydroxy-2′-deoxyguanosine (8-OHdG) is one of the predominant forms of reactive oxygen species (ROSs) lesions, which commonly used as a biomarker for oxidative stress. Studies showed that the different nanomaterials can induce toxicity by ROSs in human body. So, this study is going to review the studies about oxidative DNA damage caused by occupational exposure to nanomaterials, using 8-OHdG biomarker.

Systematic review was managed based on Cochrane systematic review guideline. Literature search was conducted in scientific databases with the main terms of “biomarkers,” “biological markers,” combined with “occupational exposure” and “nanomaterials.” All papers in the field of occupational exposure to nanomaterials until 2020 December were included. To evaluate the quality and bias of studies, GRADE method (Grading of Recommendations, Assessment, Development, and Evaluation) was used.

Two hundred twenty-six studies were primarily achieved. By considering the inclusion criteria, overall 8 articles were selected. The majority of the studies were classified as the moderate quality studies (six studies). Also, the study-level bias was critical. This review shows that there is a significant relationship between job title and amount of produced nanomaterials and the existence of 8-OHdG. Also, the levels of 8-OHdG can be measured in urine, blood, and inhalation samples by instrumental procedures.

Oxidative damages are an important threat for workers exposed to nanomaterial. Blood and EBC 8-OHdG level can be introduced as a biomarker for metal nanomaterials, but urinary 8-OHdG needs to be taken with caution. So, it is recommended that evaluation not be solely based on one biomarker.

Keywords:

• Oxidative damage
• 8-OHdG
• biomarker
• nanomaterial
• occupational exposure

Acknowledgments

The authors would like to express our special appreciation of Dr Rasoul Yarahmadi, a professor of occupational health science and engineering at Iran university of medical sciences, who helped to managing this study. Their willingness to give their time so kindly is very much appreciated.

Ethical approval

The authors had not applied for ethics committee approval, as it was based on the available studies or literature search method, it was not experimental.

Disclosure statement

The authors declare that they have no conflict of interest.

Data availability statement

All data generated during this study are included in this published article.