Measurement of 8-hydroxyguanine as an oxidative stress biomarker in saliva by HPLC-ECD

Kazuaki Kawai, Hiroshi Kasai, Yun-Shan Li, Yuya Kawasaki, Shintaro Watanabe, Masanori Ohta, Toru Honda, Hiroshi Yamato

Oxidative stress leads to many kinds of diseases. Currently, urinary 8-hydroxydeoxyguanosine (8-OHdG) is widely measured as an oxidative stress biomarker. There is a specific advantage if saliva can be used as the sample to measure the oxidative stress biomarker, because saliva is much easier to collect than urine. In this study, we investigated the measurement of 8-hydroxyguanine (8-OHGua) as an oxidative stress marker in saliva, by a column switching HPLC system equipped with an electrochemical detector (HPLC-ECD). The 8-OHGua in saliva could be detected as a single peak by HPLC-ECD. The average level of 8-OHGua in saliva was 3.80 ng/mL in ordinary, non-smoking subjects. The salivary 8-OHGua levels of smokers were significantly higher than those of non-smokers. Salivary 8-OHGua may be a useful noninvasive and promising oxidative stress biomarker.