Clinical Research
Copyright ©2006 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Sep 28, 2006; 12(36): 5846-5852
Published online Sep 28, 2006. doi: 10.3748/wjg.v12.i36.5846
Improved method of plasma 8-Isoprostane measurement and association analyses with habitual drinking and smoking
Soichi Kitano, Hisashi Hisatomi, Nozomu Hibi, Katsumi Kawano, Shoji Harada
Soichi Kitano, Hisashi Hisatomi, Nozomu Hibi, Katsumi Kawano, Technology Development Department, SRL Inc., Hachioji, Tokyo, Japan
Shoji Harada, Center for Molecular Biology and Cytogenetics, SRL Inc. , Hino, Tokyo, Japan
Author contributions: All authors contributed equally to the work.
Correspondence to: Soichi Kitano, Development Planning Section, Technology Development Department, SRL Inc., 5-6-50 Shinmachi, Hino-shi, Tokyo, 191-0002, Japan. kitano@srl.srl-inc.co.jp
Telephone: +81-42-6484076 Fax: +81-42-6484094
Received: April 13, 2006
Revised: July 5, 2006
Accepted: July 20, 2006
Published online: September 28, 2006
Abstract

AIM: To develop a simple and accurate method for quantifying 8-isoprostane in plasma by employing a combination of two-step solid-phase extraction of samples and a commercially available ELISA kit, and by this method to examine the effects of drinking and smoking habits against the levels of plasma 8-isoprostane in healthy Japanese volunteers.

METHODS: Plasma 8-isoprostane was extracted with ODS gel suspension followed by NH2 Sep-Pak column. The 8-isoprostane fractions were assayed using a commercially available ELISA kit. We measured plasma 8-isoprostane levels in 157 healthy Japanese volunteers divided into three groups (64 non-habitual drinkers, 56 moderate drinkers and 37 habitual drinkers) according to their alcohol consumption per week. Genotypes of aldehyde dehydrogenase 2 (ALDH2) were also determined to investigate the plasma 8-isoprostane levels with reference to drinking habits. In addition, the plasma 8-isoprostane levels of 96 non-smokers and 61 smokers from the same subjects were compared.

RESULTS: Our method fulfilled all the requirements for use in routine clinical assays with respect to sensitivity, intra- and inter-assay reproducibility, accuracy and dynamic assay range. Significant increases of plasma 8-isoprostane levels were observed in female habitual drinkers when compared with those of non-habitual drinkers (t = 5.494, P < 0.0001) as well as moderate drinkers (t = 3.542, P < 0.005), and 8-isoprostane levels were also significantly different between ALDH2*2/1 and ALDH2*1/1 in the female habitual drinkers (t = 6.930, P < 0.0001), suggesting that excessive drinking of alcohol may increase oxidization stress, especially in females. On the contrary, no significant difference of the plasma 8-isoprostane levels was observed between non-smokers and smokers.

CONCLUSION: Our present method was proved to be a simple and accurate tool for measuring plasma 8-isoprostane. However, the clinical utility of plasma 8-isoprostane for drinking and smoking habits was limited since elevated 8-isoprostane levels were observed in female heavy drinkers, and no association was found between smokers and nonsmokers.

Keywords: 8-Isoprostane, ELISA, Lipid peroxidation, Drinking, Smoking