Reduction of diabetes-induced renal oxidative stress by a cantaloupe melon extract/gliadin biopolymers, oxykine, in mice

Article type: Research Article

Authors: Naito, Yuji | Akagiri, Satomi | Uchiyama, Kazuhiko | Kokura, Satoshi | Yoshida, Norimasa | Hasegawa, Goji | Nakamura, Naoto | Ichikawa, Hiroshi | Toyokuni, Shinya | Ijichi, Tetsuo | Yoshikawa, Toshikazu

Affiliations: Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kamigyo-ku, Kyoto 602-8566, Japan | Inflammation and Immunology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kamigyo-ku, Kyoto 602-8566, Japan | Department of Biomedical Safety Science, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kamigyo-ku, Kyoto 602-8566, Japan | Endocrinology and Metabolism, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kamigyo-ku, Kyoto 602-8566, Japan | Department of Food Sciences and Nutritional Health, The Faculty of Human Environment, Kyoto Prefectural University, Kyoto 606-8522, Japan | Department of Pathology and Biology of Diseases, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan | Combi Corp., Saitama 338-0832, Japan

Note: [] Address for correspondence: Dr. Yuji Naito, Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan. Fax: +81 75 252 3721; E-mail: ynaito@koto.kpu-m.ac.jp

Abstract: Oxidative stress is implicated as an important mechanism by which diabetes causes nephropathy. Oxykine is the cantaloupe melon extract rich in vegetal superoxide dismutase covered by polymeric films of wheat matrix gliadin. In this study, we examined whether chronic oral administration of oxykine could prevent the progression of diabetic nephropathy induced by oxidative stress using preclinical rodent model of type 2 diabetes. We used female db/db mice and their non-diabetic db/m littermates. The mice were divided into the following three groups: non-diabetic db/m; diabetic db/db, and diabetic db/db treated with oxykine. Blood glucose level, body weight, urinary albumin, and urinary 8-hydroxydeoxyguanosine (8-OHdG) were measured during the experiments. Histological and 8-OHdG immunohistochemical studies were preformed on 12 weeks from the beginning of treatment. After 12 weeks of treatment, the levels of blood glucose and the body weight were not significantly different between the oxykine-treated group and the non-treated db/db group, however both groups kept significantly high levels rather than db/m mice. The relative mesangial area calculated by mesangial area/total glomerular area ratio was significantly ameliorated in the oxykine treated group compared with non-treated db/db group. The increases in urinary albumin and 8-OHdG at 12 weeks of treatment were significantly inhibited by chronic treatment with oxykine. The 8-OHdG immunoreactive cells in the glomeruli of non-treated db/db mice were more numerous than that of oxykine-treated db

Journal: BioFactors, vol. 23, no. 2, pp. 85-95, 2005