Kazuhiko Uchiyama¹, Yuji Naito¹, Goji Hasegawa¹, Naoto Nakamura¹, Jiro Takahashi², Toshikazu Yoshikawa¹
¹First Department of Medicine, Kyoto Prefectural University of Medicine, Kyoto, Japan
²Fuji Chemical Industry Co. Ltd, Toyama, Japan
Oxidative stress induced by hyperglycemia possibly causes the dysfunction of pancreatic ß-cells and various forms of tissue damage in patients with diabetes mellitus. Astaxanthin, a carotenoid of marine microalgae, is reported as a strong antioxidant inhibiting lipid peroxidation and scavenging reactive oxygen species. The aim of the present study was to examine whether astaxanthin can elicit beneficial effects on the progressive destruction of pancreatic ß-cells in db/db mice – a well-known obese model of type 2 diabetes. We used diabetic C57BL/KsJ-db/db mice and db/m for the control. Astaxanthin treatment was started at 6 weeks of age and its effects were evaluated at 10, 14, and 18 weeks of age by non-fasting blood glucose levels, intraperitoneal glucose tolerance test including insulin secretion, and ß-cell histology. The non-fasting blood glucose level in db/db mice was significantly higher than that of db/m mice, and the higher level of blood glucose in db/db mice was significantly decreased after treatment with astaxanthin. The ability of islet cells to secrete insulin, as determined by the intraperitoneal glucose tolerance test, was preserved in the astaxanthin-treated group. Histology of the pancreas revealed no significant differences in the ß-cell mass between astaxanthin-treated and -untreated db/db mice. In conclusion, these results indicate that astaxanthin can exert beneficial effects in diabetes, with preservation of ß-cell function. This finding suggests that antioxidants may be potentially useful for reducing glucose toxicity.
To continue reading: Astaxanthin protects ß-cells against glucose toxicity in diabetic db/db mice
