Laser research: Diabetes


Photomedicine and Laser Surgery, Volume 31, Number 7, 2013

The Effects of Low-Level Laser Therapy on Palatal Mucoperiosteal Wound Healing and Oxidative Stress Status in Experimental Diabetic Rats

Ela Tules Firat, PhD,1 Ahmet Dag� , PhD,1 Ahmet Gu¨nay, PhD,1 Beyza Kaya, PhD,2 Mehmet _Irfan Karadede, PhD,3
Berna Erso¨z Kanay, PhD,4 Aydin Ketani, PhD,5 Osman Evliyaog� lu, MD,6 and Ersin Uysal, PhD7

Objective: The biostimulation effects of low-level laser therapy (LLLT) have recently been demonstrated. In this study, we aimed to investigate the effects of LLLT on palatal mucoperiostal wound healing and oxidative stress status in experimental diabetic rats.

Methods: Forty-two male Wistar rats that weighed 250�300 g were used in this study. Experimental diabetes was induced in all of the rats using streptozotocin. A standardized full thickness wound was made in the mucoperiosteum of the hard palates of the rats using a 3mm biopsy punch. The rats were divided into groups: 1 (control group, non- irradiated), and 2 (experimental group, irradiated). Treatment using a GaAlAs laser at a wavelength of 940nm and at dose of 10 J/cm2 began after surgery, and was repeated on the 2nd, 4th, and 6th days post-surgery. Seven animals from each group were killed on the 7th, 14th, and 21st day after surgery. Biopsies were performed for the histological analysis and blood samples were collected by cardiac puncture for biochemical analysis.

Results: The histopathological findings revealed reduced numbers of inflammatory cells, and increased mitotic activity of fibroblasts, collagen synthesis, and vascularization in rats in group 2. The total oxidative status was significantly decreased in the laser-treated group on the 21st day.

Conclusion: LLLT elicits a positive healing effect on palatal mucoperiostal wounds, and modulates the oxidative status in experimental diabetic rats.

Lasers Surg. Med. 45:240�245, 2013.

Testing Infrared Laser Phototherapy (810 nm) to Ameliorate Diabetes: Irradiation on Body Parts of Diabetic Mice

Philip V. Peplow, PhD and G. David Baxter, DPhil, Department of Anatomy, University of Otago, Dunedin 9010, New Zealand
Centre for Physiotherapy Research, School of Physiotherapy, University of Otago, Dunedin 9010, New Zealand

Background and Objective: Irradiation of left flank of genetic diabetic mice with 660 nm wavelength laser, 100 mW, 20 seconds/day for 7 days did not significantly alter blood plasma glucose compared to nonirradiated controls. Infrared light would provide for a greater amount of photoenergy penetrating the skin and muscle. Genetic diabetic mice were irradiated with 810 nm wavelength laser to test for antidiabetic effect.

Methods: Sixty-five diabetic mice were used. Body weight and water intake of mice were measured daily for 7 days prior to start of treatment (Day 0). Mice were irradiated with 810 nm wavelength laser, 50 mW, 40 seconds/day, 7 days on left flank (n ¼ 11), mid-upper abdomen (n ¼ 14), or left inguinal region (n ¼ 14); some mice were not irradiated (control, n ¼ 26). Body weight and water intake of mice were measured to Day 7. On Day 7, mice were fasted for 4 hours, anesthetized with sodium pentobarbitone (s.c.) and blood collected by cardiac puncture into EDTA-treated tubes. Blood plasma was assayed for glucose and fructosamine. Blood was collected and assayed from nonirradiated nondiabetic mice (n ¼ 12).

Results: On Day 7 body weight was significantly lower and water intake significantly higher compared to Day 0 for diabetic mice irradiated on left flank (40.7 0.5 vs. 42.2 0.4 g, 28.2 1.5 vs. 23.4 1.5 g, respectively); there was no significant change for diabetic mice irradiated on mid-upper abdomen or left inguinal region and also for nonirradiated diabetic mice. On Day 7 blood plasma glucose levels for irradiated diabetic mice were not significantly different to nonirradiated diabetic mice. Blood plasma fructosamine level of diabetic mice irradiated on left inguinal region was significantly lower than for nonirradiated diabetic mice (312 6 vs. 377 15 mmol/L); for diabetic mice irradiated on left flank or mid-upper abdomen (362 22, 357 19 mmol/L) it was not significantly different to nonirradiated diabetic mice.

Conclusion: Irradiation of left inguinal region in diabetic mice with 810 nm laser has potential to ameliorate diabetes as shown by decreased blood plasma fructosamine.