Abstract:
objective: To study the therapeutic effects of low-intensity pulsed laser on neuropathic pain in type 2 diabetic db/db mice. Methods: Twenty male db/db mice with glucose levels higher than 16.7 mmol/L and 10 wild-type mice with the same background were used. The mice were assigned to three groups, including the control (Control), type 2 diabetic db/db (db/db) and db/db with the laser treatment (db/db+Laser) groups. The mice in the db/db+Laser group were subjected to low-intensity laser treatment with 3 sessions per day and 50 sec per session for overall 4 weeks. The mice in the control and db/db groups were subjected to the sham exposure. The paw mechanical pain threshold, thermal pain threshold, sensory nerve conduction velocity, and motor nerve conduction velocity were determined at 0, 1, 2, 3, and 4 weeks post the laser treatment. The mRNA expression levels of p38 mitogen-activated protein kinase (p38MAPK) and interleukin-1β (IL-1β) were measured. Results: In the context of not affecting the body weight and glucose in db/db mice, low-intensity laser significantly improved the paw mechanical pain threshold and thermal pain threshold levels at Week 0, 1, 2, 3, and 4 post treatment (P<0.05), and also significantly increased the sensory nerve conduction velocity and motor nerve conduction velocity in db/db mice at Week 0, 1, 2, 3, and 4 post treatment (P<0.05). Moreover, the mice in the db/db+Laser group exhibited lower spinal p38MAPK and IL-1β expression levels than those in the db/db group (P<0.05). Conclusion: Low-intensity pulsed laser showed positive therapeutic effects on mitigating neuropathic pain in type 2 diabetic db/db mice.