Nociceptive spinal cord neurons laminae I-III exhibit oxidative stress damage during diabetic neuropathy which is prevented by early antioxidant treatment with epigallocatechin-gallate (EGCG)

• Type: Article in International Scientific Journal
• Date: 2015

Authors

Raposo, D (Author) Other; Morgado, C (Author) Other; Pereira Terra, P (Author) Other; Isaura Tavares (Author) FMUP

Journal

Title: Brain Research Bulletin

Vol. 110

Pages: 68-75

ISSN: 0361-9230

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 35 Citations

Scopus - 39 Citations

Other information

Authenticus ID: P-00A-2D8

DOI: 10.1016/j.brainresbull.2014.12.004

Abstract (EN): Spinal cord neurons located in laminae I-III respond to nociceptive stimuli and participate in the transmission of painful information to the brain. In the present study we evaluated if nociceptive laminae I-III neurons are affected by oxidative stress damage in a model of diabetic neuropathic pain (DNP), the streptozotocin-induced diabetic rat (STZ rat). Additionally, we evaluated the effects of a preventive antioxidant treatment with epigallocatechin-gallate (EGCG) in nociceptive neuronal activation and behavioural signs of DNP. Three days after diabetes induction, a treatment protocol of STZ rats with an aqueous solution of EGCG in the drinking water was initiated. Ten weeks after the onset of treatment, the spinal cords were immunoreacted against validated markers of oxidative stress damage (8-hydroxy-2'-deoxyguanosine; 8-OHdG) and of nociceptive neuronal activation (Fos). Mechanical hypersensitivity was assessed before and after EGCG treatment. Untreated STZ rats presented increased levels of 8-OHdG immunoreaction, higher numbers of Fosimmunoreacted neurons and high levels of co-localization of 8-OHdG and Fos in laminae I-III. Treatment with EGCG normalized the increase of the above mentioned parameters and ameliorated mechanical hypersensitivity. The present study shows that nociceptive neurons in spinal cord laminae I-III exhibit oxidative stress damage during diabetic neuropathy, which probably affects ascending pain transmission during DNP. The neurobiological mechanisms and translational perspectives of the beneficial effects of a preventive and sustained EGCG treatment in DNP need to be evaluated in the future.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8