Thesis (M.Sc.) - Cairo University - Faculty of Medicine - Department of Pharmacology

Background and aim: Diabetic neuropathy (DN) is a major complication of diabetes frequently accompanied with pain sensation. Pathogenesis of painful diabetic neuropathy is multifactorial. Many factors including metabolic, vascular and immunological components are involved in the pathogenesis. Doxycycline, a second generation tetracycline, is well known to have anti-inflammatory effect beyond its antimicrobial activity. Objectives: The present study was designed to investigate the potential role of Doxycycline in treatment of painful diabetic neuropathy in comparison with pregabalin materials and methods: Male wistar strain rats weighing (150-200g) were used. Diabetic neuropathy was induced in rat by I.P. injection of single dose of STZ 50mg/kg. Two doses of Doxycycline 50 and 100 mg/kg were examined. Pregabalin was used as a standard drug for comparison. Tests for mechanical and thermal allodynia and hyperalgesia were used to assess the antinociceptive effect of the tested drugs. The serum level of glucose and HBA1C were measured and the level of IL-1Ý and TNF-Ü in spinal cord homogenate were measured. Moreever, histopathological examination of sciatic nerve was done. Results: The results of the present study showed that doxycycline administration in the two specified doses showed significant improvement of measurement of all behavioral tests including hot plate, analgesy-meter tests and acetone test which was comparable with that occurred with administration of Pregabalin. Both doxycycline tested doses and pregabalin administrated to hyperglycemic rats produced significant reduction in levels of IL1 beta and TNF alpha in spinal cord homogenate and significant reduction of blood glucose level in diabetic rats

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