title: Effects of alpha-lipoic acid on retinal ganglion cells, retinal thicknesses, and VEGF production in an experimental model of diabetes.
abstract: OBJECTIVE
  The purpose of the present study was to investigate the effect of alpha-lipoic acid (ALA) on the thicknesses of various retinal layers and on the numbers of retinal ganglion cells and vascular endothelial growth factor levels in experimental diabetic mouse retinas.
  
  
  METHODS
  Twenty-one male BALB/C mice were made diabetic by the intraperitoneal administration of streptozotocin (200 mg/kg). One week after the induction of diabetes, the mice were divided randomly into three groups: control group (non-diabetic mice treated with alpha-lipoic acid, n = 7), diabetic group (diabetic mice without treatment, n = 7), and alpha-lipoic acid treatment group (diabetic mice with alpha-lipoic acid treatment, n = 7). At the end of the 8th week, the thicknesses of the inner nuclear layer (INL), outer nuclear layer (ONL), and full-length retina were measured; also retinal ganglion cells and VEGF expressions were counted on the histological sections of the mouse retinas and compared with each other.
  
  
  RESULTS
  The thicknesses of the full-length retina, ONL, and INL were significantly reduced in the diabetic group compared to the control and ALA treatment groups (p = 0.001), whereas the thicknesses of these layers did not show a significant difference between ALA treatment and control groups. The number of ganglion cells in the diabetic group was significantly lower than those in the control and ALA treatment groups (p = 0.001). The VEGF expression was significantly higher in the diabetic group and mostly observed in the ganglion cell and inner nuclear layers compared to the control and ALA treatment groups (p = 0.001). Therefore, the number of ganglion cells and VEGF levels did not show significant differences between the ALA treatment and control groups (p = 0.7).
  
  
  CONCLUSIONS
  Our results show that alpha-lipoic acid treatment may have an impact on reducing VEGF levels, protecting ganglion cells, and preserving the thicknesses of the inner and outer layers in diabetic mouse retinas.
authors.affiliation: Department of Ophthalmology, Samsun Training and Research Hospital, 55100, Samsun, Turkey. dremrahkan@yahoo.com.
authors.forename: Emrah
authors.initials: E
authors.lastname: Kan
authors.affiliation: Department of Pathology, Samsun Training and Research Hospital, 55100, Samsun, Turkey.
authors.forename: Ömer
authors.initials: Ö
authors.lastname: Alici
authors.affiliation: Department of Endocrinology and Metabolism, Samsun Training and Research Hospital, 55100, Samsun, Turkey.
authors.forename: Elif Kılıç
authors.initials: EK
authors.lastname: Kan
authors.affiliation: Department of Physiology, Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkey.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Ayar
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D003921:Diabetes Mellitus, Experimental; D003930:Diabetic Retinopathy / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008807:Mice, Inbred BALB C; D012160:Retina / Q000187:drug effects* / Q000473:pathology; D012162:Retinal Degeneration / Q000517:prevention & control; D012165:Retinal Ganglion Cells / Q000187:drug effects*; D008063:Thioctic Acid / Q000494:pharmacology*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D042461:Vascular Endothelial Growth Factor A; D008063:Thioctic Acid
keywords: Alpha-lipoic acid; Antioxidants; Diabetic retinopathy; Neurodegeneration; Vascular endothelial growth factor