Chronic intracerebroventricular administration of dimethyl sulfoxide attenuates streptozotocin-iduced memory loss in rats

Background: The memory impairment, obtained from intracerebroventricular (i.c.v.) infusion of streptozotocin (STZ) in rats through activation of oxidative stress, is accepted as sporadic Alzheimer&rsquo;s disease (AD) model in most experimental studies. Dimethyl sulfoxide (DMSO) as a solvent is widely used in animal studies to have antioxidant effects as well. However, no report is available about DMSO effect on oxidative stress-induced cognition deficit i.e. AD. The present work was designed to assess the effect of chronic treatment of DMSO on STZ-treated rats. Materials and Methods: STZ (3 mg/ kg i.c.v. bilateral with 10 &micro;l volume in either side days 1 and 3) using a single-day version of Morris water maze (MWM). The DMSO (2.5, 5 and 10 %v/v in saline), started from the first day, was infused for 14 days. Results: The chronic administration of DMSO 10% (but not 2.5 and 5%) improved the distance to hidden platform (P<0.01) in training sessions and time spent in the target quadrant (P<0.01) in probe tests. Neither STZ nor DMSO had any intervention on velocity and visuo-motor coordination in the visible version of MWM. Conclusion: Taken together, the results suggest that DMSO may be appropriate as adjuvant therapies for the prevention of memory impairment in the experimental models of AD. Therefore, use of DMSO as a solvent in AD animal studies should be considered having beneficial effects on cognitive function.