The impact of electronic cigarette aerosol exposure on spatial memory formation: Modulation by orally administered...

The use of electronic cigarettes (ECIGs) has grown exponentially among young adolescents. Tobacco smoking, in general and ECIG use in particular, has been linked to disruption of the oxidative system, resulting in organ damage. The current investigation intends to evaluate if orally administered Vitamin E (VitE) can protect from learning and cognitive impairment induced by ECIG aerosol exposure in a rat model. This effect was determined by studying behavioral and molecular targets for potential learning and memory impairment. Adult Wistar rats were assigned to the following groups (N= 12/group): Control, ECIG, VitE, and VitE+ECIG. The animals in the groups ECIG and VitE+ECIG were exposed to ECIG aerosol (1 hr/day, 6 days/week) for four weeks. The control group and VitE group were exposed to fresh air. At the same time, the VitE group and VitE+ECIG group were given Vitamin E 100 mg/kg/ day via gavage for the same period as the exposure. The control group and ECIG group were given the vehicle via gavage. Behavioral assessment was performed using the Radial Arm Water Maze. In addition, molecular measures (BDNF, SOD, GPx, GSH, and GSSG), were measured in rats' hippocampal tissues. The results showed that VitE prevented ECIG aerosol exposure-induced impairment of spatial short-term and long-term memory formation (p<0.05), decreased BDNF, and activities/levels of GPx, SOD, and GSH (p<0.05). Moreover, VitE protected against GSSG levels increases (p<0.05) associated with ECIG aerosol exposure. In summary, exposure to ECIGs resulted in spatial memory impairments, which could be mitigated by orally administered vitamin E.