The effect of long-term exposure to heated tobacco products on the central nervous system using novel in vivo experimental methods

Abstract

Abstract Heated tobacco products (HTPs) are new products being promoted by the tobacco industry as having a reduced potential for harm compared with conventional cigarettes. However, there is insufficient information on the health risks of long-term exposure to HTPs on the central nervous system (CNS). To determine the health risks of HTP use, valid and reproducible in vivo protocols must be established. Therefore, we propose a simple experimental method to evaluate the impact of long-term exposure to HTPs on the CNS in an amyloid mouse model. App knock-in mice were exposed to HTPs for 16 weeks, five days per week. Serum cotinine concentration was used to validate the HTP exposure model. Histological analysis indicated that HTPs had minimal effects on amyloid pathology. However, gene ontology analysis was performed on differentially expressed genes in the cerebral cortex that had thresholds of |log2 Fold Change| > 1 and non-adjusted p value < 0.05. The results indicated that exposure to HTPs mainly affected non-inflammatory pathways in the CNS. Further studies are required to determine the safety of HTPs on the CNS. Our experimental method provides a convenient means for evaluating these parameters.