Effects of shisha smoke inhalation on some long-term memory forms in adult male mice

Abstract

Background: Shisha is a flavoured tobacco designed to be smoked in a water-pipe, but it effects on long-term memory has not been fully explored. This study was undertaken to evaluate the effect of Shisha smoke inhalation on some long-term memory models in adult male BALB/c mice.

Methods: Twenty male mice were divided into 4 groups of five mice each. Group I (control): fresh air; group II: exposed to bonged Shisha; group III: exposed to unbonged Shisha; group IV: exposed to activated charcoal smoke only. Each group was exposed for thirty minutes daily for seven weeks. Long-term memory was assessed using elevated plus maze (EPM), novel object recognition test (NORT) and Barnes maze (BM).

Results: There was statistically significant decrease (P<0.05) in novel object recognition in bonged Shisha group when compared with the control. There was statistically significant increase (P<0.05) in spatial learning and memory in bonged Shisha group when compared with control. There was statistically significant decrease (P<0.05) in acetylcholinesterase activity in bonged Shisha group when compared with control, but there was no statistically significant difference in anxiety related spatial memory in elevated plus maze when compared with the control. There was also increased in necrosis of hippocampal cells in bonged Shisha group and slight necrosis in unbonged and activated charcoal smoke when compared to control mice.

Conclusion: The outcomes of this study suggest that bonged Shisha smoke is neurotoxic to the brain because of combined effect of various toxicants emanating from different Shisha smoke constituents used in the set-up

Keywords: Shisha, Memory, Hippocampus, Acetylcholinesterase