Effects of co-administration of tobacco leaf or cigarette extracts with caffeine on oxidative stress markers in brain and plasma of Wistar rats
Background: Oxidative stress has been linked with diseases associated with brain damage resulting from overconsumption of psycho-active neurotoxicants such as nicotine and caffeine. This study investigated the effect of administration of extracts of Nicotiana tabacum (tobacco leaf used for production of nicotine/cigarettes) and cigarette with caffeine on biomarkers of oxidative stress in brain and plasma of Wistar rats. The outcome of this study is expected to unveil the adverse oxidative effect of the pysho-active agents.
Design: Fifty-five rats were allotted randomly into eleven groups (n=5/group). Group one (control) received the vehicle, other groups were administered the following; group 2 (caffeine 10 mg/kg), group 3 (caffeine 20 mg/kg), group 4 & 5 (tobacco extracts 170 & 340 mg/kg respectively), group 6 & 7 (cigarette extracts 170 & 340 mg/kg respectively), group 8 (caffeine 10 mg/kg + tobacco extract 170 mg/kg), group 9 (caffeine 20 mg/kg + tobacco extract 340 mg/kg), group 10 (caffeine 10 mg/kg + cigarette extract 170 mg/kg), and group 11 (caffeine 20 mg/kg + cigarette extract 340 mg/kg).
Results: In this study, administration of caffeine, and extracts of tobacco/cigarette alone or in combination to the rats markedly increased malondialdehyde (MDA) level in the brain and plasma while marked reduction in catalase activity was observed when compared to control.
Conclusion: In conclusion, the present study showed that co-administration or use of nicotine and tobacco/cigarette extracts, or lone use may induce oxidative stress by modulation of the antioxidant system via increased level of malondialdehyde and decreased catalase activity.