Abstract:
Objective: To assess effect of nicotine, major addictive component of tobacco smoke, on
outcomes of the deadly malaria parasite using mice as animal model.
Methods: Male Swiss albino mice were treated with 100 and 200 µg/mL of nicotine in
drinking water daily for 6 weeks followed by Plasmodium berghei ANKA (PbA) infection. On
the seventh day of post infection (p.i.), physical, clinical, histopathological, biochemical and
hematological parameters were assessed. Data were analyzed using SPSS software.
Results: Nicotine was significantly (P < 0.05) positively associated with lower levels of
hemoglobin (Hb), hematocrit (HCT), red blood cells (RBCs), C-reactive protein (CRP) and
uric acid (UA), higher risk to incidence of pulmonary edema, elevated level of liver and
kidney biomarkers. Also significant increment (P < 0.01) of monocyte-lymphocyte count ratio
(MLCR) was observed. Risk to high temperature, lower platelet count, high parastemia and
cerebral malaria was lesser in mice treated with nicotine (100 and 200 µg/mL) followed by
PbA infection than the positive control. Lack of neurological symptoms might be accounted to
the anti-inflammatory property of nicotine that could inhibit production of pro-inflammatory
mediators responsible for occurrence of cerebral malaria.
Conclusions: This study showed that despite down regulation of most cerebral malaria
symptoms nicotine was strongly associated with increased risk to most clinical symptoms
of malaria. Thus, like in respiratory infections, nicotine use might enhance susceptibility to
malaria.
