Phytochemical Screening of Tobacco (Nicotiana tabacum) and Its Effects on Some Haematological Parameters and Histopathology of Liver and Brain in Male Rats

This study investigated phytochemical constituents of Nicotiana tabacum (tobacco leaves), its effects on haematological parameters and its histopathology of brain and liver in albino rats. Eighteen (18) male albino rats were divided into three (3) groups with 6 rats in each group. Group A was administered 10 mg/kg body weight of aqueous extracts of tobacco, group B was administered 10 mg/kg body weight of methanol extracts of tobacco and group C was used as positive control. Two (2) rats from each group were sacrificed after every 7 days of administration for 21 days. There was a significant (p<0.05) decrease in rats’ body weight, red blood cell (RBC), hematocrite (HCT or PCV), and haemoglobin (HGB) for aqueous extracts (7.45 ± 0.93, 14.90 ± 1.89, 44.70 ±5.60 RBC, HCT and HGB respectively). Methanolic extracts of tobacco significantly decreased the value of RBC, HCT, and HGB (6.63 ± 1.04, 13.27 ± 2.07 and 39.8 ± 6.27 respectively) when compared with the control group (7.72 ± 0.57, 15.43 ± 1.14 and 46.30 ± 3.43 respectivel) but no significant (p>0.05) increase in mean cell volume (MCV), mean cell haemoglobin (MCH) and mean cell haemoglobin concentration (MCHC) for both extracts. The histopathological section of brain and liver were normal for the control group while neuronal, liver degeneration, acute necrosis and cirrhosis were observed in aqueous and methanolic extract groups. Tobacco has nutritional and medicinal potentials as seen from the phytochemical constituent results but long-time consumption of tobacco may lead to anaemia as a result of its high alkaloids or nicotinic contents which decreased the values of RBC, HCT, and HGB. The overall effect of methanolic extract of tobacco was greater than the aqueous extract suggesting that methanol is a better solvent for extraction of tobacco leaves than water.