ABSTRACT

 The effect of the ethanol extract of the leaves of Irvingia gabonensis on parasitaemia and haematological changes in albino rats infected with Trypanosoma brucei brucei. The effect of the frvingia gabonensis leaf extract was compared with that of Diminazene aceturate. The rats were divided into six groups (1, 2, 3, 4, 5, and 6) of six rats per group. Group 1 (control group) was not infected with Trypanosoma brucei brucei and was given normal saline orally. Group 2 was infected but not treated. Group 3 was infected and treated with diminazene aceturate at the dose rate of 2.5mg/kg. Group 4, 5 and 6 were infected and treated with [rvingia gabonensis leaf extract at dose rates of 200mg/kg, 400mg/kg and 800mg/kg respectively. All the infected groups showed the presence of parasitaemia within four days post infection. The treatment lasted for 7 days; and the 200mg/kg and 400mg/kg doses of Jrvngia gabonensis failed to clear the parasite but significantly reduced it (P<0.05) when compared with the infected and untreated group. The infected and untreated group value post treatment was 8.95 + 0.03 while the values of 200mg/kg and 400mg/kg of the extract were 8.55 £ 0.08 and 7.78 % 0.04. There was also a significant difference (P<0.05) between the rats that were treated with Diminazene aceturate and those treated with 800mg/kg of the extract which extremely decreased the number of the parasite and prolonged the life span of the infected rats. The standard drug value post treatment was 6.65 = 0.31 while the 800mg/kg of the extract value post treatment was 6.42 + 0.46. The haematogical studies shows significant decreased (P<0.05) in the red blood cells (RBCs), packed cell volume (PCV) and haemoglobin concentration (Hb) of the infected and untreated groups compared to the normal control group. The RBCs, PCV and Hb values of the infected and untreated group were 4.36 + 0.19, 30.00 + 0.58 and 10.35 + 0.16 while the RBCs, PCV and Hb values of the normal control group were 6.68 + 0.07, 42.33 + 0.84 and 15.50 + 0.22. The treatment of the infected rats with the extract at all doses and diminazene aceturate significantly (P<0.05) improved the RBCs, PCV and Hb values respectively. There was also a significant increased in the white blood cells (WBCs) of the infected and untreated group compared to the control group and the treated groups (3, 4, 5 and 6) (P<0.05) the WBCs value of the infected untreated group was 16.05 + 0.88 while the WBCs values of the treated groups were 10.00 + 17 for control group, 13.35 £ 0.15 for standard drugs, 13.23 + 0.08 for 200mg/kg of the extract, 13.28 + 0.26 for 400mg/kg of the extract and 13.05 + 0.18 for 800mg/kg of the extract respectively. The Mean Corpuscular Volume (MCV), Mean Corpuscular Haemoglobin(MCH), Mean Corpuscular Haemoglobin Concentration (MCHC) varied significantly (P < 0.05) in an irregular pattern in the treated groups respectively. However, with the results obtained from this study, it was concluded that the ethanol extract of Irvingia gabonensis leaf has trypanocidal effect and could be useful as a source of new trypanocidal agent from medicinal plants.