Leucocytic profile of rats experimentally infected with Trypanosoma brucei brucei and treated with a combination of methanolic leaf extracts of Azadirachta indica and diminazene diaceturate

Abstract

This study investigated the leucocytic profile of rats experimentally infected with Trypanosoma brucei brucei and treated with a combination of methanolic Azadirachta indica leaf extracts (MAILE) plus diminazene diaceturate (DDA). Acute toxicity study of the drug and extract combinations was carried. Selection of the best drug and extract combinations was carried out using 54 rats of both sexes separated into nine groups. Three dose combinations were derived from the selection of the best drug and extract combinations used for the final study viz, 7 mg/kg body weight (bw) DDA plus 125 mg/kg bw extract (group B), 3.5 mg/kg bw DDA plus 250 mg/kg bw extract (group C) and 1.8 mg/kg bw DDA plus 500 mg/kg bw extract (group D). The final study had in addition to the three groups derived from the dose–response study, four other groups viz, uninfected untreated negative control (group F), infected and treated with 3,000 mg/kg bw extract alone (group E), infected and treated with 7 mg/kg bw DDA alone (group A) and infected untreated positive control (group G). The parameters assessed were onset of parasitaemia (OP), level of parasitaemia (LOP), clearance of parasites post-treatment (COPPT), relapse infection period (RIP), total white blood cell counts (TWBC) and differential white blood cell counts. There was no significant difference (p < 0.05) in OP between the groups. A day following treatment, the LOP of groups A, B and C were found to be significantly lower (p < 0.05) than that of group D (p < 0.5), which in turn was lower (p < 0.05) than that of groups E and G, respectively. The mean LOP of group E was significantly (p < 0.05) lower than that of group G (p < 0.05) at 2 days post-treatment, and this trend continued throughout the experimental period. The mean COPPT of rats in group D was significantly (p < 0.05) longer than that of groups A, C and B. There was no significant difference (p < 0.05) in the mean COPPT among groups B, C and A. The mean RIP of group D was significantly shorter (p < 0.05) than that of group C, and that of group C was significantly shorter (p < 0.05) than that of group A. There was no relapse of infection in group B. Group B had significantly higher (p < 0.05) TWBC when compared with other infected groups. Group E had significantly higher (p < 0.05) TWBC values when compared with group G. The lymphocyte and neutrophil counts of group E were found to be significantly higher (p < 0.05) than that of group G all throughout the experimental period. It was concluded that the combination of 125 mg/kg bw MAILE plus 7 mg/kg bw DDA led to significant enhancement of leucocytic profile and that this combination therapy proved to be better than single therapy of DDA.