Erythrocytic profile of rats infected with T. brucei brucei and treated with a combination of Azadirachta indica leaf extract and diminazene diaceturate

Abstract

This study investigated the erythrocytic profile of rats experimentally infected with Trypanosoma brucei brucei and treated with a combination of methanolic leaf extract of Azadirachta indica and 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 posttreatment (COPPT), relapse of infection period (RIP), red blood cell counts (RBC) and packed cell volume (PCV). 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 was found to be significantly lower (p < 0.05) than that of group D (p < 0.05) which in turn was lower (p < 0.05) than that of group E and G, respectively. The mean LOP of group E was significantly (p < 0.05) lower than group G (p < 0.05) 2 days posttreatment, and this trend continued throughout the experimental period. Mean COPPT of 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 group C, and that of group C was significantly shorter (p < 0.05) than group A. There was no relapse of infection in group B rats. Group B rats had significantly higher (p < 0.05) PCV and RBC counts when compared to other infected groups. Group E rats had significantly higher (p < 0.05) PCV and RBC counts when compared to group G rats. It was concluded that dose combination of 125 mg/kg bw extract plus 7 mg/kg bw DDA led to significant enhancement of erythrocytic profile and potentiation of diminazene in its trypanocidal activity. This combination therapy proved to be better than single therapy of DDA.