ABSTRACT
The chemotherapy of gastrointestinal helminthiasis relies mainly on the use of anthelmintics. However, concerns over drug resistance have encouraged the search for new drug leads. This project report focused on evaluating the toxicity and anthelminthic effect produced in vitro and in vivo by the methanol extract of Duranta erecta fruits. From the study, the plant extract was found to contain several chemical components including flavonoids, tannins, polyuronides, saponins, glycosides and terpenes. Acute toxicity evaluation of the plant extract showed that the extract had an LD50 greater than 5000mg/kg BW and therefore was not acutely toxic for oral use. The in vitro assay showed that the plant extract had a poor anthelminthic effect (LC50 Extract= 0.796mg/ml) when compared with Albedazole, a standard anthelminthic (LC50 Albendazole= 0.193µg/ml). Thirty (30) male albino mice randomly distributed into six experimental groups of five animals each were used for the in vivo experiment. Twenty-five mice were infected with the murine nematode Heligmosomoides bakeri and constituted the Infected Groups (A-E) while five mice were uninfected with the parasite and served as Uninfected Control Group (F) for the experiment. Graded ascending doses (250mg/kg BW, 500mg/kg BW and 1000mg/kg BW) of the plant extract and Albendazole (25mg/kg BW) were orally administered to the mice in the infected groups respectively. Corprological and haematological parameters including Faecal Egg Counts (FEC), Packed Cell Volume (PCV), Haemoglobin Concentration (Hb), Total Red Blood Cell Counts (RBC), Total White Blood Cell Counts (WBC) were evaluated and recorded during the study period. The Body Weight (BW) and Red blood cell indices including Mean Corpuscular Volume (MCV), Mean Corpuscular Haemoglobin (MCH) and Mean Corpuscular Haemoglobin Concentration (MCHC) were also estimated and recorded. Twenty-eight (28) days post infection, the infected mice were humanely sacrificed and the Post Mortem Adult Worm Burdens (WB) were estimated and recorded. The results showed xii that the plant extract was unable to eliminate faecal egg counts or adult worms in the gastrointestinal tract of infected animals even at the high doses used, reflected by increasing FEC in treated mice throughout the study. This is in contrast to the anthelminthic effect produced by Albendazole which significantly (p