Acute Toxicity and IN VIVO Antischistosomal Effects of Entada africana Guill & Perott (Fabaceae) Methanol Stem Bark Extract in Albino Mice

The study was aimed at determining the acute toxicity and schistosomicidal effects of methanol extract (ME) of Entada africana (E. africana), in albino mice. Fresh stem bark of E. africana was shade-dried and extracted by Soxhlet extraction. Acute toxicity was carried out on 6 groups of mice (n=3) of 6-week-old, sizes 27-30g; to determine the therapeutic index, piloerection signs and possible mortality (LD50) in 24h exposure period. Cercaria from B. globosus snails were shed under a 100W bulb for 2 hours. In vivo antischistosomal assays was by used of 6-weeks old (27-30g) mice. Set I (n=10) involved investigation on schistosomules infection in the mice, 3-7 days post infection (PI). Set II (n=10) was infected and treated with E. africana ME extract, at concentrations 10-100mg/l, 35th day, PI for 5 consecutive days. Set III (n=10), were infected and treated with praziquantel– PZQ (positive control). While set IV (n=10) were infected and untreated (negative control). All were sacrificed, 75th day of PI. Data were analyzed by GraphPad® prism 8.4, version 2020. Findings revealed that E. africana ME did not generate any harmful or clinical effect within 24h, post administration; and there were no obvious reactions such as paw licking, stooling, piloerection or immediate death, except at phase II, 5000mg/kg bwt, (1⁄3) being the highest dosage. Worm burden decreased with increase in concentrations, especially at 70-100mg/l. Lower concentrations (10mg/l), had high worm population (76.00±21.28). Infected and untreated group had highest worm population (189.67±32.52). E. africana ME stem bark extract, showed antischistosomal effect and worm reduction in a dose- dependent pattern.