ABSTRACT
Background: Ischuria is a health and social problem, having a negative impact on sufferers. This study therefore was a preliminary investigation of the ischuretic property and safety for use of a hydro-ethanolic extract of Amaranthus spinosus used traditionally in managing ischuria. Methods: Phytochemical screening, thin layer chromatography and high performance liquid chromatography were performed on the extract to establish fingerprints for identification. Acetylcholine, Nicotine, and the extract were applied to an isolated rat urinary bladder to ascertain contractile response. The possible receptor site(s) of action was also investigated using isolated rabbit jejunum, and guinea-pig ileum preparations. In-house observation, hematological analysis, and liver and kidney function tests were performed on Sprague-Dawley rats, in acute and sub-acute toxicity studies. Results: The extract had contractile effects on the rat urinary bladder (similar to acetylcholine and nicotine) and rabbit jejunum. Its contractile effect of the guinea-pig ileum was significantly inhibited by hexamethonium (77.50 ± 8.50 %; P ≤ 0.001) and to a lesser extent by mepyramine (49.2 ± 6.80 %; P ≤ 0.001) and Atropine (22.45 ± 5.22 %; P ≤ 0.01). The extract (80-800 mg kg-1) was not lethal and a 160 and 240 mg kg-1 dose had no adverse effect on blood, liver, kidney metabolic function. Conclusions: The hydro-ethanolic extract of Amaranthus spinosus has ischuretic activity possibly mediated via nicotinic, histaminic and muscarinic receptor stimulation and is safety to use in ischuria.