Abstract

Aloe ferox is renowned for, amongst others, its antihelminthic properties in livestock. However, there is dearth of information on toxicity of A. ferox in livestock. Therefore, toxicity effects of A. ferox were evaluated through acute, sub-acute and chronic toxicity tests. For each test, twenty-five rats were randomly grouped into five groups of five rats. Group 1 (control) was orally administered with 1 ml/day of distilled water and groups 2 - 5 received graded levels, 50, 100, 200 and 400 mg/kg of A. ferox aqueous leaf extract respectively, Mortality, behavioural and physiological changes were monitored for 72 h, 14 and 35 days in acute, sub-acute and chronic toxicity tests respectively, Relative organ weight was noted. Haematological, biochemical and macroscopic examinations, were conducted for sub-acute and chronic tests. No mortalities, behavioural or physiological changes were observed in all the toxicity tests (p > 0.05). Red blood cells, mean corpuscular haemoglobin, platelets and monocytes were elevated while neutrophils were lower than the reference range. Heart, lungs and kidneys were fairly enlarged; spermatogenic cells degenerated. Therefore, A. ferox is relatively non-toxic if used cautiously. Future work will focus on evaluating pharmacological properties of A. ferox aqueous leaf extract in order to authenticate its anti-helminthic use in livestock.

Key words: Aloe ferox, aqueous extract, full blood count, histopathology, mortality, toxicology.

Abbreviation

WBC, White blood cell; RBC, red blood cell; RCDW, red cell distribution width; MCV, mean cell volume; MCH, mean corpuscular haemoglobin; MCHC, mean corpuscular haemoglobin concentration; AST, aspartate transaminase;  ALT, alanine transaminase; ALP, alkaline phosphatase; GGT, gamma-glutamyl transferase; GLM, general linear model; ANOVA, analysis of variance; SAS, statistical analysis system.