Abstract

This research evaluates the acute and sub-acute toxicity of aqueous extract of Alstonia boonei leaves on mice and Wistar rats and its effect on liver parameters like (ALT), (AST), and (ALP), (TP), (TB) and (DB). Mice weighing between 15 – 25 g, Twenty-four (24) male and female Wistar rats weighing between 120 – 230g were randomly assigned into eight (8) groups (A – H) of three (3) rats per group. Groups (A and E) were used as male and female controls respectively while male groups (B, C, D) and female groups (F, G, H) served as the test groups and received 500, 1000 and 2500 mg/kg of the extract respectively. All animals were sacrificed after 28 days of extract administration via oral gavage. Livers were isolated for histopathological analysis and blood was collected by cardiac puncture for biochemical analysis. In the acute toxicity study, A. boonei was found to be non-toxic at a single dose of 10,000 mg/kg body weight (b.wt) on mice. While in sub-acute toxicity study, a significant difference (p> 0.05) or increase was observed in the serum levels of ALT and AST for male and female rats at all the doses tested except serum level of ALT in males which was significantly different (p< 0.05) at all the doses tested. There was a significant (p< 0.05) decrease in serum level of ALP at the dose of 1000 mg/kg (54.42±5.27 µ/L) in male animals. There was a significant (p< 0.05) decrease in serum ALB in male animal at the lowest dose of 500 mg/kg (2.22±0.26 g/dL). A significant (p< 0.05) difference or increase in serum total bilirubin (TB) was observed in female animals treated with higher doses of 1000 and 2500 mg/kg b. wt. (1.03±0.03, 0.86±0.03 mg/dL). There was a significant (p< 0.05) decrease in serum direct bilirubin (DB) at the lowest dose of 500 mg/kg (0.13±0.04 mg/dL) in female animals when compared with the control (0.25±0.03 mg/dL). Histopathological studies revealed that both male and female animals showed necrotic liver cells and extensive necrosis of liver cells at the doses tested. Thus, prolonged oral use of low and higher doses of A. boonei aqueous leaf extract should be discouraged.