Paracetamol is a commonly used
analgesic/
antipyretic whose long-term intake or overdose is associated with renal and hepatic
injuries. The aim of this study was to determine the hepatonephroprotective mechanisms of the aqueous extract of Amblygonocarpus andongensis stem bark (AEAASB) on renal and
hepatic failure resulting from
paracetamol overdose. Forty-five rats were divided into nine groups (n = 5); these were treated once daily for 8 days with 5 ml/kg distilled water (normal, negative, and satellite controls); 0.9%
normal saline and 140 mg/kg N-acetyl-
cysteine (positive controls); 125, 250, and 500 mg/kg AEAASB (test groups); and 500 mg/kg AEAASB (satellite test). On day 8 after different treatments, hepatonephrotoxicity was induced in all the groups except the normal group by
oral administration of a single dose of
paracetamol (1000 mg/kg). Urinary, hematological, serum, and oxidative stress parameters and in vitro
antioxidant activity of AEAASB were evaluated. Histological sections of the liver and kidney were performed. AEAASB significantly decreased
urea,
creatinine,
transaminases,
alkaline phosphatase, and
bilirubin (p < 0.001) at 500 mg/kg compared to the negative control. Significant decreases in hepatic (p < 0.01) and renal (p < 0.001)
malondialdehyde levels were associated with increases in
superoxide dismutase,
catalase, and
reduced glutathione levels in 500 mg/kg AEAASB compared with the negative control. Histological analysis showed that AEAASB prevented
paracetamol-induced renal and liver tissue damage. Furthermore, AEAASB revealed a very strong
antioxidant activity (inhibitory concentration 50 = 180 μg/ml, antioxidant activity index = 5.55) with an ability to scavenge 63.03% 2,2-diphenyl-2-picrylhy-drazyl radical and reduced ferric
iron by 52.68 mgEqVitC/100 g DM. The hepatonephroprotective effect of AEAASB might result from its ability to improve the
antioxidant status through the stimulation of
antioxidant factors and the scavenging of
free radicals. This property could be ascribed to the presence of some classes of bioactive compounds such as phenolic compounds in great amounts.