Acute and sub-acute toxicity studies of aqueous and methanol extracts of Nelsonia campestris in rats

ObjectiveTo evaluate the acute and sub-acute toxicity of aqueous and methanol extracts of Nelsonia campestris (N. campestris) in rats.MethodsAcute oral toxicity study of aqueous and methanol extracts was carried out by administration of 10, 100, 1 000, 1 600, 2 900 and 5 000 mg/kg body weight of N. campestris extracts to rats in the respective groups. Sub-acute toxicity study was conducted by oral administration of the extracts at daily doses of 100, 300 and 600 mg/kg body weight to another group of rats for 28 days, while rats in the control group received 0.5 mL of normal saline.ResultsThe LD50 of the N. campestris extracts in rats was determined to be greater than 5 000 mg/kg body weight. There was no significant difference (P > 0.05) between the test groups administered with aqueous and methanol extracts in relation to the control group for serum electrolytes (Na+, K+, Cl−, HCO3−), serum albumin, total and conjugated bilirubin. Similarly, mean organ-to-body weight ratio and all haematological parameters (white blood cell, red blood cell, mean cell volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, packed cell volume) evaluated were not significantly different (P > 0.05) from the control. There was a significant increase (P < 0.05) in the activity of serum liver enzymes (aspartate aminotransferase, alkaline phosphatase), serum urea and creatinine of rats administered with 300 and 600 mg/kg body weight of the aqueous extract. Methanol and aqueous extracts at 600 mg/kg body weight resulted in a significant increase (P < 0.05) in serum urea and total protein, respectively. The activity of serum alanine aminotransferase decreased significantly (P < 0.05) when the rats received 100 and 300 mg/kg body weight of both extracts. Histopathological examination revealed mild to moderate hepatic and cortical necrosis of liver and kidney respectively on administration of both extracts at 100 and 600 mg/kg body weight. A moderate dose of 300 mg/kg body weight of the aqueous and methanol extracts caused lymphocytic infiltration and portal congestion, respectively.ConclusionsIntake of high doses of this plant extracts may exhibit mild organ toxicity.