Acute and Sub-acute Toxicity Studies of Aqueous and Methanol Extracts of Nelsinia campestris in Rats.

Abstract

Objective: Nelsonia campestris is a plant that grows in semi-arid regions, and is used as early morning drink but also administered to children suffering from measles in order to treat the prevailing bacterial infections that accompany the viral illness. Methods: Acute oral toxicity study of aqueous and methanol extracts was carried out by administration of 10, 100, 1000, 1600, 2900 and 5000 mg/kg bodyweight to rats in their respective groups. Sub-acute toxicity (twenty eight days of extract administration) study . was conducted by oral administration of the extracts at daily doses of 100, 300 and 600 mg/kg bodyweight to another group of rats, while rats in the control group received 0.5ml of normal saline. Results: The median lethal dose (LDso) of extracts of Nelsonia campestris in rats was determined to be greater than 5000 mg/kg bodyweight. There was no significant (p>0.05) difference between the test dose groups for aqueous and methanol extracts. in relation to the control group for serum electrolytes {Na+, K+, Cl-, HC03-), serum albumin, total and conjugated bilirubin. Similarly, mean organ/bodyweight ratio and all haematological parameters (white blood cell, red blood cell, mean cell volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, packed and cell volume) evaluated were not significantly (p>0.05) different 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 300 and 600 mg/kgbw of the aqueous extract . Methanol and aqueous extracts administered at 600 mg/kgbw 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 bw 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 bw. A moderate dose of 300 mg/kg bw of the aqueous and methanol extracts caused lymphocytic infiltration and portal congestion, respectively. Conclusion: Intake of high doses of this plant extracts may exhibit mild organ toxicity .