Full Length Research Paper

Assessing plasma glucose and lipid levels, body weight and acute toxicity following oral administration of an aqueous ethanolic extract of Parinari curatellifolia Planch, (Chrysobalanaceae) seeds in alloxan-induced diabetes in rats

Steve O Ogbonnia¹*^, A. Adekunle², Stella O Olagbende-Dada¹, Emmanuel N Anyika³, Veronica N Enwuru⁴ and Moses Orolepe ²

¹Department of Pharmacognosy, Faculty of Pharmacy, College of Medicine Campus, Idi-Araba, University of Lagos, Lagos, Nigeria.

²Department of Botany and Microbiology, University of Lagos, Akoka, Lagos, Nigeria.

³ Department of Clinical Pharmacy and Biopharmacy Faculty of Pharmacy, College of Medicine Campus, Idi-Araba, University of Lagos, Lagos, Nigeria.

⁴Department of Pharmaceutics and Pharmacy, Microbiology, Faculty of Pharmacy, College of Medicine Campus, Idi-Araba, University of Lagos, Lagos, Nigeria.

*Corresponding author. E-mail: steveogbonnia@hotmail.com.

Accepted 22 July, 2008

The study was aimed at evaluating the safety and hypoglycaemic effects of Parinari curatellifolia seeds used in the treatment of diabetes. The plasma glucose level and other biochemical parameters, body weight and liver, heart, renal and acute toxicities were assessed following  oral administration of an aqueous ethanol (80%) extract of the seeds in alloxan-induced diabetes in rats. Toxicity of the extract was evaluated in Swiss albino mice by feeding the animals with the graded doses of the extract between 1.0 to 2.0 g/kg body weight orally and observed continuously for the first 4 h and hourly for next 24 h, then 6 hourly for 48 h (72 h, acute toxicity). Diabetes was induced in male and female Wistar rats with alloxan monohydrate (150 mg/kg) dissolved in normal saline and administered intraperitoneally (i.p). The plasma glucose levels of the induced animals were monitored with a glucometer after 72 h. The animals with plasma glucose level >300 mg/dl were classified as diabetic and were included in the study. The diabetic animals were treated with the extract and a reference drug, glibenclamide, respectively for 30 days. Their effects on plasma glucose levels and some biochemical parameters were evaluated at the end of the experiment as indices of their antidiabetic activity. The median acute toxicity value (LD₅₀) of the extract was determined to be 7.27 g/Kg body weight. There was significant reduction (p<0.05) in the plasma glucose and low density lipoprotein (LDL)-cholesterol levels, and significant increase (p<0.05) in high density lipoprotein (HDL)–cholesterol in the treated diabetic groups compared to the control. There was no significant increase in the body weight in the diabetic and normal groups treated with the extract while there was a significant gain in weight for the diabetic rats treated with reference drug. Aspartate aminotransferases (AST) level was not affected in the treated diabetic rats while significant changes in the alanine aminotransferases (ALT) and the creatinine levels were observed in all groups treated with the extract. The LD₅₀ value indicated the drug to be quite safe as a single dose treatment. The results also showed that the extract had good hypoglycemic activity and good effects on cardiovascular risk factors.

Key words:  Parinari curatellifolia seeds, acute, toxicity, diabetes.