Toxicity Test and Impact of Onion (Alliumcepa) Leaf Methanolic Extract on Some Biochemical Parameters in Rats with Artificially Induced Diabetes

Diabetes mellitus (DM) is a group of metabolic diseases characterized by hyperglycemia resulting from defects in insulin secretion, insulin action, or both.Cultivated for its use as food, the onion ( Alluim cepa) bulb is a herbaceous plant grown twice-yearly belonging to the family of plants known as Amaryllis, specifically (Amaryllidaccae).it is indeed widely documented that onions has some properties that are beneficial to health, this discovery has existed since time immemorial ,as people of ancient time used it for treatment of diverse ailments such as headaches, mouth sores and heart diseases. It contains various bioactive components, Quercetin and polyphenols are the major constituent in onion which  possess various health benefit such as antioxidant, anti- cancer and anti- diabetic properties. This review provides  knowledge and guidance to the composition of onion, benefits of onion, producing of high-quality onion and to the food industry on developing functional foods to reduce some chronic diseases such as diabetes, cancer. The current study seeks to assess the phytochemical constituents as well as the toxicity and effects on some biochemical parameters in normal and alloxan-induced diabetic rats. The leaf extract was prepared by mixing the powdered form with methanol, allowed for 48hrs then filtered; the filtrate was air-dried to obtain the extract. The stock was prepared by diluting 10g of the extract in 100ml of distilled water. phytochemical constituent was assessed using standard methods. A total of 16 male albino rats were randomly allocated to 4 groups of 4 rats each. Intraperitoneal injection was used to cause diabetes using alloxan across groups B, C and D and treatment commenced after 48hrs of induction upon confirmation of diabetes mellitus. Alloxan-induced diabetic rats were treated with 1000mg/kg body weight. Metformin 500mg/kg body weight was used as standard control drug. Biochemical examinations (kidney and liver function test) were carried out on blood samples. Significant lowering of fasting blood glucose in extract treatment groups resulted in improved biochemical markers (p<0.05). which shows that methanolic extract was able to ameliorate this diabetic  conditions (hyperproteinemia, albuminuria and hypo bilirubinemia) Serum enzyme markers ALP and ALT showed a significantdrop (p<0.05) while Total cholesterol and Triglyceride level increased considerably when compared with diabetic control also when compared to the control. Toxicity assessment was carried out using different doses of extract 10, 100, 1000, 1600, 2900 and 5000mg/kg respectively. No mortality was recorded although there are some alterations in some biochemical parameters. Therefore, Allium cepa must be used with utmost caution due to potential toxicity even though results are indicative of its hypoglycemic, hypolipidemic, hepatoprotective and nephroprotective potentials on Alloxan-induced diabetic rats.

Keywords:- Diabetes Mellitus, Allium cepa (Onion), Phytochemicals, Toxicity, Anti-diabetes