Acute Toxicity of Quercetin From Onion Skin in Mice

Background: Quercetin is the most abundant flavonoid molecule, is widely distributed in the plant kingdom, and has a wide range of uses. Objectives: This study aimed to determine the LD50 of quercetin from onion (Allium cepa) skin (QOS) and its effect on the livers and kidneys of mice. Methods: This study consisted of two phases. In phase one, 9 mice BALB/c were divided into three groups of three mice each. The mice in each group received QOS at 10 mg/kg, 100 mg/kg, and 1000 mg/kg, respectively, and were monitored for 24 h for any signs of toxicity or mortality. In phase two, three mice were divided into three groups of one mouse each. Each mouse received QOS at 1600 mg/kg, 2900 mg/kg, and 5000 mg/kg. The mice were observed for 24 h for any signs of toxicity or mortality. Results: A significant increase was observed in serum albumin, total protein, and aspartate aminotransferase (AST) levels in mice that received 10 mg/kg, 100 mg/kg, and 1000 mg/kg QOS. A significant decrease in serum alkaline phosphatase (ALP), alanine aminotransferase (ALT), cholesterol, creatinine, urea, and the electrolyte was noticed in mice that received QOS at 10 mg/kg, 100 mg/kg, and 1000 mg/kg when compared with the control group. The livers of mice that received 1600 mg/kg and 2900 mg/kg QOS showed hemorrhage and enlarged sinusoids along with a distortion of the renal tubule and aggregation of lymphocytes within the kidneys. Conclusion: The LD50 of QOS was 3807 mg/kg in mice. QOS above 1000 mg/kg led to a distortion of the hepatocytes and renal tubule with an increase in serum AST, ALT, and creatinine, suggesting that QOS could be toxic at 1000 mg/kg and above.