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.