洋葱醇提物总黄酮含量的测定及其降脂活性研究

Determination of Total Flavonoids in Alcohol Extract of Allium cepa L.and Its Lipid-Lowering Activity

以三氯化铝-醋酸-醋酸钠缓冲溶液为显色剂,采用紫外分光光度法测定洋葱醇提物总黄酮含量,通过单因素实验与响应面法优化洋葱醇提物总黄酮含量测定的显色条件,并利用游离脂肪酸诱导HepG2细胞建立肝脂肪变性模型评价其体外降脂活性。结果表明,洋葱醇提物总黄酮含量测定的最佳显色条件为:显色温度25℃、显色时间27 min、0.1 mol·L^(-1) AlCl_(3)溶液用量1.00 mL、HAc-NaAc缓冲溶液(pH值5.2)用量0.90 mL,在该显色条件下,洋葱醇提物总黄酮含量为8.6193 mg·g^(-1),与预测值(8.3643 mg·g^(-1))的相对误差为2.96%。体外降脂实验发现,与模型组相比,洋葱醇提物可使细胞内甘油三酯和总胆固醇含量降低,且高浓度组具有统计学差异(P<0.05)。

Taking AlCl_(3)-HAc-NaAc buffer solution as the chromogenic agent,we determined the content of total flavonoids in alcohol extract of Allium cepa L.by UV spectrophotometry,and optimized the chromogenic conditions for the determination of the content of total flavonoids in alcohol extract of Allium cepa L.through single-factor experiments and response surface methodologies.Moreover,we established the free fatty acid-induced HepG2 cells hepatic steatosis model to evaluate the lipid-lowering activity in vitro of alcohol extract of Allium cepa L..The results show that the optimal chromogenic conditions can be determined as follows:the chromogenic temperature of 25℃,the chromogenic time of 27 min,the dosage of 0.1 mol·L^(-1) AlCl_(3) solution of 1.00 mL,and the dosage of HAc-NaAc buffer solution(pH value of 5.2)of 0.90 mL.Under above conditions,the content of total flavonoids in alcohol extract of Allium cepa L.can reach 8.6193 mg·g^(-1),and the relative error is 2.96%compared with the predicted value(8.3643 mg·g^(-1)).In vitro lipid-lowering experiments show that,compared with the model group,the contents of triglyceride and total cholesterol are reduced by alcohol extract of Allium cepa L.,especially the high concentration group(P<0.05).