超声微波协同提取小米糠总黄酮工艺及其抗炎活性研究

摘要

对小米糠总黄酮的超声微波协同提取工艺和抗炎活性进行研究.在单因素试验基础上,采用Box-Behnken方法设计多因素试验,研究超声微波时间、乙醇浓度、料液比、微波功率对小米糠总黄酮提取量的影响,建立试验工艺参数与提取量之间的数学模型,确立最佳提取工艺,并对其进行光谱表征;并通过小米糠总黄酮对脂多糖(LPS)诱炎症RAW264.7巨噬细胞的增殖及促炎性细胞因子试验,测定其抗炎活性.超声微波协同萃取小米糠总黄酮的最佳工艺参数为:超声微波时间为0.87 h,乙醇浓度为77％,料液比为1∶19 g/mL,微波功率为486W,此时提取量为31.26 mg/g,较传统的乙醇回流法提高205％;结果表明小米糠总黄酮结构与芦丁基本一致;小米糠总黄酮浓度在50 ～ 200 μg/mL范围内,可以明显降低LPS对巨噬细胞增殖的抑制作用、修复细胞形态及显著下调胞内促炎性因子的分泌,并且呈剂量依赖性关系.这表明小米糠总黄酮具有一定的抗炎效果,是一种潜在的免疫调节剂.%The millet bran was used as raw material to explore the optimal extraction process parameters of flavone by ultrasonic/microwave assisted extraction technology.The optimal extraction process conditions were explored through Box-Benhnken central composite design.At the same time,the purified samples were characterized by IR spectra.The anti-inflammatory activity of total flavonoids of millet bran was evaluated by measuring the cell proliferation,cell morphology and proinflammatory cytokine secretion of RAW264.7 macrophages induced by LPS.The results showed that the optimal condition was as follows:Ultrasonic microwave time of 0.87 h,ethanol concentration of 77％,material-liquid ratio of 1∶48 (g/mL) and microwave power of 486 W.Under these conditions,the extraction yield of total flavonoids was 31.26 mg/g.This method was 21.01 mg/g higher than the traditional ethanol reflux method.The structure of total flavonoids in millet bran was the same as that of rutin.The concentration of total flavonoids in millet bran was 50-200 μg/mL,which can significantly reduce the inhibitory effect of LPS on macrophage proliferation and repair cellular morphological changes and decrease the secretion of proinflammatory cytokines in a dose-dependent manner.The total flavonoids of millet bran were a potential immunomodulator with a certain anti-inflammatory effect.