摘要:
旨在为探究火龙果花的抗氧化物提取工艺及其抗炎活性。选取火龙果花为原料,用热回流法提取,以粗提液对DPPH自由基及OH自由基的清除能力为指标,先进行单因素实验,考察提取温度、料液比、提取时间以及乙醇浓度对粗提物抗氧化活性的影响,再采用L9(34)正交试验法,优化火龙果花的体外抗氧化物提取工艺。结果表明:70%乙醇,1:30 g/mL料液比,75 ℃下回流加热3.0 h为最优提取条件,在最佳提取工艺下粗提物对DPPH自由基、OH自由基的IC50值分别为0.273、0.288 mg/mL,且在一定范围内,粗提物的浓度越高,其抗氧化活性越好,量效关系明显。最佳工艺条件下,粗提物对LPS诱导RAW264.7巨噬细胞产生的NO有很强的抑制作用,且与浓度呈正相关,具有剂量依赖性,其半抑制浓度IC50值为13.94 μg/mL,该提取物具有很好的抗炎活性。
Abstract:
To investigate the optimum technology for extraction of antioxidants and the extracts' anti-inflammatory activity from pitaya flower, the antioxidant activity in vitro of the extracts from pitaya flower was determined by scavenging capacity of DPPH·and·OH.The effects of extraction temperature, solid-liquid ratio, extraction time and ethanol concentration were studied through the single factor experiments, and L9 (34) orthogonal test was used to explore the antioxidant activities of extracts from pitaya flower in vitro. The results showed that, the optimized conditions were:70% ethanol, the solid-liquid ratio of 1:30 g/mL, when treatment time was 3.0 h at 75℃. Under these optimized conditions, the IC50 for scavenging capacity of the extracts against DPPH·and·OH were 0.273, 0.288 mg/mL, respectively. And within a certain range, the higher the concentration of the crude extract, the better its antioxidant activity, which had an obviously dose-effect relationship. Moreover the extracts under the optimized conditions could decrease secretions of NO in LPS-induced RAW264.7 macrophage cells, and the anti-inflammatory activity for the extracts increased in a concentration-dependent manner with IC50 value of 13.94 μg/mL. The extracts had good antioxidant activity and anti-inflammatory activity in vitro.