忧遁草抗氧化活性评价和总黄酮、总多酚含量测定

Evaluation of Antioxidant Activity and Determination of Total Flavonoids and Polyphenols of Clinacanthus nutans

忧遁草富含黄酮类、多酚类、甾醇类、三萜类、生物碱类和糖苷类等化合物,具有清热解毒、利尿消肿和祛湿等功效。为了进一步探究忧遁草的有效活性部位,本研究对其根、茎、叶三个部位进行了清除ABTS和DPPH自由基的能力测定,建立TBHP诱导HepG2细胞氧化损伤模型,采用三氯化铝和福林酚比色法测定忧遁草不同部位的粗提物中总黄酮和总多酚的含量。结果表明,忧遁草对ABTS和DPPH自由基有一定的清除作用,根、茎、叶提取物对清除ABTS和DPPH自由基的IC50分别为:(0.68±0.074)mg/mL、(1.34±0.108)mg/mL、(0.41±0.006)mg/mL和(0.46±0.013)mg/mL、(0.644±0.016)mg/mL、(0.408±0.018)mg/mL,其作用效果叶>根>茎。忧遁草根、茎、叶提取物对HepG2细胞的氧化损伤也有一定的保护作用,且作用效果均为叶>根>茎,叶片提取物浓度为10μg/mL时,可将细胞存活率由(45.18±2.429)%提高至(78.07±3.188)%。忧遁草不同部位的总黄酮和总多酚含量分别在(3.01±0.055)%^(5.43±0.072)%和(0.74±0.043)%^(1.42±0.124)%之间,其中叶片中黄酮和多酚含量最高。忧遁草的抗氧化活性和总黄酮、多酚含量存在相关性。忧遁草提取物具有良好的抗氧化效果,尤其是叶提取物,具有较高的开发利用价值,有望开发成为新型食品添加剂或抗氧化剂。

Clinacanthus nutans is rich in flavonoids,polyphenols,sterols,triterpenoids,alkaloids and glycosides compound,who has the ability of heat clearing,detoxifying,diuresis,detumescence and dispelling dampness.In order to further explore the effective activity part of Clinacanthus nutans,with the ability to remove the ABTS and DPPH free radicals was determined in the root,stem and leaf,we established oxidative damage model of HepG2 cells induced by TBHP,The content of total flavonoids and total polyphenols in crude extracts from different parts of Clinacanthus nutans was determined by aluminum trichloride and Folin-Ciocaheau method.The results showed that Clinacanthus nutans had certain scavenging effect on ABTS and DPPH free radicals,the root,stem and leaf extract of IC50 for scavenging ABTS and DPPH free radicals were as follows:(0.68±0.074)mg/mL,(1.34±0.108)mg/mL,(0.41±0.006)mg/mL and(0.46±0.013)mg>mL,(0.644±0.016)mg/mL,(0.408±0.018)mg/mL,the action effect was leaf>root>stem.The root,stem and leaf of Clinacanthus nutans had a certain protection on the oxidation damage of HepG2 cells,and the action effect was leaf>root>stem.When the concentration of leaf extract was 10μg/mL,the cell survival rate was increased from(45.18±2.429)%to(78.07±3.188)%.The contents of total flavonoids and total polyphenols in different parts of Clinacanthus nutans were respectively(3.01±0.055)%^(5.43±0.072)%and(0.74±0.043)%^(1.42±0.124)%,and the contents of flavonoids and polyphenols in leaves were the highest.There was a correlation between the antioxidant activity and the contents of total flavonoids and polyphenols.Extract of Clinacanthus nutans has good antioxidant effect,especially leaf extract,which has high value in development and utilization,and is expected to be developed into a new type of food additive or antioxidant.