油茶叶提取物的5α-还原酶抑制活性及化学成分分析

The Inhibitory Activity of Camellia oleifera Leaves Extract against 5α-Reductase and Chemical Components Analysis

目的:研究油茶叶提取物(COLE)的5α-还原酶(5α-Reductase,5α-R)抑制活性,分析具有高5α-R抑制活性的油茶叶提取物的物质基础。方法:首先建立5α-R酶促反应体系,通过高效相色谱法测定5α-R活性;制备不同极性溶剂油茶叶提取物,测定比较其5α-R抑活性,并以度他雄安作为阳性药物;以5α-R抑制率为指标选择油茶叶最佳提取剂;采用Folin-Ciocalteu法和亚硝酸钠-硝酸铝-氢氧化钠显色法测定各提取物总酚、总黄酮含量,分析各提取物5α-R抑制率与多酚黄酮含量的相关性;采用超高效液相色谱串联三重四极杆飞行时间质谱分析(UPLC-TRIPLE TOF-MS/MS)5α-R抑制活性最高的油茶叶提取物的化学组分。结果:确定酶促反应体系如下:磷酸盐缓冲液300μL,0.76 mg/mL的粗酶提取物500μL,2.0 mmol/L的睾酮50μL,样品50μL,2.0 mmol/L的还原型辅酶II 100μL,于37℃条件下反应30 min。不同油茶叶提取物具有不同程度的5α-R抑制活性,其中油茶叶50%乙醇提取物的抑制率最高,达49.77%±4.43%,以5α-R抑制效果为指标,选择50%乙醇为最佳提取溶剂;经过Pearson相关性分析发现各油茶叶提取物5α-R抑制率与其中总酚、总黄酮含量高度相关(r>0.6,r>0.8);采用UPLC-TRIPLE TOF-MS/MS分析了油茶叶提取物中22个酚类化合物,其中有5种物质已经在文献中报道具有高5α-R抑制活性。结论:油茶叶提取物具有5α-R抑制活性,是潜在的5α-R抑制剂,其抑制活性与多酚、黄酮含量具有相关性。在油茶叶50%乙醇提取物中发现槲皮素、芦丁、儿茶素、3-O-没食子酰基-4,6,-[(S)-六羟基联苯二酰基]-α/β-D-吡喃葡萄糖(Gemin D)、3,4,6-三-O-没食子酰基-α/β-D-吡喃葡萄糖可能是COLE发挥5α-R抑制活性的物质基础。

Objective:To study the 5α-Reductase(5α-R)inhibitory activity of Camellia oleifera(COLE)leaves extract,and to analyze the material basis of its extract with high 5α-R inhibitory activity.Method:Firstly,a 5α-R enzymatic reaction system was established,and the 5α-R activity was measured by high performance phase chromatography(HPLC).The extracts of Camellia oleifera leaves with different solvents were prepared,and the 5α-R inhibitory activity was measured and compared,with Dutasteride as the positive drug;5α-R inhibition rate was used to select the best solvent of Camellia oleifera leaves extract;Folin-Ciocalteu method and sodium nitrite-aluminum nitrate-sodium hydroxide color method was used to determine the total phenol and total flavonoid content of each extract,and correlation between the 5α-R inhibition rate of each extract and the content of polyphenol and flavonoids was analyzed;ultra-high performance liquid chromatography tandem triple quadrupole time-of-flight mass spectrometry(UPLC-TRIPLE TOF-MS/MS)was used to analyze the chemical components of extract with the highest 5α-R inhibitory activity.Results:The enzymatic reaction system was determined as follows:300μL of phosphate buffer,500μL of 0.76 mg/mL enzyme extract,50μL of 2.0 mmol/L testosterone,50μL of sample,2.0 mmol/L of NADPH 100μL,reacted at 37℃for 30 min.Different Camellia oleifera extracts had different levels of 5α-R inhibitory activity.The 50%ethanol extract of Camellia oleifera had the highest inhibition rate,reaching 49.77%±4.43%.Taking 5α-R inhibitory effect as an indicator,50%ethanolwas the best extraction solvent.Pearson correlation analysis showed that the 5α-R inhibition rate of each Camellia oleifera extract was highly correlated with the content of total phenols and total flavonoids(r>0.6,r>0.8);UPLC-TRIPLE TOF-MS/MS analysis 22 kinds substances,five of which were reported that had the 5α-R inhibitory activity.Conclusion:The extract of Camellia oleifera leaves had 5α-R inhibitory activity and was a potential 5α-R inhibitor.Its inhibitory activity was related to the content of polyphenols and flavonoids.Quercetin,rutin,catechin,3-O-galloyl-4,6,-[(S)-hexahydroxybiphth-aloyl]-α/β-D-glucopyranose(Gemin D),3,4,6-tri-O-galloyl-α/β-D-glucopyranose(GAG),might be the material basis for COLE to exert 5α-R inhibitory activity.