中药材黄嘌呤氧化酶抑制剂的筛选与评价

Screening and activity evaluation of xanthine oxidase inhibitors from Chinese herbal extracts

目的建立一种黄嘌呤氧化酶抑制剂的快速筛选方法,为寻找治疗高尿酸血症的药物提供依据。方法采用黄嘌呤氧化酶,以黄嘌呤为反应底物,别嘌呤醇为阳性对照,通过紫外分光光度法检测反应体系的吸光度,判断待测物质对黄嘌呤氧化酶的抑制作用。用水提取法制备102种中药提取物,并评价其酶抑制活性。结果通过优化得到了最佳的筛选方法:底物浓度180 mg·L^(-1),酶浓度50 U·L^(-1),检测波长290 nm,温度30℃,反应时间为300 s,PBS或5%的二甲基亚砜和甲醇为样品溶剂。对102种中药材水提取物的活性筛选显示:有10种的抑制活性大于70%,其中,川西合耳菊(98.63%)、莪术(83.18%)、鹅不食草(84.31%)、雷公藤(90.08%)、陆英(89.45%)和木贼(85.59%)等6种药材提取物的抑制率大于80%,显示了较高的黄嘌呤氧化酶抑制活性和潜在研究价值。结论所用方法简单、易行、可靠,可用于黄嘌呤氧化酶抑制剂的快速筛选,并证实中药是寻找和发现有潜在活性黄嘌呤氧化酶抑制剂的重要资源。

OBJECTIVE To establish a rapid screening method for xanthine oxidase inhibitors,and to provide a basis for searching the drugs of hyperuricemia.METHODS Xanthine oxidase used as the reaction enzyme,xanthine as the reaction substrate and allopurinol as the positive control,the absorbance change of the reaction system was detected by ultraviolet spectrophotometry to determine the inhibitory effect of the test substance on xanthine oxidase.102 Chinese herbal extracts were prepared by water extraction,and their enzyme inhibitory activities were evaluated.RESULTS The optimal screening method was established as follows:the substrate concentration of 180 mg·L^(-1),the enzyme concentration of 50 U·L^(-1),the detection wavelength of 290 nm,the temperature of 30℃,reaction time of 300 s,and PBS or 5%dimethyl sulfoxide and methanol as sample solvents.The results of the activity screening showed that the inhibitory activity of 10 kinds of traditional Chinese medicine extracts was greater than 70%.Among them,the inhibitory rate of 6 kinds of extracts,including Synotis solidaginea(98.63%),Curcuma phaeocaulis(83.18%),Centipeda minima(84.31%),Tripterygium wilfordii(90.08%),Sambucus chinensis(89.45%)and Equisetum hyemale(85.59%)were more than 80%,all of which showed high xanthine oxidase inhibitory activity and potential research value.CONCLUSION This study has established a simple,easy and reliable method for rapid screening of xanthine oxidase inhibitors,and confirmed that traditional Chinese medicine is an important resource for searching and discovering potentially active xanthine oxidase inhibitors.