新疆3种植物不同提取部位的抗氧化活性及其对PTP1B的抑制作用

目的:考察新疆树莓、黑果悬钩子和天山茶藨不同萃取部位的抗氧化活性及其对蛋白酪氨酸磷酸酶1B(PTP1B)的抑制作用,筛选具有抗氧化及降血糖活性的有效部位。方法:采用甲醇提取、分步萃取的方法分别制备了不同的极性部位。测定了3种植物不同部位的总黄酮含量,果实提取物经AB-8型大孔树脂纯化后制备了果实花青素部位;利用2,2'-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐法,1,1-二苯基-2-三硝基苯肼法及PTP1B抑制活性实验比较了不同部位的相关活性,并分析了黄酮含量和活性的相关性。结果:经AB-8型大孔树脂纯化后,树莓果实花青素含量由(12.72±0.14) mg·g^-1提高到(238.13±1.18) mg·g^-1,天山茶藨果实的花青素含量由(35.36±0.45) mg·g^-1提高到(548.05±1.11) mg·g^-1,随着花青素含量的升高,其抗氧化活性和PTP1B抑制活性也显著升高。黑果悬钩子茎乙酸乙酯部位总黄酮含量最高,为(658.65±11.43) mg·g^-1;黑果悬钩子茎水部位抗氧化活性最高,ABTS和DPPH自由基清除能力分别为(4.53±0.07),(2.82±0.09) mmol Trolox·g^-1当量;黑果悬钩子茎水部位对PTP1B的抑制率最高,半数抑制浓度为(0.08±0.01) mg·L^-1。结论:这3种植物不同萃取部位均具有良好的抗氧化活性和PTP1B抑制作用,黑果悬钩子茎水部位为主要的抗氧化活性和PTP1B抑制活性的有效部位,树莓和天山茶藨果实中花青素是主要的活性成分,天山茶藨茎叶中黄酮是主要的抗氧化活性成分。

Antioxidant Activities and PTP1B Inhibitory Effect of Different Extracts from Three Xinjiang Plants

Objective: To investigate antioxidant activities and inhibitory effect on protein tyrosine phosphatase1B (PTP1B) of different fractions of Rubus idaeus, R.caesius and Ribes meyeri in Xinjiang, in order to screen out active ingredients with antioxidant activity and hypoglycemic action. Method: The different polar fractions were extracted by methanol and fractional extraction method. Then the total flavonoids content of different polar fractions were determined. The anthocyanin fractions of fruits were purified by AB-8macroporous resin. ABTS method, DPPH method and PTP1B inhibitory activity experiment were adopted to compare relevant activities of different fractions and analyze the correlation of flavonoid content and activity. Result: After AB-8macroporous resin purification, anthocyanin contents of R.idaeus and R.meyeri fruit extract increased from (12.7±0.14) mg·g^-1 to (238.1±1.18) mg·g^-1, and (35.3±0.45) mg·g^-1 to (548.0±1.11) mg·g^-1, respectively. With the increase of anthocyanin content, antioxidant activity and PTP1B inhibitory activity were also significantly increased. The ethyl acetate fraction of R.caesius stem had the highest total flavonoids content, which was (658.65±11.43) mg·g^-1. The water fraction of R.caesiusstem had the highest antioxidant activity and PTP1B inhibitory activity, which was IC₅₀(0.08±0.01) mg·L^-1, and their ABTS and DPPH radical scavenging capacity were (4.53±0.07) and (2.82±0.09) mmol Trolox·g^-1 equivalent, respectively. Conclusion: The different fractions of three plants have high flavonoid contents and good antioxidant activity and PTP1B inhibitory effect. The water fraction of R.caesius stem was the main active fraction. Anthocyanin of R.idaeus and R.meyeri fruits was the main active ingredient, and flavonoids from stem and leave of R.meyeri was the main antioxidant ingredient.