4种地衣提取物抗氧化和抗肿瘤活性研究

Antioxidant and Anticancer Activities of Extracts Derived from Four Kinds of Lichen

本研究初步评估了4种药用地衣(太白茶、金刷把、黑石耳、红石耳)不同溶剂提取物的抗氧化活性及其粗多糖的抗肿瘤活性。通过测定清除DPPH自由基、羟基自由基和还原能力,对4种地衣不同溶剂提取物进行体外抗氧化活性评价,结果表明,金刷把和黑石耳的甲醇提取相清除DPPH自由基能力高于其它溶剂提取相,其IC50值(半抑制浓度)分别为0.7847 mg/mL和0.5595 mg/mL;黑石耳甲醇提取相(IC50=0.5747 mg/mL)清除羟基自由基能力优于阳性对照物Vc(IC50=0.6126 mg/mL);黑石耳氯仿提取相、金刷把乙酸乙酯提取相和太白茶甲醇提取相清除羟基自由基能力与Vc相当;4种地衣甲醇提取相还原能力均较强,且与其浓度呈较好的量效关系。利用MTT法分析4种地衣多糖对HeLa、A375和Hep G2细胞体外生长增殖的抑制作用,结果显示黑石耳粗多糖对Hep G2细胞的抑制作用较为突出(IC50=0.2567 mg/mL),而金刷把抑制HeLa细胞的生长增殖作用最强,其IC50值为0.4332 mg/mL。

The antioxidant and anticancer activities of various extracts and crude polysac-charides derived from four kinds of medicinal lichen were evaluated preliminarily in this study. The antioxidation activities were detected by DPPH radical-scavenging,OH·radical-scavenging, and reducing power.Results showed that the methanol extracts of Lethariella cladonioides and Umbilicaria tornata had higher DPPH radical-scavenging ability （IC50 = 0.7847 mg/mL and IC50= 0.5595 mg/mL, respectively） than that of other extracts; the OH·radical-scavenging capacity of the methanol extract of Umbilicaria tornata （IC50 = 0.5747 mg/mL） was higher than Vc （IC50 = 0.6126 mg/mL）; the OH·radical-scavenging capacity of the chloroform extract of Umbilicaria tornata, ethyl acetate extract of Lethariella cladonioides, and methanol extract of Thamnolia subuliformis were equal to Vc; the extracts derived from the four lichens all had a certain degree of reducing power, which were positively correlated with the quality concentration of the extracts. Polysaccharides of the four lichens exhibited significant antiproliferative activity against HeLa, A375, and Hep G2 cells by the MTT method. The crude polysaccharide of Umbilicaria tornata exhibited the most significant antiproliferative activity against Hep G2 cells in the four lichens （IC50 = 0.2567 mg/mL）; the crude polysaccharide of Lethariella cladonioides exhibited the most significant antiproliferative activity against HeLa cells in the four lichens （IC50 = 0.4332 mg/mL）.