γ-聚谷氨酸体外抗氧化性及抑制透明质酸酶活性的研究

摘要

目的 考察γ-聚谷氨酸体外抗氧化活性及对透明质酸酶的抑制活性.方法 利用DPPH法测定高相对分子质量(Mr)(140万)和低Mr(10万)γ-聚谷氨酸的DPPH自由基清除率曲线,以IC50值作为评价试样清除DPPH自由基能力的指标,并与抗氧化剂Vc磷酸酯镁和α-熊果苷比较,评价两种Mrγ-聚谷氨酸的抗氧化性;同时利用DNS法测定以上两种Mr的γ-聚谷氨酸对透明质酸酶的抑制活性.结果 140万Mrγ-聚谷氨酸清除DPPH自由基的IC50值为25.5 mg/mL,略优于10万Mrγ-聚谷氨酸(IC5030.5 mg/mL).两者清除自由基的效果约为Vc磷酸酯镁(IC5013 mg/mL)的一半,低于α-熊果苷(IC500.016 mg/mL);另外,两种Mrγ-聚谷氨酸在低浓度(0.008%)条件下即可抑制约50%透明质酸酶活性,且其抑制率呈浓度依赖性.结论 γ-聚谷氨酸是一种优良的化妆品原料,除具有超强的保湿作用之外,还具有中等程度的抗氧化活性及良好的透明质酸酶抑制活性,表明其在功能性化妆品中具有广阔的应用前景.%Objective To investigate the anti-oxidant activity of γ-polyglutamic acid (γ-PGA) and its inhibitory activity against hyaluronidase in vitro. Methods Taking IC50 as the evaluating indicator of DPPH free radical scavenging capability, the scavenging rate curves of γ-polyglutamic acid with high and low Mr were determined. Vc magnesium phosphate and α-arbutin were used as control. The inhibitory activity of γ-polyglutamic acid with high and low Mr against hyaluronidase was determined by DNS method. Results The IC50 value of γ-polyglutamic acid with Mr of 1.4×106 was 25.5 mg/mL, slightly better than that of γ-polyglutamic acid with Mr of 100×103 (IC5030.5 mg/mL). The abilities to scavenge free radicals were about half of that of Vc magnesium phosphate (IC5013 mg/mL), and were lower than that of α-arbutin (IC500.016 mg/mL). In addition, two kinds of γ-polyglutamic acid could inhibit about 50 % activity of hyaluronidase under low concentration (0.008 %), and the inhibition rate was concentration dependent. Conclusion γ-polyglutamic acid is an excellent cosmetic raw material with a general degree of anti-oxidant activity and favourable inhibitory activity against hyaluronidase besides its strong moisturizing effect, indicating a broad application aspect in the functional cosmetics.