根皮苷及苹果幼果多酚对酪氨酸酶活性的抑制作用

Inhibitory Effect of Phlorizin and Young Apple Polyphenols on Tyrosinase Activity

摘要:

为比较苹果幼果多酚及其主要组分根皮苷作为酪氨酸酶抑制剂的潜质，本文以曲酸为阳性对照，分析并比较了三者对酪氨酸酶的抑制效果及抑制动力学。结果表明，根皮苷、苹果幼果多酚和曲酸均能有效抑制酪氨酸酶单酚酶及二酚酶活性，三者抑酶效果的强弱顺序为曲酸>苹果幼果多酚>根皮苷，对单酚酶活性的IC50分别为55.80、54.30和23.81 μg/mL，对二酚酶活性的IC50分别为75.30、56.15和23.45 μg/mL；根皮苷浓度为200 μg/mL时为竞争型抑制，低于200 μg/mL时为混合型抑制，苹果幼果多酚为非竞争型抑制，曲酸为混合型抑制。因此，抑制剂的组成成分和浓度均能影响其抑酶效果和抑酶机理，三种抑制剂均可通过抑制酪氨酸羟化生成多巴及抑制多巴氧化成多巴醌来减少黑色素的合成，苹果幼果多酚对酪氨酸酶活性的抑制效果优于根皮苷，且含量丰富，价格便宜，更适合作为酪氨酸酶抑制剂，有望开发应用于美白产品中。

Abstract:

To compare the potential of young apple polyphenols and phlorizin as tyrosinase inhibitors, the inhibitory effect and kinetics of phlorizin, young apple polyphenols and kojic acid on tyrosinase activity were analyzed and compared by spectrophotometry, in which kojic acid was used as a positive control. Results: phlorizin, young apple polyphenols and kojic acid could effectively inhibit tyrosinase activity. The order of their inhibitory effects was kojic acid>young apple polyphenols>phloridin, and their IC50 for monophenolase activity was 55.80, 54.30 and 23.81 μg/mL, respectively, and their IC50 for diphenolase activity was 75.30, 56.15 and 23.45 μg/mL, respectively. The phlorizin showed mixed inhibition at a concentration lower than 200 μg/mL and competitive inhibition at a concentration of 200 μg/mL, the young apple polyphenols showed non-competitive inhibition and the kojic acid showed mixed inhibition. In summary, the inhibitory effect and inhibitory mechanism of the inhibitor is not only related to its composition, but also related to its concentration. All three inhibitors can reduce the synthesis of melanin by inhibiting the hydroxylation of tyrosine to dopa and the oxidation of dopa to dopaquinone and dopachrome. Compared with phlorizin, young apple polyphenols is more suitable as tyrosinase inhibitors and has great potential for application in whitening products because of its better inhibitory effect, cheaper price and richer content.