Cosmetics and Natural Products Research Center, Faculty of Pharmaceutical Sciences, Naresuan University, Phitsanulok, Thailand.
Department of Thai Traditional Medicine, Sirindhorn College of Public Health, Praboromarajchanok Institute, Phitsanulok, Thailand.
J Cosmet Dermatol. 2022 Sep;21(9):4001-4008. doi: 10.1111/jocd.14707. Epub 2021 Dec 29.
The bioactivities of green tea extract were indicated to promote skin health in vitro. Few clinical studies reported on skin nourishment of topical applying green tea extract due to the limited skin absorption.
This current study evaluated the clinical effectiveness and safety of green tea extract encapsulated chitosan microparticles (GTP) in emulsion base on a split-face, double-blind, randomized placebo-controlled study. Twenty-nine female volunteers were recruited into the study. They were randomly assigned to apply GTP and placebo creams on each half face for 8 weeks. The facial skin properties on both sides were monitored and evaluated every 2 weeks.
The results revealed that skin elasticity (R2) of half face treated with GTP cream (0.748 ± 0.05) was superior to another that received placebo cream (0.722 ± 0.05) at 4th week. In addition, melanin index implying skin dullness of the half face that received GTP cream significantly improved within the 6th week after application (placebo =295.60 ± 58.81, GTP =282.70 ± 59.62). Most importantly, the photographs clearly indicated that the decreasing in facial wrinkles of volunteers applied with GTP cream was more than those applying placebo cream. Signs of skin irritation were not evident in both treatment and placebo cream groups.
Based on study outcomes, the green tea extract encapsulated chitosan microparticles appear to be the promising active candidate for promoting skin elasticity and improving skin dullness and wrinkles.
绿茶提取物的生物活性被证明有助于皮肤健康,体外研究表明。由于皮肤吸收有限,很少有临床研究报道局部应用绿茶提取物对皮肤的滋养作用。
本研究采用双盲、随机、安慰剂对照的自身对照研究,评估绿茶提取物包封壳聚糖微球(GTP)在乳剂中的临床效果和安全性。招募 29 名女性志愿者参加本研究。她们被随机分配到用 GTP 和安慰剂乳膏涂半边脸,持续 8 周。每 2 周监测和评估两侧面部皮肤特性。
结果显示,GTP 乳膏处理的半侧脸皮肤弹性(R2)(0.748±0.05)优于安慰剂乳膏处理的半侧脸(0.722±0.05)在第 4 周。此外,接受 GTP 乳膏治疗的半侧脸黑色素指数(暗度)在应用后第 6 周内显著改善(安慰剂=295.60±58.81,GTP=282.70±59.62)。最重要的是,照片清楚地表明,接受 GTP 乳膏治疗的志愿者的面部皱纹减少程度大于接受安慰剂乳膏治疗的志愿者。在治疗组和安慰剂组中均未出现皮肤刺激迹象。
基于研究结果,绿茶提取物包封壳聚糖微球似乎是一种有前途的活性成分,可促进皮肤弹性,改善皮肤暗度和皱纹。